Effects of Irrigation Levels on Biochemical Traits of Popcorn Kernels

Abstract

Popcorn, directly consumed as foodstuff, is among the most popular products. Biochemical quality traits of popcorn may exhibit significant variations based on growing conditions. Number of studies about the irrigation-dependent changes in biochemical traits of popcorn kernels is quite limited. This study was conducted to determine the effects of different irrigation levels (50%, 75%, 100% and 125% of depleted water from the field capacity) on protein characteristics (crude protein and pepsin protein digestibility), starch characteristics (total starch, resistant and non-resistant starch, amylose-amylopectin content), oil and fatty acids and mineral contents of popcorn kernels. Experimental results were assessed through variance and biplot analyses. Irrigation levels had highly significant effects on biochemical traits of popcorn kernels. Irrigations increased kernel protein and starch contents and decreased dietary fiber and amylose contents. Linoleic acid contents increased and oleic acid contents decreased with increasing irrigation levels. The greatest palmitic and stearic acid contents were obtained from I100 treatments. Na and Fe contents increased with increasing irrigation levels. The greatest Mg and Zn contents were obtained from I100 irrigation level and the greatest Ca content was obtained from I75 irrigation level. In present biplots generated for visual assessment of the changes in investigated traits with irrigation levels, oleic acid, amylopectin and dietary fiber contents were placed into the same sector with I50 treatment; Zn, stearic acid, palmitic acid and Mg contents were placed into the same sector with I100 treatment; the other traits were placed into the same sector with I125 treatment. Two principle components (PC1 and PC2) explained 96.55 of total variation indicating significance of investigated traits based on irrigation levels. It was concluded based on present findings that biochemical traits, fatty acid composition and mineral contents of popcorn kernels could be improved through the use of different irrigation levels and irrigation levels should be arranged based on soil conditions to improve quality traits of popcorn kernels.