Effect of Microwave Power and Puffing Time on the Quality of Yam Bean Cracker

Fried crackers have issues with high-fat content, oil absorption, and oxidation during storage. The objective of this research was to study the effect of microwave power and puffing time on the quality of yam bean crackers. The microwave has power settings of 160, 400, and 800 watts, with puffing times for each power setting of 30, 45, and 60 seconds, respectively. The dried semi-product has an initial moisture content of 10 to 12% on a dry basis. The cracker products contained yam bean pulp, accounting for 30 percent of the weight of the cassava starch. The results showed that increasing microwave power and puffing time resulted in a loss of lightness (L*) and an increase in redness (a*), with no significant difference in yellowness (b*) between different microwave powers. Increasing power level and puffing time affected the physical characteristics of the yam bean crackers, resulting in darker-coloured crackers. The expansion ratio ranged from 2.10±0.23 to 5.10±0.30 times the original size of the raw yam bean crackers, with the highest expansion ratio of 5.10±0.30 attained at 800 watts and a puffing duration of 60 seconds. Moisture content and water activity of yam bean crackers decreased with increasing puffing time and microwave power. Yam bean crackers puffed at 160 watts for 30 seconds had the lowest hardness and fracturability values, at 9.23±1.98 N and 5.50±1.66 N, respectively. The yam bean crackers puffed by microwave had a fat content ranging from 0.026 ± 0.054 to 0.201 ± 0.013%, while those puffed by frying had a fat content of 23.33 ± 1.36%.