Milk and cream

The leading states in milk production in decreasing order are Wisconsin, Minnesota, New York, California, and Pennsylvania. These states produce - 45% of the U.S. milk supply. Less than 5% of the total production is used on farms and the remainder is sold for commercial purposes. Whereas milk and cream were formerly shipped in 19-, 30-, or 38-L cans from the farm to the plant, in the 1990s most commercial production, particularly for fluid milk, is moved in bulk from the cows to refrigerated farm tanks to insulated bulk tmck tankers and to the manufacturing plant. The investment in equipment and the cost of hired labor are associated with large, capital-intensive production centers. 

The methylene blue and resazurin reduction methods indirectly measure bacterial densities in milk and cream in terms of the time interval required, after starting incubation, for a dye—milk mixture to change color (methylene blue, from blue to white resazurin, from blue through purple and mauve to... 

Anhydrous Milk Fat. One high milk-fat material is butter oil (99.7% fat), also called anhydrous milk fat or anhydrous butter oil if less than 0.2% moisture is present. Although the terms are used iaterchangeably, anhydrous butter oil is made from butter and anhydrous milk fat is made from whole milk. For milk and cream there is an emulsion of fat-ia-semm, for butter oil and anhydrous milk fat there is an emulsion of semm-ia-fat, such as with butter. It is easier to remove moisture ia the final stages to make anhydrous milk fat with the semm-ia-fat emulsion. 

The milk and cream in ice cream contain butterfat, proteins, and milk sugars. Butterfat adds rich flavor, smooth texture, body, and good melting properties. The triglycerides in butterfat melt over a wide range of temperatures, so there is always some bit of solid and some liquid butterfat. Some of the butterfat almost turns into butter while the ice cream is being churned, adding to the unique texture of ice cream. 

In a preliminary study, Tomasula et al. (2009) simulated the fluid milk process to identify energy usage and GHGs associated with HTST pasteurization and the related unit operations, such as homogenization. Physical property data for milk and cream were provided to the simulator. Packaging was not included as part of the simulation. GHGs were... 

Hexanone has been found as a natural substance in foods such as cheese, nectarines, nuts, bread, and chicken muscle. We do not know the levels of 2-hexanone in these foods. 2-Hexanone has been found in milk and cream at levels up to 0.018 ppm (0.018 parts of 2-hexanone in one... 

Hexanone has been identified among the natural volatile components of several foods including blue and Beaufort cheeses, nectarines, roasted filberts, and chicken muscle (Day and Anderson 1965 Dumont and Adda 1978 Grey and Shrimpton 1967 Kinlin et al. 1972 Takeoka et al. 1988) levels were not stated in these reports. It has also been detected in milk and cream at concentrations ranging from 0.007 to 0.018 ppm (7-18 ppb) and in bread (Lande et al. 1976). Because few quantitative data are available, it is not known if food is an important source of human exposure to 2-hexanone. 

Under certain conditions (e.g. moderate shear rates, at fat contents below 40% and at temperatures above 40°C, at which the fat is liquid and no cold agglutination occurs) milk, skim milk and cream are, in effect, fluids with Newtonian rheological properties. Newtonian behaviour can be described by the equation ... 

The viscosity of milk and creams tends to increase slightly with age, due in part to changes in ionic equilibria. Heating skim milk to an extent that denatures most of the whey proteins increases its viscosity by about 10%. Homogenization of whole milk has little effect on its viscosity. The increase in the volume fraction of fat on homogenization is compensated by a decrease in the volume fractions of casein and whey proteins because some skim milk proteins are adsorbed at the fat-oil interface. Pasteurization has no significant effect on the rheology of whole milk. 

Me Dowall, F. H. 1936. The determination of carbon dioxide in biological fluids, more particularly milk and cream. Analyst 61, 472-473. 

Wong, N. P. and Patton, S. 1962. Identification of some volatile compounds related to the flavor of milk and cream. J. Dairy Sci. 45, 724-728. 

