不同氯化钠浓度对Candida etchellsii CICIM Y0600生长和生物特性的影响研究

在酱油发酵过程中增香酵母的代谢产物能显著提高酱油产品的风味和品质.为了提高增香酵母菌在酱醪中的适应性,通过逐步提高氯化钠浓度的方法对酵母菌的耐盐度进行驯化培养.通过分析表明,经过5个批次的驯化,增香酵母菌的耐氯化钠浓度由180 g/L提高到240 g/L.对驯化后的三株耐不同氯化钠浓度的增香酵母菌株进行生物特性研究.结果表明,在200 g/L氯化钠浓度的培养基中,Candida etchellsii CICIM Y0600产游离氨基酸和酸解氨基酸总量分别达到2.01g/L和7.00 g/L.和其他不同氯化钠浓度条件下比较,其产有机酸种类没有变化,挥发性酯类物质含量最高,为0.80 g/L.耐盐度的提高使增香酵母菌更好地适应了在酱油发酵中的高盐度环境.     

Effects of antinutritional factors on plasma lipoprotein levels in Japanese flounder Paralichthys olivaceus

This study examined the effects of four types of antinutritional factor (phytic acid, stachyose, soy saponins and soy isoflavones) on lipoprotein levels in plasma of Japanese flounder Paralichthys olivaceus. A basal diet was prepared with fish meal as primary protein source, the other diets were supplemented with 0·2, 0·4 or 0·8% phytic acid, 0·4, 0·8 or 1·5% stachyose, 0·1, 0·35 or 0·7% soy saponins and 0·10, 0·35 or 0·70% soy isoflavones, by dry mass, in place of white flour in the basal diet. Total cholesterol (TC) and triglyceride (TG) levels in plasma of P. olivaceus were not affected by phytic acid or stachyose. In general, addition of 0·2-0·8% phytic acid or 0·4-1·5% stachyose decreased plasma high-density lipoprotein cholesterol (HDL-C) levels, increased plasma low-density lipoprotein cholesterol (LDL-C) levels, thereby increasing the LDL-C:HDL-C ratio. By contrast, supplementation with 0·35-0·7% soy saponins generally depressed plasma TC levels and the LDL-C:HDL-C ratio. Supplementation with 0·35-0·7% soy isoflavones, however, increased plasma TC and TG levels. These results indicate that soy saponins may be partly responsible for the cholesterol-lowering effects of soybean meal.     

Estimation of raw material performance in mammalian cell culture using near infrared spectra combined with chemometrics approaches

Understanding variability in raw materials and their impacts on product quality is of critical importance in the biopharmaceutical manufacturing processes. For this purpose, several spectroscopic techniques have been studied for raw material characterization, providing fast and nondestructive ways to measure quality of raw materials. However, investigations of correlation between spectra of raw materials and cell culture performance have been scarce due to their complexity and uncertainty. In this study, near-infrared spectra and bioassays of multiple soy hydrolysate lots manufactured by different vendors were analyzed using chemometrics approaches in order to address variability of raw materials as well as correlation between raw material properties and corresponding cell culture performance. Principal component analysis revealed that near-infrared spectra of different soy lots contain enough physicochemical information about soy hydrolysates to allow identification of lot-to-lot variability as well as vendor-to-vendor differences. The identified compositional variability was further analyzed in order to estimate cell growth and protein production of two mammalian cell lines under the condition of varying soy dosages using partial least square regression combined with optimal variable selection. The performance of the resulting models demonstrates the potential of near-infrared spectroscopy as a robust lot selection tool for raw materials while providing a biological link between chemical composition of raw materials and cell culture performance.     

172名上海地区成人饮食及尿雌马酚和代谢产物的调查研究

目的确定上海地区成人雌马酚代谢表型及雌马酚的生理范围;把握由于大豆异黄酮负荷而产生的雌马酚产生者比例;调查雌马酚表型和食物摄取频率及有关激素间的关系。方法应用现状调查方法,筛选出172名居住在上海市区健康成年男女。填写问卷获得研究对象日常饮食频率,检测研究对象血清获得血液激素浓度,采用HPLC法分析负荷大豆异黄酮前后尿中雌马酚等大豆异黄酮24 h排泄量,统计产雌马酚者比例及其与摄食频率和激素的关系。结果负荷前雌马酚生理范围0~33.74μmol/24 h,产雌马酚者比例为30.2%,负荷大豆异黄酮后比例提高至53.5%。产雌马酚者与非产雌马酚者之间日常食品摄取频率的差别无统计学意义(P>0.05)。产Eq者血中游离雌二醇的浓度较非产Eq者低(P<0.05)。结论在通常膳食条件下,约有1/3上海成人尿液中能检测到雌马酚,但负荷大豆异黄酮后,约有1/2能产生雌马酚。     

