Sains Malaysiana, 2016;45:677-688.

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
25o
C) regimes to identify appropriate storage temperature. Our results showed significant variations in the tested quality
attributes in response to different storage temperatures. Storage at 5o
C 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 15o
C 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 5o
C during the same storage period. Storage life of potato tubers at 25o
C 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