Home-scale food preservation methods

a) Enumerate the home-scale food preservation methods.

All of the process used for preserving food at home is based on the principles of preservation. The ones commonly used are preserving by drying & by adding sugar, salt & chemicals.

Preserving by drying:
This natural means of preserving foods are available to us in plenty most of the year. There are a large variety of items we preserve at home by sun drying. Some of the very common ones are vegetables, raw mango pieces for making mango powder, papads of all varieties, mango juice, red, chillies etc. The best time of year to sundry food items in the summer.

Preserving by pickling:
Most of the pickles rely upon salt & the acids of time, vinegar or tamarind as a preservative. Oil also acts as a preservative by not allowing air to come in contact with the pickle. The most favourite fruits of pickling are raw mangoes & limes. Most mango pickles are oil-based. Lime pickles may be preserved in oil or just in time juice with salt & spices.

Preserving with sugar:
Preserving sugar is a kind of sugar used for making jams, marmalades, murabbas etc. Jams are usually made from the whole fruit (strawberry, gooseberry). The whole fruit is cooked with a certain quantity of sugar to a setting consistency. Marmalade is made with the juice extract of a fruit with thin slices of the skin or the fruit suspended in the clear jelly-like mixture. Citrus fruits like oranges are good for making marmalades. Pectin & acid are both essential for the jelly-like consistency of marmalades. The proportion of sugar to juice is the same in jelly.

Preserving by use of chemicals:
Certain chemicals are permitted for preserving foods. The quantities to be used are also regulated by law. Tomato sauce is an example of preserving by heat & chemicals, other being squashes.

b) Comment on the measures you would adapt to enhance the nutritive value of foods.

Sprouting, fermentation & combining different foods in a meal are ways to get the maximum nutritional value from some of our foods.

Sprouting:
Dry pulses & grains do not normally contain vitamin C, but when they are allowed to sprout or germinate vitamin C is formed in the grain & in the growing sprout. Sprouting involves soaking the pulse or grain in water for 24 hours & then wrapping them in a damp cloth & after 2 or 3 days the grains germinate & the germinated grain can be eaten raw or after cooking for a very short time so as not to destroy the vitamin formed in it. The grain commonly used to sprout is Bengal gram. Sprouted green gram contains three times more vitamin C than sprouted Bengal gram.

Fermentation:
Natural fermentation in food occurs when environmental conditions permit interaction between microorganisms & the food substance. Fermented whole wheat flour is used to make bathura or nan & the dosa & idli mixtures are examples of natural fermentation.

Food combinations:
The importance of proteins to the human body & about the fact that cereals or pulses taken by themselves cannot provide our body with adequate proteins-one or the other essential amino acids would be lacking. Pulse, cereal, idli-sambar, rice-dal, chola-bhatura, khichri, dal-roti are some examples of nutritionally beneficial combinations of foods.

Fortification:
Fortification is a technique to add nutrients to a particular food item. Nutrientschosen for fortification is those that are likely to run into short supply. Food items selected to fortified are those that are consumed by the largest, cross-section of the population. Examples of fortification in our country are vitamins A & D in hydrogenated fats, iodine in common salt.