Establishing the optimal period of storage for frozen Agaricus bisporus, depending on the preliminary processing applied

In the present paper optimal periods of frozen Agaricus bisporus storage were established. The freezing procedure was applied to raw and blanched mushrooms as well as to mushrooms soaked and blanched either in water or aquatic solutions of citric, L-ascorbic, and lactic acids. During 12 months of storage, sensory evaluation, instrumental colour measurements, and chemical analyses were carried out every 4 months. A maximum storage period for the unblanched product was 4 months, while for the remaining frozen products was 8 months. Preliminary processing, freezing, and 8-month frozen storage resulted in a decrease in colour intensity, a loss of yellow colour and increase in red colour when compared to fresh mushrooms. The mushrooms also contained significantly smaller amounts of vitamins B-2 and C, while total acidity was higher. Of the various technological treatments applied in freezing, preliminary processing had the greatest effect on the final quality of mushroom products. (C) 2007 Elsevier Ltd and IIR. All rights reserved.