抗氧化剂(BHT)对小孩酥糖中油脂抗氧化酸败效果的研究

小孩酥糖是以花生为主体原料制成的 ,是徐州地区名特食品之一。但由于该产品含油脂较高 (约为酥糖总量的2 0 % ) ,容易发生油脂酸败。为使该产品一年四季都能满足人们的需要 ,特在产品中加入抗氧化剂 2 ,6二叔丁基对甲酚(BHT) ,以期达到延长保质期的效果。1　材料与方法1.1　材料1 1 1　BHT的含量　小孩酥糖加入BHT的量 (g/kg) (以脂肪计 ) 0组不含BHT ;1组 0 0 5g/kgBHT ;2组 0 10g/kg ;3组 0 2 0g/kg。1 1 2　检验项目　酸价 ,过氧化值 ,羰基价。1 1 3　试验条件　 3 5℃恒温与秋冬季自然温度 (〈2 0℃ )库房存放。1 2　测定方法…     

用高效液相色谱法同时测定油脂中的9种抗氧化剂

研究了分离和测定油脂中9种酚类抗氧化剂的反相高效液相色谱法，以甲醇-水-乙醇体系为流动相，采用梯度洗脱，可在30min内将9种物质完全分离并进行定量测定。经性范围为1&;#215;10^-6～200&;#215;10^-6（r=0.9985～0.9997），检出限为2&;#215;10^-6，回收率为82.4%～98.7%，相对标准偏差为1.01%～4.74%。方法具有快速、简便、准确的特点。     

油脂过氧化值的检测结果分析

油脂是人们膳食中的重要组成部分,是提供体内脂肪的主要来源,也是机体内热能的主要供给者之一。油脂在光、热、放射线、过渡金属离子等因素的存在下,其不饱和脂肪酸会吸收空气中的氧,进行自动氧化反应,油脂经自由基反应历程,产生脂     

食品油脂过氧化值测定方法的研究

当前油类市场的混乱层出不穷，其中以泔水油现象为主。实践中以现行方法对之进行检测还有很多不确定性，而过氧化值是鉴定食品中油类物质好坏的主要方法。为此，从油脂发生酸败的机理出发，以国标法、行业标准及各文献资料进行分析，以探讨更好的方法。     

碘量比色法测定食品油脂中过氧化值的研究

「目的」就碘量比色法测定油脂中过氧化值含量的方法进行研究。「方法」油脂中的过氧化物与碘化钾作用生成游离碘,在酸性条件下与淀粉显蓝色,在含碘量为２￣１０μｇ时符合郎伯－比尔定律。「结果」在油脂取样量为０．００５￣０．０５ｇ时,其过氧化值的灵敏度为０．０６￣８５ｍｅｑ／ｋｇ,变异系数为２．７８％。「结论」本法与国标碘量滴定法相比,无显著性差异（Ｐ〉０．０５）。但具有快速、简便、用样量少的特点。     

油脂中过氧化值的分光光度测定法

目的建立油脂中过氧化值的分光光度测定方法。方法在无水酸性条件下,油脂中的过氧化物使I-定量的氧化成I2,I2与I-结合生成易溶于水的I3-,利用I3-的颜色与标准碘液进行比较定量。结果该方法牟精密度与准确度试验结果其变异系数为1.53%～6.19%;回收率为86%～108%。分光光度法测定油脂中的过氧化值与国家标准检验方法比较差异无统计学意义(t=0.11,P0.05)。结论方法简单易行,准确可靠,灵敏度高,适合于基层大批量样品的检测分析。     

不同储存时间对未精练油脂过氧化值的影响

油脂在储存过程中,因油脂氧化酸败使其过氧化值升高。但不同的油脂由于所含成分的差异,其酸败程度不同;同一种油脂由于加工及储存方法不同,其酸败程度也不完全一致。本文采用含单不饱和脂肪酸较高的茶油及含多不饱和脂肪较高的麻油,对其刚压榨出的毛油经储存一段时间后的过氧化值进行了测定,现报道如下。1 材料和方法1．1 仪器与试剂(1)酸式滴定仪(2)饱和碘化钾溶液(3)三氯甲烷—冰乙酸混合液:取40ml三氯甲烷,加60ml冰乙酸混匀。(4)0.002N硫代硫酸钠标准掖(5)1%淀粉指示剂     

