We live in an era of convenience foods, the processing of it changes its chemical structure and more often than not micronutrients composition of vitamins and minerals get lost due to chemical added and/or extreme temperatures changes, even some foods may lose its taste, flavor, and color.

In this two-part post we’ll talk first about the profile of processed foods and on the second part what manufacturers add to them in order to compensate, at the end, all the information exposed can help you decide on either you should limit processed food intake or maybe even at some point remove them completely from your life.

PART I

PACKAGE OPENING 

Natural foods, as we find it in nature, like fruits, vegetables, cereals, and legumes, are meant to be eaten in a short period of time, that why seasons dictates blossom or perish of natural foods, so, to compensate for that manufacturers add a variety of chemicals, additives, and preservatives to prolong their shelf life.

As mentioned before, changes in chemical composition take place due to heat, pressure and added chemicals that lead to 3 main factors of severe nutritional value reduction: fats get hydrogenated, minerals/vitamins lose and proteins denatured [1].

 

 

HYDROGENATED FATS = TRANS FATS

We have three main fats found in nature, monounsaturated, polyunsaturated and saturated fats, the latter is mainly found in animal source foods like eggs and meat, as a side note, from a nutritional standpoint none of them are bad and should not be labeled as such, because all of them have a purpose in our body, they all help to promote wellness, the problem relays once excess intake takes place, saturated fats may have a bad reputation but that because they can be very easy to overeat by general populations, compared to nuts or avocado (sources of monounsaturated and polyunsaturated respectively).

Now, back again with the topic of hydrogenated fats, chemically their structure is very unstable, especially when exposed to high temperatures for a prolonged period of time, processed food is subject to that, and regardless of its source (mono, poly or saturated) its chemical structure will change, hydrogenated fats its nothing more than a change in chemical structure composition to trans [2], and trans fats because of its altered structure are not very well metabolized and with very little we can have health problems, one of the main disease excess trans-fat can cause is Atherosclerosis in which the inside of an artery narrows due to the buildup of plaque [3].

 

NO VITAMIN AND NO MINERALS = ZERO TO NONE NUTRITIONAL PROFILE

We have discussed previously that micronutrients dictate a food nutritional profile when you found a food high not only in one but multiple vitamins you are looking at a very good nutritional source of nourishment.

As fats, vitamins and minerals are very sensitive to not only temperature but exposure to oxygen [4], whole foods tend to have an outer layer (skin peel) it protects them from insects and environmental treats, when vitamins, minerals, and cereals are processed most of the times they peel off leaving them to exposure of oxygen and loses in micronutrients, take for example Vitamin C, this vitamin can be found mainly in citric fruits like oranges, vitamin C is highly reactive to oxygen, once oranges are peeled off or squeezed to make juice you only have 5 minutes to consume it and really take advantage of vitamin C [5], otherwise you’ll only be getting the simple sugars of oranges.

PROTEINS DENATURED = INCOMPLETE FOOD

Proteins are the building blocks in our body, in its simplest form they are called amino acids, mostly all food found in nature contains amino acids, they can be divided into complete and incomplete, in the previous post we talk about the 9 essential amino acids and how all together can form a complete protein.

Regardless of the source animal or plant-based, or its composition (complete or incomplete), proteins or to be more specific amino acids can also be affected by food processing, each protein has its own unique sequence of amino acids and the attractions between these amino acids create a specific shape. This shape determines the protein's function, if the protein is subject to changes in temperature or exposure to chemicals, amino acids may alter the shape of the protein, if the protein's shape is broken it becomes dysfunctional and the protein is considered denatured [6].

Probably the most affected sources of foods to be denatured are meats, because of its high content of amino acids, and as similar to the trans fats a denatured protein is difficult to be metabolized a, therefore, it can create an “aggregate”.

An aggregate is a term in which a denatured protein does not break down, therefore, it becomes a polymer and it can build up inside our cells and become toxic leading to a carcinogenic effect [7].

From biochemical point of view all of the changes that happen to process food diminish is nutritional value, we have covered all the factors that impact nutrition, on a second part we´ll learn about the adding of substances that manufacturers throw in to cover up, this added elements do not compensate for the ones that got lost during the process, even more, we´ll realize that they ended up worsening the nutritional profile of the final shelve/freeze product. 

 

REFERENCES - Written by Antonio Reyes RDN

1. Monteiro CA. Nutrition and health. The issue is not food, nor nutrients, so much as processing. Public Health Nutr 2009.

1. Sugano M, Ikeda. Metabolic interactions between essential and trans-fatty acids. 1996.

1. Ascherio A, Hennekens CH, Buring JE, Master C, Stampfer MJ, Willett WC. Trans fatty acid intake and risk of myocardial infarction. 1994.

1. Paul, A.A. & Southgate, D.A.T. McCance and Widdowson’s, The Composition of Foods. London: HMSO. 1979.

1. Levine, M. New concepts in the biology and biochemistry of ascorbic acid. 1986.

1. Adams A, Borrelli R, Fogliano V, De Kimpe N. Thermal degradation studies of food melanoidins. 2005.

1. Anderson D, Yu TW, McGregor DB. Comet assay responses as indicators of carcinogen exposure. 1988.