Product Processing Technologies (Part 2) PDF

MASTER DEGREE : FOOD & COSMETIC PRODUCTS ENGINEERING Products Processing Technologies Pr. Abdelilah EL ABBASSI Master IPAC (S1) Table of contents 01 02 03 Physical Size reduction & Filtration Properties of Emulsification Centrifugation Materials...

MASTER DEGREE : FOOD & COSMETIC PRODUCTS ENGINEERING Products Processing Technologies Pr. Abdelilah EL ABBASSI Master IPAC (S1) Table of contents 01 02 03 Physical Size reduction & Filtration Properties of Emulsification Centrifugation Materials Powder production Extraction 04 05 06 Frying Crystallization Extrusion Baking Dissolution Dehydration Roasting Mixing Distillation 07 Concentration & Preservation processes 03 Filtration Centrifugation Extraction  Unit of measure 1 Micron = 1 Micrometer Red Blood Cells = 8 Microns Human hair = 100+ microns = 1 μm Smallest Visible Particles to human eye is 30 to 35 Microns = 0.001 millimeter Configuration of filtration systems The most basic form of filtration is dead-end filtration (Filtration frontale). The complete feed flow is forced through the membrane and the filtered matter is accumulated on the surface of the membrane. The dead-end filtration is a batch process as accumulated matter on the filter decreases the filtration capacity, owing to clogging. Cross flow filtration (Filtration tangentielle) is when the flow is applied tangentially across the membrane surface. As feed flows across the membrane surface, filtrate passes through while concentrate accumulates at the opposite side of the membrane. Why we use liquid filtration in industry The removal of undissolved particulate matter from a fluid stream (air or liquid) for the purpose of meeting specifications for solids removal, solids recovery, optical clarity, a specific particle distribution in the fluid or protection of downstream equipment. Solids removal This is what we commonly think of when we discuss filtration – removing solid particle contamination. ○ Incoming water/fluids may contain sand, pipe scale, iron, algae or other unwanted solids ○ Fluids may pick up tank debris during transport or in storage tanks ○ Prevent mold spores, bacteria, virus and dirt from entering a tank. Solids recovery Some processes require isolation/recovery of the solids in the fluid due to the intrinsic value or it is the product being produced. ○ Harvesting a microalgae (Spirulina, Chlorella, etc.) ○ Recovery of protein components Optical clarity Visual appearance or the aesthetics require no visible particles (35 microns or larger) ○ Bottled water ○ Soft drinks Equipment Protection Preservation of equipment is critical to prevent downtime and repair costs ○ Pump seals ○ Fine nozzles ○ Seal flush glands ○ Small orifices Filtration Efficiency : Retention Ratings Retention ratings refer to what a filter does, not what it is (the size of the pores in the filter). ○ Many mechanisms usually work together to create the filter's actual removal efficiency. Retention ratings refer to the efficiency with which a given filter can remove particles of a specific size or size range from a particular carrier fluid. ○ Changing the variables in any of these categories (filter, particle size, etc.) will alter the outcome of filtration. ○ May be difficult for a direct comparison between Manufacturers  Retention ratings are expressed as: ○ Percentages ○ Ratios between upstream and downstream counts for particles of a specific size There is no universally accepted way to evaluate filter performance. ○ Industry standards are very limited. ○ Changing the test parameters on the same filter would yield different results - ie modifying flow ○ Filters that are actually quite different might look identical when modifying test conditions – modify the test particle type. Nominal rating Absolute rating Removes Some/Most Particles Removes “All” Particles at/above the Rated Size at/above the Rated Size In practice, most filter manufacturer’s assign values of Typically Used for Depth Filters 98% to 99.99% to their absolute ratings. Usually Based on 90% or Less Values may be: Derived under arbitrary test conditions that vary by manufacturer Interpreted in a variety of ways Initial Efficiency Average Efficiency Final Efficiency Surface filtration vs. Depth filtration Surface filtration is a process, often used in water Depth filtration filtration systems, to remove particles from the Capture Particles Through Filter Depth surface. The particles retained form a layer of ○ Filters by Inertial Impaction and Direct material, commonly called “cake layer or filtration Interception cake” ○ Effective from 0.5 μm to 100 μm The cake layer helps increase efficiency of this ○ Most are nominally rated process and is formed when retained particles form a thin sheet over time. Graded Density vs. Constant