萌发苦荞粉的加工和消化特性分析

Analysis on Processing and Digestion Characteristics of Germinated Tartary Buckwheat Powder

摘要:

为探索萌发苦荞粉在食品中的应用，该文研究了苦荞萌发过程中水分含量的变化，并以苦荞原粉为对照，分析了萌发苦荞粉的加工特性（冻融稳定性、凝胶能力、水合特性和透明度）、体外消化模拟过程中还原糖释放率、淀粉的组成以及估计血糖生成指数。结果表明，苦荞含水率在萌发0~3 h时迅速增加，并随时间的延长而缓慢提高；萌发处理显著降低了苦荞粉的冻融稳定性，析水率达18.94%，为苦荞原粉的3.01倍。沉降体积降低了11.30%，表明凝胶能力增强。持水力和膨胀度有一定程度下降，但溶解度显著提升，增加了26.70%。萌发苦荞粉的透光率为4.29%，相对于原粉降低了0.38%；在浸泡15 h、萌发12 h内还原糖释放量持续增大，随后呈下降趋势，最大释放量分别为13.85%和10.67%；20 ℃下浸40 h后，在25 ℃、湿度80%和光照强度7500 Lx的条件下萌发48 h，苦荞淀粉的含量从66.94%下降到59.43%，快消化淀粉的含量提高至85.69%，抗性淀粉含量降低至9.45%；萌发苦荞粉的消化速率显著提高，最终水解率达到92.80%，但水解指数（88.24）和估计血糖生成指数（88.15）上升不显著。因此，萌发苦荞粉相比于苦荞原粉具有更好的凝胶性、溶解性和消化性，适用于制凝胶类和易消化类食品，该研究为萌发苦荞食品的开发提供了一定的理论依据。

Abstract:

To explore the application of germinated Tartary buckwheat powder in food, moisture content changes during Tartary buckwheat germination were studied. The processing characteristics of germinated Tartary buckwheat powder, such as its freeze-thaw stability, gel-forming capacity, hydration characteristics, and transmittance, were analyzed and compared against those of normal Tartary buckwheat powder (control). In addition, the reducing sugar release rate during in vitro digestion simulation, starch composition, and the estimated glycemic index were measured. The results show that the moisture content of Tartary buckwheat increases rapidly in the initial stage of germination (0~3 h) and then continues to increase slowly. Germination significantly reduces the freeze-thaw stability of the Tartary buckwheat powder, and the water release rate reaches 18.94%, which is 3.01 times that of the original powder (control). The sedimentation volume decreases by 11.30%, indicating enhanced gel-forming capacity. Moreover, the water holding capacity and degree of swelling decrease, but the solubility increases significantly by 26.70%. The light transmittance of germinated Tartary buckwheat powder is 4.29%, which is 0.38% lower than that of the control. The release amounts of reducing sugars increase continuously in the first 15 h of soaking and the first 12 h of germination, reaching the maximum release amount of 13.85% and 10.67%, respectively. Subsequently, the release amounts decline. The starch content of the Tartary buckwheat powder drops from 66.94% to 59.43% after soaking at 20 ℃ for 40 h and germination for 48 h at 25 ℃, 80% humidity and 7500 Lx light intensity. The content of rapidly digestible starch increases to 85.69%, while the resistant starch content decreases to 9.45%. The germinated Tartary buckwheat flour digestion rate rises significantly, and the final hydrolysis rate reaches 92.80%. However, the hydrolysis index (88.24) and the estimated glycemic index (88.15) did not increase significantly. Therefore, compared with normal buckwheat powder, germinated buckwheat powder has better gel-forming capability, solubility, and digestibility; thus, it is applicable for preparing gelled and easily digestible food. The findings of this study provide a theoretical basis for the development of germinated buckwheat food.