分光光度法测定油脂过氧化值

测定油中的过氧化值,是对油中卫生指标效果的客观评价。目前报道的方法有碘滴定法,简易比色法。但因试样量,放置时间,溶剂,温度的改变,结果也有所不同。为此,我们建立操作简便,快速,精密度和准确度均接近于部颁法(以下简称甲法)分光光度法测定油中过氧化值的新方法(以下简称乙法),经实际用效果良好。1 原理 在酸性条件下,油中的过氧化物能快速氧化碘离子,碘与淀粉呈兰色,显色的深浅与含碘量成正比,与标准系列比色定量。     

复合抗氧化剂对局部放疗荷瘤大鼠外周血保护作用研究

目的　探讨复合抗氧化剂对荷瘤大鼠局部放疗时外周血损伤的保护作用。方法　采用Walker- 2 5 6肿瘤细胞株制成大鼠荷瘤模型 ,将荷瘤大鼠分成 3组 ,分别为模型对照组 (TG)、单纯放疗组 (RG)和抗氧化剂保护组 (PG) ,同时选取正常大鼠作为阴性对照组 (NCG)。抗氧化剂保护组每日给予复合抗氧化剂灌胃。分次对单纯放疗组和抗氧化剂保护组的荷瘤大鼠进行 6 0 Coγ射线局部放疗 4次 ,每次间隔 1wk,累计照射剂量为 4 7Gy,最后一次放疗后 7d,处死大鼠 ,测定外周血各项细胞指标的变化。结果　与模型对照组相比较 ,单纯放疗组动物外周血中 WBC、RBC、HGB、PL T、MCV、MPV、PDW、L YM%显著降低 (P <0 .0 5 ) ,MCH、MCHC、RDW、MON%和 GRA%显著升高 (P <0 .0 5 ) ,而抗氧化剂保护组与单纯放疗组相比较呈现出了显著的拮抗作用。结论　局部放疗可以引起全身的血液损伤 ,而抗氧化剂可以起到有效的保护作用 ,这为临床减轻放疗副作用、有效杀灭肿瘤细胞提供了一条新的研究思路     

Determination of five phenolic antioxidants in edible oils: Method validation and estimation of measurement uncertainty

An analytical protocol and the measurement uncertainty for determination of butylated hydroxylanisole, butylated hydroxyltoluene propyl gallate, octyl gallate and dodecyl gallate in edible oils were reported. Details of the validation including application of certified reference materials and participation in proficiency tests were discussed. Traceability of measurement was established through traceable standards and calibrated volumetric equipment and measuring instruments. The protocol, comprising a TLC screening step, quantification by gas chromatography-flame ionization detection (GC-FID) and high performance liquid chromatography-photodiode array detection (HPLC-PDA) techniques, and unequivocal confirmation by mass spectrometry or a second chromatographic technique, provides a reliable and validated means for fast turnaround and high sample throughput analysis of the five antioxidants in edible oils. This protocol was also found to be applicable to other fat-containing food matrices.     

