Assessment of carotenoid degradation of grits from orange corn packaged in high barrier thermosealed pouches

Genetically improved maize varieties with high carotenoid levels and dark orange color have been developed to increase dietary consumption of macular carotenoids. However, postharvest and food processing conditions can cause isomerization and oxidation of carotenoids, reducing their potential impact on consumers' health. The purpose of this study was to assess the effectiveness of high barrier pouches in reducing carotenoid losses during the storage of dry-milled corn products. Orange corn grits were packaged in paper pouch bags, and three types of low-oxygen and low-moisture permeable (LOMP) pouches. Grits were packaged in each type of LOMP pouch with (LOMP-oxy) and without (LOMP-noxy) an oxygen scavenger. For six months, all pouches were stored at semi-controlled environmental conditions (22.5 ± 1.3°C, 32 ± 18% RH). After the storage period, orange corn grits stored in paper pouch bags lost 55% of total xanthophylls, whereas grits packaged in LOMP pouches only lost 8% of total xanthophylls. Orange Corn grits packaged in LOMP-oxy pouches had slightly higher carotenoid content than in LOMP-noxy pouches. Relative humidity fluctuation in the storeroom could have caused fluctuation in moisture content in the orange corn grits packaged in paper pouches, which may affect the rate of carotenoid degradation in the orange corn grits. Therefore, an effective control of the moisture content of the packaged dry-milled product and effective control of the temperature of pouches during storage conditions is essential to maximize carotenoid retention during the storage of dry-milled high carotenoid orange corn grits.