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该文以聚乙烯醇为原料,利用戊二醛为交联剂,聚合得到交联球形聚乙烯醇,并将其与环氧氯丙烷反应用以固载环氧基团,得到可用于酶固定化的载体。讨论了交联聚乙烯醇球环氧基的固载条件和酶的固定化条件。植酸酶经过固定化后,机械性能和化学稳定性都得到提高,可以重复多次对植酸钠进行水解反应。同时对该自由酶和固定化酶进行酶学特性研究。发现自由酶和固定化酶的最适pH值分别为5.5和7.0,最适反应温度分别为55℃和70℃。植酸酶经固定化,提高了酶的操作、温度、pH值和贮藏稳定性。 相似文献
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针对影响糙米可食用性的主要抗营养因子(ANF)--纤维素与植酸,直接外源添加纤维素酶和植酸酶作用于糙米皮层,使其分解,对影响两种酶酶解作用的主要反应条件:温度、pH、酶用量、酶解时间分别进行单因子试验,在此基础上,按L9(34)设计,通过正交试验分别对酶解环境进行了优化.结果表明:纤维素酶酶解优化条件为温度55℃,pH3.5,酶用量10ml,酶反应时间90min植酸酶酶解优化条件为温度55℃,pH2.5,酶用量15ml,酶反应时间150min.同时使用纤维素酶和植酸酶可有效地降低糙米皮层纤维素与植酸含量,在与单一酶酶解效果相当的情况下,明显缩短了酶解时间. 相似文献
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《食品工业科技》2016,(10)
以脱脂米糠分级去除清、球、醇溶蛋白后的残渣为原料,以植酸去除率为评价指标,以酶解温度、酶解p H、酶解时间和植酸酶添加量为影响因素进行单因素实验。在此基础上,根据Box-Benhnken中心组合实验设计原理,设计三因素三水平响应面优化实验。在分析各个因素的显著性和交互作用后,得出去除植酸的最佳工艺条件为:植酸酶添加量2.5 U/g,p H5.6,酶解温度48℃,酶解时间3 h,此条件下,模型实际值为85.47%。在最优植酸酶解条件下,米糠谷蛋白的提取率和纯度分别提高了24.53%和10.16%,与此同时,谷蛋白中植酸含量降低了93.2%,溶解性也一定程度上得到了改善。 相似文献
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分别以海藻酸钠、聚乙烯醇(PVA)及聚乙烯醇(PVA)-海藻酸钠复合凝胶为载体,对植酸酶进行固定化研究.结果表明,由于PVA复合凝胶的多孔性网状结构,有利于物质传递.海藻酸钠有助于阻止酶活力的漏失,包埋效果优于其他两种方法.植酸酶经过固定化后,机械性能和化学稳定性都得到提高,可以重复多次对植酸钠进行水解反应.同时对该自南酶和固定化酶进行酶学特性研究.发现自南酶和固定化酶的最适pH值分别为5.5和7.0,最适反应温度分别为45和60%.固定化酶的Km(20mg/mL)大于自由酶的Km(14 mg/mL).植酸酶红固定化,提高了酶的操作、温度和贮藏稳定性. 相似文献
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利用发芽大麦的植酸酶去除大豆中的植酸。试验表明:将发芽3d的大麦与浸泡1d的大豆以6:4的比例混合粉碎后,在55-60℃,pH=5,5条件下酶解3h,麦豆混合物中植酸去除率可达93%以上。 相似文献
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Delphine Lioger Fanny Leenhardt Christian Demigne Christian Remesy 《Journal of the science of food and agriculture》2007,87(7):1368-1373
Fibre‐rich fractions of wheat are an important source of minerals but also contain considerable amounts of phytic acid, known to impair mineral absorption. This study explores the efficiency of wheat bran sourdough fermentation on phytate hydrolysis and mineral solubility, in comparison with whole‐wheat flour. In vitro trials were performed to assess the consequences of the addition of calcium carbonate (CaCO3), an alkalinising salt, on phytic acid breakdown and mineral bioavailability during sourdough fermentation. Sourdough fermentation was found effective for solubilising minerals in whole‐wheat flours but was less effective with bran. In addition, sourdough acidity was blunted by the addition of CaCO3, whereas degradation of phytic acid remained effective. Despite extensive breakdown of phytic acid (almost 70%), the addition of calcium exerted a very negative effect on zinc solubility. In conclusion, a pre‐fermentation process of whole cereals or bran, in suitable conditions of hydration, allows degradation of the major part of phytic acid and optimal mineral bioavailability. Copyright © 2007 Society of Chemical Industry 相似文献
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米糠中植酸磷的体外消化试验 总被引:1,自引:0,他引:1
试验采用体外消化的方法,借助植酸酶制剂将米糠中的植酸磷转化为无机磷,对植酸酶制剂的消化率作了初步测定,植酸磷的消化率可达60.3%;并对其最适pH值、适宜用量、适宜作用时间进行了探讨。 相似文献
