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采用PEG/硫酸铵双水相体系对啤酒酵母中SOD进行萃取研究。以酶的纯化倍数和回收率为指标,探讨了无机盐种类、PEG分子量、PEG浓度、硫酸铵浓度以及pH对SOD萃取效果的影响。结果表明:PEG4000浓度为14%,硫酸铵浓度为24%,pH 7.5时,下相中SOD回收率达73.4%,纯化倍数达1.76。回收率较PEG/磷酸钾盐缓冲液体系高了37.97%,纯化倍数较PEG/磷酸钾盐缓冲液体系高了21.38%。 相似文献
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研究不同来源的脂肪酶催化餐厨废油水解反应制备脂肪酸,通过单因素实验考察了酶用量对酶解率的影响,在此基础上采用正交实验对水解工艺参数酶用量、水解温度、油水比和水解时间进行优化。结果表明:猪胰脂肪酶L3621和假丝酵母脂肪酶LS20在适宜条件下均可实现餐厨废油的高效酶催化水解;L3621最佳水解条件为酶用量700 U/g、水解温度45℃、油水比1∶1.2、水解时间36 h,在此条件下酶解率达94.30%;LS20最佳水解条件为酶用量600 U/g、水解温度40℃、油水比1∶1、水解时间36 h,在此条件下酶解率达96.84%。 相似文献
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传统的固态固定化脂肪酶存在载体易破碎、制备成本高等问题,制约了其工业应用。利用前期开发的三液相体系中相作为脂肪酶液态固定化载体,研究了不同种类的成相物质、成相物质的比例以及不同种类的脂肪酶对液态固定化酶回收率的影响。同时考察了该液态固定化载体固定脂肪酶的稳定性。结果表明:正己烷/PEG400/Na_2SO_4三液相体系中相为更优的液态固定化酶载体;最优的制备条件为PEG400比例20%、Na_2SO_4比例14%,此条件下AY30脂肪酶的回收率可达98%以上,其他类型脂肪酶中相回收率均大于90%;该液态固定化载体在30℃的环境下能有效保持脂肪酶的催化活性,保护效果在不同温度下均明显优于传统水-有机溶剂体系;同时,脂肪酶在此液态固定化载体中的保藏稳定性也优于水环境,低温保藏2周后仍能保留约78. 4%的酶活力,体现出较好的保藏稳定性。 相似文献
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《食品工业科技》2015,(11)
采用聚乙二醇(PEG)/硫酸铵[(NH4)2SO4]双水相体系对大豆中脂肪氧合酶进行分离萃取研究;通过综合考察酶分配系数、相比和回收率,探讨了(NH4)2SO4、PEG2000、Na Cl浓度以及p H对脂肪氧合酶萃取的影响,并通过正交实验进一步优化实验条件,结果表明在单一因素下的最佳工艺条件为:(NH4)2SO415%(wt%)、PEG2000 13%(wt%)、Na Cl 1%(wt%)、p H5.8;正交实验优选出的最佳工艺条件为:(NH4)2SO417%(wt%)、PEG2000 13%(wt%)、p H5.2,可获得酶的分配系数最高可达9.710,萃取率为87.6%。 相似文献
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为解决单一食用油中营养组分缺陷问题,以大豆油、橄榄油、鱼油和亚麻籽油为基料油,测定其酸值、过氧化值、水分及挥发物含量和脂肪酸组成,然后按照中国营养学会关于脂肪酸推荐摄入量的要求,依据不同基料油的脂肪酸组成计算其配比并配制调和油,最后测定调和油的营养成分。结果表明:大豆油、橄榄油、亚麻籽油、鱼油的酸值、过氧化值、水分及挥发物含量均符合相关国家标准,4种油脂配制调和油的最适配比为45%、45%、8%、2%;调和油中主要微量营养成分及其含量为角鲨烯2.18 mg/kg、β-胡萝卜素0.474 mg/kg、α-生育酚73.6 mg/kg、β-生育酚0.6 mg/kg、γ-生育酚132.0 mg/kg、δ-生育酚20.4 mg/kg、总甾醇5 700 mg/kg。所得调和油符合中国营养学会关于脂肪酸推荐摄入量的要求,是一种营养平衡调和油。 相似文献
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Vegetable Oils Replace Pork Backfat for Low-Fat Frankfurters 总被引:6,自引:0,他引:6
Low-fat frankfurters (10% fat, 12.5% protein) with olive, corn, sunflower or soybean oils, compared to control (29.1% animal fat, 10.4% protein) had 67% lower total fat, 40–45% lower saturated fatty acids, 50–53% lower calories, reduced cholesterol and 20% higher meat protein. Although they had darker red color they were 6–7.2% lower in processing yield and had higher purge accumulation, were firmer and less juicy. The type oil had no effect (P>0.05) on these characteristics but affected fatty acid composition. Frankfurters with olive oil had 41.8% higher monounsaturated fatty acids and those with seed oils 5–7 times higher polyunsaturated fatty acids. Soybean oil increased lin-olenic acid content and negatively affected overall acceptability and shelf-life. 相似文献
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Microencapsulation of Oils: A Comprehensive Review of Benefits,Techniques, and Applications 总被引:1,自引:0,他引:1
