Microbiome 2 – how does the food industry come into the picture?

By: Trademagazin editor Date: 2024. 12. 03. 18:47

Following on from the previous article “Microbiome 1 – elements of a super-organism”, it is very important to link theory to practice, since it is microbes that are involved in the technological processes known as fermentation.

This article is available for reading in Trade magazin 2024/12-01

Guest writer:
Dr. Erzsébet Némedi biotechnologist and food engineer

In different parts of the world there are different traditions of fermented foods. For instance in Europe fermented foods are mostly meat and milk, and for years Hungary was ranked high among the fermenting countries.

Fermentation is the microbial transformation of sugars into organic acids, mainly lactic acid or ethanol. In the first case we are talking about lactic fermentation (e.g. yogurt, kefir, cheese, pickles), while in the second case we are talking about alcoholic fermentation (e.g. wine, beer, bread).

Fermentative microorganisms belong to two different groups: lactic acid bacteria (LAB) and yeasts. In addition to their fermentation capabilities, LABs and yeasts also contribute to the final taste, smell and aroma of fermented food by producing hydrolytic enzymes such as proteases and lipases. Over the past decade fermented foods have attracted a lot of attention because they are considered to be healthy, since they contain a large number of bacteria known to be beneficial. It is important to note: fermented foods can’t be called probiotic foods, as they generally don’t contain probiotic bacteria.

Fibres: friends of the intestinal tract

Dietary fibre is a type of carbohydrate that can’t be digested and isn’t absorbed in the small intestine, where most foods are broken down and their nutrients absorbed. Some fibres reach the large intestine, where they are fermented by intestinal bacteria. This fermentation makes it possible for the good bacteria to grow and multiply. However, fibre can be further classified into digestible fibre, non-digestible fibre and resistant starch. Digestible fibre is found in foods such as fruit and oats. Indigestible fibre is in whole grains and nuts. Resistant starch (RS) is used as a source of energy by the cells of the large intestine and it is contained in whole grains, seeds, pulses, potatoes and banana.

Fermentation technologies have a long history and are on the verge of an incredible evolution

Bioactive compounds in the “big ferment”

The main function of the large intestine is to be a great “anaerobic fermenter” and to re-absorb water and electrolytes. In the large intestine there are so-called “primary digesters”, which have special enzymes to break down the fibres. Proteins are the primary source of amino acids. All proteins are made up of amino acids, but the gut microbiota reacts differently to proteins of animal or plant origin. For instance proteins of plant origin such as pea protein have been observed to increase the number of beneficial bacteria and decrease the number of potentially pathogenic bacteria. Fat indirectly modulates the composition of the gut microbiota. Nutrition is the main source of vitamins plus the gut microbiota can synthesise vitamin K and B-group vitamins in our gut. It is important to know that microbiota can ferment certain amino acids and release gases such as hydrogen sulphide (H2S), a bioactive compound responsible for certain foul odours. If there is too much, H2S can damage the intestinal lining. What can we learn from all of this? Nutritional information on food labels only tells us about the nutritional “potential” of the food, but we need to understand the structure, digestion and absorption of the food to be able to better predict its nutritional value or health effects. The structure of food and how it is processed affects our gut microbiome. The true nutritional value of our food products depends on many more parameters than a label can tell us. //