共查询到18条相似文献,搜索用时 218 毫秒
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以高粱为原料,通过挤压协同淀粉酶法提取高粱蛋白,研究物料水分、挤压温度和淀粉酶活力这3个因素对高粱蛋白提取率和纯度的影响,发现蛋白质提取率和纯度随着物料水分和挤压温度的升高表现出先上升后降低的趋势,在物料水分为19%、挤压温度为150℃有最大值;蛋白质提取率和纯度随着淀粉酶活力的增加而增加,当淀粉酶活力大于2.0 U/g淀粉时,提取率与纯度的变化趋势趋于平缓。在此基础上以蛋白质纯度为指标设计正交实验,得到挤压协同淀粉酶法制备高粱蛋白的最优工艺:挤压温度165℃,物料水分19%,淀粉酶活力2.0 U/g淀粉。此条件下高粱蛋白提取率83.20%,纯度79.23%。氨基酸分析和营养评价显示,本实验制备的高粱蛋白具有良好的氨基酸平衡和较高的氨基酸利用率。SDS-PAGE凝胶电泳显示,此法提取的高粱蛋白包含醇溶蛋白和谷蛋白。 相似文献
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早籼米为原料,碱法提取大米蛋白并把提取蛋白质后的物料发酵制备酒精.研究了大米粉粒度、碱液浓度、料液比、提取时间以及提取温度等因素对大米蛋白纯度和提取率的影响,对比了提取部分蛋白质后的物料和大米粉发酵制备酒精的效果.实验确定了提取大米蛋白的较佳工艺条件为:大米粉粒度为过0.8 mm筛、碱液浓度0.05 moL/L、料液比1:4、提取时间3 h、提取温度30℃.此条件下提取得到的大米蛋白纯度为94.5%,提取率为52.0%.大米提取部分蛋白质后对发酵制备酒精的影响不大:最主要是发酵时间延长. 相似文献
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大米蛋白提取工艺研究进展 总被引:1,自引:0,他引:1
综述了国内外大米蛋白提取工艺,介绍了制备大米蛋白的常用方法:溶剂提取法、蛋白酶提取法、物理分离法、淀粉酶法、复合酶法,以及这些方法的优点和缺陷。溶剂法中非碱液提取法存在生产成本高、食品安全隐患等问题;碱法提取则耗用大量碱液,存在环境保护问题;蛋白酶法提取亦存在提取率低、成本高的问题;物理分离法目前我国还不具备相当成熟的技术实力。 相似文献
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碱法与酶法提取大米蛋白工艺及功能特性比较研究 总被引:32,自引:3,他引:32
对大米蛋白的提取工艺和功能特性进行了比较研究。大米蛋白的提取采用碱法和酶法分别提取。研究结果衣明.碱法提取大米蛋白的工艺条件为在室温下,用0.1mol/L的NaOH以1:7的同液比提取4h。提取得到的大米蛋白纯度达到90%,提取率55%。酶法提取大米蛋白的工艺条件为温度50℃,pH为8,E/S为5%,液固比为3:1,酶解时间为4h。提取的大米蛋白提取率为40%,蛋白质纯度为45%。碱法提取的大米蛋白持水性、吸油性和起泡性优于酶法提取的大米蛋白,而酶法提取的大米蛋白的溶解性、乳化稳定性和泡沫稳定性优于碱法提取的大米蛋白。两种方法提取得到的产品乳化能力相当。 相似文献
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Effect of ozone treatment on physicochemical properties of waxy rice flour and waxy rice starch 下载免费PDF全文
Wenping Ding Yuehui Wang Wei Zhang Yongcheng Shi Donghai Wang 《International Journal of Food Science & Technology》2015,50(3):744-749
The effect of ozone treatment on physicochemical properties of waxy rice flour and waxy rice starch was investigated. Results showed that ozone treatment increased the pasting viscosity of waxy rice flour. Compared with untreated waxy rice flour, the peak viscosities of waxy rice flour for 0.5, 1 and 2 h of ozone treatments were increased by 27.4%, 32.8% and 45.5%, respectively. The alpha‐amylase in waxy rice flour was inactivated during the treatment. The gelatinisation temperature and enthalpy of waxy rice flour were kept unchanged after the treatment. For waxy rice starch, pasting viscosity, swelling power and molecular weight were increased after 0.5 h of treatment, but decreased as treatment time extended. The ozone treatment decreased gelatinisation temperature and enthalpy of waxy rice starch. 相似文献
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Hyung Joo Suh Jin Man Kim & Yang Moon Choi 《International Journal of Food Science & Technology》2003,38(2):145-151
Summary To increase the industrial applications of sweet potato, a rice beverage was prepared by adding barley sprouts, sweet potato, or a mixture of barley sprouts and sweet potato (1:1). Amylases from barley sprouts and sweet potatoes had a similar hydrolysis pattern to β‐amylase. Heat stability of this enzyme in sweet potato was higher than that in barley. Reducing sugar content in the mixture of barley sprouts and sweet potato was higher than in either barley sprouts or sweet potato alone. After the preparation of the rice beverage, the maltose content of the mixture with barley sprouts, either barley sprouts and sweet potato, or sweet potato was 37.2, 44.1 and 40.3 mg mL?1 after 6 h, respectively. The amylase activity in the mixture with barley sprouts and sweet potato decreased more than that of the mixture with only sweet potato. The use of sweet potato resulted in an increase of sweetness, flavour and improved preference in rice beverage. 相似文献
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Alberto Romero Valérie Beaumal Elisabeth David-Briand Felipe Cordobes Antonio Guerrero Marc Anton 《Food Hydrocolloids》2012
