Starch gelatinization measured by pulsed nuclear magnetic resonance
1996
Mendes Da Silva, C.E. | Ciacco, C.F. | Barberis, G.E. | Solano, W.M.R. | Rettori, C.
The extent of starch gelatinization was quantified by pulsed-proton nuclear magnetic resonance (NMR) analysis. To quantify the gelatinization of starch, a relative liquefying index (RLI), calculated from the ratio of liquid to solid phases determined by pulsed NMR, was defined. A correlation coefficient > 0.94, at 5% significance level, was found between the RLI and the degree of gelatinization determined by a method of enzymatic susceptibility. Studies on the kinetics of gelatinization of wheat starch in starch-water systems by the NMR method showed a first-order reaction until the degree of gelatinization reached a fixed and constant value which increased with the temperature and with the amount of water in the system. The minimum activation energy occurred 45.0% water. The similarity between the activation energies found at 55.0 and at 65.0% water indicated that 55.0% water is the minimum water content for the complete gelatination of wheat starch.
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