Blanching effect on frozen french fries quality and starch gelatinization degree

In this study, Shepody was selected as raw material, using two step blanching processing to produce frozen-french fries, through sensory evaluation appraise french fries quality. In order to obtain high-quality French fries, firstly, measured the physical and chemical composition of fresh potato(moisture, starch, reducing sugar) and secondly, investigated the effects of preheating and two steps of blanching on chips starch gelatinization degree, finally, measured the sugar degree of blanching water under different blanching process. With french fries quality, starch gelatinization degree and blanching water sugar degree as evaluation indicator, so as to optimize two step blanching process parameters. The optimized method of two step blanching was blanching at 85 ℃ for 6 min, then at 75 ℃ for 20 min. Under this condition, the starch of french fries completely gelatinized and sensory score of fried fries reached up to 95. The results showed that: blanching process had a great effect on the quality of French fries. With increasing of the blanching time and temperature, the gelatinization degree of fries and sugar degree of blanching water augmented. Combination of high temperature short time and low temperature long time, namely two-step process was regarded as reasonable blanching process. The research results can provide the theoretic basis and technical support for the study of french fries' blanching process.