Density vs. Graded pore structure Centrifugation Industrial centrifuge What is a Centrifuge? A centrifuge is a device that uses centrifugal force to separate the components of a mixture based on their different densities. Basically, the process involves spinning a container at maximum speed, generating a centrifugal force that pushes the denser particles to the outside of the container, while the lighter particles remain in the center. This principle of operation is used in a wide range of applications in the food industry. Laboratory centrifuge Centrifuge Applications in the Food Sector Centrifuges are used in various stages of food production, playing a key role in the separation, purification, and clarification of liquids and solids. Some examples include: ▎ Juice and beverage production: During juice production, the centrifuge is used to separate the juice from the pulp and other impurities. This process ensures a clearer and higher quality end product. ▎ Dairy processing: In the dairy industry, centrifuges are essential for separating cream from milk, a crucial step in the production of butter and other dairy products. ▎ Olive oil: In olive oil production, centrifuges are used to separate the oil from the water and olive paste, helping to produce a high-quality oil with excellent purity. Relative Centrifuge Force (RCF) expressed in xg (multiple of earth gravitational force) RFC = 1,118 x R x (rpm /1000)² R is radius in cm rpm : Speed in Revolutions per minute The relationship between RPM and RCF is as follows: g = (1.118 × 10-5) x R x S² Where g is the relative centrifugal force, R is the radius of the rotor in centimeters, and S is the speed of the centrifuge in revolutions per minute. Extraction ▎ The commonly employed technique for separation of active substance from crude drugs is called ‘Extraction’ which involves the use of different solvent. ▎ Whether samples are plants, microbes, marine animals or insects they are referred to as biomass. ▎ Dried materials are usually powdered before extraction, whereas fresh plants (e.g. leaves, etc.) can be homogenized or macerated with a solvent such as alcohol. ▎ The grinding process is important as effective extraction depends on the size of the biomass particles; large particles will be poorly extracted, whereas small particles have a higher surface area and will therefore be extracted more efficiently. Decoction Decoction extraction refers to the process of extracting active compounds from plant materials, such as roots, bark, or leaves, using hot water. This traditional method is often used in herbal medicine and food production. The decoction is used for active ingredients that are not sensitive to relatively high temperature. In this process the drug is boiled in water for 15 to 60 minutes depending on the plant or the active ingredient to extract. Distillation Fractional distillation has been traditionally used for separation of the components of volatile mixtures; in phytochemistry it has been widely used for isolation of components of volatile oils. Failure to extract biomass properly may result in loss of access to active compounds ▎ Using an inappropriate extraction method, such as strong heating of biomass with a solvent, may result in degradation of natural products and consequent loss of biological activity. ▎ The choice of extraction procedure depends on the nature of the material and the components to be isolated. ▎ Alcohols are general solvents for many plant constituents (phenolic compounds, steroids, etc.) ▎ Water-immiscible solvents are widely used; petroleum ether (essential and fixed oil, steroids), ether and chloroform (alkaloids, quinines). ▎ The extraction of organic bases (e.g. alkaloids) usually necessitates basification of plant material if a water-immiscible solvent is to be used; for aromatic acids and phenols acidification may be required. Extraction methods The commonly known traditional processes are Soxhlet extraction, heat reflux extraction, agitating extraction, soaking extraction, and liquid–solid extraction. Oil and fat from solid material are extracted by repeated washing (percolation) with an Extraction of essential oils using organic solvent, usually hexane or petroleum Clevenger apparatus ether, under reflux in a special glassware (Soxhlet apparatus). Special methods for volatile oil, such as Clevenger and sometimes Enfleurage process. Enflourage is the process of extracting fragrance from flowers by using odorless fats or oils to capture the essential oils. Oil is usually extracted by The perfumes of jasmine petals Soxhlet from grinded material could only be extracted by enfleurage Supercritical Fluid Extraction (SFE) The main solvent used at supercritical conditions for food applications is carbon dioxide (CO2). Some examples are