Prepare Foods Separately

Prepare foods on clean, separate surfaces to minimize the spread of germs. Utilize clean cutting boards as safe surfaces for preparing foods. If possible, designate individual cutting boards for 

Store the cutting board in a dry place and away from raw foods to avoid contamination. 

Plastic cutting boards are often available in different colors. Each color is designed for use with a specific food type. Adopting a color-coding system both increases easy employee training and reduces cross contamination. 

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Facilities for rest and eating meals must be provided so that workers may sit down during break times in areas where they do not need to wear personal protective equipment. It should be possible for workers to make hot drinks and prepare food. Separate rooms should be provided for smokers and non-smokers. Facilities should also be provided for pregnant women and nursing mothers to rest. Arrangements must be in place to ensure that food is not contaminated by hazardous substances. Many fires have been caused by placing clothes on an electric heater. Damp clothes should not be positioned in contact with the heater and there should be adequate ventilation around the heater. If possible, the heater should be fitted with a high temperature cut-out device. 

Application of rotating coiled columns has become attractive for preparative-scale separations of various substances from different samples (natural products, food and environmental samples) due to advantages over traditional liquid-liquid extraction methods and other chromatographic techniques. The studies mainly made during the last fifteen years have shown that using rotating coiled columns is also promising for analytical chemistry, particularly for the extraction, separation and pre-concentration of substances to be determined (analytes) before their on-line or off-line analysis by different determination techniques. 

The reader should find it helpful that the most recent published articles of the last few years are discussed. As in the first edition, special attention is paid to reversed-phase separations without neglecting other HPLC techniques. Specialists describe in detail, step by step, sample preparation and separation conditions. The applications to food chemistry are specific and practical. The book will once again find a large audience in the fields of chromatography, analytical chemistry, and, especially, food chemistry and food technology. 

Glassware or utensils that have been used for laboratory operations should never be used to prepare food or beverages. Laboratory refrigerators, ice chests, and cold rooms should not be used for food storage separate equipment should be dedicated and prominently labeled for that use. 

Keep fecal material away from food preparation areas (separate kitchen and toilet areas). 

In acid environments proteins may form protein-phosphate complexes of low solubility. The metaphosphates, which are less hydrated than the ortophosphates, form complexes that are less soluble than those with ortophosphates. This has been utilized for the modification of functional properties of protein concentrates and preparations, for separation of proteins in different food processing operations, and in treatment of protein-containing food plant effluents. 

Mixtures used in preparing food, such as Italian salad dressing, are often a mixture of oil, vinegar, and spices. The dressing will separate into three layers if you let it sit long enough. 

The accuracy of the total diet study depends on two fundamental data components (i) the quantity of each prepared food consumed by individuals, usually obtained in a separate study by the dietary assessment method and (ii) the background concentration of analytes of interest in the foods as ready for consumption. In order not to overestimate dietary intakes, the analytical methods used to measure analytes of interest should have appropriately low detection limits. 

Formation, factors affecting concentrations, legal limits and occurrence of polycyclic aromatic hydrocarbons in smoked meat products and smoke flavor additives are briefly reviewed by Simko. The most widely employed techniques such as thin-layer chromatography (TLC), gas chromatography (GC), and high-performance liquid chromatography (HPLC) are evaluated. Moreover, sample preparation, pre-separation procedures, separation and detection systems being used for the determination have been evaluated with emphasis on the latest developments in applied food analysis and... 

Usually, for the production of small quantities of high-priced chemicals, such as in th manufacture of pharmaceuticals, foods, electronic materials, and specialty chemicals, batch fed-batch, and batch-product removal processes are preferred. This is often the case in bio processing, for example, when drugs are synthesized in a series of chemical reactions, eacl having small yields, and requiring difficult separations to recover small amounts of product This is also the case for banquet facilities in hotels, which prepare foods in batches, and fo many unit operations in the manufacture of semiconductors. As discussed in Chapters 3 am 4, these processes usually involve a recipe, that is, a sequence of tasks, to be carried out h various items of equipment. In the latter sections of this chapter, variations on batch proces schedules are discussed, as well as methods for optimizing the schedules. 

The introduction of improved sample preparation and separation techniques has made IR a popular identification tool in food chemistry (Eskamani, 1975). One of the most useful applications of IR spectroscopy in food processing is the identification of cis trans unsaturation. This subject has been partly dealt with under the heading Fatty acids (Section 9.1.4a). In the food industry, cis trans determination may be helpful in the detection of fat adulteration. Bartlett and Chapman (1961) used IR spectroscopy to determine hydrogenated (saturated) fats in butter. Butter... 

A serious analytical problem is the analysis of preservatives used in food preparation. Usually, separation is carried out on chemically modified silica, utilizing suppressed conductivity detection and UV/Vis detection for preservatives containing chromophores. ... 

Some reports on dietary Pb measure lead content in diet distinct from any Pb intakes in water used for preparation of beverages or food. This chapter discusses drinking water Pb separately, and attempts to address the additive nature of water Pb intakes from beverages and prepared foods when such data can be separately identified. 

Recently, Lichtenthaler (61), Lefevere et ai. (73), and Lambert and De Leenheer (74), brought excellent overviews of TLC separations of vitamin Ki, prenylquinones, menaquinones and menadiones. TLC applications were described for the analysis of vitamin Kj or menaquinones in infant formulas, pharmaceutical preparations, foods, plants, bacteria, and tissue samples (6,73,74). Following the nature of the sorbents used for these separations we will overview the most recent literature (from 1980 on) on TLC on vitamin K] and related compounds. 

Qualitative analysis requires that mixtures be separated into their components, which can be compounds or simple elements. Compounds, in turn, may be further separated into their constituent elements. In geology and the mining industry, for example, rocks, minerals, or soils are analyzed to find out what metals (such as copper, nickel, or titanium) or other elements (such as chlorine or phosphorus) are present. Municipal water faciUties have to identify and remove any contaminants (such as arsenic, lead, or nitrates) that might be present in surface or groundwater supplies before the water enters a city s water supply system. The food industry analyzes its products so that the labels can inform consumers of what kinds of fats, proteins, carbohydrates, vitamins, minerals, and fiber are present in canned, packaged, and prepared foods. The pharmaceutical industry analyzes samples of all of its products in the attempt to ensure against contamination. 

Analytical Techniques. Sorbic acid and potassium sorbate are assayed titrimetricaHy (51). The quantitative analysis of sorbic acid in food or beverages, which may require solvent extraction or steam distillation (52,53), employs various techniques. The two classical methods are both spectrophotometric (54—56). In the ultraviolet method, the prepared sample is acidified and the sorbic acid is measured at 250 260 nm. In the colorimetric method, the sorbic acid in the prepared sample is oxidized and then reacts with thiobarbituric acid the complex is measured at - 530 nm. Chromatographic techniques are also used for the analysis of sorbic acid. High pressure Hquid chromatography with ultraviolet detection is used to separate and quantify sorbic acid from other ultraviolet-absorbing species (57—59). Sorbic acid in food extracts is deterrnined by gas chromatography with flame ionization detection (60—62). 

Tofu. Tofu is prepared by adding a coagulant such as calcium sulfate to soymilk to precipitate the protein and oil into a gelatinous curd. The curd is then separated from the soluble portion (whey), pressed, and washed to yield a market-ready product. Tofu, a traditional food in Japan (90), was populari2ed in the United States in the late 1970s and is available in many U.S. supermarkets. 

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