膨化谷物的水溶性成分研究

本文以玉米和黍米为对象,应用水浸渍法,研究了谷物膨化前后的水溶性成分,从而可为膨化谷物在食品及其发酵工业中的应用提供依据.     

Proteolytic specificity of Lactobacillus delbrueckli subsp. bulgaricus influences functional properties of mozzarella cheese

Low-moisture part-skim Mozzarella cheeses were manufactured from 2% fat milk and aged for 21 d. Treatments included cheeses made with one of three different strains of Lactobacillus delbrueckii ssp. bulgaricus in combination with a single strain of Streptococcus thermophilus. A fourth, control treatment consisted of cheeses made with only S. thermophilus. Although total proteolytic ability of these strains, as indicated by the o-phthaldialdehyde analysis, was similar in each of the three strains of L. bulgaricus, these strains exhibited different proteolytic specificities toward the peptide, alpha(s1)-CN (f 1-23). On the basis of their alpha(s1)-CN (f 1-23) cleavage patterns and a previously described classification, these strains were assigned to the groups I, III, and V. The objective of this study was to investigate the influence of lactobacilli proteolytic systems, based on specificity toward alpha(s1)-CN (f 1-23), on functionality of part-skim Mozzarella cheese. Moisture, fat, protein, salt-in-moisture, and moisture in nonfat substances content of cheeses made with groups I, III, and V strain were similar. Control cheese had a lower moisture content than did other treatments. Significant differences were observed in functional properties between cheeses manufactured using groups III and V strains. Cheeses made with groups I and III strains were similar in their meltability, hardness, cohesiveness, melt strength, and stretch quality. Meltability and cohesiveness increased with age, while melt strength and stretch quality decreased with age for all cheeses. Additionally, HPLC showed that total peak areas of water-soluble peptides derived from cleavage of alpha(s1)-CN (f 1-23) by different strains of lactobacilli could be highly correlated to meltability and stretch characteristics of cheeses made with those strains.     

Surface activity of aqueous solutions of cellulose acetate with low degree of substitution

Surface activity of aqueous solutions of cellulose acetate (CA) with total degree of substitution (〈F〉) ranging from 0.58 to 0.80 was examined. Critical micelle concentration (CMC) of the aqueous CA solutions, determined from the polymer concentration dependence of surface tension (γ), is unequivocally determined by 〈F〉, and an increase in 〈F〉 of CA brings about a lowering of the CMC. From light scattering measurements on aqueous solutions of CA with 〈F〉 = 0.8 at 20°C, it was revealed that in the vicinity of the CMC the micelles in the solution consist of c. four CA molecules, which is very close to the value obtained by analysing the data obtained from the mass action model. The surface tension of aqueous solutions of CA (〈F〉 = 0.8) in the polymer concentration range above the CMC was c. 0.74 times that of pure water over the temperature range 0–80°C.     

复方丹参注射液中水溶性酚酸总量的测定

研究建立复方丹参注射液中水溶性酚酸总量的测定方法,以控制该制剂的内在质量。在1mol/L的冰醋酸溶剂中,利用丹参中水溶性酚酸类成分与铁氰化钾—三氯化铁的显色反应,比色法测定该制剂中水溶性酚酸(以原儿茶醛计)的总量。结果显示,原儿茶醛在0.4448—2.002μg/mL范围内呈良好的线性关系,回归方程为:A=0.05237C 0.07654(r=0.9998),加样平均回收率为100.0%,RSD为0.93%。该法简便快速,结果准确,重现性好,可用于该制剂的质量控制。     

水基丙烯酸改性聚酰胺皮革涂饰剂的研究

合成了一种水溶性尼龙，并在水溶液中以丙烯酸类单体对其进行接枝改性研究，合成出一种丙烯酸发生聚酰胺乳液，具有很好的成膜性，可作为皮革涂饰剂使用。     

Catalytic performance of chiral rhodium complex with water-soluble sulfonated (R)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl for enantioseletive hydrogenation in ionic liquid biphasic system

Asymmetric hydrogenation of dimethyl itaconate by the chiral rhodium complex ligated with water-soluble sulfonated (R)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (labeled as (R)-BINAPS) was performed in ionic liquid-isopropanol biphasic catalytic system. A moderate enantiomeric excess (ee) of 64% and initial turnover frequency (TOF_max) as high as 1234 h⁻¹ could be obtained at 303 K and 2.0 MPa when the molar ration of substrate to rhodium was set at 1000. Application of imidazolium ionic liquid [bmim]BF₄ (bmim = 1-butyl-3-methyl imidazolium cation) made it possible to reuse the catalyst several times, showing rather good stability in the catalyst performance. According to the ICP-OES analyses, the total extraction of rhodium species by the reactants from the ionic liquid phase was about 3.24 wt% after the catalyst for four runs, which was about three times lower than that of total loss of phosphorous species. The slight decreases in the ee value and TOF_max during the catalyst reuse could be recovered essentially to the pristine levels by replenishing certain amount of the fresh ligand into the used catalyst.     

含氧化叔胺侧基的水溶性酚醛树脂的合成与成像性能

本实验通过一锅、两步法制备改性酚醛树脂．首先利用环氧酚醛树脂F-44与二甲胺反应，得到叔胺化酚醛树脂，叔胺化树脂被双氧水氧化后得到最终目标产物，即含强极性氧化叔胺基团的酚醛树脂．实验表明，该新型树脂易溶于水和一些强极性溶荆，如四氢呋喃、乙二醇独甲醚和N，N-二甲基甲酰胺等．在热的作用下，树脂能够分解并失去水溶性，但仍可溶于一些有机溶剂．由该树脂与830nm激光增感染料匹配使用，树脂体系对红外光敏感，并能够通过中性水显影得到较为清晰的阴图型图像，表明该树脂有望用于免化学处理热敏激光成像领域．