Food Technology Past Paper PDF 2024-2025 - Brainware University

BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Module 2 Standards for food analysis (Food Technology BBT10002) _____________________________________________________...

BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Module 2 Standards for food analysis (Food Technology BBT10002) ________________________________________________________________________________________ Table of Contents S. No. Topic Page No. Standards of identity, purity, and methodology for 1 2 analysis 1.1 Cereal Grains, Legumes and Oilseeds 2-13 1.2 Fruits, vegetables, tubers, and their products 15-25 Tea, coffee, cocoa, chocolate, Spices, sugar, condiments 1.3 25-30 2 Model questions 31-34 3 References 34 Department of Biotechnology Brainware University, Kolkata 1 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 1. INTRODUCTION: STANDARDS OF IDENTITY, PURITY, AND METHODOLOGY FOR ANALYSIS Purpose: Ensure the quality, safety, and authenticity of food products by defining specific standards for identity, purity, and analysis methods. Scope: Covers a wide range of food categories, including cereals, legumes, oil seeds, fruits, vegetables, tubers, beverages, milk, meat, and other miscellaneous foods. Standards of Identity: Define the essential characteristics and ingredients that a food product must have to be labeled as a particular type of food. For example, to label a product as "chocolate," it must meet specific criteria regarding cocoa content. Standards of Purity: Ensure that food products are free from contaminants and meet specific purity requirements, such as the absence of harmful substances and adherence to maximum permissible limits for additives. Methodology for Analysis: Standardized methods are used to test food products to ensure they meet the required identity and purity standards. This includes chemical, physical, and microbiological tests. 1.1 CEREAL GRAINS, LEGUMES AND OILSEEDS Cereals, legumes, and oil seeds are staple foods globally, providing essential nutrients like carbohydrates, proteins, and fats. Standards of identity, purity, and methodology for analysis ensure the quality, safety, and consistency of these food products. These standards are established by national and international regulatory bodies, including the Food and Agriculture Organization (FAO), World Health Organization (WHO), Codex Alimentarius, and local food safety authorities. CEREAL GRAINS AND LEGUMES Standards of Identity: Standards of identity for cereals, legumes, and oil seeds specify the essential characteristics that a product must have to be recognized under a specific name.  Cereals: o Wheat Flour: Must contain a specific range of protein, fiber, and ash content. May be enriched with vitamins and minerals. o Rice: Classified into types (e.g., long-grain, short-grain) based on grain length, shape, and amylose content. o Maize (Corn): Identified by variety (e.g., sweet corn, field corn) with specific moisture content and kernel size.  Legumes: o Soybeans: Defined by protein content, oil content, and moisture levels. o Lentils and Chickpeas: Classified based on size, color, and moisture content.  Oil Seeds: o Sunflower Seeds: Characterized by oil content, kernel size, and shell thickness. o Sesame Seeds: Standards include oil yield, moisture content, and purity levels (absence of hulls and foreign matter). Department of Biotechnology Brainware University, Kolkata 2 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Standards of Purity: Purity standards ensure that cereals, legumes, and oil seeds are free from contaminants, adulterants, and undesirable substances, ensuring the safety and quality of the food products. Contaminants and Adulterants: o Mycotoxins: Standards ensure that levels of aflatoxins, ochratoxins, and other mycotoxins produced by mold are below safe thresholds. o Heavy Metals: Limits are established for metals like lead, cadmium, and arsenic to prevent toxic exposure. DETERMINATION OF MYCOTOXIN Mycotoxins are metabolic products of fungi, which are capable of producing acute or chronic toxic effects (e.g carcinogenic, mutagenic, and teratogenic) on animals and probably on men at the levels of exposure. Toxic syndromes, resulting from the intake of mycotoxins by man and animals, are known as mycotoxicosis. Although mycotoxicosis cause by mould Claviceps purpurea have been known for a long time. Mycotoxins remained neglected until the discovery of Aflatoxins in 1960. Mold growth in foods is very common, especially in warm and humid climates. It can occur in fields or in storage after harvest. Mould infection of foods such as grains, seeds and nuts is often localized in pockets, especially in bulk storage and warehouses Currently a few hundred mycotoxins are known, often produced by genre, Aspergillus, Penicillium and Fusarium. The chemical structures of some important mycotoxins are shown in Figure Figure: Chemical structures of a few mycotoxins AFLATOXINS Aflatoxin is probably the most common and widely known mycotoxin contaminant. It is produced by the moulds, Aspergillus flavus and Aspergillus parasiticus. In fact the name is a composite word derived from ‘A. flavus toxin’. Foods that are commonly affected include all nuts, Department of Biotechnology Brainware University, Kolkata 3 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 especially groundnuts, tree nuts such as pistachio and Brazil nuts, cottonseed, copra, rice, maize, wheat, sorghum, pulses, figs and oilseed cakes. Unrefined vegetable oils made from contaminated seeds or nuts usually contain aflatoxin. However, aflatoxin is destroyed in the refining process so that refined oils are safe. There are six aflatoxins of analytical interest (Figure below). Four occur in foods and two as metabolites in the milk of animals who have been fed contaminated feed. Figure: Chemical structure of the six aflatoxins Safety requirements for handling mycotoxins  All food samples suspected of being contaminated with mycotoxins must be handled with care. Use disposable gloves and protective masks if grinding the food creates dust.  Aflatoxins are potent carcinogenic substances. While handling pure aflatoxin reference material, extreme precautions must be taken as they are electrostatic.  All work must preferably be carried out in a hood.  Swab any accidental spill of toxin with 1% sodium hypochlorite bleach (NaOCl), leave 10 minutes and then add 5 % aqueous acetone. Rinse all glassware exposed to aflatoxin with methanol, add 1% sodium hypochlorite solution and after 2 hours add acetone to 5 % of total volume. Let it react for 30 minutes and then wash thoroughly.  Use a laboratory coat or apron soaked in 5% sodium hypochlorite solution over night and washed in water. Department of Biotechnology Brainware University, Kolkata 4 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Preparation of sample Preparation of Lot sample - Mould contamination in food isn't evenly spread, so mycotoxins are concentrated in certain areas. In grains and nuts, these toxins can cluster in specific spots. When sampling, it's crucial to include the entire sample and reduce particle size to ensure even distribution. For instance, a single contaminated peanut (0.5g) can contain enough aflatoxin to impact 5kg of peanuts. To make sure the contamination is evenly spread, grind the peanut and mix thoroughly. When working with large samples, start by coarsely grinding and mixing the whole sample. Then, take about 1/20 of it, grind it to a finer size, and mix well. For liquids, mix thoroughly to ensure a uniform sample. Determination of Aflatoxins b1, b2, and g1 in corn, cottonseed, peanuts, and peanut butter by CB method The CB (Chemical Bromatology) method for the determination of aflatoxins in food commodities like corn, cottonseed, peanuts, and peanut butter typically involves a series of steps that include sample extraction, purification, and quantification of aflatoxins. Here's an overview of the process: Sample Preparation:  Grinding: The sample (corn, cottonseed, peanuts, or peanut butter) is finely ground to ensure uniformity.  Weighing: A specific amount of the ground sample is weighed for analysis. Extraction:  Solvent Extraction: The ground sample is mixed with a suitable solvent, typically a mixture of methanol and water, or acetone and water. The mixture is shaken to extract aflatoxins from the matrix.  Filtration: The mixture is filtered to separate the liquid extract containing aflatoxins from the solid residue. Purification:  Liquid-Liquid Partitioning: The extract is subjected to liquid-liquid partitioning using solvents such as chloroform or dichloromethane to further isolate aflatoxins. Quantification:  Calibration Curve: Quantification is performed using a calibration curve prepared with known concentrations of aflatoxins. Result Interpretation:  Calculation: The concentration of aflatoxins in the sample is calculated by comparing the sample's response with that of the calibration standards. Other Purity Criteria: o Foreign Matter: Standards specify the maximum allowable percentage of non- food materials (e.g., stones, soil, plant debris) in cereals, legumes, and oil seeds. Department of Biotechnology Brainware University, Kolkata 5 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 o Moisture Content: Standards set maximum moisture levels to prevent spoilage and mycotoxin production. o Adulteration: Products must be free from adulteration with inferior or non-food substances (e.g., mixing wheat flour with cheaper flours like tapioca). FOREIGN MATTER DETECTION Refractions mean all components of food grains, that differ from normal grains such as foreign matter, other food grains, damaged grains, broken, shriveled grains etc.  