Storage stability of potato variety Lady Rosetta under comparative temperature regimes

Abstract

Potatoes are usually stored under low temperatures for sprout prevention and to ensure their continuous supply. Low temperature sweetening in potato is the major temperature related disorder being faced by the growers and is also known to be associated with variety specific storage temperature. The present study aimed at identifying the appropriate storage temperature for the premium potato variety Lady Rosetta with special reference to the changes in its quality attributes, that is weight loss, total sugars, starch, ascorbic acids, total phenolic contents, radical scavenging activity, enzymatic activities and potato chip color. The selected potato variety was stored under different temperature (5, 15 and 25oC) regimes to identify appropriate storage temperature. Our results showed significant variations in the tested quality attributes in response to different storage temperatures. Storage at 5oC maintained tuber dormancy up to 126 days, however, found associated with increased sugar accumulation (2.32 g/100 g), rapid starch depletion (13.25 g/100 g) and poor post processing performance (L-value, 52.00). In contrast, potato storage at 15oC retained lower sugar contents (1.33 g/100g) and superior chip color (L-value, 59.33) till the end of storage. However, they were found associated with the increased polyphenol oxidase (38.47 U/g f.w) and peroxidase (15.25 U/100 g f.w) activities as compare to those potatoes stored at 5oC during the same storage period. Storage life of potato tubers at 25oC was significantly reduced due to dormancy break on 84th day and subsequent starch degradation (15.29 g/100 g) increased sugar accumulation (1.32 g/100 g) and increased polyphenol oxidase (79.89 U/g f.w) and peroxidase activities (40.69 U/100 g f.w). Our results showed that potato variety Lady Rosetta is cold sensitive and requires specific temperature for prolonged storage and best post processing performance.