Cold Induced Sweetening and Antioxidant Activity of Potato Genotypes During Cold Storage

Abstract

Cold-induced sweetening (CIS) of potatoes is an industrial problem. Tuber antioxidant activity during cold storage may relate to CIS-resistance and quality storage but not well studied. CIS and antioxidant activity were measured in tubers of eleven potato genotypes during cold storage of four months. During first month, tubers were found to lose starch and produce CIS but improve starch later between 1-2 months. Loss of starch during first month was seen less and gain of starch between 1-2 months was seen high in CIS-resistant genotypes versus CIS-susceptible genotypes. Acid invertase activity increased during first month but this increase was related to CIS in CIS-susceptible genotypes as CIS-resistant genotypes also increased acid invertase. Redox state of ascorbate decreased and H₂O₂ increased during first month of storage and this change was related to CIS-susceptibility. Catalase and peroxidase levels at one month of storage related to CIS-resistance. During further storage, redox state of ascorbate decreased, H₂O₂/toxicity increased but tuber quality related to maintained antioxidant levels specially in the form of catalase. Results concluded that genotype with high tuber antioxidant activity may be beneficial for both CIS-resistance and quality storage.

Keywords:
ascorbate; catalase; invertase; malondialdehyde; peroxidase; protein carbonyls; invertase, Solanum tuberosum.

HIGHLIGHTS

• Starch metabolism during cold exposure relates to cold-induced sweetening (CIS).

• Tuber antioxidant activity during cold exposure relates to CIS-resistance.

• Tuber antioxidant activity during long storage relates to quality storage.

• Catalase is an important antioxidant enzyme for quality storage.