Pasteurization: what is it and how does it affect dairy and probiotic foods

With so many products on the market, we better always be well informed.  There are a lot of products with very little or no life, or quality offered on supermarket shelves that promise great benefits, but that lack them.  One of those products are probiotics, yogurts, or fermented foods, which, after going through severe pasteurization processes, lose a lot of properties.

What is pasteurization?

Pasteurization is the thermal process used on foods, especially liquids, with the purpose of reducing harmful agents or pathogens, like bacteria, protozoas, yeast, mold, etc.  We should point out that during the pasteurization process, the basic objective is not the “complete elimination of pathogenic agents”, but the noticeable reduction of these populations, so that the pathogen levels do not cause dietary intoxicants in humans (supposing that the pasteurized product has been correctly refrigerated and consumed before the indicated expiration date).

How is pasteurization performed?

By means of heating the product.  Unlike sterilization, pasteurization does not destroy microorganism spores, nor does it eliminate all the thermophilic microorganism cells.

Temperatures lower than boiling point are generally used in pasteurization, because in nearly all cases, higher temperatures could irreversibly affect certain physical and chemical characteristics of the food.

Why do probiotics and yogurts lose their properties through pasteurization?

Currently, pasteurization is the subject of more and more discussions in certain groups of consumers around the world, due to the existing doubts regarding the destruction of vitamins, and the alteration of organoleptic properties (taste and quality) of treated food products.  In regards to probiotics, they frequently lose their beneficial bacteria under this process.

Know how to select probiotic products

In order to distinguish a good probiotic product, you must know that they are characterized by having beneficial bacteria for the restoration and conservation of the stomach lining.  Laura Kohan, in her book “Alimentos saludables para el siglo XXI” (available in Spanish), says that “for several yogurts that have been subject to such an aggressive pasteurization process, few bacteria survive.  This takes us to the extreme of having to add them afterwards, as is the case, for example, in those that are advertised as having bifidus, after having destroyed the original bacteria.  This is irrational nonsense.”

To avoid this, it is advisable to review the label to see if it has been subject to pasteurization or strong sterilization.

It is best to try to make a homemade product like kefir (Bulgarian) at home, with non-pasteurized (fresh) milk, to obtain the best results in regards to nutrients and benefits.

You should remember that pasteurized products in supermarkets have the primary mission of prolonging their shelf life, with the purpose of reducing costs and benefiting the business’ economy.

A bit of history about pasteurization…

In antiquity, there were undesirable changes in food products due to the presence of microorganisms in food.  They causes very diverse health problems.  By applying heat, it was discovered that one could avoid said germs.  Pasteur, along with other known scientists of his time, made important contributions to the equipment design used for dairy processing systems.

In 1898 Denmark declared a law, ordering all calf dairy foods to be heated to a temperature of 185 degrees F, in order to prevent the spread of Bovine tuberculosis.  This was, in fact, one of the first gigantic steps of modern commercial milk pasteurization.

Pasteurization got its name from its discoverer, the French scientist-chemist Louis Pasteur (1822-1895) in 1964, by himself and a colleague named Claude Bernard.

Pasteur’s scientific advancement improved the quality of life by allowing certain basic dietary products, like milk, to be transported long distances without being affected by decomposition.

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