Effect of processing methods on reduction of α-galactoside content of red gram (Cajanus cajan L.) flour

The effect of processing methods such as defatting following by dry heating and cold soaking on the levels of α-galactosides in two locally grown cultivars of red gram seeds has been investigated. The levels of raffinose, stachyose and verbascose were found to decrease as a result of defatting followed by dry heating and cold soaking, microwave cooking and cooking in 1% turmeric solution. The defatting followed by dry heating was effective as compared to cold soaking, microwave cooking and cooking in 1% turmeric solution. The per cent losses of raffinose, stachyose and verbascose in red gram seeds after defatting followed by dry heating for 1 h at 100°C were 63.21%, 64.65% and 48.91%, respectively. Cold soaking of red gram seeds resulted in a decrease of 48.80% for raffinose, 56.63% for stachyose and 51.08% for verbascose. Microwave cooking the red gram seeds for 15 min resulted in a decrease of 46.73%, 24.81% and 31.12% for raffinose, stachyose and verbascose, respectively. Cooking in 1% turmeric solution for 60 min led to a decrease of 62.27% for raffinose, 61.77% for stachyose and 53.67% for verbascose, respectively.