Table 2.1 lists the approximate percentages of the total milk supply used for various products in the United States and in nine major milk-producing countries. In such countries as New Zealand and Ireland, where per capita production of milk is high, most milk is used in storable manufactured products like butter, cheese, and nonfat dry milk. Where per capita production is low, as in the United States and the United Kingdom, greater amounts are used as fluid milk and creams. 

Fluid milk and cream based upon whole milk equivalent (fat solids basis). 

Kitchen, B. J. 1974, A comparison of the properties of membranes isolated from bovine skim milk and cream. Biochim. Biophys. Acta 356, 257-269. 

Koops, J. 1969. The effect of the pH on the partition of natural and added copper in milk and cream. Neth. Milk Dairy J. 23, 200-213. 

FDA, Department of Health, Education, and Welfare. 1973. Milk and Cream. Title 21, Part 18. Federal Register 38, 27924-27929. 

FDA, Department of Health and Human Services. 1982A. Code of Federal Regulations. Title 21, Chapter 1, Part 131, Milk and Cream, Section 131-110, Milk. Revised as of April 1. Federal Register. 

McPherson, A. V., Dash, M. C. and Kitchen, B. J. 1984B. Isolation and composition of milk fat globule membrane material. I. From pasteurized milks and creams. J. Dairy Res. 51, 279-287. 

Many food colloids are stabilized from proteins from milk or eggs [817]. Milk and cream, for example, are stabilized by milk proteins, such as casein micelles, which form a membrane around the oil (fat) droplets [817]. Mayonnaise, hollandaise, and bearnaise, for example, are O/W emulsions mainly stabilized by egg-yolk protein, which is a mixture of lipids (including lecithin), proteins, and lipoproteins [811,817]. The protein-covered oil (fat) droplets are stabilized by a combination of electrostatic and steric stabilization [817]. Alcohols may also be added, such as glycerol, propylene glycol, sorbitol, or sucrose sometimes these are modified by esterification or by... 

Cream is the fat-rich portion of milk that is separated by skimming and contains at least about 18-20% fat (still in the form of an O/W emulsion). As the fat content increases from skimmed milk through thick creams, the solids-not-fat content decreases as illustrated in Figure 13.2 [826]. The viscosities of milk and cream depend on the concentrations of both fat and solids-not-fat as shown in the following empirical equation [215] ... 

Bjerke, E.L., Herman, J.L., Miller, P.W., Wetters, J.H. (1972) Residue study of phenoxy herbicides in milk and cream. J. Agric. Food Chem. 20, 963-967. 

McKellar, R.L., Dishburger, H.J., Rice, J.R., Craig, L F., Pennington, J.J. (1976) Residues of chlorpyrifos, its oxygen analogue, and 3,5,6-trichloro-2-pyridinol in milk and cream from cows fed chlorpyrifos. J. Agric. Food Chem. 24, 283-286. 

Condensed and evaporated milk Fluid milk and cream (prod.weight) Ice cream (product weight)... 

MAFF 1999, Nutrient analysis of other milks and creams. In, Archive - food surveillance information sheets, Number 178 May 1999, U.K. Food Standards Agency. Available at http //archive.food.gov. uk/maff/archive/food/infsheet/1999/nol78/178milk.htm... 

Factors that Affect the Surface Layers of Fat Globules in Milk and Cream... 

If fat globules are present as separate particles, the fat content is <40% and the milk fat completely molten, milk and cream behave as Newtonian fluids at intermediate and high shear rates (Phipps, 1969 McCarthy, 2003), i.e., its viscosity is not influenced by shear rate (t = rj / y, where r is the shear stress [Pa], 17 is the viscosity [Pa s] and y is the shear rate[l/s]). For a Newtonian fluid, Eilers equation (Eilers, 1941) is generally obeyed (Walstra, 1995) ... 

Rheological properties of milk and cream are influenced by various processes (e.g., heat treatment, cooling or homogenization). McClements (1999) reported that the main factors that determine the rheological properties of emulsions can be divided into five groups ... 

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