DETERMINATION OF PROCESSING CONDITIONS FOR GORGON NUT (EURYALE FEROX)

Gorgon nuts are processed for their kernels in expanded form and this is known as makhana in India. Operations involved in the traditional m ethod of processing make it laborious, time consuming and costly. This paper reports an investigation into the effect of five combinations o f operations on recovery of makhana, viz., (1) roasting and popping; ( 2) drying, roasting and popping; (3) drying, tempering, roasting and p opping; (4) first roasting, tempering, second roasting and popping; an d (5) drying, first roasting, tempering, second roasting and popping. The design of the experiments was based on response surface methodolog y and they were conducted using thin-layer drying and a manual roastin g method. The best combination of operations, based on the recovery of grade 1 makhana, was found to be number 5 above, that is, drying, fir st roasting, tempering, second roasting and popping. The data was anal ysed to find the optimum processing conditions, to give 97% grade 1 ma khana. These were found to be a combination of first roasting of dried nut (moisture content 33% d.b.) at 335 degrees C for 3.9 min, temperi ng for 23 h and second roasting at 335 degrees C for 2.8 min. These co nditions reduced the processing time to less than one-half as compared with the traditional method. (C) 1996 Silsoe Research Institute