Popping Properties of Corn Grains of Two Different Varieties at Different Moistures

In this study, the effects of moisture content and corn variety on the physicochemical properties of popcorn were investigated and modeled using response surface methodology. Each of the two corn varieties (Hybrid corn KSC ۶۰۰ PC and American) was prepared with a range of moisture (six moisture levels ranging from ۱۰ to ۲۰%) and popped by a hot air popper. Variety and moisture content affected the density, air bubble diameter as determined from electron micrographs, textural hardness and color parameters. The lowest densities for American and hybrid corns were obtained at moisture contents of ۱۴ and ۱۸%, respectively. As water content deviated from the optimum levels the popcorn density significantly decreased. For both corn varieties, with increasing water content, the lightness of the samples increased while b (yellowness-blueness) values decreased. For American popcorn no significant impact of the moisture content on the hardness was observed, however in hybrid corn, hardness of popcorns significantly decreased with increasing water content, and the lowest density and hardness were observed at moisture content of ۱۸%. Experimental models are presented for the prediction of density, color parameters, air bubble diameter and hardness of popcorns at different moisture contents for American and hybrid corns.