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Free radicals in lyophilised food materials
Author(s) -
Munday K. A.,
Edwards M. L.,
Kerkut G. A.
Publication year - 1962
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740130902
Subject(s) - radical , chemistry , food science , free water , lipid oxidation , antioxidant , biochemistry , environmental engineering , engineering
Food materials dried by the accelerated freeze drying (A.F.D.) process have been tested for free radicals and the concentration and properties of the free radicals compared with those in fresh heart muscle. In fresh muscle at 77° K, the free‐radical concentration was between 2.0 and 5.2 × 10 15 per g. of tissue; A.F.D. minced beef 8.28 × 10 15 ; A.F.D. herring 6.47 × 10 14 ; A.F.D. maize 1.78 × 10 14 ; A.F.D. rat cake 1.30 × 10 14 . No free radicals were detected in either the minced beef or maize before A.F.D. processing; nor could free radicals be detected in a quick‐frozen (−15° c) sample of minced beef stored some weeks. There is a higher concentration of free radicals when the lipid content of the food is high. The free‐radical concentration increased in A.F.D. food in the presence of air and oxygen and also when it was heated to 100° c. The addition of water to A.F.D. food reduced the free‐radical concentration to undetectable levels.