Many people wonder what food processing actually is, if processed foods provide more or less nutrients, and when food started to be processed. 

Given the few opportunities primitive humans had to get something to eat, they were forced to hunt and gather, and food was eaten in its natural state. However, through time people started cooking it and since then humankind has processed foods to make them edible, safe and harmless, as well as to save them for times of scarcity.

A Brief History of Food Preservation

Eight thousand years ago, food used to be smoked and dried–mainly in Europe. Aiming at preserving milk, cheese production was developed four thousand years ago in the Middle East. Meanwhile, twenty-five thousand years ago, both Egyptians and Europeans preserved their foodstuff using salt. In 1800, canning extended shelf life of perishable foods. In the 19^th Century, pasteurization made milk safe by using heat to destroy disease-causing bacteria. This was followed by the ability to freeze food, which allowed for a wide variety of fruits and vegetables to be available along the year.

Certainly, food might suffer alterations during its storage–alterations that could include a loss of certain traits such as flavor, aroma, color, texture, nutritional value, hygienic state, and pleasant appearance. These changes might be the result of physical, chemical or biological factors. Products may be affected by heat, cold, light or radiation, oxygen, humidity, dryness, enzymes naturally present, microorganisms, food proximity, or even the passing of time.

This wide variety of factors, additional to the great diversity of foods we enjoy every day, are the reason why nowadays there are so many food preservation and processing methods happening along the journey of food from the fields to our tables.

But What Is Processed Food?

The term “processed foods” tends to be confused with highly processed foods, which should be avoided for being less nutritious and not healthy. However, many techniques used to prepare and cook food in our kitchen are similar to those applied by food manufacturers.

Some kitchen appliances and utensils can be used to grind seeds to get flour, or purée fruits and vegetables to get a sauce, etc. It is also possible to dry fresh herbs and later use them to season different dishes. These are all examples of food processing.

Perhaps pre-washed lettuce, yogurt or brown rice are not commonly considered processed foods, yet they are. Processed foods are all of those which are not in their natural state. This includes all the actions taken to transform plant and animal products, grains, seeds, vegetables, fruits, meat, poultry, fish and milk into edible products.

Food processing can be as basic as grinding wheat into flour or nixtamalizing corn to make its grains edible, as well as refrigerating, freezing, and canning fruits and vegetables to preserve them throughout the year. It can also be so complex and valuable as developing gluten-free baked goods–attractive and necessary for some–or fortifying bread with folic acid due to public health reasons.

Food processing refers to, in broad terms, everything that takes places in a food manufacturing plant: washing, cleaning, cutting, chopping, grinding, heating, pasteurizing, scalding, fermenting, cooking, canning, freezing, drying, dehydrating, mixing, packaging, refining, among others. Actually, most foods are processed one way or another.

The methods used to preserve food have gradually evolved, developing a wide range of technologies whose objective is an efficient and effective preservation. Is there a perfect method? Despite technological advances, there is not one method which provides unlimited preservation. Every product, natural or processed, has an expiration date.

Food Preservation Methods

With such a wide range of natural and processed foods available in the market, how can we decide what processed foods to get and which ones to limit? Here are some tips that could help you make better decisions: 

• Choose foods considering their nutrient density and energy provided.
• Read labels, including the ingredient list, to make healthy choices when it comes to processed foods and beverages. A long list of ingredients does not necessarily mean the product is more or less healthy. 
• Before cancelling additives altogether, remember some are used to protect food from damaging bacteria. Others make nutritious food have better flavor, texture or appearance.
• Combine less processed foods, such as a fresh salad, with healthy processed products. If chosen carefully and consumed moderately, processed foods can make your meals safer, more convenient, delicious, and nourishing. 

• Desrosier, N. W. (2007). Conservación de alimentos (2a edición). Grupo Editorial Patria.
• Potter, N. N., & Hotchkiss, J. H. (1999). Ciencia de los alimentos (5a edición). Editorial Acribia.
• Duyff, R. (2017). Academy of Nutrition and Dietetics Complete Food and Nutrition Guide (5a edición). Houghton Mifflin Harcourt.
• Aguilar Morales, J. (2012). Métodos de conservación de alimentos (1a edición). Red Tercer Milenio.