THE INFLUENCE OF FROZEN STORAGE ON SOME COMMERCIAL MUSHROOMS

Abstract

The aim of our study was to determine some specific parameters of two mushroom species that  were  frozen  and  stored  under  freezing  conditions  for  six  months.  The  sensorial  variation  of thawed  mushrooms  was  also  analyzed. With  reference  to  macronutrients,  reducing  sugars  and  total protein were determined. We found that Agaricus mushrooms had a larger amount of reducing sugars than Pleurotus and after six months of frozen storage, Agaricus showed a decrease in reducing sugars amount by 2.38% and Pleurotus by 7.69%. The total protein content was higher for Agaricus than for Pleurotus,  and  after  six  months  of  frozen  storage  Agaricus  showed  a diminution  of  5.17%  and Pleurotus  a  diminution  of  8.74%.  A biochemical  analysis  was  made  in  order  to  study peroxidase
enzyme. The initial value of peroxidase was 0.78 abs/g for Agaricus and 0.48 abs/g for Pleurotus. The variation of two micronutrients: niacin and ascorbic acid were also determined. Niacin was found in high amount in both mushroom species and after frozen storage it decreased slightly. Ascorbic acid decreased dramatically at frozen storage. After the first month of storage the ascorbic acid amount in Agaricus decreased by 64.43% and in Pleurotus by 34.56%. After six months of storage, it decreased by 76.73% and by 76.91% respectively. The sensorial analysis showed that the firmness, appearance and taste of Agaricus and Pleurotus were lower after six months of storage.