Oxidation Changes Affecting Odor and Flavor of Freeze-Dried Meats

摘要

Samples of commercially prepared freeze-dried cooked and raw beef, raw pork, raw fish and shrimp have been examined in a Warburg apparatus and their oxygen absorption characteristics have been measured. The moisture content, glyceride fat and bound lipids have been determined also. The oxidation of these materials appears to be complete. It is a two-step process involving first oxidation of the bound lipids, followed, after a variable period of lower oxygen absorption, by oxidation of the glyceride fat. The rates of oxidation during these two steps and the length of the period of low oxygen absorption between them are determined by the nature and history of the sample. In these commercially prepared samples of unknown history no correlation could be established between absorption of oxygen and type of product, moisture content, bound lipids or glyceride fat content. Large variations in the over-all rates of oxygen absorption were observed between different lots of the same type of material, between different containers of the same lot and even between different portions of product taken from the same container. The oxidation of freeze-dried raw tissue appears to be due to autoxidation rather than to enzymatic action. (Author)