A comparative study between biorefining combined with other processes and physical refining of high-acid mohua oil

The biorefining process under optimum conditions de-acidified the high-acid mohua oil by nearly 85% with considerable improvement of color. The process, in combination with alkali-refining, bleaching and deodorization, yielded excellent oil with respect to color, unsaponifiable matter content and triglyceride content. The combination of biorefining and physical refining significantly reduced the loss of oil, and the color, unsaponifiable matter and diglyceride content increased while triglyceride content decreased. The physical refining process alone, on the other hand, produced oil with considerably darker color, increased unsaponifiable matter and diglycerides, and decreased triglyceride. Biorefining followed by alkali-refining, bleaching and deodorizing steps or by physical refining can be regarded as a much better alternative refining process than the physical refining process alone for oils of high acidity.     

Kinetic resolution of secondary alcohols with commercial lipases

The relative rates of enzyme-catalyzed esterification of the enantiomers of 2-octanol with various acids were determined for several commercial lipases. Interesterifications and hydrolyses of racemic 2-octanol esters catalyzed by these enzymes were also examined. Novo'sMucor miehei lipase exhibited considerable enantioselectivity and was therefore employed to prepare 8-methyl-2-decanols with high configurational purity at the carbinol carbon. Esters of these alcohols had been previously identified as sexually attractive to several rootworm (Diabrotica) species, and the stereochemistry of those esters had been shown to be critical to the attraction. The enzymatic resolution provides a convenient method to obtain such esters in a desired state of configurational purity.     

Transesterification of cocoa butter by fungal lipases: Effect of solvent on 1,3-specificity

Transesterification and alcoholysis reactions catalyzed by immobilized lipases fromMucor miehei andHumicola lanuginosa in hexane gave fatty acid esters that did not reflect the expected 1,3-specificity of the enzymes, due to competing acyl migrations in the partial glyceride products. However, both lipases were 1,3-specific in reactions when diethyl ether was used as a solvent, and this provided a convenient analytical methodology in combination with gas chromatography and nuclear magnetic resonance spectroscopy for the determination of fatty acid distribution within triglycerides.     

酶法脱除蛋白水解产物苦味的研究进展

本文主要概述了蛋白酶解产物苦味形成机理、常用的苦味脱除方法、毛霉蛋白酶的特性。并探讨了酶法脱苦的方法 :即利用双菌种协同发酵生产的高活力复合蛋白酶降解蛋白 ,达到消除蛋白水解产物苦味的目的。     

中国腐乳的现代研究

从腐乳现代研究的营养价值、生产菌种、辅料介质与工艺和品质、腐乳独有的发酵变化以及腐乳的生物活性物质等方面进行了详尽的论述，并根据多年的生产实践提出了一些新颖的观点，阐述了腐乳的研发思路。     

卷枝毛霉发酵产壳聚糖酶的条件优化

以壳聚糖为诱导物,诱导卷枝毛霉产生壳聚1糖酶,并对产酶备件进行了优化。通过单因素实验确定最佳产酶条件为：壳聚糖浓度0．8g·L-1、培养温度40℃、培养基pH值5．5、培养时间84h、摇床转速180r·min-1。     

毛霉产蛋白酶特性及条件研究

研究了毛霉产蛋白酶属性 ,毛霉的最适发酵方式 ,并采用正交试验确定了毛霉的培养基和培养条件。研究结果表明 :毛霉产蛋白酶以中性为主 ,毛霉更适合固体发酵培养 ,2 5 0ml三角瓶装入麸皮 10g ,加入 11ml水 ,按 8%的量接种菌悬液 ,30℃培养可使酶活达最高。     

Production,properties, and some new applications of chitin and its derivatives

Chitin is a polysaccharide composed from N-acetyl-D-glucosamine units. It is the second most abundant biopolymer on Earth and found mainly in invertebrates, insects, marine diatoms, algae, fungi, and yeasts. Recent investigations confirm the suitability of chitin and its derivatives in chemistry, biotechnology, medicine, veterinary, dentistry, agriculture, food processing, environmental protection, and textile production. The development of technologies based on the utilization of chitin derivatives is caused by their polyelectrolite properties, the presence of reactive functional groups, gel-forming ability, high adsorption capacity, biodegradability and bacteriostatic, and fungistatic and antitumour influence. Resources of chitin for industrial processing are crustacean shells and fungal mycelia. Fungi contain also chitosan, the product of N-deacetylation of chitin. Traditionally, chitin is isolated from crustacean shells by demineralization with diluted acid and deproteinization in a hot base solution. Furthermore, chitin is converted to chitosan by deacetylation in concentrated NaOH solution. It causes changes in molecular weight and a degree of deacetylation of the product and degradation of nutritionally valuable proteins. Thus, enzymatic procedures for deproteinization of the shells or mold mycelia and for chitin deacetylation were investigated. These studies show that chitin is resistant to enzymatic deacetylation. However, chitin deacetylated partially by chemical treatment can be processed further by deacetylase. Efficiency of enzymatic deproteinization depends on the source of crustacean offal and the process conditions. Mild enzymatic treatment removes about 90% of the protein and carotenoids from shrimp-processing waste, and the carotenoprotein produced is useful for feed supplementation. In contrast, deproteinization of shrimp shells by Alcalase led to the isolation of chitin containing about 4.5% of protein impurities and recovery of protein hydrolysate.     

毛霉蛋白酶的制备及催化特性的研究

该文研究了毛霉蛋白酶的催化特性以及影响其活力的一些因素,包括温度、pH值以及金属离子等。结果表明,毛霉蛋白酶有2个较为合适的作用pH值,分别为pH7.5和pH10.0,在60℃有最大催化活力;在pH6.0和40℃以下毛霉蛋白酶有很好的稳定性。SPI水解试验表明,毛霉蛋白酶是一种适于水解大豆蛋白的酶种,在大豆多肽制备方面有较好的前景。     

总状毛霉发酵生产壳聚糖工艺研究

壳聚糖是天然多糖中唯一大量存在的碱性氨基多糖,具有一系列特殊功能性质,广泛应用于食品、生物医用材料、纺织、环保等行业领域,市场前景非常可观.本文选择总状毛霉作为菌种,在单因素实验的基础上,用部分因子设计方法对相关影响因素的效应进行筛选并选出有显著效应的蔗糖、NaNO3、时间三个因素.最后用中心组合实验及响应曲面、等高线分析确定主要影响因素的最佳含量和培养的条件.确定最适发酵培养基和培养条件为:接种量(5%)、蔗糖(64g/L)、酵母膏(3g/L)、硝酸钠(3.5g/L)、磷酸氢二钾(1.5g/L)、硫酸镁(0.1g/L)、硫酸铁(0.1g/L)、温度(28℃)、转速(140r/min)、培养时间(43h),并通过实验得壳聚糖产量为1.43g/L.