Food Processing: Is it good or bad for us?

How we wish we could get fresh fruit and vegetables from our own backyard! And fresh milk from the dairy in the courtyard or eggs from the hens in the hen house at the back of our house! If only horses could fly!

Many of us live in urban areas and some of us in high rise apartment buildings. We have about ten to twenty pots in our balcony or small backyard which we call our garden. It is just a patch of green we can afford and pacify ourselves that we are contributing to the greenery of this world.

Some of us cannot even grow a few herbs in our homes leave alone getting fresh produce for our cooking purposes. And if we are non-vegetarians where do we get our ration of chicken or fish?

Without processed food we cannot afford to have food on our tables. Do we really have a choice to say no to processed food? What with so many of us living in urban areas away from where food is grown or animals are raised/slaughtered, we have no choice but to depend on processing of food for our daily rations.

Most of us work away from home and have limited time to spend on cooking/preparation of food and therefore depend on processed food which needs less time to prepare. Processing of food makes our lives easier in more ways than one.

Processing is the treatment of food substances in such a manner as to change its properties with a view to preserving it, improving its quality or making it functionally more useful.

Why do we need to process or prepare foods?

1. Foods are preserved so that they can be kept edible for longer. Preservation reduces wastage and cost. It enables people to eat foods all around the year. Preservation helps to feed the growing population of the world.
2. Processing or preparation makes food safe to eat by destroying or retarding the growth of pathogenic micro-organisms or inactivating natural toxins/antinutritional factors.
3. Processing or preparation improves the attractiveness of food, its flavour and its appearance.
4. Processing also provides convenience. The milk which reaches our door every morning is also processed as it is pasteurized.

Our foods are made of cells which contain numerous enzymes and biochemical compounds that are similar to those in human body. Foods are also inhabited by micro-organisms. These multiply rapidly after harvesting or slaughter and nearly all the basic foods deteriorate rapidly because of autolytic decay or microbial activity. Foods are not edible because of these activities unless they are treated / processed /prepared in suitable ways.

Staples such as cereals are the exceptions because of their low moisture content. Still minimal processing steps have to be undertaken such as cleaning, dehulling etc. Cereals can be kept for years when dry at ambient temperatures. The early civilizations therefore depended on these cereals and even now cereals/staples are stored by Governments to combat food shortages.

Some common methods of food processing and preservation

Drying: Traditionally sun drying and smoking were used but nowadays solar energy drying, tunnel drying, spray drying and freeze drying are used to produce concentrated forms of foods such as milk powder etc. Bacteria cannot grow without water and autolytic enzymes are inhibited.

Freezing: Bacterial growth is prevented because of the low temperature and also the water in the food is not in available form for spoilage reactions.

Refrigeration: The low temperatures do not destroy micro-organisms but stop them from multiplying or slow them down. It also slows autolysis by enzymes in the food.

Addition of salt or sugar: The water activity is lowered by increasing osmotic pressure and preventing bacterial growth.

Acidification: This process also prevents microbial growth, foods pickled in vinegar.

The other types of processing are heat processing (blanching, pasteurization, cooking, canning etc), food irradiation, fermentation, chemical preservation etc.

Certain nutrients may be lost to a certain extent while processing in some foods which cannot be avoided. But for the foods to be safe, stay long and be economical certain compromises have to be made. Also, sometimes processing may include fortification which makes certain foods healthier.

We have to make an informed choice while choosing processed foods also. We should keep away from refined foods, high sodium snacks and foods containing trans-fats etc. In this world of convenience, we need to educate ourselves to make the right choices.