碱法分离大米蛋白和淀粉工艺的优化及其产品功能性质研究

本文以籼米为原料，研究了碱法提取分离大米蛋白和淀粉的工艺，并对大米分离蛋白和大米淀粉的功能性质进行了研究。确定了碱法分离大米蛋白和淀粉的最佳工艺条件：氢氧化钠溶液浓度为0．075mol／L；提取时间6h：料液比1：7g／mL；温度40℃。该优化条件下可以得到纯度高于80％大米分离蛋白，蛋白提取率为86．23％，淀粉回收率为92．12％。所得大米分离蛋白溶解性、起泡性好，乳化性能欠佳。     

碱法分离大米蛋白质和淀粉的工艺研究

大米蛋白质中80％以上是碱溶性谷蛋白，可采用碱提酸沉的方法分离大米蛋白质。本实验研究得到碱法分离大米蛋白质的最佳工艺条件为：碱液质量分数为0．3％，提取时间为4h，提取温度为室温，料液比为1：6。可得到纯度为80．7％的大米分离蛋白，蛋白质提取率为87．46％，淀粉损失率为2．77％。     

大米蛋白分离提取的研究进展

阐述了大米蛋白分离提取的方法、作用条件和影响因素。大米蛋白分离提取的方法主要有碱法、单酶法、多酶法和分步水解法等。蛋白酶的选择、酶解时的固液比、加酶量、pH值、温度、时间等酶解条件，是影响大米蛋白酶水解的主要因素。适宜的物理作用和非蛋白酶的存在可提高水解效果。     

大米蛋白的分离提取和应用

阐述了目前较常见的大米蛋白的分离提取方法以及应用现状,为今后大米蛋白的进一步研究提供了基础。大米蛋白的分离提取方法包括碱法提取、酶法提取、分步水解、溶剂提取和物理分离等,主要用作营养补充、食品添加剂和功能性食品。     

高纯度大米淀粉的提取分离纯化

大米淀粉和大米蛋白这两种大米深加工产品目前市场价格昂贵，是低品质大米转化为高附加值产品的有效途径。本研究利用生物酶技术对大米淀粉的提取分离纯化进行了研究，找到了大米淀粉的最佳分离工艺，对纯化前后的淀粉进行了性质的比较，发现纯化后的淀粉溶解度增加、膨润力下降，糊化温度升高、黏度降低。     

碱法提取大米蛋白的研究

对碱法提取大米蛋白进行了研究,采用正交试验优化了工艺条件,结果表明：影响米蛋白提取率的主次因素顺序为：料液比〉碱液浓度〉提取时间〉提取温度,最佳工艺条件为：料液比1：10,碱液质量分数0.35%,提取时间6 h,温度40℃,在此条件下,大米蛋白提取率可达88.87%。     

高纯度糯米淀粉的分离工艺研究

采用碱法工艺提取分离糯米淀粉和蛋白,并对其进行优化.通过单因素试验和正交试验确定最佳的提取分离工艺条件为:在氢氧化钠浓度为0.085mol/L,料液比1:5 g/mL,温度40℃,提取时间为3 h,在此条件下糯米淀粉纯度达93.44%,蛋白含量低于0.5%.     

酶法提取大米浓缩蛋白工艺条件的研究

以早籼米或节碎米为原料，采用淀粉酶对大米淀粉进行分解，分离后得大米蛋白和大米淀粉糖。研究了最佳的工艺条件。结果表明，采用淀粉酶，5LU／g的添加量，pH6．3～6．5，喷射液化，分离后的蛋白质含量为59．82％。采用旋流分离除杂，可将灰分降低到1．52％。纤维素酶和脂肪酶复合水解，可将蛋白中脂肪的含量降低到2．72％。大米浓缩蛋白中蛋白质的含量达70％，得率为73．96％。     

碱消化法提纯大米淀粉的研究

蛋白质残留量是决定大米特性的主要因素,也是影响大米淀粉应用的关键因素。文中采用三因素正交实验设计,筛选了碱消化提纯大米淀粉的优化工艺条件:碱液浓度4g/L,提取时间4h,浆液浓度300g/L)。所得淀粉蛋白质残留量0·34%,低于Yamamoto法的0·42%;大米淀粉得率71%,比Yamamoto65%高6%。大米粉经碱消化去蛋白质提纯后,其膨润力和溶解度明显提高。     

碱法提取浓缩大米蛋白工艺条件的研究

大米蛋白中80％以上是碱溶性谷蛋白,采用碱法提取具有提取率高、成本低的优点。蛋白质的回收可采用等电点沉淀法,适于工业化生产。本实验研究得到碱法提取浓缩大米蛋白的最佳工艺条件为:NaOH浓度为0.09mol/L,提取时间为4h,提取温度为室温,固液比为1:7,可得到纯度为80.16%的浓缩大米蛋白。蛋白提取率为90.1％。      

