6 Food Processing Techniques To Maintain Food Nutrition

Food processing techniques are all those different methods we use to turn fresh foods into food products. While most associate food processing techniques with convenience food, almost all food is processed to a certain extent before it is ready for consumption. Even washing and cutting fresh vegetables constitutes food processing. Another misconception about food processing is that it's a recent phenomenon. Researchers claim that even early humans were pounding, cutting, grinding, and sun-drying their food [1]. In more recent history, however, food processing has gone through a number of changes that have influenced food nutrition and our health. Here, we discuss some of the latest changes in food processing and nutrition.

Why is Proper Food Processing Important for Health and Nutrition?

There are two main reasons why proper food processing methods are important: to remove harmful microorganisms and to extend shelf life. In other words, proper processing makes food safer to eat for longer. Another common reason is to make food more nutritious and tasty. These have been the main goals of food processing since early times and continue to be so today. Unsurprisingly, the food industry's main focus has also been on making food safe to eat, tasty, and convenient. Less attention has been paid to the actual quality of the food consumers offer. As a result, today's "ultra-processed foods" are often high in calories, added sugar, unhealthy fats, and additives. This has more than likely contributed to the surge in chronic diseases (e.g. heart disease, diabetes, and osteoporosis) seen in the last two centuries [2].  For this reason, there has been a global push for switching from ultra-processed to minimally processed foods to reduce the burden of chronic disease. The WHO along with several UN organizations has called for food system transformations, which also includes switching to proper food processing methods [3]. 

What Are The Benefits of Proper Food Processing?

Proper food processing techniques can reduce the global burden of chronic disease and help protect health throughout one's lifetime. Because good nutrition is at the heart of health and well-being, changing how food is processed can influence many aspects of our health. Just some of the countless benefits of proper food processing for health and nutrition include: 

• Prevention of nutrient deficiencies 
• Normal growth and development in children
• Reduced risk of chronic disease
• A stronger immune system
• Enhanced physical and mental performance
• Greater well-being
• Better hair and skin health
• Improved fertility

6 Food Processing Techniques To Maintain Food Nutrition

Many traditional food processing techniques are relatively good at maintaining nutrition. Examples include cooking, freezing, canning, and drying [4]. But these methods aren't perfect since many of them can reduce the vitamin and mineral content of food.  Other traditional and some new food processing techniques can counteract this problem: These classic and new types of food processing include: 

1. Freeze-Drying

Many nutrients are heat sensitive. This is especially true for vitamin C, folate, and vitamin B6 [5]. Since traditional dehydration involves some level of heat processing, those dehydrated apples, plum tomatoes, and mushrooms you often enjoy don't have the same level of nutrients as fresh counterparts. Besides that, traditional dehydration completely changes the flavor and structure of the food.  Also called lyophilization, freeze-drying solves this problem. The food is first frozen before being placed under a vacuum to remove its water content. In freeze-drying, ice goes from solid to vapor without going through the liquid stage. The result is greater retention of vitamin C, phenolic compounds, and antioxidants [6]. A major supplier of freeze-dried foods and services in the U.S. is Empire Freezing & Drying offering freeze-dried liquids like yogurt, soups, and sauces, to name a few.

2. Fermentation

Fermentation is the natural breakdown of sugar molecules by bacteria and fungi into simpler compounds. Humans have been exploiting this natural process to preserve and change the quality of food and drink for millennia. Examples of food and drink produced through traditional fermentation are cultured yogurt, kefir, kombucha, sauerkraut, miso, kimchi, wine, and beer. What's great about fermentation is that they contain probiotic bacteria that can improve gut and overall health [7]. Fermentation also leads to the formation of bioactive peptides, which are small protein molecules that have anti-inflammatory and antioxidant benefits. Furthermore, fermentation reduces anti-nutrients in foods while changing phenolic compounds into their biologically active form. 

3. Food Irradiation

To make food safe and shelf-stable, manufacturers often rely on milling, heat treatment, dehydration, pasteurization, additives, and artificial food ingredients. All of these food processing techniques result in food that is often lower in nutrients than its fresh counterparts [8].  Food irradiation is a relatively novel alternative to traditional food processing techniques. This process uses ionizing radiation to destroy microorganisms that cause foodborne illness. Food treated this way is safe to eat and retains most of its nutrients [9, 10]. And because low levels of radiation are used, food processed this way isn't radioactive, despite wide-held belief.

4. Pulsed Electric Field Food Processing

Another non-thermal food processing method that's been slowly emerging over the past years is pulsed electric field (PEF) processing. It relies on microsecond, high-voltage pulses to make food safe and shelf-stable while preserving its nutritional value. This method creates pores within food cells, and in this way inactivates any microbes present [11]. PEF processing is so effective that it can inactivate Gram-negative and Gram-positive bacteria in whole milk at just 50 °C. And since there's very little heating involved, the food's taste and texture remain largely unaffected. Foods that have been treated this way include yogurt drinks, apple sauce, and liquid egg products. 

5. Vacuum-Steam Pulsed Blanching

Blanching involves scaling vegetables for a short time in boiling water. Despite the short cooking time involved, studies show that it can decrease vitamin content [12]. Luckily, there's a new and better way to balance vegetables, and it's called Vacuum-steam pulsed blanching (VSPB).  VSPB is essentially steam balancing in which air and water vapor are expelled with a pump. Only a couple of seconds and very little water are needed to fully balance a vegetable with this method. Because nutrients won't get lost in the water or due to long cooking times, this method also helps preserve nutritional quality as well as antioxidant potential [13].

6. Isochoric Freezing

Frozen food may be more nutritious than its thermally treated counterparts, but studies show that consumers still prefer fresh counterparts. This is because freezing fruits and veggies inevitably change their flavor and texture [14]. That's simply due to ice crystal formation within plant cells. Isochoric freezing solves this issue by not exposing the fruits and veggies to air. Instead, food is stored in hard containers filled with liquid before being frozen. Not only is this more energy-efficient, but it was scientifically proven to not lead to ice crystal formation and deterioration of nutritional and sensory quality [15].

Summary

Humans have been processing food since their early history, and early food processing methods involved cutting, grinding, drying, and bonfire cooking. Since we've been processing food since the dawn of humanity, we've become very proficient in it. That fact has made food safer, more shelf-stable, and more convenient over the past two centuries. However, this has also come at the cost of low nutritional quality. Luckily, things have been taking a turn for the better. As both consumers and organizations have recognized the need for better food processing techniques, we've seen a huge surge in novel and improved technologies. Food is now being minimally processed using methods that preserve its nutrients as well as taste and texture.