Dairy products, fermentation

Improves the taste of dairy products fermenting component of milk... 

Under normal processing conditions, the vitamin content in milk does not change too much. The loss caused by pasteurisation is up to 10% and about 10-20% in UHT milk. In the manufacture of hard cheeses, the vitamin retention is about 60-90% of the original content. Dairy products fermented using Propionibaaerium sher-manii (such as Swiss-type cheeses), have increased vitamin content in comparison with the original milk (up to 30 times). 

The LAB group is remarkably diverse in their habitats, which are well reflected by their metabolic and transport capabilities. These organisms include the closely related Lactobacillus easel and Lact. brevis, Pediococcuspentosaceus, as well as the more distant Lact. gasseri and Lact. delbrueckii which are often found in plants and their products as well as natural inhabitants of the human gut (Vaughan et al. 2002 Makarova et al. 2006 Lorca et al. 2007). These organisms are used by man for the fermentation of plant, dairy, and meat products. Two other LAB, Lactococcus lactis subspecies cremoris and Streptococcus thermophilus, distantly related to the other LAB but closely related to each other, are both found in milk and are useful for dairy product fermentations. Finally, two additional LAB, closely related to each other but more distantly related to the others, are Leuconostoc mesenteroides, useful for food fermentation purposes, and Oenococcus oeni, important in wine production (Hastings et al. 1991 Mills et al. 2005). 

Cousin, F.J., Foligne, B., Deutsch, S.M., et al. (2012)Assessmentof the probiotic potential of a dairy product fermented by Propionibacterium freudenreichii in piglets. JAgric Food Chem 60, 7917-7927. 

Milk is not a rich source of dietary folate compared to other foods however, as is the case for riboflavin, folate concentrations can be significantly increased in many dairy products due to microbial fermentation. Among dairy products, fermented milks are considered a good potential matrix for folate fortification because folate-binding proteins present in milk improve folate stability and enhance the bioavailability of both 5-methyltetrahydrofolate (the most predominant natural form of the vitamin) and folic acid (Jones and Nixon 2002 Aryana 2003 Verwei et al. 2003). However, due to the potential risks of fortification with folic acid, the elaboration of fermented milks containing elevated levels of natural folates would be a better suited alternative. 

LeBlanc, J.G., Rutten, G., Brainenberg, R, et al. (2006) A novel dairy product fermented with Propionibacterium freudenreichii improves the riboflavin status of deficient rats. Nutrition 22, 645-651. 

Lactic acid-producing bacteria associated with fermented dairy products have been found to produce antibiotic-like compounds caUed bacteriocins. Concentrations of these natural antibiotics can be added to refrigerated foods in the form of an extract of the fermentation process to help prevent microbial spoilage. Other natural antibiotics are produced by Penicillium wqueforti the mold associated with Roquefort and blue cheese, and by Propionibacterium sp., which produce propionic acid and are associated with Swiss-type cheeses (3). 

Cells of microorganisms have constituted a portion of human food siace ancient times. Yeast-leavened baked products contain the residual nutrients from the yeast cells destroyed duriag bakiag (see Bakery processes and leavening agents). Cultured dairy products, such as yogurt, buttermilk, and sour cream, contain up to lO cells of lactic acid bacteria per gram (19) (see Milk and milkproducts). Other examples of fermented foods consumed siace early times iaclude fermented meats, fish, and soybean products. 

Uses. High fmctose symp is used as a partial or complete replacement for sucrose or invert sugar in food appHcations to provide sweetness, flavor enhancement, fermentables, or humectant properties. It is used in beverages, baking, confections, processed foods, dairy products, and other apphcations. Worldwide HES production in the 1994—1995 fiscal year was estimated at about 8.6 x 10 t (dry basis) (18). About 75% of total world production is in the United States. 

Microorganisms have been identified and exploited for more than a century. The Babylonians and Sumerians used yeast to prepare alcohol. There is a great history beyond fermentation processes, which explains the applications of microbial processes that resulted in the production of food and beverages. In the mid-nineteenth century, Louis Pasteur understood the role of microorganisms in fermented food, wine, alcohols, beverages, cheese, milk, yoghurt and other dairy products, fuels, and fine chemical industries. He identified many microbial processes and discovered the first principal role of fermentation, which was that microbes required substrate to produce primary and secondary metabolites, and end products. 

Lactose is mainly used as a fermentation substrate for lactic acid bacteria in dairy products, such as yogurt and cheese. These bacteria break down lactose into lactic acid, which solidifies the milk, and creates an acid environment that favors the benign lactic acid bacteria over those that are more harmful. 

The term dextran has been applied to carbohydrate slimes originating from sugar sirups, fermenting vegetables and dairy products. 

