Very often some foods are not available throughout the year because of changing seasons. I am sure that you would like to eat all vegetables and fruits throughout the year. How will you eat mangoes in winter and carrots in summer? We all wish to enjoy fresh mangoes all round year but is it possible? No, we cannot relish fresh mangoes as such but preserved mango products like pickle, chutney, juice, squash and jam can be enjoyed right round the year.
Therefore, preservation of food is very important to improve the nutritional content and have variety in diet. This article will give a brief enlightenment on how to preserve vegetables and fruits when they are in abundance. We all handle, cook and eat food regularly.
For every step or action we do proper care needs to be taken to keep the food fresh and safe from spoilage or contamination. For this preserving the food properly will increase the shelf life of food and prevent from spoilage.
Food preservation is a process in which:
Why do we need to preserve food? There are various food types such as perishable, semi-perishable and shelf stable. Perishable foods last for less time about 2 days to 1 week, for example Fruits, milk, meat and vegetables. Semi-perishable last for around 2 months and are processed foods, for example, cheese, ice-cream etc.
Shelf stable foods have longer shelf life more than 6 months such as grains. Food items are classified on the basis of their stability during storage into non- perishable, semi perishable and perishable foods.
Non- perishable food includes: whole grain cereals, pulses, nuts and oil seeds, sugar and jaggery.
Semi perishable food includes:
processed cereals and pulse products (e.g. maida, suji), eggs, potatoes, onions, biscuits and cakes. Perishable foods include: green leafy vegetables, peas, beans, tomatoes, apple, bananas, bread, butter and cream. Advantage of
Increases the shelf life of the food. Adds variety to the food Decreases wastage of food Retains the quality of food in terms of color, texture, flavor & nutrition value Increases food supply The components of food are proteins, fats, carbohydrates, vitamins and minerals; hence destruction of any of these components is food spoilage.
Main Techniques of Food Preservation:
Thermal Processing Method:
This process of food preservation is related with heating the food. This process is also known as heat treatment of the food. Heating is done in range of 85 to 90 deg C for some time as micro-organisms like bacteria are killed at temperatures above 82 deg C. Examples of heating treatment are pasteurization of milk, dipping of vegetables in boiling water for some time.
Cold Processing (removal of heat):
In this process the food is subjected to low temperature around 0 deg C. This process is done through chilling, freezing using refrigerator, cold storage etc as the microbial growth is slowed down, storage life of food product is increased. Examples: Cheese, Ice-cream
Controlling Water - Dehydration:
In this process, water is removed from the food product, i.e., the food product is subjected to dryers. Through this process, the microorganisms need water for biochemical reactions hence if water is removed, microorganisms will not grow on food product. By this process, the micro organisms don’t get free water thus growth of micro organisms is stopped. Examples: Dried Mango powder, dried vegetables etc.
Chemical - Preservatives:
They are two types of preservatives, one Natural preservative and Chemical preservatives. These preservatives contain a certain chemical composition which controls micro organisms growth.
Examples of Natural preservatives are:
Salt, Sugar, Lemon juice, Spice
Examples of Chemical preservatives:
Organic and inorganic foods like Sodium Benzoate, Potassium Meta bisulphate, Citric Acid. Salt when added in the food product as natural preservative returns water through osmosis process in food product thus changes composition of food, as a result no free water is left for microorganisms to grow.
Sugar absorbs free water from food products thus restricting growth of microorganisms. Oil and Spices form a layer over the food product hence it forms a layer between air and microorganisms thus restricting them.
Acids resist the growth of micro organism. Ex:
Onions are preserved in vinegar or acetic acid. Citric acid is used for fruit squashes.
Tips useful for taking care of the preserved food items:
Do look out for your favorite and many more yummy, appetizing and exotic recipes at:
Enjoy cooking and eating healthy foods to stay hale and hearty.
Always remember that: “VahrehVah is all about inspiring others to cook”!
VahChef Sanjay Thumma