Filth – Any objectionable matter contributed by animal contamination of the product such as rodent, insect or bird matter, or any other objectionable matter contributed by insanitary conditions (a) Heavy Filth – Heavier filth material separated from product by sedimentation based on different densities of filth, food particles and immersion liquids such as Chloroform etc. Examples of such filth are insect and rodent excreta pellets and pellet fragments, sand and soil. (b) Light filth – Lighter filth particles that are oleophilic and are separated from product by floating them in an oil – aqueous liquid mixture. Examples are insect fragments, whole insects, rodent hairs and feather barbules. (c) Sieved filth – Filth particles of specific size ranges separated quantitatively from product by use of selected sieve mesh sizes.  Karnal bunt – Karnal bunt is a fungal disease that affects wheat, caused by the fungus Neovossia indica. The disease gets its name from the town of Karnal in India, where it was first identified. Karnal bunt primarily affects the grains of wheat, giving them a foul odor and taste, similar to rotting fish, due to the production of trimethylamine. The infected grains develop dark, blackish patches, and in severe cases, the entire kernel can be destroyed.  Ergot – Ergot is a type of fungus that primarily infects grains like rye, wheat, and barley. The fungus, Claviceps purpurea, produces toxic compounds known as ergot alkaloids. When grains are infected, they develop dark, hardened structures called sclerotia, which contain these toxic alkaloids. Detection procedure: Examine the test sample for its general condition, such as appearance: freedom from moulds, insect infestation, off odour, poisonous and deleterious matter. DETERMINATION OF FOREIGN MATTER To determine the amount of foreign matter, start by transferring 500g of the sample onto a set of sieves. Arrange the sieves so that the one with the largest perforations is on top, followed by sieves with smaller perforations in descending order, with a solid pan at the bottom. Thoroughly agitate the sample to sift out foreign matter at different levels. After sifting, larger foreign objects such as large grains, clay pieces, and chaff will remain on the upper sieves, while smaller, shriveled grains, insect-damaged grains, and smaller foreign matter Department of Biotechnology Brainware University, Kolkata 6 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 will collect on the lower sieves. Separate the sieves and collect all the foreign matter, adding it to what has accumulated in the bottom pan. Weigh the total foreign matter and calculate its percentage. For rice, millets, and smaller grains, use a 250g sample. To reduce the sample size, spread the entire sample in a tray, divide it into four equal parts, and collect two opposite quarters. Repeat this process until the required sample size is obtained DETERMINATION OF LIGHT FILTH in Whole Wheat Flour Whole wheat flour does not break down insect exoskeletons or mammalian hair contaminants during digestion. These oleophilic (oil-attracting) contaminants can be separated from non-oleophilic food components by using an oil-water mixture. The contaminants are drawn to the oil phase, which is then separated, filtered, and examined microscopically for the presence of filth Materials and Equipment  Sieve (U.S. No. 20 or finer): To separate the flour from larger particles.  Microscope: For examining the collected filth.  Floatation liquids (e.g., mineral oil, light paraffin oil, or heptane): Used to separate light filth from the flour.  Filtration apparatus: For collecting and isolating the filth.  Petri dishes or glass slides: For microscopic examination. Procedure 1. Sample Preparation: o Weigh a representative sample of whole wheat flour, usually around 50-100 grams, depending on the method being followed. 2. Sieving: o Pass the flour sample through a sieve (typically a U.S. No. 20 or finer) to remove large particles. This step helps in the separation of larger contaminants. 3. Flotation Separation: o Transfer the sieved flour into a separation flask containing the flotation liquid. Light filth, such as insect fragments and rodent hairs, will float to the surface, while the denser flour particles will sink. o Shake the mixture gently to ensure thorough contact between the flour and the flotation liquid. o Allow the mixture to settle, and then decant the liquid containing the floating filth onto a filtration apparatus lined with filter paper. 4. Filtration: o Filter the flotation liquid to collect the light filth on the filter paper. o Rinse the residue on the filter paper with additional flotation liquid to ensure all contaminants are collected. 5. Microscopic Examination: o Place the filter paper or collected residue on a petri dish or glass slide. Department of Biotechnology Brainware University, Kolkata 7 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 oExamine the material under a microscope at appropriate magnifications (e.g., 30- 100x) to identify and count the contaminants, such as insect fragments, rodent hairs, or other foreign materials. 6. Recording Results: o Document the number and types of contaminants found in the sample. Results are usually reported as the number of filth units per 50 grams or per 100 grams of flour. o Compare the results against regulatory standards (e.g., FDA Defect Action Levels) to determine if the sample meets the acceptable limits for light filth. Importance  Ensuring that whole wheat flour is free from light filth is crucial for food safety and quality assurance. Regular monitoring helps in maintaining product integrity and consumer trust. MOISTURE CONTENT ANALYSIS Apparatus (a) Grinding Mill - capable of grinding rapidly and uniformly without development of appreciable heat. The ground material should pass through 1.0 mm I.S sieve. Cold grinding mills can be used instead. (b) Moisture dishes – made of Aluminium or stainless steel approx 7.5 mm wide and 2.5 mm deep with tight fitting lids. (c) Electric oven – well-ventilated and thermostatically controlled to maintain temperature between 130 – 133°C. (d) Desiccators containing an effective desiccant. Procedure a) Mix the test sample thoroughly. b) Grind a suitable quantity of the sample to obtain enough material for replicate determinations. c) Ensure that the ground material is not too coarse or too fine and can pass through a 1.0 mm sieve. d) Weigh accurately about 5 grams of the sample in a previously dried and tared dish. e) Place the dish with its lid underneath in the oven for 2 hours. f) Start timing once the oven reaches 130°C after placing the dishes inside. g) After 2 hours, remove the dish from the oven, cool it in a desiccator, and weigh it. h) Continue heating the dish in the oven at 30-minute intervals until a constant weight is achieved. i) Include the specification for the size of the dish used in the procedure. Calculation Department of Biotechnology Brainware University, Kolkata 8 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Where, W1 = Weight in gms of the dish with the material before drying W2 = Weight in gms of the dish with the material after drying W = Weight in gms of the empty dish. ((Ref: - IS 4333 (Part II) : 2002 Methods of Analysis of food grains Part II Moisture). DETERMINATION OF TOTAL ASH The determination of total ash content in grains is a common food quality test that serves several important purposes: Why is it required??? a. Assessment of Mineral Content: The ash content represents the total amount of mineral elements in the grain, such as calcium, magnesium, potassium, phosphorus, and trace elements. These minerals are crucial for nutritional value, and their levels can give insight into the grain's overall quality. b. Purity and Adulteration Check:  Detection of Adulterants: High total ash content may indicate the presence of impurities or adulterants, such as dirt, sand, or added mineral matter. By comparing the ash content to known standards for a particular grain, it is possible to detect contamination or deliberate adulteration.  Verification of Processing: Ash content can also reflect the extent and quality of processing. For example, excessive ash might suggest poor milling practices or contamination during processing. c. Quality Control and Standards Compliance:  Standard Compliance: Many food quality standards specify maximum permissible ash content for different types of grains. Regular testing ensures that grain batches comply with these standards, which is important for regulatory compliance and consumer safety.  Batch Consistency: Measuring ash content helps ensure consistency between different batches of grain, which is vital for maintaining quality in food production. d. Indicator of Grain Composition: The ash content can provide information about the grain's composition, which affects its nutritional value and functional properties in food processing. For example, high mineral content might influence the grain's behavior during baking or its suitability for certain food products. e. Estimation of Organic Matter: This is an indirect measure of organic content. Since ash represents the inorganic residue remaining after combustion, it indirectly reflects the organic matter in the grain. By subtracting the ash content from the total weight, one can estimate the organic content, which includes proteins, carbohydrates, and fats. Procedure Determining the total ash content in food, such as grains, involves incinerating the sample to remove organic material, leaving behind the inorganic mineral residue (ash). Here's a brief procedure: a. Sample Preparation: Accurately weigh a known amount of the dried sample (typically 2- 5 grams) using an analytical balance. Department of Biotechnology Brainware University, Kolkata 9 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 b. Incineration:  Crucible Preparation: Place a clean, dry crucible in a muffle furnace at 500-600°C for about 30 minutes to remove any contaminants. Cool it in a desiccator and weigh it.  