Cool-textured diets for use in baculovirus production

The incorporation of baculovirus into semi-synthetic diets has been used for the inoculation of large batches of insect larvae reared under gregarious conditions. The preparation of most artificial diets involves heating to dissolve the agar gelling agent followed by cooling to ～55–60°C whereupon virus occlusion bodies (OBs) are incorporated into the diet. To avoid exposure of thermolabile OBs to high temperatures, a cool-textured diet using soy fiber was evaluated as a simple method to inoculate batches of larvae with the baculovirus OBs. Spodoptera exigua larvae that fed on a diet with 120, 140 or 160?g/l of soy fiber, as a substitute for agar, had a similar weight gain over a 24?h period than larvae that consumed a standard agar diet. The larval weight gain with cool-textured diets with 140?g/l of soy fiber was not improved by the addition of chlorophyll, green food dye colour, or by the removal of ascorbic acid, sodium benzoate and potassium sorbate. Preliminary tests performed to determine the optimal OBs concentration needed for the inoculation of groups of four instar larvae in agar and soy fiber diets revealed no virus inactivation in heated diets with a similar optimal concentration of 36?OBs?mg^?1 for both diets. Moreover, no significant differences were observed in OB production when each type of diet was used to inoculate groups of 250 larvae reared gregariously in plastic containers. Cool-textured diets could be of interest for the production of baculoviruses that require a diet that can be prepared quickly and easily.     

Zinc distribution in the small-intestinal digesta of pigs fed skim milk powder or defatted soybean flour

Zinc distribution in the small-intestinal digesta was studied in pigs fed a skim milk powder (SMP)-based or defatted soybean flour (DSF)-based diet. Ten pigs were fed experimental diets for 30 d. Serum and femoral zinc concentrations were lower in the DSF group than in the SMP group, suggesting the lower zinc availability in the DSF diet than in the SMP diet. In the digesta of small intestine, zinc solubility was higher in the SMP group than in the DSF group. A gel permeation high-performance liquid chromatography showed that the SMP group exhibited four zinc peaks in the chromatogram of the supernatant of digesta. The chromatogram in the DSF group showed four zinc peaks corresponding to those of the SMP group. However, the first zinc peak was smaller and the second peak was larger in the DSF group than in the SMP group. Dietary treatment did not affect the other peaks of zinc. Although the high solubility of zinc in the digesta of SMP group is considered to result in the high availability of zinc, the difference of zinc distribution in the liquid phase of digesta may partly affect zinc availability.     

Identification of 2,4-Dihydroxy-2,5-dimethyl-3(2H)-thiophenone as a Low-Molecular-Weight Yellow Pigment in Soy Sauce

The color of soy sauce is considered to be mainly attributable to melanoidins formed by the Maillard reaction. However, the chemical structure of melanoidins cannot be clarified, because melanoidins are high-molecular-weight heterogeneous polymers. We isolated a low-molecular-weight pigment from soy sauce and identified 2,4-dihydroxy-2,5-dimethyl-3(2H)-thiophenone as this pigment formed by the Maillard reaction, although its contribution to the total color of soy sauce was very low.     

Comparative Activities of the S-Enantiomer and Racemic Forms of Equol on Bone Fragility in Ovariectomized Mice

We compared the effects of the S-enantiomer and racemic forms of equol on bone using ovariectomized (OVX) mice. Femoral bone mineral density and bone strength decreased in the OVX mice, but not in OVX mice administered 0.5 mg/d S-equol. This, however, did not hold for racemic equol. Serum and urine S-equol concentrations were higher in the mice administered S-equol than in those administered racemic equol. These results suggest that the inhibitory effects of S-equol on bone fragility in OVX mice are greater than those of racemic equol.     

Genistein prevents the glucose autoxidation mediated atherogenic modification of low density lipoprotein

Hyperglycemia has been assumed to be responsible for oxidative stress in diabetes. In this respect, glucose autoxidation and advanced glycation end products (AGE) may play a causal role in the etiology of diabetic complications as e.g. atherosclerosis. There is now growing evidence that the oxidative modification of LDL plays a potential role in atherogenesis. Glucose derived oxidants have been shown to peroxidise LDL. In the present study, genistein, a compound derived from soy with a flavonoid chemical structure (4′, 5, 7-trihydroxyisoflavone) has been evaluated for its ability to act as an antioxidant against the atherogenic modification of LDL by glucose autoxidation radical products. Daidzein, (4′, 7-dihydroxyisoflavone) an other phytoestrogen of soy, was tested in parallel. Genistein — in contrast to daidzein — effectively prevented the glucose mediated LDL oxidation as measured by thiobarbituric acid-reactive substance formation (TBARS), alteration in electrophoretic mobility, lipid hydroperoxides and fluorescence quenching of tryptophan residues of the lipoprotein. In addition the potential of glucose-oxidized LDL to increase tissue factor (TF) synthesis in human endothelial cells (HUVEC) was completely inhibited when genistein was present during LDL oxidative modification by glucose. Both phytoestrogens did not influence the nonenzymatic protein glycation reaction as measured by the in vitro formation of glycated LDL. As the protective effect of genistein on LDL atherogenic modification was found at glucose/genistein molar ratios which may occur in vivo, our findings support the suggested beneficial action of a soy diet in preventing chronic vascular diseases and early atherogenic events.     

"豆皮"的表面结构修饰及其性能研究

以ＳＤＳ修饰“豆皮”的表面结构，赋予保鲜及复水的新性能豆皮的天然风味。