Chemical components of kernel quality in sh2 sweet corn genotypes (Zea mays L. saccharata Sturt.) as affected by harvest date

Abstract

Kernel water (KW) and total soluble sugars (TSS) are major components of sweet corn taste, while total carotenoids (TC), total phenols (TP) and antioxidant activity (AA) contribute to its health benefits. Main objective was to determine the effect of genotype, harvest date and year on chemical components of kernel quality in shrunken (sh2) sweet corn. Nine sh2 genotypes were harvested at 3-day intervals from 20 to 32 days after pollination (DAP) over two years. Growing season significantly affected TC and TP only. Significant differences among genotypes were found for KW (75.3 - 77.4%), TTS (282.4 - 343.2 mg/g), TC (9.3 - 15.7 µg/g), TP (243.6 - 289.4 mg GEA/100 g) and AA (74.6 - 83.6 % inhibition). Effect of harvest date and genotype by harvest date interaction was significant for all traits. Compared to the 20 DAP, KW and TSS decreased, while TC, TP and AA tended to increase with later harvest dates. Based on KW, genotypes OS 5Esh and Overland extended harvest window up to 29 DAP. In contrast, optimum harvest window for genotype OS 244sh finished at 20 DAP. Extended harvest window for genotype Overland resulted in significant increase of TC (62.8%), TP (12.1%) and AA (12.4%).

Keywords

• sweet corn
• soluble sugars
• carotenoids
• phenols
• antioxidant activity