Sample Addition: Transfer the weighed sample into the pre-weighed crucible.  Initial Heating: Heat the sample on a low flame or in a low-temperature oven to char the organic matter without loss of ash due to spattering. c. Ashing or High-Temperature Incineration: Place the crucible with the charred sample in a muffle furnace set at 500-600°C. Allow the sample to incinerate for several hours (typically 4-6 hours) until the sample turns to grayish-white ash, indicating complete combustion of organic matter. d. Cooling and Weighing: Remove the crucible from the furnace and allow it to cool in a desiccator to avoid moisture absorption. Weigh the crucible with the ash using an analytical balance. e. Calculation of Total Ash Content: Interpretation: Express the ash content as a percentage of the initial sample weight. f. Quality Control:  Replicates: Perform the procedure in triplicate to ensure accuracy and consistency.  Standards: Compare the results with known standards or reference materials to validate the procedure. This method provides the total ash content, which represents the inorganic residue in the sample after complete combustion of the organic material. Methodology for Analysis: Standardized methods are used to assess the identity and purity of cereals, legumes. These methods are validated and recognized by organizations like the International Organization for Standardization (ISO) and the Association of Official Analytical Chemists (AOAC). Here, we are providing an example of how to analyse the overall quality of wheat flour. ANALYSIS OF ATTA (WHEAT) Preparation of sample Invert and roll container several times to ensure homogeneous mixture. Avoid extreme temperatures and humidities while opening containers for analysis. Keep sample in a closed container. (Ref: AOAC 17th edn, 2000, Official method 925. 08 Sampling of flour). Determination of moisture Weigh accurately about 5 gm of sample in a previously dried and tared dish and place the dish with its lid underneath in the oven maintained at 130 – 133°C for 2 hours. The time should be reckoned from the moment the oven attains 130°C after the dishes have been placed. Remove the dish after 2 hours, cool in the desiccators and weigh Department of Biotechnology Brainware University, Kolkata 10 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Calculation Determination of total ash Take fresh sample for the determination, rather than left over after determination of moisture. Ignite the dried material in the dish left after the determination of moisture with the flame of a burner till charred. Transfer to a muffle furnace maintained at 550 – 600°C and continue ignition till grey ash is obtained. Cool in a dessicator and weigh. Repeat the process of heating, cooling and weighing at half hour intervals till the difference in weight in two consecutive weighings is less than 1 mg. Note the lowest weight. If ash still contains black particles add 2-3 drops of preheated water at 60°C. Break the ash and evaporate to dryness at 100-110°C. Re-Ash at 550°C. Until ash is white or slightly grey. Safety and GLP (Good Laboratory Practice) aspects  Crucibles/Dishes must be cleaned carefully. Never use abrasive products such as sand, hot concentrated nitric acid, free alkalis or aqua regia.  Very hot crucibles/dishes must not come into contact with silica, quartz or metal oxides since there is a risk of alloy formation resulting in perforations.  After use, wash the crucibles/dish with tap water, using a laboratory brush to remove any adhering material. Remove any stains with cold concentrated hydrochloric acid. In some cases it may be necessary to melt potassium hydrogen sulphate (KHSO4) in the crucible/dish. If this does not help, carefully rub the stain with wet Keiselguhr, talc or kaolin.  During the analysis do not touch crucibles/dish with fingers but handle them with platinum-tipped tongs Maintain Internal control plan of the instruments, eg: Check actual temperature of the muffle furnace on a regular basis using a reference certified thermocouple. Re-calibrate the temperature controller of muffle furnace if actual operating temperature is not within the range 550±25°C. Department of Biotechnology Brainware University, Kolkata 11 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Calculation Determination of GLUTEN Gluten is a group of proteins found in wheat and related grains, such as barley, rye, and oats. The two main proteins in gluten are glutenin and gliadin. These proteins give dough its elasticity, helping it rise and maintain its shape, and provide the chewy texture found in many baked goods like bread and pasta. While gluten is safe for most people, it can cause health issues for some. People with celiac disease, an autoimmune disorder, experience an immune reaction to gluten that damages the lining of the small intestine, leading to nutrient absorption problems and various symptoms like stomach pain, diarrhea, and fatigue. Others might have non-celiac gluten sensitivity, where they experience similar symptoms without the autoimmune response. Gluten is also a key ingredient in many processed foods, used as a stabilizer or thickener in products like soups, sauces, and dressings. Procedure Weigh 25g of the sample into a dish, add about 15 mL of water, and mix it into a dough, making sure all the material is incorporated. Place the dough gently in a beaker filled with water and let it sit for 1 hour. After that, remove the dough and place it in a piece of silk cloth with a 0.16 mm aperture (No. 10 XXX). Wash it with a gentle stream of water until the water passing through no longer turns blue when tested with iodine solution. Stretch the silk tight on a porcelain plate to scrape off the residue. Collect the residue into a ball, squeeze it to remove excess water, and transfer it to a watch glass or petri dish. Dry it in an oven at 105±1°C. When partially dried, remove it, cut it into several pieces, and return it to the oven to dry fully. Cool in a desiccator, weigh, and return it to the oven for another half hour. Cool and weigh again to ensure a constant weight. Calculation Department of Biotechnology Brainware University, Kolkata 12 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Determination of calcium carbonate in fortified atta Principle: Calcium is precipitated as the insoluble oxalate from an ammonical solution, precipitate is dissolved in dilute sulphuric acid and titrated with Potassium permanganate until pink colour appears. Procedure:  Ash approximately 5 gm of sample at 550°C.  Wash the ash into 250 mL beaker with 40 mL concentrated HCl and 60 mL water.  Add 3 drops concentrated Nitric acid and boil for 30 minutes. Cool and transfer to a 250 mL volumetric flask. Make upto mark with water, mix and filter.  Pipette a volume of the filtrate into a beaker containing 10 – 40 mg of calcium. Add 1 mL of 30 % citric acid solution and 5 mL of 5% Ammonium chloride solution. Make up to approximately 100 mL with water and bring to boil.  Add 10 drops of bromo-cresol green solution (0.04%) and 30 mL of warm saturated ammonium oxalate solution. If a precipitate form dissolve it by adding a few drops of concentrated HCl. Neutralise very slowly with ammonia solution, stirring continuously until indicator changes colour at pH 4.4- 4.6.  Then place beaker on steam bath for 30 minutes. Remove the beaker and after 1 hour filter through a fine sintered glass crucible or No 42 filter paper. Thoroughly wash the beaker and crucible/filter paper and dissolve the ppt by passing through 50 mL of warm 10% sulphuric acid. Rinse the crucible/filter paper and make up the filtrate to about 100 mL with water. Heat the filtrate to 70–80ºC and titrate with 0.02 N Potassium permanganate solution until a pink colour persists. Determination of total protein in protein rich atta Principle The protein content is determined from the organic Nitrogen content by Kjeldahl method. The various nitrogenous compounds are converted into ammonium sulphate by boiling with concentrated sulphuric acid. The ammonium sulphate formed is decomposed with an alkali (NaOH) and the ammonia liberated is absorbed in excess of standard solution of acid and then back titrated with standard alkali. Procedure Sample Preparation: Accurately weigh a small, representative sample (usually 0.5 to 2 grams) and transfer it into a Kjeldahl digestion flask. Digestion:  Add Catalyst: Add a catalyst mixture (typically containing selenium, copper, or mercury) and anhydrous sodium or potassium sulfate to the flask. The catalyst speeds up the digestion process.  Add Concentrated Sulfuric Acid: Add a measured amount of concentrated sulfuric acid (about 10-20 mL) to the flask. The acid digests the organic material, converting nitrogen into ammonium sulfate. Department of Biotechnology Brainware University, Kolkata 13 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25  Heat: Heat the flask gently at first to prevent frothing, then increase the heat until the solution becomes clear, indicating complete digestion. This process usually takes 1 to 2 hours. Neutralization:  Cool and Dilute: Allow the flask to cool, then carefully add distilled water to dilute the solution.  