大米变性淀粉的制备研究

对比研究了挤压法和湿法制备乙酰化大米淀粉与交联大米淀粉的工艺与理化特性。结果表明要得到相同取代度的变性淀粉,湿法的原料消耗量远远大于挤压法。挤压法制备的乙酰化大米淀粉和交联大米淀粉的溶解度大幅增加、糊化温度消失,说明挤压法制备的两种变性淀粉还有预糊化淀粉的特性。超微结构表明挤压法制备的大米变性淀粉的淀粉结构已经消失。     

Improving gel formation of rice starch added with cross‐linked resistant starch prepared from rice starch

The gel formation properties of non‐waxy rice starch with cross‐linked resistant starch with phosphate (RS4, 10, 20, and 30% based on rice starch) prepared from three rice varieties with different amylose (AM) content were investigated to increase dietary fiber content, improve gel structure, and reduce the glycemic index of rice products. The AM contents of rice starches were 1.71% in Hanganchal1, 22.47% in Nampyeong, and 33.39% in Goamy. All RS4 showed A‐type crystallinity and their RS levels were 46.91, 54.54, and 66.01%, respectively. The initial pasting temperatures of RS4 added rice starches increased as RS4 contents increased, but peak and breakdown viscosities and enthalpy change (△H) reduced. The RS4 addition improved gel shape and texture properties including hardness, cohesiveness, and gumminess, except the 30% Goamy RS4 added gel. The 20% RS4 addition was appropriate to form rice starch gels. The network structure of RS4 added gel formed more regular and firmer than that of control, because RS4 granules were entrapped within the gel matrix like observed by light microscope and scanning electron microscopy. It is suggested that RS4 not only assist in forming a rigid network structure but also increasing a dietary fiber content.

     

Hydrothermal treatments of rice starch for improvement of rice noodle quality

Two types of hydrothermal treated rice starches were prepared by annealing and heat-moisture treatment (HMT). Annealing of starch slurry was conducted at 55 °C for 24 h and HMT was applied in starch with 20 g/100 g moisture at 110 °C for 1.5 h, based on the optimization of the treatment conditions. The apparent changes on gelatinization, swelling, RVA paste viscosities and gel hardness of starch were observed. The study on 50% substitution of rice flour with untreated (UR), annealed (AR) or heat-moisture treated (HR) rice starches proved that the cooking and texture quality of rice noodle was substantially affected by the treatments. The composite noodles of flour and hydrothermal treated rice starches exhibited quality parameters which were closer to those of commercial noodles. The results revealed the possibility of utilizing these starches with low quality rice flour so as to produce noodles of acceptable quality. The study also inferred that characterization of RVA paste viscosities and gel texture of flour could become a practical method for predicting the quality of the derived noodle.     

燕麦蛋白和淀粉的提取纯化工艺研究

通过对pH、水料比、温度、时间等因素进行单因素试验,然后进行正交试验,对燕麦蛋白和淀粉进行初步分离,得到燕麦蛋白的初步提取工艺条件,并对分离的蛋白和淀粉进行纯化。试验得出燕麦蛋白纯化的最适酶解条件及燕麦淀粉纯化的最适酶解条件,燕麦淀粉得率为86.2%,纯度为77.6%。     

核桃蛋白对大米淀粉凝胶化及凝胶特性的影响

研究不同核桃蛋白添加量下大米淀粉的糊化特性、流变特性、热特性及凝胶质构和水分子状态.结果表明,核桃蛋白以浓度依赖的方式降低了大米淀粉糊的黏度和相变焓值,而使糊化温度升高,当核桃蛋白添加质量分数达12％时,峰值黏度、谷值黏度、最终黏度分别降低了 30.77％、12.35％和14.65％,糊化温度升高了 8.89％;所有样...     

Preparation of products rich in slowly digestible starch (SDS) from rice starch by a dual-retrogradation treatment

In this work, a dual-retrogradation treatment (gelatinization–retrogradation–gelatinization–retrogradation) was designed for preparing slowly digestible starch (SDS) products from rice starch. The results showed that a maximum SDS yield in the tested samples increased from 39.3% to 56.7% by the dual retrogradation with the time interval of 36 h. The dual retrogradation also seemed to increase with the melting temperature range (T_c–T_o) of the SDS products. This increase indicated that more imperfect crystallites were formed during the dual-retrogradation treatment. Furthermore, compared to the single retrogradation, the dual retrogradation generated larger cavities and more solid connection parts in the SDS products. This internal microstructure could result in the increase of slow digestibility. These findings suggest that the dual retrogradation can be used in starchy products to increase the yield of SDS.