presented, from the traditional decaffeination of coffee up to the micronization of vanilla, passing through innovative processes such as the extrusion of protein-based snacks and drying of beetroot. Phase diagram of CO2 (Tc : critical temperature, Pc : critical pressure) Subcritical Water Extraction (SWE) Subcritical water extraction (SWE, or Hydrothermal Extraction) is a processing technique that uses water at a temperature and pressure below its critical point (374°C and 221 bar) to extract bioactive compounds from plant or food materials. SWE is considered a green technology as it requires minimal energy and does not involve the use of solvents, making it an attractive alternative to traditional extraction methods. Phase diagram of water Ultrasound assisted Extraction (UAE) ▎ Ultrasound-assisted extraction (UAE) is a novel technique used to extract bioactive compounds from plants, microorganisms, and other materials. ▎ In the food, pharmacy, and biotech industries, UAE offers several advantages. It enhances extraction efficiency, reduces solvent usage, and preserves the natural composition of the extracts. ▎ The technology utilizes high-frequency ultrasound waves to disrupt cell membranes, allowing for the release of desired compounds. ▎ This technique is particularly useful for extracting bioactive compounds such as polyphenols, terpenes, and essential oils. Microwave Assisted Extraction (MAE) ▎ Microwave-assisted extraction (MAE) is a technique used to extract compounds from various materials, such as plants, foods, and pharmaceuticals. ▎ This method utilizes microwave energy to heat the sample, resulting in increased extraction efficiency and reduced extraction time. ▎ MAE has several advantages over traditional extraction methods, including lower solvent consumption, higher yields, and improved extraction selectivity. ▎ The technique is commonly applied in various fields, including food science, pharmaceuticals, and biotechnology. Emerging Trends in Green Extraction Techniques for Bioactive Natural Products 04 Cooking methods (Frying, Baking & Roasting) Definition of cooking The art of process by which food is prepared by applying direct or indirect heat is called cooking. Cooking sterilizes and softens the food, introduces variety, increases food consumption and increases availability of nutrients. Cooking increases palatability as it imparts flavor and aroma. It also helps in blending of flavors and spices, which increases its appeal. Cooking helps in the digestibility of food by converting raw food into simpler substances. Cooking destroys microorganism as the food is subjected to heat. This makes the food safe for consumption. Cooking makes the food more appetizing by improving its appearance. Cooked food is softer and easily digestible (modified consistency). It makes chewing easier, especially for children's and elderly. Ensures balanced diet - helps to combine various food groups which help the person to get a balanced diet. Cooking methods Moist heat Steaming (cuisson à la vapeur), Pressure cooking (caisson sous pression), Poaching (pochage) , Blanching (blanchiment) Dry Heat Roasting (torréfaction ou rôtissage), Grilling (grillage), Toasting (toastage), Baking (cuisson au four), Frying (Friture), Sautéing (Sauté) Combination Braising (Braisage), Microwave cooking (cuisson au micro- ondes), Solar cooking (Cuisson solaire)  Fraying Frying is a process of immersing food in hot oil with a contact among oil, air, and food at a high temperature of 150°C to 190°C. The simultaneous heat and mass transfer of oil, food, and air during deep-fat frying produces the desirable and unique quality of fried foods. Innovative frying methods (hot-air frying, microwave frying, vacuum frying, etc.) are nowadays used to reduce the oil absorption in fried snacks such as chips. Frying is considered to be a primary method of cooking throughout many food chains and catering industries. Pre-treatment: Ultrasound, Pulsed Electrical Field, coating, seasoning, drying, marination, blanching, acidic treatment. Application of Pulsed Electrical Field (PEF) technology to French fry production This technology, which uses brief pulses of electricity (microseconds) to modify and disrupt the membranes of cells in plant or animal material or microorganisms, has a wide variety of applications across many food processing industries. Source : https://www.youtube.com/watch?v=-doPfIKimNY Baking The baking process is responsible for major weight loss in the dough/batter, mainly moisture (8– 12%) and volatile organic compounds, Dough especially in pan bread and buns. Chemically leavened products may have higher bake losses. For labeling purposes, the loss in weight during baking is taken into account during dough dividing or batter depositing. Buns Batter