Neutralization with Alkali: Add an excess of sodium hydroxide (NaOH) solution to the flask to neutralize the acid. This converts ammonium sulfate into ammonia gas. Distillation:  Distill the Ammonia: Connect the flask to a distillation apparatus. As the solution is heated, the ammonia is distilled off and captured in a receiving flask containing a known volume of standard acid (usually boric acid solution).  End of Distillation: The distillation is complete when all the ammonia has been driven over into the receiving solution. Titration:  Titrate the Ammonia: Titrate the ammonia absorbed in the boric acid solution with a standard acid solution (such as 0.1 N hydrochloric acid or sulfuric acid) using a suitable indicator (such as methyl red or bromocresol green) until the endpoint is reached (a color change is observed). Calculation of Nitrogen Content: Calculation of Protein Content:  Convert to Protein Content:  The protein conversion factor is typically 6.25 for most food proteins, but it can vary depending on the specific type of protein. 1.2 FRUITS, VEGETABLES, TUBERS, AND THEIR PRODUCTS Thermally processed fruits and vegetables (canned/bottled/ flexibly packaged) PHYSICAL EXAMINATION: Note the external condition of the can such as rusty spots, body dents, scratches, leakage around seams, condition of the ends etc. The external condition of the can is described in terms such as: a) FLAT (both ends concave) b) FLIPPER (a mechanical shock producing distortion in one end or both ends) Department of Biotechnology Brainware University, Kolkata 14 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 c) SPRINGER (one end is distorted while other end is flat) and d) SWELL (both ends convex) DETERMINATION OF VACUUM: Place the pointed end of the vaccum gauge in the middle of the top plate of the can and press firmly to pierce the can. Note down the vaccum in millimeters of mercury. FILL OF CONTAINER: This method determines the percent total volume of a container occupied by the contained food. It is designed primarily for cans but can be used for wide mouth glass containers also. Calculation: INTERNAL CONDITION OF THE CAN: Examine the internal surface for any corrosion, pitting, scratching, defects in lacquering, leakages, discolouration, detinning etc. DETERMINATION OF SOLUBLE SOLIDS: Measurement of the refractive index of the test solution at 20 ºC, using a refractometer, and use of tables correlating refractive index with soluble solids content (expressed as Sucrose), or direct reading of the soluble solids content on the refractometer. Preparation of test solution: (a) Clear liquid products: Thoroughly mix the sample and use it directly for determination. (b) Semi thick products (purees etc.): Thoroughly mix the sample. Press a part of the sample through a gauge/muslin cloth folded in four, rejecting the first drops of the liquid and reserving the remainder of the liquid for the determination. (c) Thick products (jams, Jellies etc): Weigh a suitable quantity (upto 40 gm) of the sample and add 100 – 150 mL of distilled water. Heat the contents of the beaker to boiling and allow to boil gently for 2- 3 minutes, stirring with a glass rod. Cool the contents and mix thoroughly. After 20 minutes, filter it into a dry vessel. Reserve the filtrate for determination. DETERMINATION OF METALLIC CONTAMINANTS: The term “Trace Metals” refers to metals which may be present in foods in amounts well below 50 mg/kg and which have some toxicological or nutritional significance While some inorganic elements such as, sodium, potassium calcium, phosphorous are essential for man, elements like lead, cadmium, mercury, Department of Biotechnology Brainware University, Kolkata 15 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 arsenic are found to cause deleterious effects even in low levels of 10 – 50 mg/kg. Although iron, copper, zinc, etc., are found to be necessary in certain quantities in foods, the same elements can cause ill effects when consumed at higher levels. Hence, determination of both major and trace levels of metal contents in food is important for both food safety and nutritional considerations. There are four major steps involved in the analysis of foods for the metal contents, viz. (a) Obtaining a representative sample from the bulk received for testing (b) Destruction of organic matter (c) Separation and concentration of the element of interest (d) Determination Sampling: The object of this step is to obtain a small and representative portion from the large sample in such a way that any subsequent test on the sample will give a reproducible value.  For fresh foods, the homogenization process is like macerating in a blender whereas dry products are normally ground mechanically and then mixed and the powder is sieved before analysis. Contamination during this step can be avoided with the use of stainless steel equipment.  Hard foods, such as, chocolates are sampled by grating/chopping finely by hand.  Meat and meat products are thoroughly minced and then ground in a mortar and in this case, too small quantities should not be taken for analysis.  Fats are melted before analysis. Wet foods such as pickles, etc should be homogenized in high-speed blender. Liquids are normally sampled after they have been thoroughly mixed by repeated slow inversion of container. After the sample is properly homogenized and reduced to usable form, it should be stored in an air tight container. Dry Ashing and Preparation of Solution: This procedure is also used for destruction of organic matter. Precautions are to be taken to avoid losses by volatilization of elements, retention of element on the surface of vessel used or incomplete extraction of ash. These problems can be avoided by using controlled muffle furnace, by adding ash aid wherever necessary (Magnesium nitrate, sodium carbonate, sulphuric acid etc) to the food before ashing and by using a suitable acid for extraction. Silica or platinum vessels are to be preferred. Analysis of metals by  Determination of lead, cadmium, copper, iron and zinc in foods by Atomic absorption spectrophotometer: This method is applicable for determination of Lead, Copper, Cadmium, Iron, and Zinc in food by Atomic Absorption Spectrophotometer using Flame and Furnace Technique. Test portions are dried and then ashed at 450°C under a gradual increase (about 50°C/hr) in temperature, 6 N HCl (1+1) is added and the solution is evaporated to dryness. The residue is dissolved in 0.1N HNO3 and the analytes are determined by flame and graphite procedures.  Determination of mercury in food using mercury analyser Department of Biotechnology Brainware University, Kolkata 16 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Principle: Sample is digested with nitric acid and sulphuric acid under reflux in special apparatus. By reduction mercury vapour is generated which is measured using Mercury Analyser.  Determination of arsenic in foods by colorimetric molybdenum blue method The sample is digested with nitric acid and sulphuric acid. After the digestion/oxidation is complete, the digest is treated with saturated ammonium oxalate solution to remove yellow coloration due to nitro compounds, fats, etc. Arsine is generated from digest using zinc and HCl and trapped in Sodium hypobromite (NaOBr) solution and is treated with ammonium molybdate to form a blue compound which absorbs as 845 nm.  Determination of cadmium in food by colorimetric dithzone method The sample is digested with H2SO4 and HNO3. The pH of the solution is adjusted to 9.0. The dithizone metals along with cadmium are extracted from aqueous solution with dithizone chloroform solution. Cadmium is separated from Cu, Hg and most of any Ni or Co present, by stripping CHCl3 solution with dil. HCl solution leaving Cu, Hg, Ni and Co in organic phase. Aqueous layer is adjusted to 5% NaOH and is extracted with dithizone – CCl4 solution. At this alkalinity Zn, Bi and Pb do not extract whereas cadmium dithizonate is relatively stable. Cadmium is finally estimated photometrically at 510 nm.  Determination of copper in food by colorimetric carbamate method (IUPAC method) The sample is digested with HNO3 and H2SO4. Copper is isolated and determined calorimetrically at pH 8.5 as diethyl dithiocarbamate in presence of chelating agent EDTA. Bi and Te also give coloured carbamates at pH 8.5, but are decomposed with 1N NaOH. Range of colour measurement is 0 to 50 μg.  Determination of iron in foods Organic matter in the sample is destroyed by ashing and the resulting ash is dissolved in hydrochloric acid and diluted to a known volume with water. Whole of the iron present in the aliquot of ash solution is reduced with hydroxylamine hydrochloride and the Fe (II) is determined spectrophotmetically as its coloured complex with, α- α-dipyridyl, the solution being buffered with acetate buffer solution. Absorption of the resulting complex is read at 510 nm.  Determination of lead in food The sample is ashed and the acid solution of ash is neutralized with ammonia in the presence of citrate. Several other interfering elements are complexed with cyanide and lead is isolated as lead dithizonate into CHCl3. The chloroform layer is shaken again with dilute nitric acid and chloroform layer is discarded. The aqueous phase is buffered to pH 9.5 to 10.0 and lead is re-extracted with dithizone in chloroform. The colour produced is read at 510 nm and is compared with known standard.  