Impact of high-dose antioxidants on outcomes in acutely injured patients

BACKGROUND: The profound oxidative stress that occurs following injury results in significant depletion of many endogenous antioxidants (vitamin C, E, selenium). Increasing evidence suggests antioxidant supplementation reduces infectious complications and organ dysfunction following injury and hemorrhagic shock. The purpose of this study was to evaluate the impact of high-dose antioxidant administration on the mortality rate of acutely injured patients. METHODS: In October 2005, we implemented a 7-day high-dose antioxidant protocol for acutely injured patients admitted to our trauma center. A retrospective cohort study, evaluating all patients admitted to the trauma service between October 2005 and September 2006 following protocol implementation (AO+), was performed. The comparison cohort (AO-) was made up of those patients admitted in the year prior to protocol implementation. RESULTS: A total of 4,294 patients met criteria (AO+, N = 2,272; AO-, N = 2022). Hospital (4 vs 3 days, P < .001) and ICU (3 vs 2 days, P = .001) median length of stays were significantly shorter in the AO+ group. Mortality was significantly lower in the AO+ group (6.1% vs 8.5%, P = .001), translating into a 28% relative risk reduction for mortality in patients exposed to high-dose antioxidants. After adjusting for age, gender, and probability of survival, AO exposure was associated with even lower mortality (OR 0.32, 95% CI 0.22-0.46). Patients with an expected survival <50% benefited most (OR 0.24, 95% CI 0.15-0.37). CONCLUSIONS: A high-dose antioxidant protocol resulted in a 28% relative risk reduction in mortality and a significant reduction in both hospital and ICU length of stay. This protocol represents an inexpensive intervention to reduce mortality/morbidity in the trauma patient.     

Screening of the antiradical action of vegetable oils

Information on radical scavenging activity (RSA) and antioxidant potential of vegetable oils are not reported, or reporting has been rather limited. Such data is of importance for the evaluation of nutritional and health impact of these oils. The main objective of this short study was to compare the antiradical performance of some common and unusual vegetable oils. The described arrangement for our simple experiment uses the addition of stable radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) to vegetable oils, which are decomposed by components having antioxidant properties. The order of effectiveness of oils in inhibiting free radicals was as follows: coriander>blackcumin>cottonseed>peanut>sunflower>walnut>hemp seed>linseed>olive>niger seed. This initial survey might serve as a springboard for future research into this area.     

The toxicity of commercial jet oils

Jet oils are specialized synthetic oils used in high-performance jet engines. They have an appreciable hazard due to toxic ingredients, but are safe in use provided that maintenance personnel follow appropriate safety precautions and the oil stays in the engine. Aircraft engines that leak oil may expose others to the oils through uncontrolled exposure. Airplanes that use engines as a source of bleed air for cabin pressurization may have this source contaminated by the oil if an engine leaks. Examination of the ingredients of the oil indicates that at least two ingredients are hazardous: N-phenyl-1-naphthylamine (a skin sensitizer) and tricresyl phosphate (a neurotoxicant, if ortho-cresyl isomers are present). Publicly available information such as labels and MSDS understates the hazards of such ingredients and in the case of ortho-cresyl phosphates by several orders of magnitude.     

印刷包装行业VOCs污染对工人体内抗氧化指标的影响

目的研究印刷包装行业VOCs污染对工人体内抗氧化指标的影响。方法使用紫外-可见分光光度法和荧光光度法测定从业工人血清超氧化物歧化酶(SOD)活性、组织抗氧化能力(GSHPxLPO)、维生素C(VC)、维生素E(VE)含量。结果印刷包装工人血清中SOD活力为(112.58±16.56)Uml,高于正常对照组(P<0.01);组织抗氧化能力为(105.43±63.87)Uml,VC含量为(15.46±9.05)μgml均低于对照组(P<0.01),VE含量为(7.6±3.16)μgml与对照组相比差异无显著性。结论印刷包装行业存在的VOC污染导致从业工人的抗氧化水平降低。     

Toxicological characteristics of refinery streams used to manufacture lubricating oils

In the past, reports on the tumorigenic potential of lubricating oils in experimental animals have poorly defined the materials under study. In this paper the results of mouse skin painting studies with 46 clearly defined samples of refinery streams associated with lubricating oil processing show that modern conventional solvent refining of distillates removes tumorigenic potential while conventional acid refining may not. Furthermore, dewaxing, hydrofinishing, and clay treatments do not appear to mitigate the tumorigenicity of the lubricant distillates. Lubricant processing has changed over the years and assessments of the carcinogenicity of present-day lubricating materials must be based on knowledge of modern processing.     