During baking: – Heat is slowly conducted from the outside in. – Heat transforms batter/dough from a foam that traps air bubbles to a porous sponge that does not (term sponge is used whether product has a springy, spongy texture or not). Baking involves at least eleven events : (1) Fats Melt (2) Gases form and expand (3) Microorganisms die (4) Sugar dissolves (5) Egg and Gluten proteins coagulate (6) Starches gelatinize (7) Gases evaporate (8) Caramelization and Maillard browning (9) Enzymes are inactivated (10) Changes Occur to Nutrients (11) Pectin breaks down. Roasting Roasting is a slow-cooking process, using indirect, diffused heat to cook its ingredients. It is a dry-heat cooking method where hot air surrounds the food and cooks it evenly on all sides at a temperature of at least 150 °C. This method brings out the natural flavors and textures of the ingredients, creating a caramelized crust on the outside and a tender interior. Examples Coffee : roasting coffee beans is a process that transforms the green coffee beans into the aromatic, flavorful drink we all love. There are several types of roasts, including Light, Medium, Medium-Dark, Dark, and Espresso. Each roast level affects the flavor, acidity, and body of the coffee. Argan : roasting argan kernels enhances the oil flavor and nutritional properties. Roasting argan oil increases its antioxidant capacity and gives it a nutty flavor, making it suitable for use in cooking and as a finishing oil for dishes. Roasted nuts: a variety of nuts such as almonds, cashews, and peanuts roasted to enhance their flavor and texture. 05 Crystallization Dissolution Mixing  The process in which the solid dissolve in the liquid arranges itself in well-defined 3-D structures called the crystal is called crystallization. Technique for purification of substances. It is a technique that separates a solid from its solution. When any substance undergoes crystallization, its molecule arranges itself in a fixed structure at an angle to form a 3-D structure called the crystal and then the crystal is removed from the solution. Theory of Crystallization The three major stages in the process of Crystallization are: Supersaturation of Solution: It can be done in three ways: Heating the solution, Cooling the solution, and Salting it out. Nucleation: This takes place in several steps. During their random motion, the atoms/ molecules/ ions will come closer to one another and form aggregates called Clusters. These clusters will combine to form an EMBRYO. In this stage, only the lattice formation begins. These embryos combine to form nuclei. From nuclei, crystals are formed. Crystal Growth: Once the crystals are formed, nuclei formation stops and crystal growth begins. 1. The solution is heated in an open container 2. The solvent molecules start evaporating, leaving behind the solutes 3. When the solution cools, crystals of solute start accumulating on the surface of the solution 4. Crystals are collected and dried as per the product requirement 5. The undissolved solids in the liquid are separated by the process of filtration 6. The size of crystals formed during this process depends on the cooling rate 7. Many tiny crystals are formed if the solution is cooled at a fast rate 8. Large crystals are formed at slow cooling rates Example : Salt crystallization The fixed number of water molecules contained in one formula unit of a salt is known as water of crystallization. Or, to put it another way, water that is stoichiometrically bonded into crystal. CuSO4 5H2O is the chemical formula for hydrated copper sulphate, for example. Copper sulphate crystallizes with 5 molecules of water. Salt crystallization is the most practical use of crystallization, and it is also the most cost- effective technique to create salt today. Compound purification and crystal synthesis are two further uses for the technology. Applications in food industry Crystallization is also used in the manufacture of other sugars, such as glucose and lactose, in the manufacture of food additives, such as salt, and in the processing of foodstuffs, such as ice cream. Other applications Purification of seawater Separation of alum crystals from impure samples In the pharmaceutical industry, crystallization is used as a separation and purification process for the synthesis and isolation of co-crystals, pure active pharmaceutical ingredients (API), controlled release pulmonary drug delivery, and separation of chiral isomers. Dissolution & mixing ▎ The dissolution process refers to the breakdown of a solid, liquid, or gas into smaller components, typically through the interaction with a solvent. ▎ Formally, dissolution is defined as mixing of two phases with formation of a new homogenous phase. ▎ This can occur naturally, such as the dissolution of sugar