Effect of low-temperature storage on the content of folate, vitamin B6, ascorbic acid, chlorogenic acid, tyrosine, and phenylalanine in potatoes

BACKGROUND Changes in the metabolite composition of potato tubers during low-temperature storage can affect their nutritional value, susceptibility to bruising, and processing qualities. Here, we measured changes in the amounts of folate, vitamin B-6, and vitamin C, and the blackspot pigment precursors chlorogenic acid and tyrosine, as well as phenylalanine, in five potato varieties stored at 7.8 degrees C for 8 months in 2015 and 2016. RESULTS Folate content increased in all varieties in both years during low-temperature storage, with statistically significant changes occurring in six out of eight conditions. Increase rates ranged from 11% to 141%. Vitamin B-6 content increased in all varieties during the storage period, but changes were statistically significant in only two out of eight conditions. Increase rates ranged from 5% to 24%. Ascorbic acid content decreased in all varieties in both years during the storage period. Decrease rates ranged from 16% to 78%, and were statistically significant in seven out of eight conditions. For chlorogenic acid, no consistent trend was observed. Changes varied between -14% and +14%, but none was statistically significant. Tyrosine content increased in all varieties in both years, except in Sage Russet in 2015. Increase rates ranged from 19% to 238% and were statistically significant in three out of seven conditions. Changes in phenylalanine content were very similar to those observed for tyrosine, with increases up to 272% in Teton Russet. CONCLUSIONS These results show that storage at low temperature substantially affects tuber nutritional quality and biochemical bruising potential. (c) 2019 Society of Chemical Industry