Food Products Technology

Phenylalanine has become a very important fermentation product because it is a precursor in the manufacture of the sweetener aspartame.

The Legal Metrology (Packaged Commodities) Rules, 2011 govern packaging of commodities in India, commonly referred to as Packaged Commodity Law. The other options are incorrect - there is no law called Packaging Consumer Goods Law or Packed Consumers Law.

Parboiling involves soaking rice in water and heating it, which causes water-soluble vitamins and minerals from the outer bran and hull layers to migrate into the endosperm. This process improves the nutritional value of polished rice by retaining nutrients that would otherwise be removed during milling.

Thermostabilisation of eggs is a preservation method that involves heating at a specific temperature-time combination. 54°C for 15 minutes is the correct condition to stabilize the egg and extend its shelf life by denaturing enzymes that cause deterioration.

Pectin methyl esterase (PME) is the enzyme responsible for the thickening of tomato paste over time. PME demethylates pectin, allowing calcium ions to cross-link pectin chains and form a gel network, increasing viscosity. The other options list non-existent enzymes.

Tempering and conditioning are both processes that involve adding controlled amounts of water to wheat grains before milling. This increases moisture content to optimize bran separation and endosperm milling. Parboiling is typically considered a pre-milling treatment for rice, not a standard wheat processing operation in this context.

Erucic acid is a toxic fatty acid found in mustard seeds and oil. High levels of erucic acid can cause health problems including cardiac lipidosis. Modern varieties have been bred to reduce erucic acid content. The other acids listed are either beneficial or not major concerns in mustard.

Salt preservation works through multiple mechanisms, including precipitation of enzyme proteins. High salt concentration causes proteins to precipitate (salt-out effect), reducing enzymatic activity that leads to spoilage. This is one of the primary ways salt acts as a preservative in foods.

Exposing ghee to high clarification temperatures causes multiple negative effects: vitamin A is heat-sensitive and degrades, the color darkens due to Maillard reactions and caramelization, and keeping quality is reduced due to formation of oxidation products. Therefore all the listed effects occur.

Bitterness in citrus fruit juice is primarily caused by limonoids, particularly limonin. Dipping in 2% boiling NaOH solution helps break down these bitter compounds, reducing bitterness. The other methods (open air, high temperature, low temperature) do not effectively reduce bitterness.

Homogenization of milk forces the milk through a small nozzle under high pressure, breaking fat globules into smaller sizes. The goal is to reduce the globule size to less than 2 microns to prevent cream rising and improve stability. This creates a uniform, stable emulsion.

Benzoates and sorbates are both commonly used preservatives in jam, jellies, and pickles. They inhibit mold and yeast growth. Acetate has limited preservative action in these products, and toluene is toxic and not used as a food preservative. Therefore only options (a) and (b) are correct.

Refrigeration slows down metabolic activity but does not stop vitamin degradation entirely. Over time, vitamins (especially vitamin C and some B vitamins) continue to degrade slowly even at refrigeration temperatures, though at a much slower rate than at room temperature.

Yogurt is made through bacterial fermentation of milk using specific starter cultures. Lactobacillus bulgaricus and Streptococcus thermophilus are the two essential bacteria used together in a symbiotic relationship to produce yogurt's characteristic texture and flavor. Both are required.

Firming agents provide structure and Calcium carbonate is commonly used for this purpose. Ester gum works as an emulsifier to keep ingredients mixed. Dimethyl polysiloxane is an anti-foaming agent that prevents surface foam formation. Pectin is a natural thickening agent derived from fruit.