in water, or artificially, like in pharmaceutical manufacturing. ▎ Factors influencing dissolution include temperature, surface area, and the presence of catalysts or inhibitors. ▎ Understanding the dissolution process is crucial in various fields, including chemistry, pharmacology, and environmental science, where it affects the behavior and properties of substances in solution. In the industry, dissolution is crucial in the production of pharmaceuticals, food, and beverages, as well as in chemical and materials processing. Some common methods of dissolution in industry include: 1. Chemical dissolution: using solvents to break down particles 2. Physical dissolution: using heat, pressure, or mechanical energy to break down particles 3. Biological dissolution: using enzymes or microorganisms to break down particles The dissolution process can be influenced by factors such as temperature, pH, and concentration of solutes. Mixing process In industrial process engineering, mixing is a unit operation that involves manipulation of a heterogeneous physical system with the intent to make it more homogeneous. Mixing is performed to allow heat and/or mass transfer to occur between one or more streams, components or phases. Modern industrial processing almost always involves some form of mixing. The type of operation and equipment (high-shear mixers, magnetic mixers, static mixers, etc.) used during mixing depends on the state of materials being mixed (liquid, semi-solid, or solid) and the miscibility of the materials being processed. In this context, the act of mixing may be synonymous with stirring. Mixing is fundamental to food and cosmetic products processing, such as in the preparation of ingredients, the addition of solids to liquids and the development of structure and incorporation of air in the dough mixing process. Different types of system are required for the different requirements of the food industry, for example: ▎ Gas-liquid mixing: ensuring that enough air is mixed into a fermenter liquid to ensure microbial growth is not oxygen-limited; ▎ Liquid-liquid mixing: the creation of liquid-liquid emulsions is central to the manufacture of margarines and spreads; ▎ Solid-liquid mixing: the addition of solids to liquids is involved in the reconstitution of fluids, such as when tea or coffee solids are added to hot water. The addition of liquids to solids is key to the production of many food batters, pastes and doughs.  Mixing in the food industry The main applications of mixing in food include: Uniform distribution of ingredients: Mixing helps to distribute ingredients evenly, ensuring that each bite tastes the same. Emulsification: Mixing combines oil and water-based ingredients, creating a stable emulsion that enhances texture and flavor. Aeration: Mixing incorporates air into batters, dough, and mixtures, leading to lighter and fluffier textures. Enhancing flavor and texture: Mixing can also enhance the overall flavor and texture of food by breaking down ingredients and incorporating seasonings. Mixing in the cosmetic industry Hot mixing application : Cold mixing applications: ▎ Lipstick ▎ Shampoo, conditioners ▎ Mascara ▎ Body wash and moisturizers ▎ Eye cream ▎ Topical gels ▎ Hand and face creams ▎ Liquid soap ▎ Clay Masks ▎ Hand sanitizer ▎ Serums ▎ Essential oils ▎ Sunscreen lotions 06 Extrusion Dehydration Distillation 6.1. Extrusion Extrusion is a method of forming substances by forcing them through a perforated plate (die) or other desired shapes. Extrusion can take place under high temperatures and pressures or can be simply a non-cooking (cold extrusion), forming process. The main purpose of extrusion is to increase the variety of foods in the diet by producing a range of products with different shapes, textures, colors and flavors from basic ingredients.  Extrusion process ▎ The extruded food is cut to a specific size by blades. The machine which forces the mix through the die is an extruder, and the mix is known as the extrudate. ▎ Extrusion enables mass production of food via a continuous, efficient system that ensures uniformity of the final product. ▎ These include some pasta, breads, many breakfast cereals and ready-to-eat snacks, confectionery, pre-made cookie dough, some baby foods, textured vegetable protein, and dry and semi-moist pet foods. ▎ Food products manufactured using extrusion usually have a high starch content. Pasta die (macaroni) Extrusion has the following effects: ▎ Destruction of certain naturally occurring toxins ▎ Reduction of microorganisms in the final product ▎ Slight increase of iron-bioavailability ▎ Loss of lysine and destruction of Vitamin A (beta-carotene) ▎ Simplification of complex starches ▎ Increase of glycemic index of the processed food, as the "extrusion process significantly