不同粒径小麦全粉的营养及加工特性比较

Comparison of Nutrition and Processing Characteristics of Whole Wheat Flours with Different Particle Sizes

本研究探讨不同粒径范围小麦全粉的化学成分及黏度变化,并对小麦全粉的加工特性进行评价,以期为小麦全粉在食品加工中的应用提供理论依据。结果表明,不同粒径小麦全粉的灰分含量差异不明显,但其蛋白质、脂肪及淀粉含量存在差异。蛋白质和脂肪含量最高(分别为15.34%和2.25%)的为粒径<100μm的小麦全粉,含量最低的分别是300~600μm(10.91%)和>1430μm(0.81%)。淀粉含量最高(66.23%)的是最大粒径(>1430μm)的小麦全粉,而其它粒径的样品间无显著差异。此外,小麦全粉的破损淀粉含量随其粒径的减小而逐渐升高,当粒径由>1430μm减小到<100μm时,其破损淀粉含量由0.28%升高至4.79%。在加工特性方面,粒径由>1430μm减小到<100μm使小麦全粉的黏度升高,持水性和持油性分别提高了33.19%和39.32%,溶解度和膨胀度也明显提高。同时,粒径降低还有利于提高小麦全粉的冻融稳定性,使其冻融初期的析水率从68.67%(>1430μm)降低到48.69%(<100μm)。这说明小麦全粉的粒径过大或过小均会对其营养及加工特性产生不利影响,而通过精准控制小麦全粉的粒径范围,可在保证小麦制品营养性的同时提高其加工品质。

This study investigated the chemical composition,viscosity changes and processing characteristics of the whole wheat flours with different particle sizes,in order to provide a theoretical basis for the application of whole wheat flour in food processing.The results showed that the whole wheat flour samples with various particle sizes had insignificantly different ash contents but significantly different protein,fat and starch contents.The whole wheat flour with the particle size<100μm had the highest protein and fat contents(15.34%and 2.25%,respectively),with the four with the particle size of 300~600μm having the lowest protein content(10.91%),and the flour with the particle size>1430μm having the lowest fat content(0.81%),respectively.The highest starch content(66.23%)was found in the sample with the largest size(>1430μm),with the others flour samples showing in significant differences.In addition,the content of damaged starch in whole wheat flour increased gradually with the decrease in particle size.When the particle size was reduced from>1430μm to<100μm,the content of damaged starch in whole wheat flour increased from 0.28%to 4.79%.In terms of processing characteristics,the reduction of particle size from>1430μm to<100μm increased the viscosity of whole wheat flour,and raised the water-holding and oil-holding abilities by 33.19%and 39.32%,respectively,and increased the solubility and swelling degree.In the meantime,the decrease in particle size of whole wheat flour could improve its freeze-thaw stability,and made the water separation rate at the initial stage of a freeze-thaw cycle reduce effectively from 68.67%(>1430μm)to 48.69%(<100μm).These results indicate that inappropriate particle size of whole wheat flour(too large or too small)could have negative influences on the nutrition and processing characteristics of whole wheat flour,and it is possible to ensure the nutritional properties while improving the processing quality of wheat products through monitoring precisely the particle size of whole wheat flour.