工程重组方便米复配机理的研究

Formulating Study on New Type Instant Rice

长期以来,方便米的复水特性和复水后的食用品质是制约传统工艺发展的主要症结之一,人们为此进行了不懈的努力。本文以大米粉作为主原料,复配食品添加剂,采用挤压技术生产“工程重组米”的新思路,完全克服传统工艺对大米进行表面处理的局限性,试图为制备具有良好品质的方便米另辟蹊径。本文研究了单甘酯(GMS)、大豆卵磷脂(LC)、硬脂酰乳酸钠(SSL)对米粉挤压过程中理化特性的变化以及对制备的方便米复水特性的影响,研究表明随着乳化剂添加量的增加,工程重组米的糊化度(DG)、水溶性碳水化合物(WSC)有所降低。随着GMS的增加,挤出物的膨胀度、水溶性蛋白质(WSP)、吸水指数(WAI)、方便米的复水率下降,硬度增加,而粘度在低于添加量0.8%时上升,高于0.8%时下降。而添加SSL,膨胀度变化较小,WSP、WAI有所增加;添加LC,膨胀度和WAI都有所增加,WSP变化较小。与对照组相比,大豆磷脂和SSL添加量小于0.8%时,复水率有所提高,硬度与粘度下降。

Rehydration characteristics and edible quality of traditional instant rice are the main points of restricting the popularization since its initiation. Therefore people have made unremitting efforts its improvement. The objective of this paper was to make a fresh start with high temperature-high pressure-short time extrusion technology to produce ＇engineering rice＇, a further type of reformed instant rice with well rehydration characteristics and better edible qualities and with nutrition-fortified attributes that would be acceptable to different levels of consumers. Effects of glyceryl monostearate（GMS）, sodium stearyl lactylate（SSL）, and lecithin（LC） on physicochemical properties of extruded rice flour and rehydration characteristics of the engineered instant rice showed that the degree of starch gelatinization（DG） and water-soluble carbohydrate（WSC） of the extrudates decrease with the increase of added emulsifier in general. Expansion, wafter-soluble protein（WSP）, and water absorption index （WAI） of the extruded rice flour, and rehydration rate and hardness of the engineered instant rice increase with the increase in added GMS, but the stickness of instant rice rises with less than 0.8% GMS, decreased with higher than 0.8%. WSP and WAI increased with the increase of added S SL, but expansion of extrudates changed tittle. Expansion of extrudates and WAI rised with LC increase, but WSP changed little. Rehydration ratio of instant rice rised, but hardness and stickness decreased when LC and SSL less than 0.8% compared with the control sample.