M.P. Singh, H.S. Sodhi, A. Singh and P.K. Khanna
Department of Microbiology, Punjab Agricultural University, Ludhiana, Department of Processing and Food Engineering, Punjab Agricultural University, Ludhiana-141004, India.
Abstract: White button mushrooms,
Agaricus bisporus (strains U3 and S11) were dried in cabinet at two temperatures (45 and 55?C) and microwave oven at 380W for 30 minutes. Dried mushrooms were subjected to physical (color, texture, rehydration ratio, dehydration ratio), biochemical (carbohydrates, proteins and lipids) and microbiological (total bacterial count) parameters after three months of storage period. In strain U3, carbohydrate content was highest in 0.1% KMS treated mushrooms dried at 45?C, protein ranged between 3.43 to 3.89 g/100 g of fresh mushrooms, lipid content ranged between 0.06 to 0.30 g/100 g of mushrooms and the total bacterial count ranged between 1.48 to 2.07 log cfu/g which was within the permissible limits of dried fruit products while in microwave oven dried mushrooms there was no significant difference in two strains in terms of carbohydrate, protein and lipid contents. Bacterial count was found to be within the permissible limit of dried fruit products (1.85-2.17 log cfu/g). The weight of dried mushrooms remained almost constant throughout the storage period of 3 months. However, cabinet drying was preferred for most of the color and texture index parameters. Springiness was maximum for microwave oven dried mushrooms of S11 strain treated with 0.1% KMS, followed by the unwashed mushrooms. Resilience ranged between 0.23 to 0.33 in all the treatments. Cohesiveness was maximum in unwashed mushrooms of U3 dried at 55?C, followed by cabinet dried mushrooms of S11 strain (55?C) both unwashed and 0.1% KMS treated. Chewiness and gumminess were also maximum for cabinet dried unwashed mushrooms of U3, followed by microwave oven dried 0.1% KMS treated mushrooms.
A. bisporus was most acceptable in cabinet drying for 0.1% KMS treated U3 strain at both 45?C and 55?C while in case of microwave oven drying, total color difference (2.88 for U3 and 2.58 in S11) was minimum and rehydration ratio (1.91 to 3.06) was found to be maximum for U3 strain.