DETERMINATION OF TIN IN FOOD by Spectrophotometric Catechol Violet Method (IUPAC Method) The sample is wet digested with a mixture of nitric and sulphuric acids followed by subsequent treatment with perchloric acid and hydrogen peroxide and the residue is diluted with water to give an approximately 4.5M concentration of the acid. Potassium iodide is added Tin (IV) iodide is selectively extracted into cyclohexane. Tin (IV) is returned Department of Biotechnology Brainware University, Kolkata 17 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 to aqueous solution by shaking organic layer with sodium hydroxide solution which is subsequently acidified. After removal of free iodine, Tin (IV) is determined spectrophotometrically as its coloured complex with catechol violet, the Solution being buffered to pH 3.8. The absorption maximum of the resulting complex is 555 nm. MICROBIOLOGICAL EXAMINATION: Apparatus/Instruments 1. Protective cabinets (Biosafety Cabinet/Laminar Air Flow): Protective cabinets are enclosed workspaces with a ventilated hood designed to contain pathogenic microorganisms, dust and other particles during food microbiological examination. These cabinets are equipped with HEPA (high-efficiency particular air filters) and a shortwave ultraviolet germicidal lamp that sterilizes the workstation. HEPA filters remove 99.97% of the particles having a size of more than 0.3 μm. For cabinets used in food microbiology, the number of particles shall not exceed 4000 per cubic meter. These are intended to capture and retain infected airborne particles released during the food analysis and to protect the food analyst from the infection that may arise from inhaling them. Four types of cabinet are use in food microbiology laboratory. a. Class I is the most basic cabinet that protects the environment and the laboratory personnel. However, does not provide protection to the product. Biosafety cabinets of this class are either ducted (connected to the building exhaust system) or un-ducted (recirculating filtered exhaust back into the laboratory). The unsterilized room air is drawn in through opening, over the work surface. An airflow of between 0.7 and 1 m/s must be maintained through the front of the cabinet. Advanced cabinets have airflow indicators and alarming devices. The filters must be changed when the airflow falls below this level. They are not recommended for work with risk category 3 pathogens because of the difficulties in maintaining and ensuring appropriate operator protection. b. Class II safety cabinets protect the product, the operator, and the environment. Class II Biosafety Cabinet (BSCs) are designed with an open front with inward airflow (personnel protection), downward HEPA-filtered laminar airflow (product protection) and HEPA-filtered exhaust air (environmental protection). These cabinets are further differentiated by types based on construction, airflow and exhaust systems. The types include A1, A2, B1, B2 and C1. They are suitable for work with risk category 2 and 3 pathogens. 2. Autoclave: An autoclave is a pressurized chamber used for sterilization by combining three factors: time, pressure, and steam. It uses steam under pressure as its sterilization agent at approx. 121 °C temperature and 15 lb./in2 pressure for about 15–30 min. The autoclave must be able to maintain an internal temperature of 121° under a pressure of 1 bar (15 psi); it should be equipped with a calibrated temperature probe to measure the temperature within the sterilizing chamber; a calibrated pressure gauge (0-20 psi range), timer and safety valves. The autoclave should preferably be equipped with a temperature recorder to provide a permanent record of the sterilizing cycle. Department of Biotechnology Brainware University, Kolkata 18 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 3. Incubators: An incubator consists of an insulated chamber which enables the temperature to be kept stable and uniformly distributed to within the maximum permissible temperature error specified in the test method. BOD incubator has both heating and cooling option and should be used in case of temperature requirement of less than 300C. For the growth of anaerobic bacteria, CO2 incubators are available that have an internal atmosphere of 5–8% CO2. Media/ Reagents and Reference culture Microbiological examinations used a vast variety of culture media, the formulation of which varies as a function of the microorganism(s) that will be cultivated and the tests for which they are intended. The formulation is the complete set of ingredients that, in well-balanced and adequate proportions, will confer to the culture medium their required distinct characteristics. The ingredients used to formulate culture media are generally commercially available in dehydrated form, and include sources of nutrients, selective agents, differential agents, reducing agents, buffering agents, chromogenic and fluorogenic substrates and agar (gelling agent). The ingredients of the formulation are dissolved in water, the quality of which is critical for the good performance of the media to be prepared. Sufficient testing should be carried out to demonstrate a) the acceptability of each batch of medium, b) that the medium is “fit for purpose”, and c) that the medium can produce consistent results Methods of Analysis for foods Method for Enumeration of Coliforms (FSSAI 15.004:2023) Introduction Coliforms are a broad group of aerobic or facultative anaerobic, rod-shaped, gram-negative non-spore forming bacteria which can ferment lactose with the production of acid and gas when incubated at 32–37°C. Coliform are members of Enterobacteriacae family. Most common genera are E. coli, Citrobacter, Enterobacter, Klebsiella and Hafnia. Principle Violet red bile lactose agar (VRBL) medium is used for enumeration of coliforms. VRBL contains selective inhibitors - inhibit the accompanying gram-positive and unrelated flora. Coliforms rapidly ferment lactose and produce red colonies surrounded by red purple halo. Lactose non- fermenters and late lactose fermenters produce pale colonies. Confirmation is carried out in brilliant green bile broth medium, which is also having selective components for the growth of coliforms. Department of Biotechnology Brainware University, Kolkata 19 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Equipment Laminar airflow, Biosafety cabinet, Hot air oven, Autoclave, Incubator (Operating at 30 ± 1°C or 37± 1°C), Water bath (at 44 °C to 47 °C or at 100 °C), pH meter with measuring accuracy ±0.1, Microscope, Refrigerator (at 2°C – 8 °C), Petri dishes (Glass or plastic of 90-100mm diameter or 140mm), Graduated pipettes (0.1 ml divisions) of capacity 1 ml (Class A), Micropipette with tips, Tubes and glass bottles, Durham tubes, Vortex, Mechanical stirrer, Spreader (glass or plastic), Inoculation loops and straight wire, Spiral plater/rotator Culture Media Primary Diluent and Reagents Violet Red Bile Lactose Agar (VRBL) Brilliant Green Lactose Bile Broth (BGBB) ISO 4832:2006 Reference Cultures Specific strains or equivalent member of coliform group (E. coli etc.) Procedure Test portion, initial suspension and dilution Weigh or measure the test portion, to a tolerance of ±5 %, into a sterile container or plastic bag. A mass of m g or a volume of V ml (minimum 10 g or 10 ml, unless otherwise stated) representative of the laboratory sample shall be used. Add a quantity of diluent equal to 9 × m g or 9 × V ml to prepare a primary decimal dilution. Homogenize the sample with a peristaltic blender or rotary homogenizer or vibrational mixer. This corresponds to 10−1 dilution. For further decimal dilution, transfer, using a pipette, 1 ml ± 0.02 ml of the initial suspension into a tube containing 9 ml ± 0.2 ml of sterile diluent. Mix thoroughly, preferably by using a mechanical stirrer for 5 s to 10 s, to obtain a 10−2 dilution. If necessary, repeat these steps using the 10−2 and subsequent dilutions and a new sterile pipette or tip for each operation, to obtain sufficient (10−3, 10−4, etc.) dilutions to enumerate the appropriate number of microorganisms. Inoculation and Incubation Label all Petri dishes with the sample code, dilution, date and any other information.  Pipette 1ml of the test sample (if the product is liquid), or 1 ml of primary suspension (if prepared) to the centre of each petri dishes. Similarly prepare plates from subsequent dilution as required.  Pour approximately 15 ml of the molten VRBL agar, (cooled at 44 °C to 47 °C) into each petri dishes. Time elapse between inoculation and addition of agar into plates shall not exceed 15 mins.  Carefully mix the inoculum with the medium and allow the medium to solidify. Also prepare a control plate with 15 ml of the medium for checking its sterility.  After complete solidification, pour about 4 ml of molten VRBL agar (cooled at 44 °C to 47 °C) onto the surface of inoculated medium Department of Biotechnology Brainware University, Kolkata 20 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 and allow to solidify. Invert the inoculated plates and incubate them at 30 °C or 37 °C for 24 ± 2 h. Enumeration: After completion of incubation period, count purplish red colonies with a diameter of at least 0.5 mm (sometimes surrounded by a reddish zone of precipitated bile). Consider all these as typical colonies of coliform and do not require further confirmation. Count other atypical colonies (smaller size) also and all colonies derived from milk products that contain sugar other than lactose, immediately after the incubation and confirm. Confirmation Select 5 colonies of each atypical types and inoculate into tubes of brilliant green lactose bile broth and incubate at 30 °C or 37 °C for 24 ± 2 h. Consider all colonies as coliforms that show gas formation in Durham tubes. Take the results into account in the calculation. Calculation  Select petri dishes having 10 to 150 colonies for enumeration.  