黄豆中有机氯和拟除虫菊酯类农药多组分残留的气相色谱法测定研究

目的：以加速溶剂萃取技术和凝胶渗透色谱法处理样品,建立气相色谱法测定黄豆中有机氯和拟除虫菊酯类农药多组分残留的方法。方法：样品经加速溶剂萃取,凝胶渗透色谱净化,浓缩后由气相色谱法测定,进行准确度、精密度及线性试验。结果：α-HCH、β-HCH、γ-HCH、δ-HCH、ρ,ρ′-DDE、O,ρ′-DDT、ρ,ρ′-DDD、ρ,ρ′-DDT、氟氯氰菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯的检测限范围为0.357-7.468μg/kg,回收率在78.4%-116.0%之间,相对标准偏差均小于8.0%。结论：方法快速简便,回收率、精密度较好,符合检测要求,适合于豆类食品中多种有机氯和拟除虫菊酯类农药的测定。     

Subchronic feeding study of herbicide–tolerant soybean DP-356Ø43-5 in Sprague–Dawley rats

Optimum™GAT™ ¹ soybean is a genetically modified (GM) soybean containing event DP-356Ø43-5 (356043) that was produced by integration of the coding sequences of the GAT4601 and GM–HRA proteins. In planta expression of these proteins confers tolerance to glyphosate and sulfonylurea/imidazolinone herbicides, respectively. This paper reports the results from a subchronic rat feeding study conducted with 356043 soybeans. Dehulled/defatted toasted meal and toasted ground hulls were prepared from soybeans from untreated plants (356043), herbicide-treated plants (356043 + Gly/SU), non-transgenic isoline control (091), and three commercial non-transgenic reference varieties (93B86, 93B15, and 93M40). Individual diets conforming to standard certified rodent chow formulation (Purina Rodent LabDiet^® 5002) were prepared with 20% meal (w/w) and 1.5% hulls (w/w). Diets were fed to young adult Sprague–Dawley rats (12/sex/group) for at least 93 days. Compared with rats fed the isoline control or conventional reference diets, no biologically-relevant, adverse effects were observed in rats fed diets containing 356043 or 356043 + Gly/SU soybean with respect to body weight/gain, food consumption/efficiency, clinical signs, mortality, ophthalmology, neurobehavioral assessments (sensory response, grip strength, motor activity), clinical pathology (hematology, coagulation, serum chemistry, urinalysis), organ weights, and gross and microscopic pathology. The results from this study indicate that 356043 soybeans are as safe and nutritious as conventional non-GM soybeans.     

豆油对螺旋霉素发酵的影响

以螺旋霉素链霉菌SPM1 1 0 8为出发菌株 ,经波长为 2 54nm、功率 30W的紫外诱变处理 50s,筛选豆油耐性突变株 ,得到一株螺旋霉素高产菌株SPM2 89,其发酵效价较出发菌株提高了 2 2 5 %。以此为试验菌株 ,采用含豆油培养基进行发酵试验 ,结果表明 ,豆油的最佳加入量为 2 0 % ,加入时间以 0～ 1 2h为宜。采用上述含豆油培养基并补加前体正丙醇 ,发酵效价比不添加前体提高 2 1 %。此工艺应用于 50m3发酵罐工业生产 ,月平均发酵水平较原工艺提高 30 %～ 50 % ,产品质量稍有提高     

Melatonin-loaded lecithin/chitosan nanoparticles: Physicochemical characterisation and permeability through Caco-2 cell monolayers

In this study, the potential of lecithin/chitosan nanoparticles (NPs) as a mucoadhesive colloidal nanosystem for transmucosal delivery of melatonin was investigated. The size, zeta potential and melatonin loading of the lecithin/chitosan NPs were investigated as a function of lecithin type (Lipoid S45, S75 and S100) and chitosan content in the preparation. The NPs were characterised by mean diameter and zeta potential ranging between 121.6 and 347.5 nm, and 7.5 and 32.7 mV, respectively, and increasing with lecithin-negative charge and chitosan content in the preparation. Melatonin loadings were up to 7.1%. All NPs were characterised by prolonged release profiles with an initial burst (approximately 25%), followed by a slow release phase. Approximately 60–70% of melatonin was released in 4 h. The permeability of melatonin was investigated using Caco-2 cells as an in vitro model of the epithelial barrier. Melatonin permeability from an NP suspension prepared with Lipoid S45 lecithin and a lecithin-to-chitosan weight ratio (L/C) of 20:1 (sample C2) was significantly improved compared to the permeability of melatonin from the solution (P < 0.001) and from all other NPs investigated (P < 0.05). The results obtained by the cell viability studies (MTT and LDH leakage assays) showed that C2 NP suspension did not induce plasma membrane damage or decrease cell viability and could be safely applied to Caco-2 cells in the concentration range tested (<400 μg/ml).     

