Effects of blanching time and dehydration condition on moisture and ascorbic acid retention in tender pumpkin (Cucurbita moschata) leaves

A study was conducted to assess retention of moisture and ascorbic acid in tender pumpkin (Cucurbita moschata) leaves subjected to different blanching times and dehydration conditions. Equal portions of the leaves were blanched at 5, 10 and 15 min. A half of each portion was dehydrated under a shade and the other under direct sunlight. All the samples were then analysed for moisture and ascorbic acid contents in comparison with those of the raw-leaf sample. The fresh samples (wet basis) had 79.26±5.08 mg/100 g ascobic acid compared to the processed samples, which ranged from 41.10±2.94 to 73.39±5.87 mg/100 g in the blanched shade-dehydrated sample and 17.61±0.00 to 35.23±5.08 in the sun-dehydrated blanched sample. The results further showed that the samples that were blanched for a shorter time and dehydrated under a shade retained a significantly higher (p<0.05) amount of ascorbic acid compared to those that were blanched longer and dehydrated under direct sunlight. There was no significant difference in moisture content between the shade-dehydrated and sun-dehydrated samples, which were found to be in the ranges of 13.22±0.09 to 14.23±0.27% and 12.45±0.035 to 13.42±0.52%, respectively. It was, therefore, concluded that shorter blanching time and shade-dehydration can retain ascorbic acid in tender C. moschata leaves without compromising moisture content of the product.