加工工艺对荞麦蛋白热性质和体外模拟消化过程的影响  

Thermal Properties and in vitro Digestibility of Buckwheat Protein Products: Processing Effects Study

作　　者：米宏伟[1] 郑宗坤[1] 唐传核[2] 杨晓泉[2] 

机构地区：[1]深圳大学化学与化工学院,广东深圳518060 [2]华南理工大学蛋白工程研究中心,广东广州510640

出　　处：《食品科学》2007年第12期32-36,共5页Food Science

基　　金：国家自然科学基金资助项目(20306008)

摘　　要：本实验研究了加工工艺对荞麦蛋白(BWP)的热性质和体外模拟消化过程的影响。荞麦蛋白有两个变性温度,在80℃和102℃附近,分别对应8S和13S球蛋白的变性。脂肪的存在对荞麦蛋白的变性温度影响不大,但会降低其热焓。在模拟的胃蛋白酶消化过程中,BWP的氮释放量较大豆分离蛋白(SPI)先高后低;而在胰蛋白酶消化过程中,BWP的氮释放量较SPI高。这与其蛋白组成以及SPI中存在活性较高的胰蛋白酶抑制剂有关。荞麦蛋白的球蛋白(13S和8S)易被降解(胃蛋白酶消化阶段),而2S清蛋白的降解主要集中在胰蛋白酶消化阶段。经脱脂处理、超声协助提取的荞麦蛋白(DFU-BWP)和搅拌提取的荞麦蛋白(FM-BWP)的氮释放量在整个胃蛋白酶消化过程中类似,均明显高于超声提取的荞麦蛋白(FU-BWP)(p<0.05),说明胃蛋白酶对BWP的降解过程与其脂肪含量以及加工工艺有关。The effect of processing on thermal properties and in vitro digestibility of buckwheat protein （BWP） products were investigated. All the BWP samples exhibited two observable endothermic peaks with similar peak temperature （Td） values with the major peak at about 102 ℃ and the minor one at near 80 ℃. The two transition peaks observed may be attributed to 13S globulin with the Td near 102 ℃ and 8 S globulins with the Td near 80 ℃ respectively. The presence of high level of lipid （e.g. 17.8% in the FU-BWP） significantly decreases the enthalpy changes （ A H） （p 〈 0.05）, and in some extent increases the A Tlt2 （t3〈0.1） so as to suggest a decline of the extent of ordered structure. In simulated gastric fluid, the digestion pattern of BWP was evidently different from that of SPI. In the pepsin digestion, the % N release of BWP increased more quickly than SPI at the beginning, but more slowly than SPI after 30 rain, However, the % N release of BWP increases much faster than that of SPI in the trypsin- digested stage, This is because of different components of them and the presence of high activity of trypsin inhibitors in SPI. Most of the protein constituents of BWP globulins （including 13 S and 8 S globulins） are rapidly and completely hydrolyzed by pepsin within 1 min to form the protein hydrolysate products （with MW lower than 20 kDa）, when 2 S albumins are almost intact during the whole pepsin digestion but hydrolyzed totally in the trypsin digestion. BWP with low lipid content shows high % N release in comparison with those with high lipid content（p 〈0.05）. These results suggested that the digestibility of BWP can be associated with its lipid contents, which are affected by processing.

关 键 词：荞麦蛋白(BWP) 热变性 体外消化 加工工艺 

分 类 号：TS201.21[轻工技术与工程—食品科学] R151.2[轻工技术与工程—食品科学与工程]