General Science Quiz: Food Preservation, Adulteration and Food Safety

A harvested fruit is still a living tissue that keeps respiring, using up its own sugars and acids and giving off heat, carbon dioxide and ethylene.

Argemone mexicana, the prickly poppy known in India as satyanashi, has seeds that look very like mustard seeds, so its oil is a classic adulterant of mustard oil.

Khesari dal, botanically Lathyrus sativus and also called grass pea, is a hardy pulse that survives drought and is therefore sometimes mixed with arhar dal or besan.

Pasteurisation is not sterilisation: it is a mild heating that kills disease-causing organisms such as Mycobacterium tuberculosis, Salmonella and Brucella and most spoilage bacteria, while leaving the taste and nutritive value of milk largely unchanged.

In lyophilisation the material is first frozen and then placed under a strong vacuum, so that the ice changes directly into vapour without passing through the liquid state.

Indian food standards divide preservatives into two classes. Class I preservatives are the natural ones that cooks have always used, and no limit is placed on the quantity: common salt, sugar, dextrose, spices, vinegar or acetic acid, honey and edible vegetable oils.

Lumps of calcium carbide hidden in a crate of mangoes react with the moisture in the air and release acetylene gas, which forces the fruit to colour quickly, though the pulp inside stays unripe and tasteless.

That Act consolidated several scattered food laws, the most important of them the Prevention of Food Adulteration Act of 1954, into a single statute and created one authority to lay down science-based standards for food, regulate its manufacture, storage, distribution, sale and import, and licence food businesses; its headquarters is…

Codex Alimentarius is Latin for food code, and the Commission of that name draws up model standards, codes of practice, and limits for additives, contaminants and pesticide residues, which member countries use when writing their own food law and which serve as the reference in international food trade.

Iodine forms a deep blue-black complex with the long coiled chains of amylose in starch, and this colour change is the standard classroom and field test for starch.

Cobalt-60 is an artificial radioisotope that emits penetrating gamma rays and has a half-life of about 5.27 years, which makes it a convenient and long-lasting source for irradiation plants.