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Amr M. Bakry Shabbar Abbas Barkat Ali Hamid Majeed Mohamed Y. Abouelwafa Ahmed Mousa Li Liang 《Comprehensive Reviews in Food Science and Food Safety》2016,15(1):143-182
Microencapsulation is a process of building a functional barrier between the core and wall material to avoid chemical and physical reactions and to maintain the biological, functional, and physicochemical properties of core materials. Microencapsulation of marine, vegetable, and essential oils has been conducted and commercialized by employing different methods including emulsification, spray‐drying, coaxial electrospray system, freeze‐drying, coacervation, in situ polymerization, melt‐extrusion, supercritical fluid technology, and fluidized‐bed‐coating. Spray‐drying and coacervation are the most commonly used techniques for the microencapsulation of oils. The choice of an appropriate microencapsulation technique and wall material depends upon the end use of the product and the processing conditions involved. Microencapsulation has the ability to enhance the oxidative stability, thermostability, shelf‐life, and biological activity of oils. In addition, it can also be helpful in controlling the volatility and release properties of essential oils. Microencapsulated marine, vegetable, and essential oils have found broad applications in various fields. This review describes the recognized benefits and functional properties of various oils, microencapsulation techniques, and application of encapsulated oils in various food, pharmaceutical, and even textile products. Moreover, this review may provide information to researchers working in the field of food, pharmacy, agronomy, engineering, and nutrition who are interested in microencapsulation of oils. 相似文献
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Malongil B. Reena Belur R. Lokesh 《International Journal of Food Science & Technology》2012,47(1):203-209
The effect of feeding blended and interesterified oils containing palm oil (PO) and rice bran oil (RBO) on serum and liver lipids was evaluated in rats. The PO and RBO were blended to contain saturated, monounsaturated and polyunsaturated fatty acids in the proportion of 1:1.5:1. The blended oil was subjected to transesterification reaction using immobilized lipase, lipozyme IM‐RM. Rats were fed a diet containing blended or interesterified oils for 8 weeks. Rats fed PO showed significantly higher levels of cholesterol in serum and liver as compared to those given RBO, blended oil of PO with RBO or interesterified oil. Rats fed blended oils showed a significant decrease in serum cholesterol by 51% compared to rats fed PO. Feeding interesterified oil to rats resulted in decrease in serum cholesterol by 56% compared to rats fed PO, which was 10% lower compared to that observed in rats given blended oil. The present study indicated that a combination of PO with RBO can significantly lower serum lipids in rats as compared to those given diet containing PO alone. 相似文献