Inhibit mold in natural cheeses and other fermented dairy products. 

Food products Dairy products, General food additives Natural oils and fats Beverages Flavors and fragrances Fermentation reactions Blending control Composition monitoring Raw materials screening Quality control... 

Antibiotics in milk can affect dramatically the production of fermented dairy products such as cheese, yogurt, buttermilk and sour cream. Routine application of antibiotic test kits such as the Delvo kit are required to avoid major losses on the line. 

P. J. Groenen and E. Busink, Alkylating activity in food products - especially sauerkraut and sour fermented dairy products - after incubation with nitrite under quasi-gastric conditions. Eood and Chemical Toxicology An International Journal Published for the British Industrial Biological Research Association, 26(3), 215-225. 1988. 

Bacteria from the genera Lactobacillus and Streptococcus are involved in the first steps of dairy production (3). The raw materials produced by their effects usually only acquire their final properties after additional fermentation processes. For example, the characteristic taste of Swiss cheese develops during a subsequent propionic acid fermentation. In this process, bacteria from the genus Propionibacterium convert pyruvate to propionate in a complex series of reactions (2). 

Eat foods rich in vitamin Bj 2 including clams, dairy products, egg yolks, fermented cheese, herring, muscle and organ meats, oysters, and red snapper... 

Hydroxy-2-butanone (acetoin) is a characteristic constituent of butter flavour used for flavouring margarine and can be obtained as a by-product of molasses-based and lactic acid fermentations [49, 71]. The closely related 2,3-butanedione (diacetyl) has a much lower organoleptic threshold than acetoin and is an important strongly butter-like flavour compound in butter and other dairy products [72] in buttermilk, for instance, the diacetyl concentration is only about 2-4 mg [73]. a-Acetolactate (a-AL) is an intermediate of lactic acid bacteria mainly produced from pyruvate by a-acetolactate synthase. In most lactic acid bacteria, a-AL is decarboxylated to the metabolic end product acetoin by a-AL decarboxylase (ALDB) [71] (Scheme 23.5). 

The closely related 5-decanolide (5-decalactone), not only found in many fruits but also found in dairy products, exhibits a creamy-coconut, peach-like aroma [49] and can be synthesised from the corresponding a,(3-unsaturated lactone 2-decen-5-olide found in concentrations of up to 80% in Massoi bark oil using basidiomycetes or baker s yeast [229]. After about 16 h of fermentation, 1.2 g 5-decanolide was obtained. At the same time, the minor lactone in... 

Traditionally, dairy products (cheese, fermented milks, butter) were produced on an artisanal level, as is still the case in underdeveloped regions and to some extent in highly developed dairying countries. Industrialization commenced during the nineteenth century and dairy manufacturing is now a well-organized industry. One of the features of the past few decades has... 

Apart from public health impacts, residual antimicrobials in animal products can bring about technoeconomic losses in the food processing industry. It has long been known that the presence of some antimicrobial compounds in milk can dramatically affect the production of fermented dairy products such as yogurt, cheese, buttermilk and sour cream (72, 73). As shown in Table 10.2, even minute concentrations of antibiotics in milk can cause inhibition of the growth of commonly used dairy starter cultures (74). 

Fermented milks are cultured dairy products manufactured from whole, partly skimmed, skim, or slightly concentrated milk. Specific lactic acid bacteria or food-grade acids are required to develop the characteristic flavor and texture of these beverages. Fermented milks are either fluid or semifluid in consistency, with various proportions of lactic acid. Fermented products are regulated by federal standards in the United States, as stated in Table 2.2. Other fermented milks without established federal standards are regulated by state standards. Compositional standards for fermented milks have been proposed by the International Dairy Federation (Hargrove and Alford 1974). Typical analyses of various fermented milks, as well as of their condensed and dried counterparts, are given in Table 2.4. 

Law, B. A. 1979. Reviews of the progress of dairy science Enzymes of psychrotrophic bacteria and their effects on milk and milk products. J. Dairy Res. 46, 573-588. Law, B. A. 1981. The formation of aroma and flavor compounds in fermented dairy products. Dairy Sci. Abstr. 43, 143-154. 

The most important fermentative reaction used in dairy processing is the homofermentative conversion of lactose to lactic acid. The efficient manufacture of high-quality cultured products, including most cheese varieties, yogurt, and cultured buttermilk, requires a rapid and consistent rate of lactic acid production. Lactic acid helps to preserve, contributes to the flavor, and modifies the texture of these products. Nearly all starter cultures used to produce acidified dairy products contain one or more strains of lactic streptococci, because these organisms can produce the desired acidity without causing detrimental changes in flavor or texture. Strains of lactic streptococci can be classified as... 

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