Preservation, additives, chemical

Preservatives may inelude disinfeetant and antiseptic chemicals together with eertain compounds used almost exclusively as preservatives. They are added to mar industrial, including pharmaceutical, products which may, by their nature, support the growth of bacteria and moulds causing spoilage of the product and possibly infection of the user. In the field of pharmaceutical preservation, addition of an inhibitory substance to a multidose injection (Chapter 21) or the prevention of growth in aqueous suspensions ofdmgs intended for oral administration (Chapter 18) are prime examples. 

Uses Chemical research organic synthesis. According to HSDB (1005), U.S. has discontinued manufacturing of chlorinated naphthalenes since 1977. Chlorinated naphthalenes were formerly used as a wood preservative, additives in cutting oils, and as an additive in fireproofing and waterproofing cable insulation. 

Sampling and characterization. 10 ml samples, including liquid and solid phases, were withdrawn periodically from the autoclave during the crystallization. The slurries were collected in 70 ml of cold deionized water. The solid fraction was recovered by filtration and washed first with 250 ml of water. The clear solution, containing the diluted mother liquor, was preserved for chemical analysis. After additional washing (up to a pH of 9), the solid was dried at 70°C in air. 

Chemical Additives. Chemical additives may be used to extend the shelf life of some minimally processed foods, but they must not affect flavor or be perceived to impair product safety. When chemical additives are used they should be used as an aid to preservation, not as the primary mode of preservation. 

Justification for the preparation of any review for this book series is that it deals with some aspect of the many real problems arising from the presence of any foreign chemical in our surroundings. Thus, manuscripts may encompass case studies from any country. Added plant or animal pest-control chemicals or their metabolites that may persist into food and animal feeds are within this scope. Food additives (substances deliberately added to foods for flavor, odor, appearance, and preservation, as well as those inadvertently added during manufacture, packing, distribution, and storage) are also considered suitable review material. Additionally, chemical contamination in any manner of air, water, soil, or plant or animal life is within these objectives and their purview. 

Ecological stabilization of polyethylenes is a proper solution for the elimination of any health risks of users. The addition of vitamin A [04J2, 06S1], rosemary [09Z1], and capsaicin [lOZl] has the effect of antioxidation in the preservation of chemical state of polymers, whose activities were demonstrated by chemiluminescence. Comparatively, the amplitude of stability improvement induced by vitamins was found to be on the same level as phenols [02Z1, 03D1]. 

Pasteurized hquid egg products are generally also preserved by chemical means, e. g., addition of sorbic or benzoic acid. 

The chemical potential pi, has been generalized to the electrochemical potential Hj since we will be dealing with phases whose charge may be varied. The problem that now arises is that one desires to deal with individual ionic species and that these are not independently variable. In the present treatment, the difficulty is handled by regarding the electrons of the metallic phase as the dependent component whose amount varies with the addition or removal of charged components in such a way that electroneutrality is preserved. One then writes, for the ith charged species. 

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