Quantification of horny and floury endosperm in popcorn and their effects on popping performance in a microwave oven

The amounts of horny and floury endosperm in popcorn kernels, as indicated by their measured areas over median longitudinal sections parallel and perpendicular to the face of the kernels (lateral and sagittal sections, respectively) were measured using a technique combining photography and planimetry. Correlations were sought between these measurements and indicators of popping performance in a microwave oven. The horny endosperm measured over the sagittal section was correlated positively with unpopped kernel ratio. Measurements from the lateral section were found to have better correlation with expansion volume. Expansion volume increased with decreasing area of floury endosperm. The same trend was found relative to the floury/horny endosperm ratio. Since the floury endosperm envelopes the germ, a larger germ area measured over the lateral section indicated a more symmetrical orientation of the floury endosperm within the popcorn kernel. Expansion volume increased with increasing germ area. While the results obtained were for only a limited number of popcorn cultivars and kernels, the data indicated that microwave popping performance is affected by the spatial orientation and proportion of the floury endosperm.