糙米复配粉中淀粉直/支比对挤压速食粥品质与结构的影响

Effect of the Ratio of Amylose to Amylopectin in Brown Rice Compound Powder on the Quality and Structure of Extruded Instant Porridge

糙米是一种营养丰富的全谷物食品,但较差的适口性、蒸煮性和消化性制约着其成为主流餐桌食品。为改善其食用品质,本文通过分析不同淀粉直/支比(0.176、0.196、0.216、0.236、0.256、0.276)糙米复配粉的原料特性以及其对挤压速食粥糊化特性、复水品质、质构特性与结构的影响,探究制作糙米挤压速食粥原料复配粉最优的淀粉直/支比。结果表明:随着淀粉直/支比的增加,糙米复配粉的糊化温度和峰值温度增加,挤压速食粥米粒横截面的光滑度及紧密度增加。当淀粉直/支比为0.256时,挤压速食粥米粒横截面的结构最均一、最紧密,复水时间达到12.6 min,米汤固形物损失率和径向膨胀率最小(0.153 g和2.282%),此时的硬度、胶着度和耐咀性明显高于淀粉直/支比0.276,达到3323.85 g、1242.76 g·s和744.73 g。可见,糙米复配粉中淀粉直/支比0.256为制作挤压速食粥的较佳比例。

Brown rice is a nutritious whole grain food,but poor palatability,cooking quality and digestibility prevent it from becoming a mainstream table food.In order to improve its edible quality,the raw material characteristics of brown rice composite powder with different amylose to amylopectin ratios(0.176,0.196,0.216,0.236,0.256,0.276)and their effects on gelatinization,rehydration quality,texture and structure of extruded instant porridge were analyzed,the optimum amylose to amylopectin ratio for making brown rice extruded instant porridge raw material composite powder was explored in this paper.The results showed that with the increase of amylose to amylopectin ratio,the gelatinization temperature and peak temperature of brown rice compound powder increased,and the smoothness and tightness of cross-section of extruded instant porridge rice grain increased.When the amylose to amylopectin ratio was 0.256,the cross-section structure of the extruded instant porridge rice grain was the most uniform and compact,and the rehydration time reached 12.6 min.The loss rate of the solid content of the rice soup and the radial expansion rate were the smallest(0.153 g,2.282%).The hardness,gumminess and chewiness were significantly higher than the starch straight/branched ratio of 0.276,reached 3323.85 g,1242.76 g and 744.73 g.From this point of view,the amylose to amylopectin ratio of 0.256 in the brown rice compound powder was a preferred ratio for making the extruded instant porridge.