【作者】 崔亚丽；

【导师】 栾广忠； 冯玉珠；

【作者基本信息】 西北农林科技大学 ， 食品工程， 2012， 硕士

【摘要】 目前，家庭自制豆浆已成为我国豆浆消费的主要形式之一。但家用豆浆机会产生豆渣，这不仅不利于清洗过滤，还会造成原料浪费和环境污染。前期工作及文献表明，豆浆颗粒度大小对豆浆感官品质、蛋白质回收率及消化吸收率都有影响。将大豆预先去皮及粉碎可减少豆渣的量并减小豆浆的颗粒度。为了研究颗粒度对豆浆品质及蛋白质消化率的影响，以未脱皮大豆和脱皮大豆为原料，利用三种主流家用豆浆机（九阳精磨豆浆机JY1、美的无网豆浆机MS、九阳无网豆浆机JY2）分别制备干豆及湿豆豆浆，分析不同豆浆机所制备豆浆的粒径及粒度分布规律，进而分析粒径与豆浆品质及蛋白质吸收率间的关系，探究豆浆黏度与豆浆口感及稳定性的关系。通过研究主要得到以下结果：（1）以未脱皮干豆、未脱皮湿豆、脱皮干豆、脱皮湿豆为原料，三种豆浆机制备豆浆的粒径存在着较大差异。JY2制备的豆浆体积平均粒径D[4,3]最大，分别为63.34μm、32.04μm、45.84μm、49.21μm；MS豆浆的D[4,3]次之，分别为40.14μm、31.29μm、47.73μm、41.33μm；JY1豆浆的D[4,3]最小，分别为35.35μm、20.42μm、34.43μm、29.98μm。在相同处理条件下（大豆浸泡或未浸泡），以脱皮豆为原料制备豆浆产生的豆渣比未脱皮豆为原料产生的豆渣显著减少（P<0.05）。湿豆豆浆体积平均粒径小于干豆豆浆，蛋白质含量、蛋白吸收率及感官评分（脱皮豆除外）亦显著高于干豆豆浆，说明豆浆颗粒度减小有助于改善豆浆品质。（2）利用粉碎机将脱皮大豆分别粉碎20s、40s、60s、100s，得到颗粒度不同的豆粉，其D[4,3]依次为238.99μm、120.09μm、130.89μm、85.88μm，随着粉碎时间的延长，所得豆粉的粒径显著减小。以粉碎20s、60s、100s的豆粉，超微粉碎大豆粉（一种商品，D[4,3]67.39μm）及未粉碎的脱皮豆为原料使用豆浆机JY1制备豆浆，其蛋白质体外消化率依次为57.67%、63.34%、64.26%、64.50%、49.82%。豆浆的蛋白消化率随着豆浆颗粒度的减小而显著增大，当豆浆粒径D[4,3]减小到一定值（112.20μm）时，随着粒径的进一步减小，豆浆消化率的变化不显著。（3）将脱皮大豆粉碎40s并使用JY1打浆，在制备的豆浆中添加0.05%~0.25%的黄原胶，豆浆的黏性指数在2.30~31.57g·sec。随着豆浆黏性指数增大，豆浆颗粒敏感性降低，但豆浆黏性对稳定性没有显著影响。在不同颗粒度豆浆中添加0.15%的黄原胶，随着豆浆粒径的减小，颗粒敏感度降低，豆浆稳定性增加。研究结果说明，豆浆颗粒度的减小有利于豆浆口感的改善、原料利用率的提高及蛋白质消化率的提高。以脱皮大豆粉为原料，可制备出口感细腻、消化率高、豆渣质量少或子叶全利用豆浆，是作为家庭全子叶豆浆粉比较理想的原料。更多还原

【Abstract】 Recently, preparing soymilk with household soymilk maker is getting more and morepopular in China. But Okara increased gritty mouth feel of soymilk, which may also decreasethe digestibility of soymilk. The objective of this research was to analyze the effects ofparticle size on quality and protein digestibility of soymilk. Three soymilk makers, JoyoungFine-grinding (JY1), Joyoung Dry-bean (JY2), and Midea Dry-bean (MS) were used toprepare soymilk from raw and dehulled soybeans by “dry-bean” and “soaked bean” programrespectively. The relationship among particle size, soymilk quality and protein absorption ratewere analyzed. Then using dehulled soybean powder of different particle size as material andusing JY1make soymilk. The relationship between particle size and protein digestibility ofsoymilk made by household soymilk maker was analyzed. Then explore the relationshipbetween viscosity and mouth feel, stability of soymilk.The main results are as follows:(1)The materials were intact dry soybeans, intact soaked soybeans, dehulled drysoybeans and dehulled soaked soybeans. The average particle size D[4,3] of soymilk made byJY2was63.34μm,32.04μm,45.84μm and49.21μm. The D[4,3] of soymilk made by MS was40.14μm,31.29μm,47.73μm and41.33μm. The D[4,3] of soymilk made by JY1was35.35μm,20.42μm,34.43μm and29.98μm. The average particle size of soymilk D[4,3]wasJY2>MS>JY1. The Significant difference was showed in the particle size of soymilk made bythree soymilk makers. In the same processing conditions (soaked or unsoaked), the okara indehulled-bean soymilk was smaller than that of raw-bean soymilk significantly (P<0.05). Theaverage particle size of soaked-bean soymilk was smaller than dry-bean soymilk. The proteincontent, protein absorption and sensory score (except dehulled soybeans) of soaked-beansoymilk were also higher than dry-bean soymilk significantly. This indicated that smaller theparticle size was the higher quality of soymilk was.（2）The dehulled soybean powder of different particle size was obtained by grinder. Thegrinding time was20s,40s,60s and100s. The D[4,3] of it was238.99μm,120.09μm,130.89μm and85.88μm, respectively. The soybean powder (grinding time:0s) and finegrinding powder (D[4,3]67.39μm) were also used as materials. The particle size of soybean powder reduced significantly with the grinding time increasing. Using soybean powder (0s,20s,60s and100s) as material, soymilk of different particle size was obtained. The proteindigestibility of soymilk was49.82%,57.67%,63.34%,64.26%and64.50%. It indicated thatthe protein digestibility of soymilk increased when the particle size of soymilk reduced. Theprotein digestibility of soymilk didn’t increase significantly when the particle size of soymilkdeclined to a certain value (112.20μm).(3) The dehulled soybean was ground (40s) and prepared with soymilk maker JY1.Adding xanthan gum (dosage:0.05%~0.25%) to the soymilk, the index of viscosity was2.30~31.57g·sec. When the index of viscosity of soymilk increased, people’s sensitivity onparticle size decreased. But the stability of soymilk didn’t increase. Adding xanthan gum(dosage:0.15%) to the soymilk of different particle size, people’s sensitivity on particle sizedecreased when the particle size reduced to a certain value. The smaller the particle size was,the more stable the soymilk system was.The results suggested that decreasing in particle size of soymilk can make highutilization of raw materials. The soymilk was smoother and protein absorption was higher.The protein digestibility of soymilk didn’t increase significantly when the particle size ofsoymilk declined to a certain value. Using dehulled soybean powder as material, we can makefull use of soybean. The soymilk contained less okara and was easily digested. It can providea theoretical basis for the development of special soybean powder for household soymilkmaker.更多还原