配方粉中脂溶性维生素稳定性分析研究

通过对配方粉中脂溶性维生素在前期生产加工和后期贮存过程中的稳定性研究,确定了主要影响因素,进而确认最佳的生产工艺以及适宜的贮存条件。试验结果表明,贮存温度和湿度、受热时间、光照等因素均会对维生素A的稳定性产生显著影响;光照因素对维生素D和维生素K的稳定性均会产生显著影响;贮存温度和湿度除对维生素A的稳定性产生显著影响外,还对维生素D和维生素E的稳定性产生显著影响。     

高效液相色谱法测定白牦牛乳B族维生素的方法研究

以ODS-C18(5μm,4.6 mm×150 mm)为色谱柱,庚烷磺酸钠离子对试剂(PIC-B7)和甲醇为流动相并采用梯度洗脱,在流速为1 mL·min-1、柱温为30℃条件下,用波长为275 nm的紫外检测器进行高效液相色谱法(HPLC)检测和分析白牦牛乳中B族维生素的含量.结果表明:白牦牛乳中维生素B3的含量最高...     

Comparative studies on chlorpyrifos and methyl parathion induced oxidative stress in different parts of rat brain: Attenuation by antioxidant vitamins

Organophosphate (OP) pesticides are among the most widely used synthetic chemicals for controlling a wide variety of pests. Chlorpyrifos (o,o′-diethyl-o-3,5,6-trichloro-2-pyridyl phosphorothionate, CPF) is among the leading OP pesticides used extensively throughout the world including India while methyl parathion (o,o-di methyl-o-p-nitrophenyl phosphorothioate, MPT) another OP compound, widely used as insecticide and acaricide to control many biting or sucking pests of agricultural crops. Present study was carried out to compare the chronic toxicity of CPF and MPT, their potential to generate oxidative stress and ameliorating effects of antioxidant vitamins in brain of rats. Results of the present study clearly demonstrated that the oral exposure of CPF or MPT, generated oxidative stress in different parts of rat brain consequently accumulating malondialdehyde (MDA) and 4-hydroxynonanal (4HNE), the two major end products of lipid peroxidation, in all the three brain regions i.e. fore-, mid- and hind-brain. The levels of hydrogen peroxide (H₂O₂) were also increased in all the three brain regions when compared with control. CPF and MPT exposure caused decrease in the levels of reduced glutathione (GSH) and increase in the levels of oxidized glutathione (GSSG) in all the three brain regions. The increase in the levels of MDA, 4HNE, H₂O₂ and GSSG was less pronounced when CPF or MPT was given to the rats fed with a mixture of vitamin A, E and C. The present findings clearly show that oral intake of a mixture of vitamin A, E and C protects the rats from MPT or CPF induced oxidative stress and suggest that this treatment alleviates the toxicity of these pesticides to a greater extent.     

HPLC法测定菠萝果实中8种维生素含量的研究

优化了利用高效液相色谱法测定菠萝果实中脂溶性维生素（VA、VE）和水溶性维生素（VC、 VB3、 VB12、 VB6、 VB2、 VB1）的方法; 脂溶性维生素以甲醇 ∶ 乙酸乙酯（V甲醇 ∶ V乙酸乙酯=95 ∶ 5）溶液为流动相, 流速为1.0 mL/min, 柱温25 ℃, 检测波长275 nm。 水溶性维生素以0.005 mol/mL己烷磺酸钠（pH3.2）∶ 甲醇（V乙烷磺酸钠∶ V甲醇=7∶ 3）为流动相, 流速为1.0 mL/min, 柱温30 ℃,于254 nm处测定吸光值。试验结果表明： 其线性相关系数在0.999 7～1.000 0之间, 线性关系良好。VA、 VE的峰面积RSD分别为1.48％、1.31％;VC、 VB3、 VB12、 VB6、 VB2和VBl的峰面积RSD分别为1.35％、 1.78％、 1.50％、 1.52％、 0.93％和1.10％。VA、 VC、 VB3、 VB6的平均加样回收率分别为94.2％、 102.3％、 91.0％、 95.2％。     

牛奶中抗氧化物质研究进展

牛奶易氧化腐败变质,牛奶中的抗氧化物质在维持牛奶营养品质稳定方面具有重要作用。作者综述了牛奶中重要的抗氧化物质及抗氧化机理,可为生产高品质牛奶和优化生产工艺提供资料。     