Use the following formula for calculation Expression of Results shall be expressed as a number between 1.0 and 9.9 Results multiplied by 10 x, where x is power of 10. If plates from all dilutions have no colonies, the result is expressed as less than 1 cfu/ml or 10 cfu/g or mL (if primary suspension prepared) Department of Biotechnology Brainware University, Kolkata 21 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Thermally processed fruit and vegetable juices fruit beverages/fruit drinks and fruit nectars (canned/bottled)/flexibly/aseptically packaged and non-thermally processed fruit beverages/drinks A. TOTAL SOLIDS Insoluble matter absent (applicable to jellies and syrups also): Digest pure quartz sand that passes No 40 but not No 60 sieve with HCl, wash acid free, dry and ignite. Preserve in stoppered bottle. Place 26- 30 gm sand and a short stirring rod in the dish about 55 mm in diameter and 40 mm deep, fitted with cover. Dry the dish thoroughly cool in a dessicator and weigh immediately. Add enough sample to yield about 1 gm dry matter and mix thoroughly with sand. Heat on steam bath 15 – 20 minutes, stirring at 2 – 3 minutes interval or until mass becomes too stiff to manipulate readily. Dry at less than 700C under pressure of about 50 mm Hg in vaccum oven passing a current of dry air (dried over CaSO4 or P2O5). Make trial weighings at 2 hours interval after 18 hrs until change in weight is equal to 2 mg. Insoluble matter present (applicable to fresh and canned fruits, jams, marmalades and preserves): Accurately weigh into a large flat bottomed dish sufficient sample that will give 2- 3 gm dry matter. If necessary to secure thin layer of material, add few mL water and mix thoroughly. Dry at 700C under pressure less than 100 mm Hg until consecutive weighing’s made at 2 hr intervals vary less than 3mg. B. TOTAL SOLUBLE SOLIDS: As mentioned above C. DETERMINATION OF pH VALUE: pH is the measurement of H+ ion activity; It measures active acidity. pH may be determined by measuring the electrode potential between glass and reference electrodes; the pH meter is standardized using standard pH buffers. Use a homogenized sample for the determination of pH. Liquids: Immerse the standardized electrode tip into the solution and stir the sample gently by means of a rod or "flea" to give a constant pH value. Non-homogeneous products: If it is useful to know the pH of different components of the sample or differences between the pH at several points of the test portion, separate these as best as possible, homogenize and read them separately. For a bulk pH measurement, homogenize a representative aliquot to give a moist homogeneous mixture. Dry products: Have a standard practice for the dilution of dried materials - particularly when comparing the pH of sub-samples of the same product, as pH may change with the extent of dilution. For example, homogenize with an equal volume of distilled or deionized water. Immerse the electrode in the sample and mix gently until a constant pH reading is obtained. D. DETERMINATION OF ACIDITY (APPLICABLE TO JAMS, JELLIES ALSO): Titrable acidity can be expressed conveniently in gm acid per 100 gm or per 100 mL as appropriate, by using the factor appropriate to the acid as follows: Department of Biotechnology Brainware University, Kolkata 22 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 E. DETERMINATION OF TOTAL SUGARS: The presence of added sucrose can be detected by determining sugars before and after inversion by copper- reduction methods. Standardization of Fehling’s solution:  Prepare a standard dextrose solution in a 100 mL volumetric flask.  Determine the volume (titer) of the dextrose solution needed to reduce all the copper in 10 mL of Fehling's solution (refer to the table).  In a 300 mL conical flask, pipette 10 mL of Fehling’s solution and add most of the required dextrose solution from a burette, leaving over 1 mL for later.  Heat the flask over wire gauze and boil gently for 2 minutes.  After 2 minutes of boiling, add 1 mL of methylene blue indicator without stopping the boiling.  While boiling, slowly add the dextrose solution (a few drops at a time) until the blue color disappears. Complete this within 1 minute.  Record the total volume of dextrose solution used (the titer).  Multiply the titer by the mg of anhydrous dextrose in 1 mL of standard solution to find the dextrose factor. Compare this factor to the expected value and adjust accordingly. Dextrose factors for 10 mL of Fehling’s Solution Titre (ml) Dextrose factor Dextrose content per 100 ml of solution (mg) 15 49.1 327 16 49.2 307 17 49.3 289 18 49.3 274 19 49.4 260 20 49.5 247.4 Transfer test sample representing about 2- 2.5 gm sugar to 200 mL volumetric flask, dilute to about 100 mL and add excess of saturated neutral Lead acetate solution (about 2 mL is usually enough). Mix, dilute to volume and filter, discarding the first few ml filtrate. Add dry Potassium or Sodium Oxalate to precipitate excess lead used in clarification, mix and filter, discarding the first few mL filtrate. Department of Biotechnology Brainware University, Kolkata 23 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Take 25 mL filtrate or sample containing 50-200 mg of reducing sugars and titrate it using the Lane and Eynon Volumetric method with Fehling A and B solutions.  Fehling A: Dissolve 69.28 g of copper sulfate (CuSO₄.5H₂O) in water and dilute to 1000 mL. Store in a dark bottle.  Fehling B: Dissolve 346 g of Rochelle salt and 100 g of NaOH in water, dilute to 1000 mL, and store in a dark bottle.  For inversion at room temperature:  Transfer 50 mL of the clarified and de-leaded solution to a 100 mL flask.  Add 10 mL of HCl and let it sit for 24 hours at room temperature.  (For faster inversion, heat the sample with HCl at 70°C for 1 hour.)  Neutralize the solution with NaOH using phenolphthalein as an indicator, and dilute it to 100 mL.  Titrate the solution against the mixed Fehling A and B solution (use 25 mL of Fehling’s solution).  Calculate the total sugar as invert sugar, then subtract the reducing sugars to find the added sugar. F. DETERMINATION OF VITAMIN C (ASCORBIC ACID): The ascorbic acid content in fruits and vegetables can be estimated by macerating the sample with stabilizing agents such as 20% metaphosphoric acid. 2, 6 -dichlorophenol indophenol is reduced to a colourless form by ascorbic acid. The reaction is specific for ascorbic acid at pH 1 to 3.5. The dye is blue in alkaline solution and pink in acid. G. DETERMINATION OF ETHANOL CONTENT: This test method covers only the product which does not contain ethanol as an ingredient. The method is not applicable to products containing more Department of Biotechnology Brainware University, Kolkata 24 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 than 5 % (m/m) of ethanol. Separation of ethanol by distillation followed by oxidation by Potassium dichromate in a sulphuric acid medium and determination of excess dichromate by Ferrous ammonium sulphate in the presence of Ferrous 1, 10 phenathroline as indicator TEA, COFFEE, COCOA, CHOCOLATE, SPICES  TEA How to determine Tea Quality: There are following 6 ways to determine the quality of tea The picked tea leaf: The picked tea leaves should be in good shape, whole, and without tare (not broken). This tells that the tea leaves were picked with care and not just plucked quickly or by a machine. Uniformity in the tea leaves: For quality tea, the tea leaves should mostly adhere to the same shape and size. This is also determined by the plucking standard of a particular tea type. For example, many (but not all) high-quality teas comprise only the first buds and tea leaves. If there is a mix of large tea leaves and small, young tea leaves, this may indicate that the plucking standard wasn’t adhered to. Cultivar: Depending on the tea variety, the cultivar may actually say a lot about the tea. While some teas of the same category can be produced using different cultivars, others must stick to one cultivar to indeed be considered an authentic tea. It may be important to inquire about the cultivar when buying tea. Harvest Time: Each tea has a particular harvest time that should be adhered to. Many top-shelf teas are harvested at the very beginning of spring, right after the last frost. There is often a window of just a week where the ideal tea leaves being harvested without over maturing from sun exposure and warmer temperatures. Tea leaves harvested at the end of spring or even during summer will generally have larger leaves. Tea farm location: Many teas are tied to their production region. One great example is Darjeeling Tea A tea could only be considered a high-mountain tea if it was grown at least 3,300 feet (1000 m) above sea level Packaging: We would like to believe that most tea vendors adhere to proper storage and packaging practices. Some basic rules are: tea shouldn’t be sold in plastic bags, clear Ziploc’s, or glass jars. Exposure to light is not suitable for tea leaves. They may lose their vitality, taste, and aroma more quickly. Tins or opaque bags with inside lining are both excellent choices. Also, try to make sure that the lining doesn’t contain aluminum, as this may be harmful to our health and the taste of the tea.  