Buttermilk

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. 

Lactic acid [50-21-5] (2-hydroxypropanoic acid), CH CHOHCOOH, is the most widely occurring hydroxycarboxylic acid and thus is the principal topic of this article. It was first discovered ia 1780 by the Swedish chemist Scheele. Lactic acid is a naturally occurring organic acid that can be produced by fermentation or chemical synthesis. It is present ia many foods both naturally or as a product of in situ microbial fermentation, as ia sauerkraut, yogurt, buttermilk, sourdough breads, and many other fermented foods. Lactic acid is also a principal metaboHc iatermediate ia most living organisms, from anaerobic prokaryotes to humans. 

Large quantities of evaporated milk are used to manufacture ice cream, bakery products, and confectionery products (see Bakery processes and LEAVENING agents). When used for manufacturing other foods, evaporated milk is not sterilized, but placed in bulk containers, refrigerated, and used fresh. This product is caHed condensed milk. Skimmed milk may be used as a feedstock to produce evaporated skimmed milk. The moisture content of other Hquid milk products can be reduced by evaporation to produce condensed whey, condensed buttermilk, and concentrated sour milk. 

Buttermilk. Buttermilk is drained from butter (chum) after butter granules are formed as such, it is the fluid other than the fat which is removed by churning. Buttermilk may be used as a beverage or may be dried and used for baking. Buttermilk from churning is - 91% water and 9% total sohds. Total sohds include lactose [598-82-3] 4.5% nitrogenous matter, 3.4% ash, 0.7% and fat, 0.4%. Table 17 gives the U.S. specifications for dry buttermilk (DBM) and whey. 

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. 

Dried buttermilk is made by either the dmm or spray process. Buttermilk is usually pasteurized before drying, even though the milk was previously pasteurized before churning. Dried buttermilk is used primarily for baking, confectionery, and dairy products. 

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. 

Milk and Milk Replacers. White pan bread was long made with about 3—4% nonfat dry milk (NEDM) in the United States, for reasons of enhanced nutrition, increased dough absorption, improved cmst color, fermentation buffering, and better flavor. Eor some years, however, sharply increased milk prices have led to a decline in its use in breadmaking. Many bakers have turned to the use of milk replacers to control the costs of their products, and these ingredients are now commonly utilized. Milk replacers were designed to dupHcate some of the functions and nutrition of milk. These blends may contain soy flour or cereals, with whey, buttermilk soHds, sodium or calcium caseinate, or NEDM. Milk replacers or NEDM used in bread dough amount to about 1—2%, based on flour. 

Milk. Imitation milks fall into three broad categories filled products based on skim milk, buttermilk, whey, or combinations of these synthetic milks based on soybean products and toned milk based on the combination of soy or groundnut (peanut) protein with animal milk. Few caseinate-based products have been marketed (1,22,23). Milk is the one area where nutrition is of primary concern, especially in the diets of the young. Substitute milks are being made for human and animal markets. In the latter area, the emphasis is for products to serve as milk replacers for calves. The composition of milk and filled-milk products based on skim milk can be found in Table 10. Table 15 gives the composition of a whey /huttermilk-solids-hased calf-milk replacer, which contains carboxymethyl cellulose (CMC) for proper viscosity of the product. 

Fat = 10.5 wt % and CMC stabilizer = 0.5% in all formulations, which are based on clotted-cream buttermilk. Without vitamins and trace elements. 

Kem-mehl, n. best grade of flour, firsts, -membran, /. nuclear membrane, -milch, /. buttermilk. 

Lactic acid, QH C, is a weak organic acid present in both sour milk and buttermilk. It is also a product of carbohydrate metabolism and is found in the blood after vigorous muscular activity. A buffer is prepared by dissolving lactic acid, HLac (ffa = 1.4 X 10-4), and sodium lactate, NaC3H503, NaLac. Calculate [H+] and the pH of the buffer if it is made of... 

To reduce the risk of superinfection, take yogurt, buttermilk, or acidophilus capsules. 

The release of gas causes the batter to rise. The weak acids are provided by the recipe, generally in the form of lactic acid from sour milk or buttermilk, citric acid from lemons, or the acetic acid in vinegar. Baking powder contains a solid weak acid as well as the hydrogen carbonate, and carbon dioxide is released when water is added. 

Commercially available nonfat dried milk and dried buttermilk have also been shown to contain small but detectable levels of NDMA (, , ). It has been suggested that N-nitrosamine formation is possible in foods that are dried in a direct-fired dryer (65). In such a dryer, the products of combustion come into direct contact with the food being dried, and N-nitrosamine formation is probably due to the reaction between secondary and/or tertiary amines in the food and the oxides of nitrogen that are produced during fuel combusion (65). 

Nonfat dried milk Dried buttermilk Whole milk (pasteurized) 0.05 - 0.17 N-Nitrosamine in Beers and Malt... 

In similar concentrations, Irish moss extract, by virtue of its peculiar thickening properties in the presence of many proteins, has been advantageously used to suspend the milk solids in buttermilk and yogurt. 

Common acidic ingredients include vinegar, lemon juice, sour milk, buttermilk, yogurt, tart fruits, and cream of tartar. Commercial bakeries often use ammonium bicarbonate or ammonium carbonate as a leavening agent. The gas-producing reaction with ammonium bicarbonate actually generates both carbon dioxide gas and ammonia gas ... 

Soda bread is a chemically leavened bread made in Ireland. Instead of yeast the bread is raised chemically using sodium bicarbonate. The traditional source of acid is buttermilk, which contains lactic acid. The use of cream of tartar is now more common. This prevents the bread becoming too alkaline. 

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. 

The environmentally benign digestion process (EBDP) uses nitro-reductase enzymes commonly found in spinach, buttermilk, fungi, bacteria, or porcine heart to reduce explosive compounds... 

Odorants that cause aroma changes, e.g. olf-flavours, may be detected by a comparative AEDA of fresh and deteriorated samples. Studies on storage defects of soybean oil [22, 51], buttermilk [52], boiled cod [53], dry parsley [54] and black and white pepper [55] are examples. 

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). 

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