Effect of ultrasound treatment on dehulling efficiency of blackgram

Present study was conducted to evaluate the effect of Power ultrasound, on dehulling efficiency, dhal yield, dehulling loss and total colour difference of black gram using response surface methodology. Nine treatments were performed with variation in ultrasound power 343-525 W and treatment time 1-3.5 h. It was observed that ultrasound treatment significantly improved the dehulling efficiency and dhal yield of the black gram and reduced the dehulling loss. The optimized treatment condition obtained for optimum dehulling yield (75.71%), dhal yield (74.63%) dehulling loss (12.72%), and total colour difference (5.08) was ultrasound power of 513.39 W and exposure time of 2.12 h. Moreover the blackgram pretreated with ultrasound required lesser cooking time when compared to soaked alone sample. The SEM analysis revealed the significant effect of ultrasound on the blackgram kernel which led to uniform cavitation of the surface of the kernel compared to the soaked sample without ultrasound treatment. In food industry blackgram is preprocessed i.e. soaked and cooked to produce various soups, canned products, batter, snack foods etc. Hence ultrasonic treatment can be applied to improve and facilitate a faster dehulling efficiency, with added advantage of increased soaking rate and a decrease in the cooking time for blackgram.