外源维生素对高NaCl胁迫下紫花苜蓿种子萌发及恢复性的影响

为给改进紫花苜蓿在盐碱地区的生产提供依据,笔者研究了14610 mg/L高浓度NaCl胁迫下,外源水溶性维生素（VB₁、VB₂、VPP、VB₆、VH、VB₁₂与VC）对紫花苜蓿种子萌发及恢复萌发性状的影响。结果表明：62.5 mg/L VPP显著提高了恢复萌发后的芽鲜重,1000 mg/L VB₆、500 mg/L VB₁₂和1000 mg/L VC促进了紫花苜蓿高盐胁迫下的萌发,但对胁迫减轻后的恢复萌发没有显著影响。250 mg/L VB₁₂对高盐胁迫下紫花苜蓿的萌发及恢复萌发均有显著性改进,使高NaCl的致死性从19.667%降低到4.667%。VB₁、VB₂和VH未能有效改进高NaCl胁迫对萌发的抑制效应。试验显示外源VB₆、VB₁₂、VC对高NaCl胁迫下紫花苜蓿种子的萌发特性有一定程度的调节作用。     

草莓中几种水溶性维生素的毛细管电泳测定

[目的]建立高效毛细管电泳同时分离和检测草莓中6种水溶性维生素的方法。[方法]采用高效毛细管电泳方法分离和测定维生素B1、B2、B6、C、PP和叶酸含量,同时研究了缓冲液pH值、电压、检测波长等对测定结果的影响。[结果]实现了6种水溶性维生素的同时分离,回收率为89.9%～97.8%。在柱温20℃,电压20kV,磷酸硼砂缓冲液pH值8.6,进样时间5s,检测波长265nm时,检测效果最好。[结论]建立了毛细管电泳同时测定草莓中6种水溶性维生素含量的方法,并为其他水果维生素的测定提供了依据。     

复合氨基多维乳剂提高肉鸡生长性能的研究

本试验将肉鸡分为4组,每组50只。药物混饲添加,分别为高剂量组（4ml／kg饲料）、中剂量组（2ml／kg饲料）、低剂量组（1ml／kg饲料）、空白对照组不用药。本品连续试验47天,试验过程中第18、30、43天称重,并计算平均值。结果表明,试验药物高、中剂量组肉鸡平均增重与其它试验组差异显著（t〉1.96,P〈0.05）;低剂量组与对照组差异不显著（t〈1.96,P〉0.05）,表明在同样情况下高、中剂量组试验效果较好。     

Nutritive value of different grape musts (Vitis vinifera L.)

Musts of 11 different grape sorts were analyzed for titratable acids, total sugars, nitrogen, vitamin B group (B₁, B₂, B₆, pantothenic acid) and macro- and micro elements (K, Ca, Mg, Fe, Zn, Cu, Mn, Mo). Analyses were done on samples collected in 1983 and 1984. The nutritive value of each sample was characterised by indices based on the nutrient concentrations and recommended dietary allowances (RDA). The nutritive values of the various grape must sorts were generally similar to those of the following vintage. Favourable climatic conditions had a positive effect on the nutritive values.     

Serial determination of biomarkers of oxidative stress and antioxidant status in dogs with naturally occurring gastric dilatation-volvulus

Objective: To serially determine the biomarkers of oxidative stress and antioxidant status of dogs with gastric dilatation‐volvulus (GDV) over 48 hours. Design: Prospective study. Setting: Veterinary teaching hospital intensive care unit. Animals: Thirteen client‐owned dogs with GDV. Interventions: None. Measurement and main results: For all dogs, biomarkers of oxidative stress and antioxidant status were ascertained. Indicators of oxidative stress measured included F_2α‐isoprostanes (isoprostanes) and malondialdehyde (MDA). Vitamin C, vitamin E, glutathione peroxidase (GSHPx), and oxygen radical absorbance capacity (ORAC) were measured to assess antioxidant status. Oxidants and antioxidants were measured at the time of admission and at 24 and 48 hours post‐admission. There were significant decreases in vitamin E (P=0.002), vitamin C (P=0.001), ORAC (P=0.02), and MDA (P=0.001) during hospitalization. There was no significant change in GSHPx and isoprostane concentrations over time. Conclusion: Oxidative stress and antioxidant capacity in dogs with GDV change over time. Further studies measuring oxidative stress in more severely affected dogs and performing measurements earlier in the disease process may be beneficial in determining when oxidative stress is most severe during the course of GDV management.