Non-enzymatic antioxidants in potato (Solanum tuberosum L.): Determination of polyphenol and flavonoid contents in different tissues

Abstract

Potato is the fourth agronomically important food crop. Various biotic and abiotic stresses are known to affect plant growth and development, crop productivity and the quality of produce during storage. Antioxidants are the secondary metabolite of plants that help to cope up with stress conditions by scavenging the reactive oxygen species (ROS). Potato is one of the polynutrient crops having high amount of antioxidants, vitamins, starch and proteins which are beneficial for human health. In mature tuber, polyphenols, flavonoids and Vitamin C are present in considerable amount. Extent of assismilation of these vital nutrients differ in the the different cultivars varying in the genetic makeup. This study focused on the estimation and comparison of phenolics and flavonoids. Antioxidant capacity was also measured in the tubers and other tissues of different potato cultivars by ferric reducing antioxidant potential (FRAP). The phenolic content was highest in mature leaf tissue of cultivar Kufri Chipsona-2 (14241.3μg GAE. g-1 FW) and was lowest in the growing tubers of Kufri Jyoti (569.83μg GAE. g-1 FW). The flavonoid content was also found to be highest in mature leaf of Kufri Chipsona-2 (31000 μg quercitin eq. g-1 FW) and was lowest in Kufri Chandramukhi (616.6 μg quercitin eq. g-1 FW ). The antioxidant capacity was observed to be highest in leaf Kufri Chipsona-2 (22685.2 μg ascorbate eq. g-1 FW) and was lowest in mature tissue of Kufri Jyoti (17.6 μg ascorbate eq. g-1 FW ). The total phenolic content was observed to be increase from the 0 day of storage (DOS) to the 60 DOS. The highest increase was observed in the case of storage at room temperature. Same trend was followed in the case of flavanoid content. Polyphenolic extract of Kufri Jyoti was found to have highest cytotoxic effect on the cells.