米粉碎料膨化成的米棒的性质研究

Study on properties of rice stick made from rice fragments by extrusion puffing process

研究了米粉碎料经挤压膨化加工成米棒后,蛋白、粗脂肪、还原糖含量以及溶胀能力、粘度曲线、结晶结构等理化性质的变化,采用改进的体外消化模型模拟人体消化道环境,研究米粉和米棒粉中淀粉的消化速率。结果表明,与碎料米粉相比,米棒中蛋白质含量变化小,脂肪含量减少,还原糖含量;溶解度增加、膨润力增加,冷水可溶,粘度降低至很小;红外谱图中1 526 cm-1处附近出现了游离COO-的吸收峰,表明挤压膨化过程中存在脂肪的降解;XRD图谱和偏光显微镜照片共同表明,加工过程中淀粉的结晶结构遭到破坏;膨化加工后消化速率提高。

Extrusion puffing process was widely utilized in food industry, its effects on rice fragments＇ properties were studied in this paper. Molecular and crystalline structure was investigated to research physical and chemical changes occurred during the process. Improved in-vitro digestion model was used to simulate the human digestive tract environment to study the digestive properties of the processed rice. The results showed that, compared with the raw rice fragment, the protein content of the extrusion puffed rice kept invariant, while the crude fat content reduced, the sugar content increased significantly. The solubility and the swelling ability of the processed rice flour was also increased, the beginning gelatinization temperature and maximum viscosity was lower. The FT-IR spectra showed that there was an obvious free COO- absorption peak nearby 1 526 cm^-1, due to the degradation of the fat. The morphology appearance and the crystalline structure of the granules were destroyed seriously according to the polarized microscope and XRD pattern. The in-vitro results indicated that the digestion rate of the processed rice improved remarkably.