Collection and Characterization of Soot from an Optical Fiber Preform Torch

To follow the development of particle morphology, silica soot is extracted from four axial positions in the flame of a torch used to manufacture optical fiber preforms by the vaporphase axial deposition method. The soot, collected by three extraction techniques, is analyzed by transmission electron microscopy and gas adsorption to identify which characteristics of the soot morphology are dependent on the sampling technique and which upon the position in the flame. Comparison is also made to other work in which silica soot was extracted from a nondiffusion flame.     

STARCH DEGRADATION IN ENDOSPERMS OF DEVELOPING BARLEY KERNELS*

Shortly after anthesis, empty endosperm cells adjacent to the embryo were crushed between the developing embryo and endosperm tissues to form the crushed cell layer. Starch granules in cells adjacent to this layer were hydrolysed and the empty cells were added to the crushed layer. In this way, the crushed layer increased in thickness throughout kernel development. α-Amylase 2 was detected in the crushed cell layer region of barley endosperms during the period that starch granule hydrolysis was occurring.     

羟乙基淀粉印花糊料合成的研究

介绍了一种以玉米淀粉为原料,将淀粉用酸水解后与环氧乙烷进行醚化反应制备羟乙基淀粉的方法。     

克鲁维酵母突变株UV-G-40-3菊粉酶性质的研究

研究了克鲁维酵母突变株（Ｋｌｕｙｖｅｒｏｍｙｃｅｓ－ＵＶ－Ｇ－４０－３）所产菊粉酶的分布为胞外酶∶胞壁酶∶胞内酶比是５．７∶１．６∶１。该酶Ｓ／Ｉ为５．３,最适温度为５０℃,最适ｐＨ为４．５,在５０℃以下、ｐＨ４．５～８的范围内比较稳定,４℃贮存稳定性好,１４ｄ后仍保持７６％活力,为外切型菊粉酶,酶解粗菊糖（洋姜提取液）活性为纯菊糖的４倍。     

用制糖米渣制备脱苦蛋白肽的研究

采用胰蛋白酶和含有外切酶的复合蛋白酶同时酶解脱糖米渣,制得脱苦蛋白肽产品。采用凯氏定氮法测定所得脱苦蛋白肽的蛋白质含量,并用甲醛滴定法测定其水解度。结果表明,脱苦蛋白肽产品中蛋白质含量大于88%,水解度达19%。     

大豆多肽复合酶解工艺条件研究

以大豆分离蛋白为原料,经蛋白酶酶解、分离、提纯可以制得大豆多肽。试验采用复合酶解法结合正交试验分析,确定大豆蛋白复合酶解的最佳工艺条件为:三酶复合蛋白酶(由中性蛋白酶、木瓜蛋白酶和菠萝蛋白酶以1∶2∶Z的比例复合而成)、底物浓度4%、pH7.0、酶解时间9h、大豆蛋白酶水解度(DH)84.40%。     

Lactic acid production using waste generated from sweet potato processing

Organic waste generated from industrial sweet potato canning is estimated to be 30% of incoming raw material with significant residual carbohydrate content. The purpose of this study was to evaluate the potential of waste generated from sweet potato processing material to support the growth of lactic acid bacteria and the production of lactic acid. The waste was comprised of 16.5% solids consisting of 18.5% ash, 4.4% protein, 20.5% simple sugars and 19% soluble starch. Following a screening of three lactic acid bacteria strains, Lactobacillus rhamnosus was deemed the best candidate for lactic acid production. The potential of various dilutions of the enzyme‐hydrolysed waste, with and without pH control, as a fermentation substrate was evaluated. Lactic acid production was highest in hydrolysed waste (without dilution) at pH set point 5.0, yielding 10 g L^?1 in 72 h. Thus, lactic acid, a valuable organic compound, can be generated from sweet potato waste.     

离子液体[Bmim]Cl预处理对两种高结晶多糖酸水解的影响

以酵母β-葡聚糖和凝结多糖这两种高结晶多糖为研究对象,采用偏光显微镜、X射线衍射(XRD)和DNS法研究了离子液体[Bmim]Cl预处理对多糖结晶结构和酸水解效率的影响。XRD图谱分析发现,[Bmim]Cl预处理后酵母β-葡聚糖和凝结多糖的结晶度明显下降。离子液体[Bmim]Cl预处理酵母β-葡聚糖和凝结多糖显著提高其酸水解效率。在4mol/LTFA及100℃条件下,酵母β-葡聚糖(水解时间2h)和凝结多糖(水解时间3h)酸水解产物中还原糖的含量分别为84.36g/100g和96.07g/100g,明显高于未经离子液体处理的53.44g/100g和46.80g/100g。     

角蛋白的提取及其在制革工业中的应用

角蛋白的来源广泛,特别是在动物毛中的含量极其丰富。角蛋白的应用也十分广泛,目前已经被应用于医药、涂料、皮革等多个行业。通过对角蛋白组成和分子结构的了解,从角蛋白的物理性质和化学性质的角度出发,总结了现阶段主要提取角蛋白的方法。同时,论述了皮革行业对毛发废弃物的处理现状,提取角蛋白以及角蛋白在皮革行业中的应用。     

Migration of bisphenol A from polycarbonate baby bottles under real use conditions

Migration of the potential endocrine disrupter, bisphenol A (BPA), from 31 polycarbonate (PC) baby bottles into aqueous food simulants was studied under real repetitive use, using a sensitive and fully validated liquid chromatographic method with fluorescence detection. Confirmation of the presence of BPA was performed by liquid chromatography–mass spectrometry (LC–MS). The effects of cleaning in a dishwasher or with a brush, sterilization with boiling water and the temperature of migration were examined. It was shown that temperature was the crucial factor for the migration of BPA from the plastic bottles to water. All samples released BPA in the concentration range 2.4–14.3 µg kg^?1 when filled with boiled water and left at ambient temperature for 45 min. The decrease of BPA release in the sterilization water and in the food simulant over 12 cycles of use indicated that the hypothesis of polymer degradation in water is dubious. Estimated infantile dietary exposure, regarding the use of PC baby bottles, ranged between 0.2 and 2.2 µg kg^?1 bw day^?1, which is below the Tolerable Daily Intake of 50 µg kg^?1 bw recently established by EFSA.