Nutrition Meets Food Science

Processed Foods: Are They Unhealthy?

Our forefathers have been processing foods for thousands of years and we really do not consider them processed as we became so used to them. Wheat flour, poha, dried grapes, tea or coffee as we get it at home, do not grow in the field. Even the wheat kernel or rice paddy does not grow in farms. After it grows, farmers harvest it and then they dry it. Drying is one of the most ancient processing. After drying the chaff is removed by threshing so we get the grain. Similarly, paddy is prepared after harvesting of rice by drying and then husk is removed by milling to get rice kernels, either brown or white. So, what we consider natural is actually processed either by farmers or by machines on farms.

Same continues further. Our grandmothers used to grind the whole wheat to atta (whole wheat flour). Now either chakki or bigger roller mill does it using big machines to a variety of products like whole wheat flour, refined flour (maida), semolina (rawa) and many more. Rice kernels are converted by machines to poha. So, when you prepare poha or upma at home, it is really not a natural food but processed. Technically even cooking is a process, which is no different whether you do it at home or in a processing unit.

Therefore, processing itself cannot be universally dismissed as something unhealthy and certainly we should not distinguish processing at home from that in factory. What we must see is whether it causes changes in chemical nature of food, making it unhealthy or less nutritious. Addition of too much sugar, fat or salt will make it unhealthy whether it is done at home or in factory. Heating too long or too often will cause loss of sensitive nutrients by thermal degradation. We can always analyse nutrients in foods to find the effects of processing. Refining wheat to make refined flour or maida will remove the dietary fibre so it will make it less healthy.

Processing was developed from early times in to make food not only last longer but to make it safer. Drying of fruits, fish and spices and freezing of fish would make them last longer but pasteurising of milk would make it safer as there would be many disease-causing bacteria or pathogens would be naturally present. When we cook vegetables and meat & fish, the heat destroys pathogens. Legumes have some anti-nutritional substances that are destroyed by heat.

Heat also makes food more digestible so we can get more of nutrients, both macro- and micronutrients. Cooking as well as thermal processing, both enable our digestive enzymes to access the nutrients that are sometimes not accessible in raw foods.

There are also other processes that we don’t think much about and these are washing, soaking and fermentation which are many times useful in making the food safe by removing many antinutritional substances. In fact, fermentation also produces many B vitamins in the batter as the bacteria and yeast are growing in it. So processing is used either at home or in factories, that do not always make the food inferior but may make it both safer and more nutritious.

Sometimes, the processes in factory with machines are more efficient. For example, if you want to boil one or two litres of milk at home, it takes several minutes and there is always the fear of burning. Further, the cooling needs to be done to avoid excess heat causing further damage to nutrients and flavour. In the processing dairies, they use heat exchangers that are so efficient that heating and cooling can be adjusted in the matter of a few seconds so losses are minimal and it performs the job of destroying the pathogens adequately in pasteurisation and aseptic technology.

Many agricultural produces like fruits and vegetables are now grown in faraway places so when consumers in cities get them, they have to travel hundreds of miles and for days during which there are losses of nutrients and quality or overripening with spoilage. So, farmers harvest them before they achieve their maximum nutritive and eating quality, so they are brought to market places before they ripen, so they can artificially ripen them.

Processing units are normally situated near place of growing so they can access the produce after reaching its full potential of quality and then rapidly process them to avoid further losses. There will be some losses during process but just minimal. So frozen vegetables we get mostly have higher contents of nutrients as well as better quality. This, of course, needs not just prompt & proper processing as well as requisite storage in deep freeze.

This does not mean that all the processed foods are superior and of better quality. Use of excessive amounts of fat, sugar and salts in processed foods are going to be unhealthy and should be controlled. Use of trans fats and highly refined ingredients that reduce dietary fibre and other nutrients also causes food products to be unhealthy. This information is easily available on the labels in nutrition information table.

We need not use all processed foods but whenever it is difficult find time and energy for working people to prepare good and nutritious home-cooked food, we could always use some of these processed food products and ingredients that are convenient, save time and efforts in preparing foods. Also, we should make it a habit to look at ingredients list to avoid unhealthy ingredients and at nutrition information to ensure that products and ingredients are of high quality.

As urbanisation increases and there will be lesser time available for preparing food at home in traditional way, consumers will rely more on convenient, nutritive and safe foods and ingredients to prepare their meals. We should rely on the food components and nutrients as well as other qualities and not on processed or not while deciding if they are healthy.

Dr Jagadish Pai

Editor, PFNDAI

Add comment

Follow us

Don't be shy, get in touch. We love meeting interesting people and making new friends.