Antioxidant activity of tuber apical and basal ends of potato during cold storage

Abstract

ABSTRACT Little is known about relation between cold-induced sweetening (CIS) resistance and antioxidant activity of Irish potato (Solanum tuberosum L) tubers during cold storage. Tuber ends produce more CIS than the rest of the tuber, and ends vary for dry matter and carbohydrate metabolism during storage but have not been sufficiently studied for antioxidants. Antioxidant activity of basal and apical tuber ends of potato genotypes, which varied in processing quality, was studied in 4°C storage up to 150 d after harvest. During 0–20 d period, there was a decrease of some antioxidants, but levels at 20 d remained higher in processing genotypes while H2O2 and malondialdehyde levels were higher in non-processing genotypes. During 20–120 d, non-enzymatic antioxidants increased, but decreased from 120 to 150 d. Among enzymatic antioxidants, catalase increased while other enzymatic antioxidants decreased to 120 d and then remained stable to 150 d. The H2O2/nitric oxide, malondialdehyde, and protein carbonyls increased during storage. Antioxidant levels were higher in apical than basal ends during storage. Antioxidant activity relates to H2O2/nitric oxide signals and tuber quality during storage and relates to processing quality of the genotype. The antioxidant activity of tubers during storage may be regulated by H2O2/nitric oxide signals and is important for CIS-resistance and tuber quality. Tuber apical end may have higher antioxidant activity than basal end during storage. Antioxidant activity of the tuber during cold storage can be used as a marker to screen potato genotypes for CIS-resistance and quality storage.