COFFEE Department of Biotechnology Brainware University, Kolkata 25 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 The analysis of coffee bean purity is essential to ensure the quality and authenticity of coffee products. Various methodologies are employed to assess the purity of coffee beans, and these typically involve a combination of visual inspection, physical measurements, and chemical analysis. Here's a brief overview of the methodology used in the analysis of coffee bean purity Visual Inspection:  Color and Size: Coffee beans of different origins and processing methods have distinct visual characteristics. Inspectors can visually assess the color, size, and shape of the beans to identify any irregularities or foreign matter.  Uniformity: Purity analysis involves checking for the uniformity of coffee beans. Any variations in color or size can indicate impurities or mixed bean types.  Defects: Examine the beans for defects such as insect damage, mold, or other physical anomalies that may affect purity. Physical Measurements:  Density Measurement: The density of coffee beans can be measured to identify any variations. Impurities or lower-quality beans may have a different density compared to pure coffee beans.  Moisture Content: Measuring the moisture content is crucial, as high moisture levels can lead to mold growth and deterioration of coffee quality. Moisture meters are often used for this purpose. Grading and Sieving:  Grading involves sorting coffee beans based on size and quality. Specialty coffees, in particular, undergo meticulous grading to ensure purity.  Sieving is a common method to separate different bean sizes, as smaller or broken beans may indicate impurities. Chemical Analysis:  Gas Chromatography-Mass Spectrometry (GC-MS): This technique is used to analyse the chemical composition of coffee beans. It can detect the presence of contaminants, such as mycotoxins, pesticides, and other chemicals that may affect purity.  Caffeine Content: Measuring caffeine levels is another method to assess the purity of coffee beans. Different coffee varieties and blends have characteristic caffeine levels. Cupping: Cupping is a sensory evaluation method where trained tasters assess the aroma, flavour, acidity, body, and aftertaste of brewed coffee. It helps in identifying any off-flavours or impurities in the coffee. Certification: Coffee certification organizations, such as Fair Trade or Organic certifiers, have their own rigorous standards and auditing processes to ensure the purity and quality of coffee beans.  COCOA Department of Biotechnology Brainware University, Kolkata 26 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Recognizing the great quality in cocoa beans is an essential skill for chocolate makers and cocoa traders. With this guide, consumers can also learn the basics through these indicators: Flavor: According to a guideline from the European Cocoa Association (ECA), the correct parameter for flavor “includes both the intensity of the cocoa or chocolate flavors, together with any ancillary flavor notes.” The primary flavors also include a mix of pleasant bitterness and the right amount of acidity, while the ancillary flavors are a variety of fruity, spicy, nutty, or floral, with notes of caramel, honey, or even hazelnut. A cut test is used to evaluate the quality of fermented cocoa beans. Some processors utilize the cut test as an indicator of flavor. This evaluation is usually used to assess if a batch of beans was properly fermented or not. To perform a cut test, you simply cut fermented cacao beans in half to evaluate their centers. They are usually performed on at least ten beans to have a representative sample of each batch. At least 70% of the beans must be fermented to the correct level to be considered successful. Physical Appearance: Fine cocoa bean quality can also be determined through the physical characteristics of the beans. One physical indicator is consistent bean size, which is an important aspect because smaller cocoa beans would warrant recalibration of machinery, affecting manufacturing processes. Varying sizes can also slow down cleaning and sorting, costing additional time and labor. Moisture content is another physical attribute to keep an eye on. Having the ideal moisture content of 7% ensures that mold and bacterial growth is avoided. This allows producers and traders to safely transport, store, or process the cocoa beans. Traceability: In the food industry, traceability allows concerned parties to “follow the movement of a food through specified stages of production, processing, and distribution,” according to the Food and Agriculture Organization. FFA Content: High levels of free fatty acid (FFA) in cocoa beans result in poor quality cocoa butter, which is the main component that creates the delicious, melt-in-your-mouth feel of good chocolate.  CHOCOLATE  Chocolate is one of the most popular drinks and snacks and contains cocoa, milk, and sugar in addition to other nutrients including proteins, carbs, lipids, minerals, and vitamins  Good source of energy and contains antioxidant like polyphenols, which include flavonoids like catechin, epicatechin, and procyanidins  Chocolate helps in avoiding low-density lipoprotein (LDL) oxidation, which lowers the risk of heart disease FSSAI definition of chocolate: According to the Food Safety and Standards (Food Products Standards and Food Additives) Regulations 2011, chocolate has been defined as a “homogeneous product obtained by an adequate process of manufacture from a mixture of one or more of the ingredients, namely, cocoa beans, cocoa nib, cocoa mass, cocoa press cake and cocoa dust (cocoa fines/powder), including fat reduced cocoa powder with or without addition of sugars, cocoa butter, milk solids including milk fat. The chocolates shall not contain any vegetable fat other than cocoa butter. The Department of Biotechnology Brainware University, Kolkata 27 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 material shall be free from rancidity or odour, insect and fungus infestation, filth, adulterants and any harmful or injurious matter. Imported chocolates While internationally chocolate can contain vegetable fats but according to Indian standards FSSAI does not permit the use of vegetable fats in chocolates. The use of vegetable fats and oils in chocolates has been the bone of contention in imported chocolates. A number of well know international chocolate companies had their consignments of chocolates withheld at ports because they did not fulfill requirements of Indian standards for chocolates.  They did not comply with Indian standards requirements which do not permit the use of vegetable fats and oil. So chocolates containing vegetable oil or fat cannot be imported & sold in India for consumption.  Imported chocolates that do not mention the use of artificial flavours on labels cannot be imported. According to FSSAI (Packaging & Labelling) Regulations, 2011 all ingredients need to be mentioned on labels in descending order of their composition by weight and volume at the time of manufacture including additives, colour, preservatives, flavours etc.  According to FSSAI labelling regulations only vegetarian and non-vegetarian Logo, the FSSAI Logo and License number of the importer and the name & address of the importer are only permitted on the stickers. Rest all information has to be printed on the label. Chocolates in Indian market The FSSAI standards allow chocolate to contain only cocoa butter and no vegetable oil and fat whereas international food standards Codex permits just 5 per cent vegetable fat. However, there are a number of ‘chocolates’ sold in the Indian market that contain vegetable oil, ranging from 5 per cent to 35 per cent. This is why a number of brands do not use the term ‘chocolate’ on the packaging. Types of chocolates in FSSR Milk chocolates: This is obtained from one or more of cocoa nib, cocoa mass, cocoa press cake, cocoa powder including low-fat cocoa powder with sugar and milk solids including milk fat and cocoa butter. Milk Covering Chocolate is made just like milk chocolates but in addition it is suitable for covering purposes. Plain Chocolate This is obtained from one or more of cocoa nib, cocoa mass, cocoa press cake, cocoa powder including low fat cocoa powder with sugar and cocoa butter. Plain Covering Chocolate is obtained in the same way as plain chocolate but is also suitable for covering purposes. Blended Chocolate means the blend of milk and plain chocolates in varying proportions. White chocolate is obtained from cocoa butter, milk solids, including milk fat and sugar. Department of Biotechnology Brainware University, Kolkata 28 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Filled Chocolates are products that have an external coating of chocolate but the centre is totally distinct in composition as compared with the external coating. This does not include flour confectionery pastry and biscuit products. The coating can be of milk, plain, blended or white chocolate only. The amount of chocolate component of the coating should not be less than 25 per cent of the total mass of the finished product. Composite Chocolate is a product that contains at least 60 per cent of chocolate by weight and edible wholesome substances such as fruits, nuts. It can contain any one or more edible wholesome substances which must be at least 10 per cent of the total mass of finished product. Other ingredients in chocolates Chocolates may contain permitted artificial sweeteners as provided in the regulations and declared on labels according to Food Safety and Standards (Packaging and Labelling) Regulations, 2011. The chocolates may also contain permitted food additives. Also the different types of chocolates may contain the following substances as required in the different types of chocolates.  