Storage foodstuffs

Organic chemicals Most organic liquids, other than the stronger acids, only attack zinc slowly. Zinc is, therefore, suitable for storage tanks for liquid hydrocarbons such as motor fuels, for phenols and for trichlorethy-lene degreasers. Zinc or zinc-coated vessels are not recommended for use in contact with acid foodstuffs, but are regularly used for dry foods. Zinc in small quantities is beneficial in the human diet. 

Containers of foodstuffs should not be unduly stained or etched and must not be perforated or allowed to become distended by pressure due to evolution of hydrogen, and the contents must not suffer unacceptable changes of colour or flavour. Long storage periods, e.g. two years, may be required. 

Sources of filth and contamination are diverse and numerous, each contributing its individual weight to the final summation and measurement. Rats, mice, and flies are themselves filthy in habit and also indicative of filthy conditions. Any evidence of their presence in or about a food product constitutes a heavy measure of filth. Insects which infest foodstuffs, or which live in or close to a food processing plant, create and leave evidence of their presence and reflect field, factory, and storage conditions. 

The way we select components to make up the basis is similar to the way a restaurant chef might decide what foodstuffs to buy. The chef needs to be able to prepare each item on the menu from a pantry of ingredients. For various reasons (to simplify ordering, account for limited storage, minimize costs, allow the menu to be changed from day to day, and keep the ingredients fresh), the chef keeps only the minimum number of ingredients on hand. Therefore, the pantry contains... 

There are certain legal requirements and standards which cover the manufacture, processing, storage and quality of some foodstuffs.10 In general, these requirements do not cover composition in any detail except in the case of milk products. 

Grain and foodstuffs are constantly attacked by weevils. Fumigation with carbon bisulfide, methyl bromide, and Chlorosol fumigant (a carbon tetrachloride-ethylene dibromide mixture) provides effective control where storage areas are built to handle these materials. Such storage equipment is limited, so there is need for an insecticide with low mammalian toxicity in order to achieve continuous protection by direct application. 

Responses to activation of the parasympathetic system. Parasympathetic nerves regulate processes connected with energy assimilation (food intake, digestion, absorption) and storage. These processes operate when the body is at rest, allowing a decreased tidal volume (increased bronchomotor tone) and decreased cardiac activity. Secretion of saliva and intestinal fluids promotes the digestion of foodstuffs transport of intestinal contents is speeded up because of enhanced peristaltic activity and lowered tone of sphincteric muscles. To empty the urinary bladder (micturition), wall tension is increased by detrusor activation with a concurrent relaxation of sphincter tonus. 

Figure 3.3 shows a typical freezing curve which results when heat is removed at a continuous rate from foodstuffs and the temperature decreases. The curve has three zones first, the removal of sensible heat from the food between the initial temperature and the freezing temperature second, the removal of the latent heat of fusion leading to a change of state and the formation of ice crystals and third, further sensible heat removal down to the required storage temperature. A number of features of the freezing curve require explanation. Whilst... 

Flavouring adjuvants are foodstuffs, food additives, other food ingredients or processing aids which are necessary to ensure the safety and quality of flavourings and to facilitate the production, storage and intended use of flavourings. 

Racemisation during processing or storage of foodstuffs, if structural features of chiral compounds are sensitive... 

Lipids are important macromolecules in food. A food product s nutritional value as well as its flavor, texture, general palatability, and storage stability are affected by lipids. Therefore, both physical and chemical criteria are needed by the food processor to assess or monitor the quality of fats and oils. The basic characteristics of certain food items, such as edible oils, will be dependent upon their source. Variation from these norms can be ascertained before the oils are used in other foodstuffs. In effect, knowledge of the quality of the lipid before shipping the product to market, or use in fabricated foods, is of economic importance to the processor. 

The time to reach a certain PV may be used as an index of oxidative stability for food lipids. The effects of antioxidants and food processing on fats are often monitored in this way. Thus, a longer time period to reach a certain PV is generally indicative of a better antioxidant activity for the additive under examination. However, a low PV represents either early or advanced oxidation the breakdown of peroxides to secondary oxidation products will result in a decrease in PVs during the storage period. For determination in foodstuff, a major disadvantage to the classical iodometric PV assay is that a 5-g test portion is required it is sometimes difficult to obtain sufficient quantities of lipid from foods low in fat. Despite its drawbacks, PV determination is one of the most common tests employed to monitor lipid oxidation. 

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