Many foods are made available throughout the year using freezing as a method of preservation. Typically, frozen foods have a long shelf-life [up to a year or longer depending on the product] and consist of a vast variety—ice-creams, fruits and vegetables, pre-prepared meals and snacks that include appetisers, pizzas, meats, and cheese.
Frozen products offer flexibility in cooking, are great time-savers, and offer consistent product quality with little effort and waste. Let us clear some of the common doubts regarding frozen foods and their consumption.
Why do frozen products have longer shelf-life compared to fresh foods?
It is the technology that plays an all important role in maintaining the quality, integrity and shelf-life of frozen foods. Frozen fruits and vegetables are fresh farm produce that have been blanched and frozen within hours of being picked i.e. at the peak of their freshness—thereby locking in most of the vital nutrients.
However, proper storage is critical for maintaining the quality of frozen foods. Frozen foods should be stored at a temperature of -18?C or lower. Frozen foods that have just been purchased from the market should be stored within 30 minutes in the freezer, as freshness and quality at the time of freezing affects their condition.
Does their nutritional composition differ from fresh foods?
Frozen items are generally on par and sometimes higher in vitamins and minerals than their equivalents sold fresh. This is because freezing is an effective form of food preservation and all the pathogens that cause food spoilage are either killed or do not grow rapidly at reduced temperatures.
Fresh foods actually hit the market and finally our food basket long after they have been plucked from the fields and this exposure to atmosphere, results in valuable nutrients getting lost. However, frozen vegetables retain their high vitamin and mineral content because they are processed within hours of harvest. They are also stored at temperatures below -18?C with practically no decrease in micronutrient content for up to a year.
Which foods can be used in the frozen form?
Not all foods are recommended to be frozen. Large ice crystals formed during freezing have the tendency to rupture cells and cell membranes of food items. This leads to destruction of texture in meats, fish, vegetables, and fruits, while also contributing to a significant loss of vitamins, nutrients and flavours.
Certain foods like salads, mushrooms and soft fruits have low tolerance to freezing. In fact, many tropical fruits tend to lose their aesthetic appeal in regular freezing. For instance, bananas turn black on thawing and oranges may break, become very flabby, bitter and lose their characteristic flavour upon thawing.
Does the process alter the taste and texture?
Frozen foods when thawed for cooking tend to have a firm and more natural texture than other foods. The process also helps capture the biological condition of the fresh food at a point at which it is frozen, and thereby presents the same flavour, colour and the taste on its de-freezing or thawing.
Let us take the example of green peas, a seasonal winter crop. However, by virtue of freezing it immediately after harvest, frozen peas are available all round the year across the country. Also, in terms of taste, they are far better than dehydrated peas or canned peas in salt water.
Do all frozen foods need to be thawed?
Not all frozen foods need to be thawed prior to cooking. It is best to follow the recommendations provided by the manufacturer on the packaging.
Also, in case only part of the pack is going to be used, it is suggested that the required quantity is taken out and the balance be put back into the freezer immediately. It is also recommended that frozen food once thawed should not be re-frozen.
What is the difference between foods frozen at home and foods frozen commercially?
Commercially-frozen products will retain their eating and nutritional qualities better than home frozen products. There are several reasons for this. Commercial freezers blow cold air over foods so they freeze food more rapidly than is possible in a domestic freezer.
This means minimum damage to the structure of the food and reduced amounts of water being lost on thawing. As a result, the nutrient contents of frozen foods are far superior when compared to foods frozen at home. In short, domestic freezers are designed to store frozen food, rather than freeze fresh produce.
What are the factors that we should consider when buying frozen foods?
Keep the following guidelines in mind:
- The time between transferring frozen food from the retail shop to your home freezer should not be more than 30 minutes
- Follow instructions on the label diligently. Check the date of manufacture of the product and consume it before its expiry period. For the ‘use by’ date to be a valid guide, follow storage instructions such as ‘keep in a refrigerator’. It is also important to follow instructions for cooking and preparation as shown on the label.
Is it safe for all to consume frozen foods?
Yes, it is safe for everyone to consume frozen foods provided the guidelines mentioned by the manufacturer are strictly followed.
What is the difference between raw frozen foods and cooked frozen foods? Which is better and why?
There is no such thing as one is better than the other. It clearly depends on the type of products and their ultimate use. Some items like green peas and cauliflower are typically frozen in raw condition and on thawing are used for cooking.
There are some products like french fries and aloo tikkis, which are partially-cooked and then frozen. Hence, these have to be transferred from the freezer directly to the fryer for further cooking.Likewise, there are some products like frozen pre-prepared dishes, which are completely cooked and then frozen. These need to be just microwaved before serving.