edible salts  spices and condiments  permitted emulsifying and stabilizing agents  permitted sequestering and buffering agents  SPICES Quality Testing and Analysis of Spices Quality assurance in the spice industry is met through four main stages:  By managing the cultivation and harvesting practices  Strict spice quality inspection during procurement  Strictly monitoring the processing methods that are used in the production unit  Ensuring spices testing is done appropriately during packaging and storing processes Following parameters are tested for analysis of spices Acid insoluble ash: Acid insoluble ash is a test used in order to determine the amount of inorganic residue present in a sample. Moisture: Moisture content in food can be defined as any water within the food product. Excess moisture can get into the food from several sources such as the atmospheric moisture from the production and packing areas, packaging method or food storage Non-volatile ether extract: A dried, ground sample is extracted with diethyl ether which dissolves fats, oils, pigments and other fat-soluble substances. The ether is then evaporated from the fat solution. The resulting residue is weighed and referred to as ether extract or crude fat. Department of Biotechnology Brainware University, Kolkata 29 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25 Cadmium: Large amounts of cadmium can severely irritate the stomach and cause vomiting and diarrhea Kidney-based risk assessment establishes the urinary Cd threshold at 5.24 μg/g creatinine, and tolerable dietary intake of Cd at 62 μg/day per 70-kg person Scoville index (measurement of pungency (spiciness or "heat") of chili peppers and other substances, recorded in Scoville heat units (SHU). 2 MODEL QUESTIONS Multiple Choice Question Why are standards of purity important in cereals, legumes, and oilseeds?  a) To increase the taste of the food  b) To ensure the food is free from harmful contaminants  c) To reduce the cost of production  d) To increase the shelf life  Answer: b) To ensure the food is free from harmful contaminants Which contaminants are standards of purity designed to limit in cereals, legumes, and oilseeds?  a) Bacteria and viruses  b) Pesticides and fertilizers  c) Mycotoxins and heavy metals  d) Color additives and preservatives  Answer: c) Mycotoxins and heavy metals What is the primary purpose of moisture content analysis in grains?  a) To improve the flavor of the grains  b) To prevent spoilage and mycotoxin production  c) To increase the protein content  d) To enhance the nutritional value  Answer: b) To prevent spoilage and mycotoxin production Which method is used to determine moisture content in grains?  a) pH testing  b) Spectrophotometry  c) Drying in an oven  d) Filtration  Answer: c) Drying in an oven Aflatoxins in food are primarily known for being:  a) Nutritional supplements  b) Carcinogens  c) Flavor enhancers  d) Preservatives  Answer: b) Carcinogens What is the first step in the CB method for aflatoxin analysis?  a) Drying the food sample  b) Grinding the food sample  c) Heating the food sample  d) Filtering the food sample  Answer: b) Grinding the food sample Why is the detection of foreign matter in food grains important?  a) To increase the volume of food grains  b) To indicate contamination or poor handling practices  c) To add nutritional value Department of Biotechnology Brainware University, Kolkata 30 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25  d) To reduce the cost of processing  Answer: b) To indicate contamination or poor handling practices What is the primary method used to detect foreign matter in food grains?  a) Chemical analysis  b) Microscopic examination  c) Sieving through a series of sieves  d) Washing with water  Answer: c) Sieving through a series of sieves What health risks are associated with mycotoxin contamination in cereals, legumes, and oilseeds?  a) Allergies  b) Weight gain  c) Cancer and other serious health issues  d) Improved digestion  Answer: c) Cancer and other serious health issues Which of the following is a critical safety measure when handling contaminated samples with mycotoxins?  a) Freezing the samples  b) Using personal protective equipment (PPE)  c) Adding preservatives to the samples  d) Diluting the samples with water  Answer: b) Using personal protective equipment (PPE) Which term is used to describe a can with both ends concave?  a) Flipper  b) Swell  c) Springer  d) Flat  Answer: d) Flat What is used to measure the vacuum in a canned product?  a) Pressure gauge  b) Refractometer  c) Vacuum gauge  d) Barometer  Answer: c) Vacuum gauge What does the drained weight of a canned product represent?  a) The total weight of the container  b) The weight of the liquid contents  c) The weight of the solid contents remaining after draining  d) The total volume of the container  Answer: c) The weight of the solid contents remaining after draining What instrument is used to determine soluble solids content?  a) Spectrophotometer  b) Autoclave  c) Refractometer  d) Incubator  Answer: c) Refractometer What method is used to determine sodium chloride content in brine?  a) Mohr’s method  b) Kjeldahl method  c) Flame photometry  d) Titration with HCl Department of Biotechnology Brainware University, Kolkata 31 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25  Answer: a) Mohr’s method Which element is NOT typically considered a trace metal in food safety analysis?  a) Iron  b) Zinc  c) Phosphorus  d) Cadmium  Answer: c) Phosphorus What type of safety cabinet provides protection to the operator, environment, and the product?  a) Class I  b) Class II  c) Class III  d) Class IV  Answer: b) Class II Which media is used for the enumeration of coliforms?  a) Nutrient Agar  b) Violet Red Bile Lactose Agar (VRBL)  c) MacConkey Agar  d) Blood Agar  Answer: b) Violet Red Bile Lactose Agar (VRBL) What is the first step in the determination of metallic contaminants in food?  a) Destruction of organic matter  b) Sampling  c) Concentration of the element  d) Determination  Answer: b) Sampling What is the purpose of using an autoclave in microbiological examination?  a) To measure vacuum  b) To sterilize equipment and media  c) To measure temperature  d) To incubate cultures  Answer: b) To sterilize equipment and media Short Answer Type Question  What is the primary purpose of standards of identity for cereals, legumes, and oilseeds?  Which two species of Aspergillus are known to produce aflatoxins?  Explain mycotoxin and the safety requirements for handling this toxin  Name two contaminants that purity standards aim to limit in cereals, legumes, and oilseeds.  What is the role of liquid-liquid partitioning in the CB method for aflatoxin determination?  How is foreign matter in food grains detected according to the provided method?  Explain the difference between a flipper and a swell in canned food packaging.  What is the significance of determining the fill of a container in food packaging?  Describe the process of determining soluble solids in a thick product like jam.  Why is it important to determine both major and trace levels of metal contents in food?  What is the purpose of using HEPA filters in protective cabinets?  How is the internal condition of a can assessed during physical examination?  What are the key steps involved in dry ashing for metal analysis in food? Department of Biotechnology Brainware University, Kolkata 32 BSCBT and 1st Semester Food Technology (BBT10002) Section B 2024-25  Why is it necessary to neutralize acidic samples before titration in the determination of sodium chloride?  What is the function of an incubator in microbiological examination? Long Questions:  Discuss the importance of standards of purity in ensuring the safety and quality of cereals, legumes, and oilseeds.  Describe the purpose of determining the total ash content of a food item and the steps involved in the quantification.  Describe the process and significance of determining the moisture content in grains.  Explain the significance of aflatoxin determination in food safety and the steps involved in the CB method for its analysis.  What are the steps involved in the detection of foreign matter in food grains, and why is it important?  Discuss the potential health risks associated with mycotoxin contamination in cereals, legumes, and oilseeds, and the safety measures required during the handling of contaminated samples.  Explain the significance of determining metallic contaminants in food, including the types of metals analyzed and the potential health implications.  Describe the microbiological examination process for the enumeration of coliforms, including the importance of using specific media and equipment.  Detail the procedure for determining the soluble solids content in thick fruit products, including the preparation of the test solution and the use of a refractometer. 3 REFERENCE  Food Science, Potter, Norman N., Hotchkiss, Joseph H. (1995), 5th Ed. Springer US  https://fssai.gov.in/upload/advisories/2018/02/5a93ebeeda71cManual_Mycotoxins_25_05_2016(1). pdf  file:///H:/BWU%20Class%20related%20semester%20wise%20data/Academic%20year%202024- 2025/Odd%20Semester%202024/Notes/BBT10002_Food%20technology/Module%202%20FSSAI%20 Reference%20Material/Manual_Fruits_Veg_25_05_2016.pdf  https://www.fssai.gov.in/upload/uploadfiles/files/Manual-Microbiology-Methods.pdf  https://www.fssai.gov.in/upload/uploadfiles/files/Manual_Metals_25_05_2016(1).pdf  https://foodsafetyhelpline.com/definition-of-chocolate-and-what-fssai-regulations-say/  https://fssai.gov.in/cms/manuals-of-methods-of-analysis-for-various-food-products.php Department of Biotechnology Brainware University, Kolkata 33