Buttermilk cultured

Richter, R. L. 1977. Manufacture of superior quality buttermilk. Cultured Dairy Prod. J. 12, 22-28. 

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. 

Cultured buttermilk is that which is produced by the fermentation (qv) of skimmed milk often with some cream added. The principal fermentation organisms used are l ctococcus lactis suhsp. cremoris l ctococcus lactis suhsp. lactis and l euconostoc citrovorum. The effect of the high processing temperature and the lactic acid provide an easily digestible product. 

Yogurt is manufactured by procedures similar to buttermilk. Milk with a fat content of 1—5% and soHds-not-fat (SNF) content of 11—14% is heated to ca 82°C and held for 30 minutes. After homogenization the milk is cooled to 43—46°C and inoculated with 2% culture. The product is incubated at 43°C for three hours in a vat or in the final container. The yogurt is cooled and held at <4.4° C. The cooled product should have a titratable acidity of not less than 0.9% and a pH of 4.3—4.4. The titratable acidity is expressed in terms of percentage of lactic acid [598-82-3] which is deterrnined by the amount of 0.1 AiNaOH/100 mL required to neutralize the substance. Thus 10 mL of 0.1 AiNaOH represents 0.10% acidity. Yogurts with less than 2% fat are popular. Fmit-flavored yogurts are also common in which 30—50 g of fmit are placed in the carton before or with the yogurt. 

Sucrose is often used as a decorative agent to impart a pleasing appearance to baked goods and confections (36). In jams and jeUies, sugar raises osmotic pressure and lowers water activity to prevent spoilage (18). Sucrose is a fermentation substrate for lactic acid in cultured buttermilk (40) and lowers the freezing point of ice cream and other frozen desserts to improve product mouthfeel and texture. 

The production of fermented milks no longer depends on acid production by the indigenous microflora. Instead, the milk is inoculated with a carefully selected culture of LAB and for some products with LAB plus lactose-fermenting yeasts (Table 10.12). The principal function of LAB is to produce acid at an appropriate rate via the pathways summarized in Figure 10.12. The yoghurt fermentation is essentially homofermentative but the characteristic flavour of cultured buttermilk is due mainly to diacetyl which is produced from citrate by Lactococccus lactis ssp. lactis biovar diacetylactis, which is included in the culture for this product (Figure 10.31). 

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). 

Cultured buttermilk is manufactured by fermenting whole milk, reconstituted nonfat dry milk, partly skimmed milk, or skim milk with lactic acid bacteria. Most commercial cultured buttermilk is made from skim milk. Mixed strains of lactic streptococci are used to produce lactic acid and leuconostocs for development of the characteristic diacetyl flavor and aroma. Buttermilk is similar to skim milk in composition, except that it contains about 0.9% total acid expressed as lactic acid. The percentage of lactose normally found in skim milk is reduced in proportion to the percentage of lactic acid in the buttermilk. According to White (1978), the fat content of buttermilk usually varies from 1 to 1.8%, sometimes in the form of small flakes or granules to simulate churned buttermilk, the by-product of butter churning. Usually 0.1% salt is added. 

A few U.S. states require buttermilk to be labeled as cultured whole-milk buttermilk with a minimum of 3.5% milk fat or as cultured lowfat milk with a minimum of 0.5% and a maximum of 2.0% milk fat, or as cultured skim milk with a maximum of 0.5% milkfat. When buttermilk is made with low-heat powder, higher solids (10%) usually are used to give a firmer body with less shrinkage and less whey separation during storage (White 1978). 

A product similar to cultured buttermilk may be prepared by direct acidification. Food-grade acids and acid anhydrides are added to unfermented milk to obtain a product with uniform acidity and smooth body. Flavoring materials are used to improve the flavor and aroma. 

Bulgarian buttermilk is similar to cultured buttermilk, except that the whole or partly skimmed milk is fermented by Lactobacillus bulg-aricus. With a titratable acidity of 1.2 to 1.5% expressed as lactic acid, it is more acidic than cultured buttermilk. 

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... 

Use of fermented whey as a food has been suggested. Jagielski (1871) combined whey and lactose with an appropriate culture and produced a whey kumiss. Later, Krul kevich mixed equal volumes of whey and buttermilk with kumiss yeasts, L. bulgaricus, and L. acidophilus. The finished product is claimed to resemble kumiss (Marth 1974). A condensed whey food composed, in part, of whey fermented by L. bulgaricus and P. shermanii has been described in a patent issued to Meade et al. (1945). Additional information on fermenting whey is given by Friend and Shahani (1979). 

Hogarty, S. L. and Frank, J. F. 1982. Low temperature activity of lactic streptococci isolated from cultured buttermilk. J. Food Prot. 45, 1208-1211. 

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... 

Vedamuthu, E. R. 1974. Cultures for buttermilk, sour cream and yogurt with special comments on acidophilus yogurt. Cultured Dairy Prod. J. 9, 16-21. 

Function Buffer sequestrant emulsion stabilizer nutrient for cultured buttermilk. 

There are several ways of making cultured butter from sweet cream. Pasilac-Danish Turnkey Dairies, Ltd. developed the IBC method (Figure 10) (81). The main principles of the IBC method are as follows. After sweet cream churning and buttermilk drainage, a starter culture mixture is worked into the butter, which produces both the required lowering of butter pH and, because of the diacetyl content of the starter culture mixture, the required aroma. The starter mixture consists of two types of starter culture (1) Lactococcus lactis and (2) L. cremoris and L. lactis ssp. diace-tylactis. With respect to production costs, the experience with this method shows that, for the manufacture of mildly cultured butter, the direct costs are only about one-third of the costs of other methods (81). 

The first steps in the manufacture of Bregott are pasteurization of the cream, followed by cooling and temperature treatment. The cultures are the same as those used in buttermaking. Measured quantities of cream and soybean oil are mixed in the churn or the oil is continuously injected before churning in a continuous butter machine. The byproduct is sour buttermilk. 

Ranch dressings containing fermented dairy products, such as buttermilk, are often a source of wild culmres. These cultures, often heterofermentative Lactobacillus, can cause gassiness and product spoilage. Processing often includes pasteurization of the dairy component. 

Use Soft drinks, photography, frozen desserts, meat products, detergents, special cheeses, electroplating, sequestrant and buffer, nutrient for cultured buttermilk, removal of sulfur dioxide from smelter waste gases, medicine (diuretic, expectorant), anticoagulant for blood withdrawn from body. 

Low Molecular Weight Carbonyl Compounds. In the dairy field, a major product made this way is starter distillate. The main component is diaceyl which is a very important aroma compound responsible for the characteristic buttery flavor of fermented dairy products such as sour cream or buttermilk. The dairy industry relies upon fermentation by lactic streptococci for the production of diacetyl in cultured products. Starter distillate is a natural product rich in diacetyl which is produced by distilling such lactic cultures. The key intermediate in the biosynthesis of diacetyl is aL-acetolactic acid which is decarboxylated to form diacetyl (Figure 3). The starting material of the biosynthetic pathway is citrate which is a natural component of milk. 

Fig. 67.—Microscopic appearance of culture buttermilk. The smaller organisms in chains are Str. lacticus. The rodlike organisms are Bacillus bulgancus.

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. 

Buttermilk is a by-product of butter manufacture, in which pasteurized cream is cultured and then churned to produce butter and buttermilk. It has approximately the same composition as skimmed milk, and can also be concentrated and spray dried. Buttermilk provides a distinctive, fresh flavour. 

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