Interfacial and emulsifying properties of rice protein concentrate (RPC) have been studied in order to evaluate its potential application to stabilize O–W emulsions. The interfacial behaviour of adsorbed proteins films constituted with RPC has been studied at the air–water and oil–water interfaces at two pH values (2 and 8). The type and the amount of soluble proteins have been determined in aqueous dispersions and results put forward the presence of most frequent rice protein profile and a significant degree of protein denaturation with a very low solubility. Air–water and oil–water interfacial properties have been determined as a function of time, concentration and pH: air–water by surface pressure under compression–expansion cycles and oil–water by interfacial tension. Interfacial rheology has been studied under dilatational deformations, either at the initial step of film formation or once the interfacial tension was at equilibrium (the film was completely formed). RPC-stabilised O–W emulsions has been also analysed by Droplet Size Distribution (DSD) measurements and interfacial protein concentration. Both interfacial and bulk emulsion properties reveal that RPC showed an enhanced potential as emulsifier at low pH. Globally; results indicate clearly important differences in the structural characteristics of rice protein films between pH 2 and 8 that impact on emulsifying properties. 相似文献
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Bett-Garber KL Champagne ET Thomson JL Lea J 《Journal of the science of food and agriculture》2012,92(2):283-291
BACKGROUND: The whiter the rice, the more it is preferred by consumers and the more value it has in the market place. The first objective of this study was to determine the interrelationships of raw colour, cooked colour, amylose content and protein content in rice. The second objective was to assess whether or not the colour of cooked rice can be predicted from raw rice colour in conjunction with amylose and protein contents. RESULTS: Protein and amylose contents were not significantly correlated with the colour measurements for raw rice. Protein and amylose showed moderate, significant associations with L* and a* and a*, b* and C* respectively for cooked rice. Only the colour variable a* of cooked rice could be predicted using protein, amylose and raw rice colour with high enough precision to be useful, and this was only for modelling using samples cooked in the same manner (rice cooker). Cooking method (rice cooker versus excess water) affected the colour of cooked rice. CONCLUSION: Being able to predict a* in cooked rice is likely of limited value. Only the model that used samples where postharvest handling conditions were controlled (US‐grown rice) was able to predict C*, a more useful measure, and then with only moderate ability. L*, a measure of brightness/whiteness, was not predicted well by any of the models. Copyright © 2011 Society of Chemical Industry 相似文献
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The underlying reasons for three waxy rice varieties, Yang-fu-nuo (Y), Su-yu-nuo (S), and Guang-ling-xiang-nuo (G), having different flour pasting properties were examined. The pasting properties of the isolated waxy rice starches did not correlate with those of the corresponding waxy rice flours. Examining the pasting properties of the flours in 0.5 mM AgNO3 solution, treated with dithiothreitol and protease, suggested that rice protein and amylase activity were the main causes of the pasting property differences among the rice starches and flours. Starch isolated from Y flour had a larger proportion of A and B1 chains, longer average chain length and longer exterior chain length, which explained its higher gelatinisation temperature, higher pasting consistency, greater extent of retrogradation, and the firm texture of cooked Y rice. 相似文献
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从原料米糠中分离出纯稻米胚和纯米糠,利用溶剂浸出法分别提取其中油脂并进行品质分析对比,以研究稻米胚及米胚油的营养品质。结果表明:稻米胚粗脂肪含量27.06%,粗蛋白含量19.50%,粗纤维含量4.88%,比米糠粗脂肪、粗蛋白含量明显提高,粗纤维含量降低;米胚油的酸值(KOH)、过氧化值、维生素E含量、谷维素含量、植物甾醇含量分别为21.7 mg/g、6.1 mmol/kg、43.18 mg/100 g、0.47%、3.07%,与米糠油相比,米胚油的酸值(KOH)降低了23.8 mg/g,过氧化值降低了1.7 mmol/kg,维生素E含量提高了17.18 mg/100 g,植物甾醇含量相差不大,谷维素含量降低0.93个百分点。米胚油在酸值和维生素E含量方面较米糠油具有明显优势,新鲜稻米胚既可以直接作为营养丰富的产品,也是优质食用油的原料。 相似文献