Low Temperature Sweetening in Susceptible and Resistant Potatoes: Starch Structure and Composition |
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| Authors: | VALERIE BARICHELLO RICKEY Y. YADA ROBERT H. COFFIN DAVID W. STANLEY |
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| Affiliation: | Authors Barichello, Yada, and Stanley are with the Dept. of Food Science, Univ. of Guelph, Guelph, ON, N1G 2W1. Author Coffin is with Agriculture Canada, Dept. of Horticultural Science, Univ. of Guelph, Guelph, ON, N1G 2W1. |
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| Abstract: | Starch isolated from ND 860–2 potatoes, which were resistant to chillsweetening, had higher amylose and lower amylopectin as well as a higher crystallinity as compared to starch isolated from Norchip potatoes, which were susceptible to low temperature sweetening. ND 860–2 starch exhibited greater resistance to α-amylase attack and amorphous swelling as well as higher gelatinization temperatures and onset swelling temperatures than starch isolated from Norchip. Examination of starch granule structure using bright field light microscopy indicated crystalline concentric rings in ND 860–2 not seen in Norchip. Scanning electron microscopy of granules incubated with a-amylase indicated more intact ND 860–2 starch granules compared to Norchip. These data strongly suggest that starch granule composition is a factor differentiating the low-temperature sweetening sensitive cultivar from the resistant potato seedling. |
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