Protective effects of B vitamins and antioxidants on the risk of arsenic-related skin lesions in Bangladesh

BACKGROUND: An estimated 25-40 million of the 127 million people of Bangladesh have been exposed to high levels of naturally occurring arsenic from drinking groundwater. The mitigating effects of diet on arsenic-related premalignant skin lesions are largely unknown. OBJECTIVES: The purpose of this study was to clarify the effects of the vitamin B group (thiamin, riboflavin, niacin, pyridoxine, and cobalamin) and antioxidants (vitamins A, C, and E) on arsenic-related skin lesions. METHODS: We performed a cross-sectional study using baseline data from the Health Effects of Arsenic Longitudinal Study (HEALS), 2000-2002, with individual-level, time-weighted measures of arsenic exposure from drinking water. A total of 14,828 individuals meeting a set of eligibility criteria were identified among 65,876 users of all 5,996 tube wells in the 25-km(2) area of Araihazar, Bangladesh; 11,746 were recruited into the study. This analysis is based on 10,628 subjects (90.5%) with nonmissing dietary data. Skin lesions were identified according to a structured clinical protocol during screening and confirmed with further clinical review. RESULTS: Riboflavin, pyridoxine, folic acid, and vitamins A, C, and E significantly modified risk of arsenic-related skin lesions. The deleterious effect of ingested arsenic, at a given exposure level, was significantly reduced (ranging from 46% reduction for pyridoxine to 68% for vitamin C) for persons in the highest quintiles of vitamin intake. CONCLUSIONS: Intakes of B-vitamins and antioxidants, at doses greater than the current recommended daily amounts for the country, may reduce the risk of arsenic-related skin lesions in Bangladesh.     

Genotoxic effect of bile acids on human normal and tumour colon cells and protection by dietary antioxidants and butyrate

BACKGROUND: Colorectal cancer is the second cause of death for tumour worldwide. Among the risk factors for this disease the dietary habits seem to have a pivotal role. An elevated intake of fats causes a high release in the gut lumen of bile acids that are positively correlated with colorectal cancer, since they act as detergents and proliferation promoters. Recently, it was evidenced that bile acids can also be able to induce DNA damage. AIM OF THE STUDY: In this study the genotoxicity of deoxycholic acid (DCA) and chenodeoxycholic acid CDCA) has been evaluated in human normal colonocytes derived from 60 colon biopsies and in tumour cells. The involvement of reactive oxygen species (ROS) and the oxidative DNA damage was assessed. In addition, the protective effect exerted by both two well-known antioxidants commonly present in the diet, beta-carotene and alpha-tocopherol, and butyrate which is known to be involved in the regulation of several cellular functions, has also been tested. METHODS: The DNA damage was evaluated by the "comet assay" or single cell gel electrophoresis (SCGE) both in its conventional use and by the Endonuclease III modified method, which allow to detect the presence of oxidized pyrimidines. RESULTS: Bile acids (CDA and CDCA) resulted genotoxic on both normal and tumour human colon cells. The inclusion of the endonuclease III digestion step in the comet assay demonstrated that bile acids induced an oxidative DNA damage. In addition, treatment of colonocytes with bile acids in the presence of the antioxidants (beta-carotene, alpha-tocopherol) and Na-butyrate caused a reduction of DNA damage. CONCLUSION: Our results suggest that bile acids may be involved in the tumour initiation by inducing a DNA oxidative damage, and so add further evidences to the preventive properties of antioxidants present in the Mediterranean diet.     

二溴海因对几种微藻杀灭效应的研究

目的 系统研究二溴海因对于三角褐指藻、小球藻、淡水混合藻、海水混合藻等藻类样本的杀灭效果.方法 模拟船舶压载水处理方式,利用二溴海因杀灭微藻.结果 各藻类样本在经过二溴海因处理后48h死亡率达到最高值.有效溴浓度为6ppm时,二溴海因对于4种藻体杀灭效果依次为:三角褐指藻100.00%,淡水混合藻97.04%,小球藻9...