increased the availability of carbohydrates for digestion" ▎ Denaturation of proteins. Extrusion products ▎ Directly expanded types include breakfast cereals and corn curls, and are made in high- temperature, low-moisture conditions under high shear. ▎ Unexpanded products include pasta, which is produced at intermediate moisture (about 40%) and low temperature. ▎ Texturized products include meat analogues, which are made using plant proteins ("textured vegetable protein") and a long die to "impart a fibrous, meat-like structure to the extrudate" and fish paste. Extrusion and functional flours (part 1) https://www.youtube.com/watch?v=sod2fxPAS7I Extrusion and functional flours (part 2) https://www.youtube.com/watch?v=Im_9Udm8il4 6.2. Dehydration (drying) is defined as the application of heat under controlled conditions to remove the majority of the water normally present in a food by evaporation. The main purpose of dehydration is to extend the shelf life of foods by a reduction in water activity. Drying process inhibits microbial growth and enzyme activity, but the processing temperature is usually insufficient to cause their inactivation. Therefore, any increase in moisture content during storage, result in rapid spoilage.  Principle of Drying State of water in food; Bound water and free water are the key concept of drying. Bound water refers to water that is unfreezable, immobile, non- squeezable, and non-solvent water. Bound water affects the drying process as more energy is required to remove bound water than free water. The main factor affecting the effectiveness of the drying process is the moisture and water activity (aw) of the food. ▎ Moisture : It can be simply defined as the total water content in the food that might exist in the free or bound state. ▎ Water activity : Water activity is the amount of free water present in a food product that is available for enzymatic activity or supports the growth of microorganisms, eventually leading to food spoilage. Preservation effect Dehydrated foods have lower water activity (Aw=0.2-0.6) This Aw is not enough (free water) for : Microorganism Growth (needs Aw > 0.93, especially bacteria) Staphylococcus aureus (Aw > 0.85) Mold ( need Aw >0.6) Enzymatic reactions Chemical reactions (Maillard browning needs Aw >0.3) Microorganisms are not killed, are kept in inactive stage. Microorganisms will resume growth after food is rehydrated (suitable environment).  Factors affecting dehydration o Surface area ▪ smaller food piece, more rapid the rate of moisture loss o Temperature ▪ increase in temperature will increase the dehydration rate o Air velocity ▪ maximize velocity of heated air moving around the food particles o Humidity of drying air ▪ the dry air absorbs moisture ▪ %RH (relative humidity) of the drying air determines the final moisture content of food. o Atmospheric pressure and vaccum ▪ water boils at 100+C (at a pressure of 1 atm) ▪ At lower pressure the boiling temperature will decrease. Under vaccum, water will boil at 32°C ▪ Important for heat sensitive food products ▪ Mostly used for freeze drying. Drying methods Drying causes deterioration of both the eating quality and the nutritional value of the food. The design and operation of dehydration equipment aim to minimize these changes. 6.3. Distillation Distillation is a separation process, separating components in a mixture by making use of the fact that some components vaporize more readily than others. When vapors are produced from a mixture, they contain the components of the original mixture, but in proportions which are determined by the relative volatilities of these components. The vapor is richer in some components which are more volatile, and so a separation occurs. Distillation enables the separation and purification of volatile food products from aqueous blends. Distillation can be used to separate flavors or essential oils, but is mainly used either for the production of potable alcohol or spirits, or for the industrial production of alcohol from agricultural raw materials (e.g. fruit, grain), which can then be used in alcoholic beverages (liquors) Distillation equipment In fractional distillation, the vapor is condensed and then re-evaporated when a further separation occurs. It is difficult and sometimes impossible to prepare pure components in this way, but a degree of separation can easily be attained if the volatilities are reasonably different. Where great purity is required, successive distillations may be used. The conventional distillation equipment for the continuous fractionation of liquids consists of three main items: a boiler in which the necessary heat to vaporize the liquid is supplied, a column in which the actual contact stages for the distillation separation are provided, and a condenser