脂肪乳剂对食管癌术后应激反应和免疫功能的影响

目的：探讨脂肪乳剂对食管癌术后应激反应和免疫功能的影响。方法：采用前瞻性随机对照设计，将３３例食管癌切除术病人随机分为两组，A组（15例）为对照组，接受不含脂肪乳剂的肠外营养，B组（18例）接受含有脂肪乳剂的肠外营养。两组病人的一般临床情况、营养热量分布一致。分别于术前、术后不同时段测定血清中皮质醇、IL－6和IL－10、T细胞亚群、NK细胞活性、免疫球蛋白和血清蛋白浓度。结果：术后第1、3天两组病人血清皮质醇和IL－6水平均显著升高（P＜0．01），且B组显著高于A组。术后两组CD3^ 、DC4^ 、CD4^ /CD8^ 均显著降低（P＜0．01）。术后10天B组CD4^ /CD8^ 比值显著低于A组（P＜0．05）。术后3天CD4^ /CD8^ 比值与血清皮质醇呈显著正相关，亦与术后第1天IL－6水平呈显著正相关。然而，术后血清IgA、IgM、IgG水平无显著变化，两组间亦无显著差异。结论：含大剂量亚油酸的脂肪乳剂能提高机体的应激反应及应激诱导的免疫抑制。     

Effect of Fermented Soybean Meal on Intestinal Morphology and Digestive Enzyme Activities in Weaned Piglets

The objective of the current experiment was to investigate the effect of Bacillus subtilis fermented soybean meal (FSBM) on intestinal morphology and digestive enzyme activities in piglets. Sixty crossbred (Duroc×Landrance×Yorkshire) piglets at an average weight of 8.62 kg were randomly allotted to two treatments and fed diets containing soybean meal (SBM) and FSBM, respectively. At the end of the experimental period, six piglets of each treatment were slaughtered humanly to collect the contents and tissue samples at three different locations in small intestine. Light microscopy and scanning electron indicated that piglets fed FSBM had a higher (P<0.05) villus height at three different locations of small intestine and had la ower (P<0.05) crypt depth in the duodenum compared to piglets fed SBM. The results showed that activities of total protease and trypsin at the duodenum and jejunum of piglets fed with FSBM increased (P<0.05) compared with the control. The trypsin activity in the pancreas of piglets decreased (P<0.05) when they were fed with FSBM. The results showed that FSBM improved intestinal morphology and digestive enzyme activities in weaned piglets.     

高效液相色谱法同时测定大豆异黄酮多种组分

目的建立同时测定保健食品中大豆异黄酮多种组分的高效液相色谱法。方法样品中的大豆异黄酮采用甲醇＋水提取,经C18柱分离,在紫外检测器254nm波长处检测。结果此方法的回收率为91．9％～102．0％,RSD为2．5％。结论此方法操作简单,准确可靠,为保健食品中大豆异黄酮含量的检测提供参考。     

Assessment of the contents of phytic acid and divalent cations in low phytic acid (lpa) mutants of rice and soybean

The objective of the study was to investigate the influence of mutational breeding on the contents of nutritionally relevant minerals in low phytic acid (lpa) mutants compared to their wild-types. Three lpa rice (Os-lpa-XQZ-1, Os-lpa-XS110-1, Os-lpa-XS110-2) and two lpa soybean mutants (Gm-lpa-TW75-1, Gm-lpa-ZC-2) were analyzed regarding their contents of phytic acid, lower inositol phosphates and the minerals calcium, iron and zinc. Additionally, cadmium was included into the spectrum of divalent cations analyzed. The phytic acid reduction in lpa rice was consistently more pronounced in Os-lpa-XS110-1 than in Os-lpa-XQZ-1 and Os-lpa-XS110-2. However, only for Os-lpa-XQZ-1, levels of calcium, iron and zinc were found to be consistently increased, whereas the cadmium level was shown to be predominantly decreased compared to the wild-type. Investigation of the two lpa soybean mutants, characterized by absence (Gm-lpa-TW75-1) and accumulation (Gm-lpa-ZC-2) of lower inositol phosphates, respectively, revealed no consistently decreased or increased contents of calcium, iron, zinc and cadmium. The data do not change the view that lpa mutations do not result in systematic increases or decreases of mineral contents in these crops. However, on the basis of the molar ratios of phytate/minerals in lpa rice and soybean mutants which are considered as predictive parameters, an improved bioavailability of minerals in the lpa materials can be expected.     

Estrogens in the daily diet: In vitro analysis indicates that estrogenic activity is omnipresent in foodstuff and infant formula

Food is a main source of exposure to endocrine active compounds, many of which have been linked to adverse health effects. Phytoestrogens, especially from soy, are the major dietary source of estrogenicity. However, foodstuff contains a variety of estrogen-like compounds that might not be detected analytically.To assess the total estrogenic activity of foodstuff, we employed the Yeast Estrogen Screen (YES). We analyzed 18 food samples and five milk-based infant formulas. Soy-based products contained potent estrogenicity of 100-1500 ng estradiol equivalents per kilogram (EEQ/kg). The estrogenicity in soy-free products was far lower (10-40 ng EEQ/kg). We also detected significant estrogenic activity in three infant formulas (14-22 ng EEQ/kg).Furthermore, we found soy lecithin to be strongly estrogenic. It might, therefore, be a major contributor to total estrogenicity. We conclude that dietary estrogens are omnipresent and not limited to soy-based food.In an exposure assessment we calculated a total dietary intake of 27.5 and 34.0 ng EEQ/d for adults and 1.46 ng EEQ/d for infants. While the dietary exposure to estrogenic activity is lower than previously estimated, our results demonstrate that many food types are a source of unidentified estrogen-like compounds still awaiting toxicological evaluation.