Effects of different drying methods of cauliflower waste on drying time, colour retention and glucoamylase production by Aspergillus niger NCIM 1054

The non-edible portion of cauliflower (cauliflower waste) was subjected to drying by different methods. While conventional sun drying (CSD) took 1920 min to dry the waste, microwave drying (MWD) took only a few minutes. As against the L value of 41.27 in samples with fresh cauliflower waste, the sample dried at 50 °C showed L value of 38.16, and those dried at 200 °C indicated an L value of 16.61. Highest glucoamylase (GA) activity was found in the samples containing waste dried at 50 °C and the least in samples dried at 200 °C. However, in samples containing waste dried at 70 °C, using combinations, such as MWD and CSD, MWD and drying at 50 °C, CSD showed comparable GA activity. The results indicate that the sample dried using the combination of MWD and drying at 50 °C resulted in shorter drying period, good colour retention in the final product, and its incorporation resulted in significant enzyme production.

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