for condensation of the final top product. The main distillation methods are : 1) steam distillation, 2) batch distillation and 3) vacuum distillation (batch distillation under vacuum or steam distillation under vacuum). Batch Distillation or flash distillation ▪ Effective for separating components that boil at widely different temperatures. ▪ It requires many successive re-distillations to get pure components, which is inefficient. Vacuum Distillation or Batch Distillation under vacuum ▪ When the vapor pressure of volatile components reaches the vacuum, the distillation occurs. ▪ Distilling at lower temperatures for heat sensitive materials Vacuum steam distillation combine the two methods and are more suitable in modern distillation equipment. Applications of distillation 1. Production of High-Quality Edible Oils Distillation is particularly effective in producing high- quality edible oils such as olive oil, soybean oil, and fish oil. This process is crucial because it allows for the purification of these oils without damaging their heat- sensitive components. The technique works by using a very high vacuum system that reduces the pressure, thereby lowering the boiling points of the components. This ensures that the oils do not degrade due to high temperatures, preserving their nutritional value and flavor. 2. Extraction of Natural Flavors and Fragrances In the food and cosmetics industries, distillation is also used to extract natural flavors and fragrances from plant extracts. Fractional distillation (short path distillation), for instance, is used to process these extracts at lower temperatures, which is essential for maintaining the integrity of the volatile compounds responsible for the flavors and scents. This method involves a short distance between the heated surface and the condenser, minimizing the exposure of the compounds to heat and preventing their degradation. 3. Purification of Essential Oils Essential oils, which are used in various food products and cosmetics (perfumes), are often purified using distillation. This process is critical for removing unwanted components and improving the quality of the oils. For example, rose oil undergoes molecular distillation to eliminate unpleasant odors and excess wax content, enhancing its value. Similarly, capsaicin from red pepper is purified through a two-stage distillation process, which increases the concentration of capsaicin and separates it from the pigment. 07 Concentration & Preservation processes The concentration process consists of the removal of water to reduce the weight and volume of the liquid food products. Concentration is similar in process to drying or dehydration, but it differs based on the final moisture content in the product and product characteristics. The method is called dehydration process when the resulting moisture content of the food material after completion of the concentration process is between 0 and 15–20%. On the other hand, in concentration process, part of the water is removed results in moisture content >20%. Different methods of concentration ▪ Concentration process is usually employed as a pre-treatment to reduce the initial moisture content of different foods like, milk, tea or coffee prior to their final dehydration in a spray or freeze dryer. ▪ It can be used to reduce the bulk by freezing or by sterilization, such as frozen orange juice or evaporated milk. ▪ It could be used as a preservation method in its own right, like maple syrup which is resistant to deterioration after concentration. ▪ Water activity, pH and temperature are the main parameters that have a direct impact on the growth of microorganisms, thus Aw and pH are two the most important parameters for food preservation. ▪ Concentration of foods can broadly be of three types: by application of heat i.e. thermal concentration; by removal of heat i.e. freeze concentration and using membranes. Concentration by application of heat Thermal concentration means increasing the total solids content of the food by evaporation of water using heat. It is more energy-consuming process than other concentration methods such as membrane concentration and freeze concentration. However, the degree of concentration achieved is higher. As concentration process increases the solids content of a food, it preserves the food by reducing its water activity. During concentration microbial destruction occurs which is mainly dependent on temperature. Concentration at 100ºC or above gives preservative effect as almost all pathogenic microorganisms get killed but not all the spores. Concentration by removal of Heat Freeze concentration process is used to overcome the two important limitations of thermal concentration which are: volatile components lost (flavors) and product quality degradation