spices & other foods analysis_litho-1.pdf

H. & H. B. Kotak Institute of Science Chemistry Skill Enhancement Course (SEC)-1 Introduction: As per Syllabus effective from 2023...

H. & H. B. Kotak Institute of Science Chemistry Skill Enhancement Course (SEC)-1 Introduction: As per Syllabus effective from 2023 What is Food Adulteration? Skill based Practical Course-1 Semester-1 Adulteration is a legal offence and when the food fails to meet the legal standards set by the government, it is said to have been adulterated. Food adulteration takes place when intentionally Index: or unintentionally substances that degrade the quality of food are added to it. Thus, food adulteration can be defined as the contamination or adulteration of food or food materials by Sr Practical Page adding harmful substances to it. No. No. Introduction 1 What is Adulterant? Adulterants in spices & condiments The substances that lower the quality of food, when added to it, are called adulterants. It is a 1 Detection of Lead salts in Turmeric powder 3 substance found within other food substances that hamper the natural quality of the food. The 2 Detection of Metanil yellow in Turmeric powder 3 adulterant may be present in any form and in any quantity. Adulterants are mostly harmful and 3 Detection of Aniline dyes in Turmeric powder 4 pose the ability to lower the potency of the product. Even if the adulterant is not harmful, it 4 Detection of Chalk powder in Turmeric powder 4 reduces the nutritional value of the food to a greater extent. Some adulterants are also identified 5 Detection of Brick powder in Chilli powder 5 as carcinogenic or lethal when exposed to them for a longer period. Different types of adulterants 6 Detection of Oil soluble colour in Chilli powder 5 are used to adulterate different types of food. 7 Detection of Rhodamine B in Chilli powder 6 8 Detection of added Starch in powdered species other than Turmeric powder 6 9 Detection of Common salt in coriander powder 7 When is Food Considered Adulterated? 10 Detection of Foreign resins in Asafoetida 7 There are some conditions that are required to conclude whether a food is adulterated or not. Adulterants in other foods These points are summarised below. 11 Detection of Chalk powder or Washing soda in Sugar/Wheat Flour/Ice-cream 8 · A substance that degrades the quality of food or turns it hazardous is added to it. 12 Detection of Metanil yellow in Pulses/ Parboiled (Sella) Rice/Ice Cream 8 13 Detection of Lead chromate in Pulses & other foods 9 · Cheaper or low-quality substances are used as a substitute for whole or a few ingredients. 14 Detection of Malachite green in Green vegetables 9 · A constituent of food is partly or wholly taken out, reducing the quality of food. 15 Determination of Boric acid in Maida/Rice flour 10 · It’s made presentable with harmful substances. or its colour is changed to make it look better. · Anything that depreciates the quality of food is added to or abstracted from it. 1|P ag e  Chemistry Skill Enhancement Course (SEC)-1 Skill based Practical Course-1 Practical-2 Adulterants in spices & condiments Aim: Detection of Metanil yellow in Turmeric powder. Practical-1 Apparatus: Aim: Detection of Lead salts in Turmeric powder. i. Pipette/ Dropper Apparatus: Reagent: Concentrated HCl i. Pipette/ Dropper Procedure: Reagent: Concentrated HCl i. Take one gram turmeric powder in a test tube. Procedure: ii. Add 5 ml of water. i. Take one g of turmeric powder in a tube. iii. Add a few drops of concentrated HCl. ii. Add 1 ml concentrated HCl. iv. Observe any change in color. Inference: iii. Observe the change in color. i. Appearance of pink/violet color which disappears on dilution with Inference: water shows the presence of unadulterated turmeric. i. The appearance of magenta color shows the presence of yellow ii. If the color persists, indicates the presence of metanil yellow. oxides of lead in turmeric powder. Result: Result: 1. The given sample of the Turmeric powder is 1. The given sample of the Turmeric powder is …………………………… with Metanil yellow. …………………………… with lead salts. 2|P ag e Practical-3 Practical-4 Aim: Detection of chalk powder in Turmeric powder. Aim: Detection of Aniline dyes in Turmeric powder. Apparatus: Apparatus: i. Test tube i. Test-tube Reagent: Reagent: i. Concentrated HCl i. Rectified spirit Procedure: Procedure: i. Take about 1 g of turmeric powder in a test tube containing 2-3 ml of i. Take one-gram turmeric powder in a test-tube and add water to make a water. suspension. Add 1-2 ml of rectified spirit. ii. Add a few drops of concentrated Hydrochloric acid. ii. Observe the color of the rectified spirit layer. Inference: Inference: Effervescence indicates the presence of chalk powder. Immediate separation of yellow color in the rectified spirit layer indicates the presence of dyes. Result: Result: 1. The given sample of the Turmeric powder contains chalk powder/does not contain chalk powder. 