Freeze‐dried turkey muscle I.—Changes in nitrogenous compounds and lipids of dehydrated turkey during storage

Abstract

Changes in proteins and lipids were followed during the storage of freeze-dried turkey breast muscle in air and in nitrogen. Oxidation of sulphydryl groups accounted for part of the oxygen uptake of air-stored samples, and was accompanied by a decrease in soluble nitrogen greater than in controls stored in nitrogen. The major deteriorative process at low moisture content was a type of 'lipid' browning reaction which was dependent on oxygen and caused discoloration and objectionable odours. Autoxidation of lipids catalysed by haem pigments and resulting in rancid flavours was not a major deteriorative process in freeze-dried turkey muscle. Lipid hydrolysis occurred at water contents of 8.2 and 5.4 % but not at 0.8 %.

A comparison of the deterioration in quality of freeze dried flesh of halibut (Hippoglossus stenolepis) during storage in air and nitrogen at low water activities

“…Tarr (1950) reported that minced flesh of fish heated with and without added arabinose browned to about the same extent whether heat processed in vacuo or in the presence of air. Fishwick and Zmarlicki (1970) found that the browning occurring in freeze dried turkey muscle during storage was slightly more marked in air than in nitrogen, and explained the browning as being due to a Maillard-type reaction between amino groups in PE and oxidation products from lipid constituents of the muscle. In contrast with these, Kline et a1 (1951), studying the role ofglucose in the deterioration ofdried whole egg powder during storage, showed that the browning reaction involving glucose and cephalin proceeded as extensively in the absence of oxygen as in its presence.…”

Storage stability of a high protein food beverage powder prepared from the Nigerian ‘red skin’ groundnut (Arachis hypogaea) protein concentrates

“…The extent of non-enzymic browning of samples was determined by the method of Fishwick and Zmarlicki (1970).…”