Lactic milk product

Yogurt. Yogurt is a fermented milk product that is rapidly increasing in consumption in the United States. Milk is fermented with Uactobacillus bulgaricus and Streptococcus thermophilous organisms that produce lactic acid. Usually some cream or nonfat dried milk is added to the milk in order to obtain a heavy-bodied product. 

SANDERS M E (1993) Summary of the conclusion from a consensus panel of experts on health attributes on lactic cultures significance to fluid milk products containing cu txae%. JDiary Sci. 76 1819-28. 

Enantiomers have very similar chemical properties, but they rotate polarized light in opposite directions (optical activity, see pp. 36,58). The same applies to the enantiomers of lactic acid. The dextrorotatory L-lactic acid occurs in animal muscle and blood, while the D form produced by microorganisms is found in milk products, for example (see p.l48). The Fischer projection is often used to represent the formulas for chiral centers (cf.p. 58). 

Figure 3.4 — (A) FIA manifold for the determination of L-lactic acid in milk products P peristaltic pump C carrier S sample V injection valve AD air damper FTC flow-through cell W waste BFB bifurcated fibre LS light source PMT photomultiplier tube R recorder. (B) Cross-section of lactic acid optrode. (Reproduced from [39] with permission of VCH Publishers).

Fermentation of lactose during the growth of micro-organisms in milk has a major effect on its redox potential. The decrease in the h of milk caused by the growth of lactic acid bacteria is shown in Figure 11.3. A rapid decrease in h occurs after the available 02 has been consumed by the bacteria. Therefore, the redox potential of cheese and fermented milk products is negative. Reduction of redox indicators (e.g. resazurin or... 

Milk Products Moisture (%) Protein (%> Total Fat (%> Total Carbo- hydrate (%> Ash (%) Calcium <%> Phosphorus (%) Sodium (%) Potassium (%) Lactic Acid <%)... 

Milk can be converted easily by lactic acid starter cultures into various cultured and culture-containing milk products. Within the last ten years, consumption of these products (e.g., yogurt, sour cream, and acidophilus milk) has increased appreciably in the United States. (Rasic and Kurmann 1978 Shahani and Chandan 1979 Helferich and... 

Vitamins and Minerals. Milk is a rich source of vitamins and other organic substances that stimulate microbial growth. Niacin, biotin, and pantothenic acid are required for growth by lactic streptococci (Reiter and Oram 1962). Thus the presence of an ample quantity of B-complex vitamins makes milk an excellent growth medium for these and other lactic acid bacteria. Milk is also a good source of orotic acid, a metabolic precursor of the pyrimidines required for nucleic acid synthesis. Fermentation can either increase or decrease the vitamin content of milk products (Deeth and Tamime 1981 Reddy et al. 1976). The folic acid and vitamin Bi2 content of cultured milk depends on the species and strain of culture used and the incubation conditions (Rao et al. 1984). When mixed cultures are used, excretion of B-complex vita-... 

Sewage wastes contain as much as 4 ppm of vitamin Bi2 (Hoover et al. 1952B Miner and Wolnak 1953). Although frowned on for aesthetic reasons as a source of vitamin Bi2 for human nutrition, wastes from activated sludge processes may well provide the cheapest source for preparation of vitamin Bi2 concentrates used in cattle feed. Symbiotic growth of lactic and acetic acid bacteria has been recommended for producing sour milk products biologically enriched with vitamin Bi2 (Rykshina 1961). Acetic acid bacteria cultured in whey fortified with cobalt salts led to an 80-fold increase in vitamin B12. Propionic acid bacteria in skim milk supplemented with dimethylbenzimidazole increased the vitamin content by 300-fold. 

Cousin, M. A. and Marth, E. H. 1977C. Lactic acid production by Streptococcus lactis and Streptococcus cremoris in milk precultured with psychrotrophic bacteria. J. Food Prot. 40, 406-410. 

Cultured milk products are manufactured by fermentation of milk or cream by lactic culture microorganisms that produce desirable flavor and rheological properties which are influenced by the composition of the milk or cream, and by the processing conditions used (Richter 1977 Foster et al. 1957 Marth 1974). Cultured buttermilk may be made from skim milk but is sometimes made from milk containing 1.0 to 3.5% milk fat. Some cultured milk products often contain added MSNF and plant gum or modified starch stabilizers to increase viscosity and control whey syneresis. Dextran-producing culture microorganisms are sometimes used to provide needed viscosity to the cultured milk product without the need to add MSNF or stabilizers. Up to 0.1% citric acid or sodium citrate is commonly added as a substrate for... 

R. Zaydan, M. Dion and M. Boujtita, Development of a new method, based on a bioreactor coupled with an L-lactate biosensor, toward the determination of a nonspecific inhibition of L-lactic acid production during milk fermentation, J. Agric. Food Chem., 52(1) (2004) 8-14. 

A milk product is described having prophylactic activity due to cultured-milk strains of microorganisms. It includes several lactic acid bacteria (e.g., Lactobacillus acidophilus strain 317/402), and inulin from Jerusalem artichoke. 

