Effects of storage conditions on phytochemical and stability of purple corn cob extract powder

Abstract Recently, purple corn cob has been gaining popularity for a dietary supplement and natural colorant. However, phytochemicals in waxy purple corn cob (WPC) are likely degraded during storage; thus, the microencapsulation by spray drying was used for lengthening those compounds. This work focused on the phenolic and anthocyanin content and antioxidant activity (AOA) in WPC extract microcapsules by hydroxypropyl beta-cyclodextrin (HPβCD) during storage at 4 and 30 °C for 60 days. The results revealed that only peonodin-3-glucoside at 30 °C was found as a higher decrease than 4 °C. Pelagonidin-3-glucoside and AOA were found more stable at both storage temperatures; however, the increase of protocatechuic acid and hydroxybenzoic acid were observed during storage, especially at 30 °C. Consequently, the storage under 4 °C was appropriate to maintain the phytochemical content in WPC extract powder.