John C. Ayres

Microbiological Implications in the Handling, Slaughtering, and Dressing of Meat Animals

Publisher Summary Whether the load of microorganisms associated with the living animal contributes a significant share of the contamination occurring in and on the carcass depends not only upon the methods of handling that the meat receives but also on the interrelation between the defensive mechanisms of the animal and the enormous microbial populations that gain access to the animal. This chapter discusses the bacteriological implications in four separate categories. The first of these deals with the animals defensive mechanisms; the second considers the antemortem microbiological problems that are involved in the live animal. The third describes the contamination introduced during the death agonies, while the last relates the contamination of the animal after death. The chapter discusses the significance of the several sources of microbiological contamination outlined above. The discussion is directed largely to the microbiology of the intact carcass and of fresh wholesale cuts. Only those avenues of infection and contamination that treat with normal animals and carcasses and cuts receiving handling procedures in accordance with commonly accepted sanitary practices have been considered.

The purity of aflatoxin G1 and use of antioxidant and chelating agent on the purification of the toxin by thin-layer chromatography.

Abstract During purification of aflatoxin G 1 by TLC procedures, about ten additional modified toxins are separated as fluorescent bands. G 2 produces only one or two modified toxin bands under similar conditions. Use of BHT in developing and eluting solvents and EDTA in preparation of TLC plates and operation of the entire procedure in a dark room effectively prevent such undesirable changes of the toxin. Crude G 1 is usually yellow in visible light and emits a green fluorescence by ultraviolet irradiation. Upon further purifications it becomes colorless in visible light and a light blue fluorescent compound under ultraviolet light. During purification, the ratio of absorbance at 360 mμ or 366 mμ to that at 264 mμ changes from about 2 to 0.5. The high absorbance in the region of 360 mμ for the crude toxin is apparently due to an unknown yellow impurity. A similar change of the ratio is also observed during purification of G 2 .