Quality control butter

It turned out that meeting a 20 ppb limit was not excessively burdensome on major manufacturers of peanut butter and other peanut products, at least in the United States aflatoxin tended to concentrate in discolored or otherwise irregular peanuts, which, fortunately, could be picked up and rejected by modern electronic sorting machines. Manufacturers did, however, have to institute substantial additional quality control procedures to meet FDA limits, and many smaller manufacturers had trouble meeting a 20 ppb limit. An extensive USDA program of sampling and analysis of raw peanuts, which continues to this day, was also put into place as the first line of attack on the problem. 

Most of the methods used to characterize the rheological behavior of butter are empirical and attempt to imitate certain sensory perceptions. They typically involve penetrometry, extrusion or sectility tests (Prentice, 1972). In these tests, the structure of the material is destroyed in order to probe its response to an applied stress or deformation. These methods mostly serve a quality control function. Their results provide an index of consistency to adjust milk-blending operations or to regulate a step in the butter-making process. While the results have practical significance, they often have no theoretical basis. Therefore, attempts have also been made to study the intrinsic properties of plastic fats. In many such cases, small deformation tests, in which the structure of the sample remains intact have been used to probe milk fat rheology. 

The quality assurance program for manufacture of butter oil, or anhydrous milkfat (AMF), also focuses on the quality of the raw materials. Naturally, many of the same considerations apply to handling raw cream for AMF manufacmre that apply to butter, except that vacreation is not used. As it is stored under ambient conditions, care against oxidation is essential. Oxidation is perhaps the most important mechanism by which milkfat deteriorates in quality. As the oxidation reaction is autocatalytic (i.e., the products of the reaction act as catalysts to promote further reaction), the normal quality-control tests, peroxide value and free fat acidity, could give misleading results when applied to stored butter. Methods of deaeration have been developed that could reduce potential oxidation (74). 

PTR-MS fingerprinting of VOC emissions in combination with statistical analysis has also been used for the classification of food products, which is important in quality control. Studies have included animal fats (milk, cow fat, pig fat and poultry fat) and vegetable oils (coconut, palm and palm kernel) [95] (with an overall 89% of the samples being correctly classified), butter and butter oils [33] (with 84% of the samples being successfully classified into butter and butter oil classes), strawberries [96] (successful classification of strawberries according to the type of cultivar (variety)), animal fats, fish oil and recycled cooking oils [97] (with 92% of the samples being correctly identified from fhe PTR-MS mass spectra) and olive oils [22,98]. 

The heat treatment of cream plays a decisive role in the butter-manufacturing process and the eventual quality of the butter. It is important that milk and cream be handled in the gentlest possible way to avoid mechanical damage to the fat, a serious problem in continuous manufacture (Fritz process) of butter (80). Cream is pasteurized or heat treated for the following reasons to destroy pathogenic micro-organisms and reduce the number of bacteria, to deactivate enzymes, to liquify the fat for subsequent control of crystalhzation, and to provide partial elimination of undesirable volatile flavors. 

Double Fractionation. Double fractionation is carried out for the production of palm olein with higher iodine value of above 60 or for the production of palm-midfraction (PMF), which contains a high proportion of oleodipalmitin used for production of palm-based cocoa butter equivalent (60, 61). Usually the first olein obtained is recycled back to the plant for further cooling, crystallization, and filtration. The second stearin otained is termed palmmidfraction. Special and skillful control of the crystallization of both stages is critical in achieving the desired quality of the products. 

Another parameter that influences the overall properties of the bulk emulsion is the physical state of the lipid droplets in an emulsion (17, 19, 28-31). Crystallization of lipid droplets in emulsions can be either beneficial or detrimental to product quality. Margarine and butter, the most common water-in-oil emulsions in the food industry, are prepared by a controlled destabilization of oil-in-water emulsions containing partly crystalline droplets. The stability of dairy cream to mechanical agitation and temperature cycling depends on the nature and extent of crystallization in milk-fat globules. It should be noted that because the density of the phases can change as crystallization occurs, the rate at which milkfat droplets cream can be altered as droplets solidify. Emulsion manufacturers should therefore understand which factors influence the crystallization and melting of emulsified substances, and be aware of the effect that droplet phase transitions can have on the properties of emulsions. 

The sources of dyes used by man include animal, vegetable, and mineral. Sir William Henry Perkins, in 1856, synthesized the first aniline dye. In 1860, a triphenylmethane dye, fuch-sine, was used by the French to color wine. On August 2, 1886, the U.S. Congress authorized the addition of color to butter. On June 6, 1896, Congress approved colorants in cheese, and by 1900 colorants were added to catsup, jellies, cordials, candies, sausage and noodles. However, there were some concerns by the public. For example, chrome yellow, martius yellow and quicksilver Vermillion were added to foods to hide poor quality or to increase weight. There was no control over the purity of colorants used. For example, it has been noted that rejected textile dyes were sometimes added to foods. Use of arsenic acid and mercury in the manufacture of colorants also created some concerns. 

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