Production of fermented foods

Bioprocess plants are an essential part of food, fine chemical and pharmaceutical industries. Use of microorganisms to transform biological materials for production of fermented foods, cheese and chemicals has its antiquity. Bioprocesses have been developed for an enoimous range of commercial products, as listed in Table 1.1. Most of the products originate from relatively cheap raw materials. Production of industrial alcohols and organic solvents is mostly originated from cheap feed stocks. The more expensive and special bioprocesses are in the production of antibiotics, monoclonal antibodies and vaccines. Industrial enzymes and living cells such as baker s yeast and brewer s yeast are also commercial products obtained from bioprocess plants. 

Microbial fermentations have been used for the production of fermented food and beverages since ancient times and the first microbial fermentation was introduced in the 1920s for the production of citric acid. This paved the way for industrial scale production of penicillin by microbial fermentation during World War II and after that several fermentation processes for the production of other antibiotics were introduced. 

Acid proteases play an important role in two major areas of food processing—cheese making and the production of fermented foods by molds from soy beans, rice, and other cereals. 

Foods that include the incorporation of microbial metabolites as part of their production are an intricate component of the world s food supply and for ethical and sensory-nutritional reasons it is essential for all the world s population to have access to this form of food. It is a process that has been in use since the early history of mankind. An Egyptian pot dating from 2300 BC (McGee, 1984) was found to contain residues of cheese and in passages in the Bible the use of some kind of fermentative starter culture is indicated. It is, therefore, possible that the use of bacteria such as the lactic acid bacteria (LAB) dates back at least four to five thousand years, although the exact principle behind the process may not have been known to the civilizations of those times (Davidson et al., 1995). Production of fermented foods, where organisms such as the LAB are involved, is a technological process that has been used for centuries at least (Herreros et al., 2005). 

Propionic acid In foods by natural processing Product of fermented foods Barbosa-Canovas et al. 2003 Food-Info 2009... 

Production of fermented foods, probiotics (microbial dietary supplements). Genomic analysis should yield functional information to enable the design of lactic acid bacteria (e.g., Lactobacillus and Bifidobacterium) better suited to industrial processes or tailored to provide nutritional benefit. 

The use of single enzymes has been commercialized for more than a half century for the production of fructose, chemicals, and semi-synthetic antibiotics. The use of cell extracts for the production of high-value vaccines, vitamins, and proteins has been studied for the last two decades. Whole cells, especially microbes, have been utilized in the production of fermented food, beer, wines, drugs, chemicals, and so forth, to meet mankind s myriad needs for thousands of years. 

Even though these examples are from the dairy industry, the principles involved are applicable to any industry using microbes for the production of fermented food or feed or for the bioconversion of biomass to valuable biochemical compounds. 

In the production of fermented food, starter cultures are used to prevent fermentation failure and to ensure high-product quality. Starter cultures are cultures with well-defined properties that ensure a fast, safe, and defined fermentation and lead to fermented food products with high and constant product quality. The use of defined starter cultures is state-of-the-art in the dairy industry, and replaces traditional procedures in the production of meat and bakery products and other fermented commodities. Starter cultures are mostly produced by specialized companies that distribute the cultures worldwide, and are being used increasingly in concentrated forms for direct inoculation into the food matrix (direct-to-vat-set cultures, DVS Hansen, 2002). 

Lactic acid bacteria with defined functionalities play a major role as starter cultures for the production of fermented foods such as yogurt, cheese, bread or fermented drinks. Additionally, specific strains of lactic acid bacteria are also widely used as health promoting additives. These so-called probiotics are added to the food in hi cell numbers to enhance their functional properties or are marketed in isolated form as special dietary supplements. Probiotics are frequently distributed as dry powder. 

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