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OXYGEN EFFECT ON THE DEGRADATION OF ASCORBIC ACID IN A DEHYDRATED FOOD SYSTEM
Author(s) -
DENNISON D.B.,
KIRK J.R.
Publication year - 1978
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1978.tb02365.x
Subject(s) - ascorbic acid , oxygen , chemistry , moisture , dissolution , water activity , degradation (telecommunications) , activation energy , kinetics , water content , inorganic chemistry , food science , organic chemistry , computer science , engineering , physics , quantum mechanics , geotechnical engineering , telecommunications
The stability of reduced and total ascorbic acid in a low moisture dehydrated model food system was determined as a function of water activity, moisture content, oxygen and temperature. Ascorbic acid degradation rates were satisfactorily described by first‐order kinetics and were dependent on water activity and temperature. Rate constants obtained for the model system stored with a large excess of oxygen (303 cans) were compared with those reported previously for the case of limited gaseous oxygen (TDT cans). At all conditions of temperature and water activity the degradation of ascorbic acid was greater for the condition of excess oxygen (303 cans). This effect is interpreted as reflecting the consumption of oxygen dissolved in the moisture of the product and the continuous dissolution of excess molecular oxygen present in the 303 cans. The significance of this oxygen effect is further manifested by the change in activation energies for RAA and TAA destruction at 0.1 a w from 7.0 kcal/mole limited oxygen to 10.7 kcal/ mole in excess oxygen conditions. These data suggest that dissolved and gaseous oxygen are primary factors in the storage stability of ascorbic acid in dehydrated food systems.