Effects of Engineering Properties on the Poppability of Nigerian Popcorn
The effects of some engineering properties on the poppability of three Nigerian popcorn hybrids were investigated. Properties such as moisture, porosity, bulk density, kernel size and ingredient used in popping were found to affect the popping volume of Nigerian popcorn. Popped ratio and popping volume increased with increasing moisture contents and reaching a peak at 14.0% moisture, then declined progressively. Sugar treatments increased popping volume while salt treatment increased popped ratio. Kernel bulk densities ranged from 730 860 kg/m3 and declined linearly with increased moisture contents. Local hybrids (4.43 5.75 mm in diameter) had specific heat capacity, porosity and popping time ranging from 1.84 ± 0.2 1.87 ± 0.2 kJ/kg K, 38.8 ± 0.2 42.9 ± 0.2% and 110 ± 0.1 129.0 ± 0.1 seconds, respectively. Smaller size kernels had the highest popped ratios while medium size kernels had the highest popping volume. The Nigerian popcorn hybrids were rich in carbohydrate (60.7 ± 0.3 64.0 ± 0.4%), protein (8.3 ± 0.3 8.7 ± 0.2%), fat (6.6 ± 0.2 8.8 ± 0.2%) and crude fiber (2.9 ± 0.2 3.9 ± 0.1%). The deep yellow Nigerian popcorn hybrid was rated significantly (P ? 0.05) higher than all the local varieties and foreign type for crispiness, taste, mealiness, flavour/aroma, and overall acceptability characteristics. Generally, Nigerian popcorn hybrid compared favourably with the foreign type for colour and overall acceptability characteristics but were rated significantly (P ? 0.05) higher for crispness.