Vitamins profile as an indicator of the quality of frozen Agaricus bisporus mushrooms

Abstract Fresh mushrooms have been known as a functional food, especially as a good source of vitamins from B-group. The work determined the effect of pre-treatment (blanching, vacuum soaking), method of freezing (air-blast and cryogenic), temperature (−20 °C, −30 °C) and period (0, 6, 12 months) of frozen storage on the vitamins profile in white A. bisporus . Niacin and riboflavin were the most abundant vitamins in all mushroom products (154–362 mg; 1.57–5.06 mg/100 g dm, respectively). The greatest influence on the vitamins profile was pre-treatment. The highest levels of vitamin B 3 and L-ascorbic acid were found in blanched mushrooms, vitamin B 6 in vacuum soaked, α-tocopherol and vitamin B 1 in unblanched. The greatest losses occurred between the 6th and 12th month of storage, and therefore mushrooms should not be stored for longer than 6 months. After storage the greatest losses were found in vitamin B 1 , L-ascorbic acid and α-tocopherol. A. bisporus mushrooms contain small amounts of L-ascorbic acid and α-tocopherol, therefore the level of vitamin B 1 may be regarded as a quality indicator. The freezing method affected only vitamin B 3 , with levels higher after cryogenic than air-blast freezing. The storage temperature generally had no effect on vitamin levels.