1. The given sample of the Turmeric powder is …………………………… with Aniline dyes. 3|P ag e Practical-5 Practical-6 Aim: Detection of Brick powder in Chilli powder. Aim: Detection of Oil soluble colour in Chilli powder. Apparatus: Apparatus: i. Beaker i. Pipette/ Dropper ii. Test tube Method-1: Reagent: Reagent: i. 50% HCl, ii. Petroleum ether i. Chloroform-Carbon tetrachloride mixture: Mix equal volumes of the Procedure: two solvents. i. Take 2 g of the sample in a test tube, add few ml of ether and shake. Procedure: ii. Decant ether layer into a test tube containing 2 ml of dilute HCl (50%) i. Take chloroform/Carbon tetrachloride mixture in a beaker. and shake. ii. Pour the sample in a beaker containing a mixture of chloroform and iii. Observe color of the lower acid layer. carbon tetrachloride. Observe the bottom of the beaker. Inference: Method-2: Red color of the lower acid layer indicates the presence of oil soluble Procedure: color. i. Take water in a beaker. Result: ii. Pour the sample in a beaker containing water. Observe the bottom of the 1. The given sample of the chilli powder contains oil soluble beaker. colour/does not contain oil soluble colour. Inference for methods-1 & 2: Brick powder and dirt will settle at the bottom. Result: 1. The given sample of the chilli powder contains brick powder/does not contain brick powder. 4|P ag e Practical-7 Aim: Detection of Rhodamine B in Chilli powder. Practical-8 Apparatus: Aim: Detection of added starch in powdered species other than i. Test tube Turmeric powder. Reagents: Apparatus: i. Acetone i. Petri dish/ Spot plate Procedure: Reagents: i. Take 2 grams sample in a test tube. i.1% Iodine solution ii. Add 5 ml of acetone. Procedure: iii. Observe color of acetone layer. i. Add a few drops of Iodine solution to the spice powder in a petri dish. ii. Observe the development of blue color if any. Inference: Immediate appearance of red color indicates presence of Rhodamine-B. Inference: i. A blue color shows the presence of starch. Result: Result: 1. The given sample of the chilli powder is …………………………… with Rhodamine-B. 1. The given sample of the powdered spices contains starch/does not contain starch. 5|P ag e Practical-9 Practical-10 Aim: Detection of Foreign resins in Asafoetida. Aim: Detection of common salt in coriander powder. Apparatus: Apparatus: i. Test tube i. Test tube Reagents: Reagents: i. 6% Ferric chloride ii. Rectified spirit i. 0.1 M silver nitrate Procedure: Procedure: i. Take 1 g of asafoetida, powder it thoroughly, and take it in a test- i. Suspend one gram of the sample in water. tube. ii. Add a few drops of silver nitrate reagent. ii. Add some rectified spirit. iii. Look for a white precipitate. iii. Filter/ decant the solution. Inference: iv. To 5 ml of filtrate add few drops of ferric chloride (6%) solution. A white precipitate indicates the presence of sodium chloride. v. Observe any color change. Inference: Note: Added water should be free from chloride. Olive green color shows the presence of adulteration with other resins. Result: Result: 1. The given sample of the coriander powder contains common salt/does not contain common salt. 1. The given sample of the Asafoetida contains foreign resins/does not contain foreign resins.. 6|P ag e  Practical-2 Aim: Detection of Metanil Yellow in Pulses/ Parboiled (Sella) Rice/Ice Adulterants in other foods Cream. Practical-1: Apparatus: Aim: Detection of Chalk powder or Washing soda in Sugar/Wheat Flour/Ice-cream. i. Test tube ii. Pipette/ Dropper Reagents: Apparatus: i. Concentrated HCl i. Test tube ii. Pipette/ Dropper Procedure: Reagents: i. Dilute HCl: Dilute concentrated HCl, 1: 1 with distilled water. i. Take one g of the pulse/food in a test tube and add luke warm water to bring in solution. Procedure: ii. Vortex the contents and let stand. i. Take small amount of sugar/ wheat flour/ice cream in a test tube. iii. Add a few drops of concentrated HCl. ii. Add few drops of dil. HCl. iv. Observe the change in color. iii. Brisk effervescence or bubbles indicates the presence of chalk Inference: powder or washing soda. The immediate development of pink color indicates the presence of Inference: Metanil yellow dye. Effervescence appears which indicates the presence of chalk /washing Result: soda in the sample. 1 The given sample of the ______ contains Metanil yellow/does not Result: contain Metanil yellow. 1. The given sample of the ______ contains chalk powder or washing soda/does not contain chalk powder or washing soda. 7|P ag e Practical-3 Practical-4 Aim: Detection of Malachite green in Green vegetables. Aim: Detection of Lead chromate in Pulses & other foods. Apparatus: Apparatus: i. Blotting paper i. Test tube ii. Pipette/ Dropper Reagents: Reagents: i. Liquid paraffin i. Concentrated HCl Procedure: Procedure: i. Take moist blotting paper and spread the greens/vegetables on moist i. Shake 5g of pulse/food with 5ml of water. white blotting paper. ii. Add a few drops of concentrated HCl. ii. Look for color on filter paper. iii. Observe any change in color. iii. Rub the outer green surface of the vegetable with liquid paraffin soaked cotton. Inference: iv. Soak green peas in a beaker of water. A pink color obtained indicates the presence of lead chromate in the sample. Inference: Result: i. Green color impressions on paper indicates the presence of Malachite green. 1. The given sample of the pulses contains Lead chromate/does not contain Lead chromate. ii. Cotton ball shows green color indicates the presence of Malachite green. iii. Water in beaker is green indicates peas are artificially colored. Result: 1. The given sample of the vegetable contains Malachite green/does not contain Malachite green. 8|P ag e Practical-5 Aim: Determination of Boric acid in Maida/Rice flour. Apparatus: i. Test tube ii. Pipette/ Dropper Reagents: i. Turmeric Indicator paper ii. Concentrated HCl Procedure: i. Take one g sample in a test tube. ii. Add 5 ml water and shake. iii. Add a few drops of concentrated HCl. iv. Dip a turmeric paper strip. v. Observe color change of turmeric paper. Inference: If the turmeric indicator paper turns red, boric acid is present. Result: 1. The given sample of the Maida/Rice flour contains Boric acid/does not contain Boric acid. 9|P ag e