due to heat. It has primarily been used where quality considerations are important and important volatile components to be retained, as in concentration of beer and wines (flavors and alcohol are to be preserved) and concentration of coffee before freeze-drying (it is important to retain flavor). This process is slower than conventional and membrane concentration processes. The high capital investment combined with high in cost due to refrigeration, results in high production costs for freeze concentrated foods. Here, the degree of concentration is lower than thermal concentration but higher than membrane processes. Concentration of food liquids using membrane Membrane processing is an interesting alternative for the clarification (reduce the turbidity) and concentration of liquid foods because it operates at room temperature, exhibits low energy consumption and high performance, scales up easily and rejects a wide range of food contaminants. Ultrafiltration membranes are suitable for concentrating syrup (such as fruit juice syrup or starch syrup) into a more concentrated form, used for making candies, pastries, and other foods. Ultrafiltration membranes can also be used for the concentration of food seasonings, sauces, and fruit juices to improve their taste and quality. Fruit juice clarification using membrane reduces the turbidity of fruit juice and has stable properties, without secondary precipitation.  Example : fruit juice concentration To choose suitable concentration technology, quality must come first. Qualified fruit juice concentrate must retain similar color, flavor and nutrition as original fruit juice after diluted. In this regard, the concentration process must be carried out under low temperature. The most popular fruit juice process technology are vacuum concentration method, freeze concentration, membrane technology concentration. Besides, in fruit juice concentration process, aroma recovery is an influential step we can’t ignore. Food Preservation Food preservation is the process in which, food is not only processed but also its desirable attributes (sensorial and nutritional) are sustained up to the maximum possible time duration. Food preservation is the process of treating and handling food to stop or significantly slow down spoilage. Through food preservation, we also prevent foodborne illnesses and maintain the nutritional value, taste and texture of food products. Principle of food preservation constitutes removal of water and subsequent reduction in water activity. Preservation methods There are three broad categories of food preservation methods i.e. inhibition of microorganisms and chemical degradation; Inactivation of microbes and enzymes with reducing the risk of recontamination before and after processing. 7 Common Food Preservation Methods Chilling Refrigerating food is one of the simplest ways of keeping it safe to eat and preserving it. The low temperature in our fridges slows down bacterial growth and reduces spoilage. Chilled food can remain safe for a few days or weeks, depending on what it is. The fridge should be set at the right temperature to safely chill food. This is between 1°C and 4°C. Food must be stored under 8°C by law for businesses that sell or produce food. Freezing Freezing conditions inhibit bacteria growth. So, storing food properly in the freezer can make it last for a long time (years). Sugaring Preserving food with lots of sugar reduces its water content, limiting bacterial growth. Sugar can be in granules, sugar syrup, honey or molasses. Salting Salt is excellent for drawing water out of certain foods. This, like sugaring, stops bacteria from growing. Wet curing (brine curing) is when salt is mixed with water and sometimes sugar. Food is added to this mixture and placed in cans. Dry curing is where salt is put directly onto foods like meat. This draws out water. Canning This method of food preservation removes oxygen from foods. The food stored in an airtight, acidic, high salt or sugar environment prevents bacteria from growing. Canned food must be handled hygienically and be of good quality. Jars should be specifically designed for canning. This is to ensure that they will be airtight. Freeze Drying Freeze-drying is a way of dehydrating food. Raw foods comprise around 80-95% water. This water can be divided into free and bound water. Free water freezes, but bound water doesn’t. When freeze-drying food, all free water and some bound water must be removed.: Vacuum Packing Extends the shelf-life of certain foods by sucking out oxygen to limit the growth of microorganisms. A benefit of vacuum packing is that it also preserves food quality without adding other ingredients, as you do with canning. So, vacuum-packed food properties, such as its smell and taste, remain intact.