As mentioned in the introduction, fermentation has been used since ancient times to conserve and alter food. Also today, it is still applied on a very large scale for this purpose. A few typical examples are described in this chapter. The principle is similar in most cases. Lactic acid produced by bacteria protects the food from deterioration by inhibiting the growth of mold and other microorganisms. Most vitamins and nutrients of the food are preserved during fermentation. Three examples are discussed in more detail below The production of sauerkraut, soy sauce, and milk products (Table 9.3). 

Lactic acid bacteria are used to produce fermented milk products, and the exopolysaccharides produced by the bacteria influence the texture of the resulting products. More importantly, these exopolysaccharides are thought to have several health benefits. There is evidence they lower cholesterol, modulate the immune system, help prevent colon cancer, and fight ulcers [342,343]. There is thus interest in establishing stmcture-function relationships for these stmctures, as well as in metabolic engineering of lactic acid bacteria to produce capsular polysaccharides with the desired properties [342,343]. 

Sour milk products are always cultured dairy products with lactic acid bacteria (depending on the food legislation of the respective country). After increasing the dry matter, pasteurisation and incubation of culture, they are processed into yoghurts of set, stirred or drinking consistency, with or without a final heat treatment. 

Lactic acid Sour milk products (yogurt, cottage cheese)... 

Hsin-Yu, C. and Chou, C.-C. 2001. Acid adaptation and temperature effect on the survival of E. coli 0157 H7 in acidic fruit juice and lactic fermented milk product. International Journal of Food Microbiology 70 189-195. 

The inhibition of the enzyme tyrosinase may very well be a key to the control of melanoma, and some of the known inhibitors include eommon substances. Thus, vitamin C, among other common and uncommon substances, has been listed as an enzyme inhibitor for tyrosinase in M.K. Jain s Handbook of Enzyme Inhibitors, 1965-1977 (1982). In addition to ascorbic acid (vitamin C), these other substances include the following halide ion (e.g., from the chloride of common salt, or from iodides and fluorides) butyric acid (from rancid butter) lactic acid (the end product of cancer cell metabolism, found naturally in sour milk products) oxalic acid (ordinarily considered toxic, although it occurs naturally in rhubarb and wood sorrel, etc.) formic acid (a component of ant stings) tyrosine itself and deadly cyanide (which is a chemically bound component of laetrile), as found in almonds (notably bitter almonds), in apricot seeds, and in certain legumes such as beans, etc., although the heat from cooking may drive off the cyanide content. 

With regard to melanoma, which involves the enzyme tyrosinase, there are a number of inhibitors listed in the handbooks for this particular enzyme. Among them, interestingly, is ascorbic acid, or vitamin C, as well as some other commonly encountered substances such as lactic acid (from sour milk products) and butyric acid (from rancid butter). The aforecited alpine sunflower/yucca extract developed by Owen Asplund of the University of Wyonming may very well act as an enzyme inhibitor for tyrosinase. 

Certain lactic acid producing bacteria have the ability to grow on dairy milk to produce various types of fermented dairy products, including acidophilus milk (sour milk), cultured buttermilk, yogurt, cheese, and other cultured milk products. The microbial action not only increases the shelf-life and nutritional value of these products, but also makes them mote pleasant to eat or drink. 

Most polysaccharides used today are of plant origin. However, also bacteria produce polysaccharides. Especially extracellular polysaccharides (eps s) produced by lactic acid bacteria may find application in foods. Lactic acid bacteria are food-grade organisms and the eps s produced offer a wide variety of structures. The presence of eps is considered to contribute greatly to texture and structure of fermented milk products. An exopolysaccharide produced by Lactococcus lactis ssp. cremoris B40 was chosen as a subject of study. The eps was a gift from the Dutch Institute of Dairy Research (NIZO), Ede, the Netherlands. The eps had no gelling properties, could not be precipitated in plates by ethanol or cetylpyridinium chloride and did not show interaction with Congo red. 

Lactic acid INS No 270, FW 90.08, Chem. name 2-hydroxypropanoic acid, 2-hydroxypropionic acid. Lactic acid is primarily found in milk products, mainly in yogurt, kefir, etc. Lactic acid is also produced in muscle. It is commercially obtained by lactic fermentation of sugars or prepared... 

Tomita M, Wakabayashi H, Yamauchi K, Teraguchi S, Hayasawa H (2002) Bovine lactoferrin and lactoferricin derived from milk production and applications. Biochem Cell Biol 80 109-112 Tsuge T, Tanaka K, Ishizaki A (2001) Development of a novel method for feeding a mixture of L-lactic acid and acetic in fed-batch culture of Ralstonia eutropha for poly-D-3-hydroxybu-tyrate production. J Biosci Bioeng 91 545-550... 

Weerkamp, A. H., Klijn, N., Neeter, R., Smit, G. (1996). Properties of mesophiUc lactic acid bacteria from raw milk and naturally fermented raw milk products. Netherlands Milk and Dairy Journal, 50, 319-332. 

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