The feel-good factor associated with probiotic food and drink is stimulating the market for these products.

What are ‘Probiotics’?

One definition, developed by the World Health Organization, is that probiotics are “live micro-organisms, which, when administered in adequate amounts, confer a health benefit on the host”. These micro-organisms are tiny living cells such as bacteria, moulds, and yeasts. The theory behind the potential benefit of probiotics dates back to the beginning of the 20th century, and the Russian biologist Elie Metchnikoff. Metchnikoff, who won the Nobel Prize for Medicine in 1908, suggested that ageing was in part caused by toxic bacteria in the gut, and that it would be possible to prolong life by replacing those harmful microbes with benign ones found in lactic acid. Research carried out in 1920 suggested that the bacteria Metchnikoff added to his own diet, in the form of soured milk, couldn’t actually survive in human intestines. And debates over whether or not probiotics do genuinely offer health benefits have raged ever since.

There is some evidence of therapeutic benefits of probiotics, for example in the prevention of allergies, and in the prevention and treatment of diarrheal diseases. However, most medical benefits have been the result of using high doses of the bacteria. ‘Dosage’ in food products and supplements varies enormously. A single pot of probiotic yoghurt drink, for example, contains 6.5 billion bacteria, whereas a 4.4 gram sachet of the supplement VSL3 contains 450 billion. There is debate over the dozens of strains of probiotic bacteria – whether some are more effective than others and whether they are better used in combination. Furthermore, the bacteria can only be effective if they are alive. Their survival in food is a complicated issue involving – amongst other things – the chemical composition of the product they are added to (including its acidity and oxygen content) and the storage conditions of the product, for example its temperature.

Scientific Evidence

However, one area in which there is evidence of benefit is in the use of probiotic supplements in foods for domestic and farm animals. Dogs, cats and horses have similar digestive tracts to humans and all are said to benefit from the addition of ‘good bacteria’ to their diet, especially as a way of reducing the side effects of antibiotics (which kill ‘good’ as well as ‘bad’ bacteria). The effect of the supplements on pigs and chickens is even more impressive, suggesting that they can increase the rate at which animals put on weight by up to 24 per cent.

GEA Technology & Microbial food cultures (MFCs)

Producing MFCs needs gentle handling in hygienic and cool conditions. It’s also crucial to avoid cross-contamination between different batches. GEA helps customers to meet these requirements through state-of-the-art separation, fermentation, heat exchange, cooling, drying and refrigeration technology. 

GEA has a range of steam sterilizable separators that can process cultures reliably and efficiently. The CFE 300 steam-sterilized centrifuge is the largest of its kind in the world, with production capacity of 10,000 to 20,000 litres an hour. It is fitted with a pressured housing to prevent the escape of bacteria or living cells. GEA culture separators allow the running of automatic clean in place and sterilization in place processes to prevent cross-contamination of different products. They are also designed to discharge the concentrate at the bowl head so that the separated cells are exposed to lower shearing forces than in conventional equipment. 

For the fermentation stage GEA provides a comprehensive range of Liquid Processing components, especially designed for handling these sensitive bacteria strains under consistent sterile conditions. The fermenters typically handle batch volumes from 100 litres up to 100,000 litres. Using GEA process equipment, the fermented product is either freeze or spray dried under sterile conditions using lenient drying temperatures to secure maximum survival rate. 

GEA manufactures and supplies market-leading heat exchangers and cooling technology for a wide range of applications, including the thermal treatment of probiotic products. Equipment includes heat exchangers, air coolers for cold cabinets and storage rooms and air cooled condensers for refrigeration and air conditioning. GEA designs, engineers, installs and maintains innovative freezing and chilling equipment used throughout the food industry.