Changes in Compositional Parameters of Tubers of Potato (Solanum tuberosum) during Low-Temperature Storage and Their Relationship to Chip Processing Quality

A four-year study of a number of compositional parameters of potato tubers during low-temperature storage was conducted to examine the compositional differences between cold-tolerant (low sugar-accumulating) and cold-sensitive (high sugar-accumulating) tubers in relation to potato chip processing quality. Compositional parameters analyzed included sucrose, reducing sugars, nitrogen, protein, ascorbic acid, and dry matter content. Pearson correlation analysis of the data illustrated that chip color was most closely correlated with reducing sugar concentration. Multiple regression analysis revealed that the relative contribution of each parameter to chip color varied greatly among the cultivars and selections evaluated and from season to season. This analysis demonstrates that the quantitative relationships between the measured compositional parameters and chip color were not sufficient to provide a general predictive index of chip color quality for tubers processed directly from low-temperature storage. Keywords: Ascorbic acid; chip color; low-temperature sweetening; nitrogen; potato; protein; reducing sugars