The contribution of sucrose, a nonreducing sugar, to nonenzymatic browning in potato chips was investigated using a model system of buffered sugars and glycine applied to filter paper discs that were then heated in oil. It was found by fiber optic calorimetry that sucrose and the amino acid produced darkening comparable to that of reducing sugars. It is postulated that sucrose enters the reaction by thermal hydrolysis to yield glucose and fructose. Addition of glucose and glycine to potato slices by vacuum infiltration resulted in increased darkening after frying but the sugar proved to be the limiting factor in nonenzymatic browning of potato chips, emphasizing the importance of sucrose in this reaction.

Differential scanning calorimetry was used to compare temperatures, enthalpies, and kinetic constants for starch gelatinization in tubers of SoZunum tube-roam L. var Norchip and a cold sweetening resistant selection, ND 860-2, in an attempt to correlate cold sweetening susceptibility with starch granule stability. For corresponding heating rates, ND 860-2 onset and peak temperatures were higher (~~0.05) while differences in enthalpies and activation energies were not (p>O.O5) different. Activation energy for amorphous swelling was 281 kJ mol-I higher, and the minimum temperature to induce crystallite disruption was 3.5"C higher, for ND 860-2 granules. Results indicate greater stability in ND 860-2 granules and suggest granular stability contributes to cold sweetening resistance.

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