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Abayomi P. Adebiyi Ayobamitale O. Adebiyi Tomohisa Ogawa & Koji Muramoto 《International Journal of Food Science & Technology》2008,43(1):35-43
Crude rice bran protein (CRBP) was prepared by alkaline extraction and then treated with 0.6 m HCl to remove phytic acid. The phytate‐free rice bran protein (PFRBP) was hydrolysed with proteases M, N, S, P and pepsin under optimal conditions. Hydrolysates obtained from various hydrolysis periods were subjected to analysis for their degree of hydrolysis (DH) and functional properties. The hydrolysates were fractionated by reversed‐phase column chromatography on Kaseigel ODS resin (120–140 μm) using a stepwise gradient of aqueous ethanol, and their activities were measured. The 40% ethanol fraction of protease P 4 h‐hydrolysate was separated by successive reversed‐phase high‐performance liquid chromatography and the amino acid sequences of isolated antioxidative peptides were determined by a protein sequencer and matrix‐assisted laser desorption ionisation‐time of flight mass spectrometry. Crude rice bran protein had higher antioxidative activity than PFRBP, due to the presence of phytic acid. Phytate contents of rice bran, CRBP and PFRBP were 2.5%, 1.42% and 0%, respectively. The activity of PFRBP increased upon protease digestion. Protease M hydrolysates showed the highest DH, but the lowest antioxidative activity. Hydrolysates with DH below 10% had higher antioxidative activity than those above 20%. This result indicates that the antioxidative activity of the hydrolysates is inherent to their characteristics amino acid sequences of peptides depending on the protease specificities. 相似文献
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Germination significantly increased inorganic P, non-phytate P and phosphorus extractable in 0.03 N HCl, the concentration of acid found in human stomach, with a corresponding decline in phytate P of pearl millet grains. HCl-extractability of calcium, iron, zinc, copper and manganese, an index of their bioavailability to humans, was also significantly improved by germination. Fermentation of pearl millet sprouts with mixtures of yeasts ( Saccharomyces diastaticus or Saccharomyces cerevisiae ) and lactobacilli ( Lactobacillus brevis or Lactobacillus fermentum ) generally improved extractability of the minerals of the sprouts, probably because of the decreased content of phytic acid in the germinated and fermented pearl millet sprouts. 相似文献
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植酸/植酸钠在食品工业上的应用研究进展 总被引:1,自引:0,他引:1
植酸/植酸钠广泛存在于谷类、豆类和油料作物等中,应用非常广泛,在食品工业上可用作食品抗氧化剂、抑菌剂、护色剂、螯合剂和保鲜剂等。本文简述了植酸/植酸钠的结构、组成和理化特性,并且综述其在食品工业中的应用与研究进展。重点介绍了植酸/植酸钠在果蔬制品、饮料、发酵食品、酿造酒、油脂和脂肪制品、水产品、肉制品、焙烤制品和面制品等加工中的应用及研究进展。同时探讨了目前植酸/植酸钠在食品工业应用中存在的问题及解决对策,并对其发展趋势进行展望。指出目前高纯度植酸和固体植酸的生产成本较高,将来可以在植酸的色谱层析分离材料上进行改进。同时,为了增加植酸在油溶性食品中的应用范围,可以通过植酸的改性或借助于乳化、微乳化技术制备植酸/植酸钠的乳液和微乳液产品,是将来的发展方向。 相似文献