维生素E酯衍生物稳定性能及其在食品中的应用研究

为了研究维生素E酯衍生物的稳定性能及其应用注意事项，本文探讨了水分、温度、pH值、脂肪酶、血清等因素对维生素E醋酸酯化学稳定的影响，并比较了游离维生索E与维生素E醋酸酯在油脂抗氧化性能方而的区别。结果表明维生素E乙酸酯在较低温度含水溶液中基本不解离；在较高温的酸性或碱性含有水条件下，维生素E乙酸酯有一定程度的解离；而在含有脂肪酶的体系中，维生素E乙酸酯十分容易解离。维生素E乙酸酯和游离的维生素E的生理活性基本相同，但是在化学稳定性和抗氧化性能方面有着明显的区别。为了提高维生素E的使用效率，在食品或保健品的生产过程中，应根据生产或产品的实际需要添加适当形式的维生素E。     

天然D-α-维生素E

天然D－α－维生素E是一种高品质的天然维生素E。本郑重介绍天然维生素E的分类,天然D－α－维生素E与合成维生素的差异以及天然D－α－维生素E先进的制备技术;国内外天然维生素E技术水平的差异;新昌制药厂在研制开发天然D－α－维生素E上所做的工作。     

SO_4~(2-)/A-TiO_2催化合成维生素E亚油酸酯工艺研究

利用催化剂固体超强酸SO_4~(2-)/A-TiO_2合成维生素E亚油酸酯,研究了亚油酸酰氯与维生素E摩尔比、反应温度、SO_4~(2-)/A-TiO_2用量、反应时间对维生素E亚油酸酯产率的影响,以单因素试验为基础,利用响应面法优化了工艺条件。结果表明,SO_4~(2-)/A-TiO_2催化合成维生素E亚油酸酯最佳工艺条件为:亚油酸酰氯与维生素E摩尔比2.9∶1,反应温度45.6℃,SO_4~(2-)/A-TiO_2用量4.8%(以维生素E质量计),反应时间3.5 h。在最佳工艺条件下,维生素E亚油酸酯产率达到93.3%。维生素E亚油酸酯与维生素E相比具有更持久的抗氧化性能。     

维生素E乙酸酯的合成及其在卷烟中的应用

以维生素E和乙酸酐为原料,合成了维生素E乙酸酯,经HPLC分析纯度达98%,结构经1HNMR、13CNMR和EI-MS确征。将合成的维生素E乙酸酯添加至卷烟烟丝中,卷烟烟气分析结果表明,维生素E乙酸酯能增加主流烟气中的维生素E;卷烟评吸实验表明,添加维生素E乙酸酯能减少卷烟的刺激,改善卷烟的柔和口味,具有烟气细腻、提高卷烟品质的效果。     

开发天然维生素E市场前景广阔

介绍了国内外维生素E的提取应用现状和我国在植物油脱臭馏出物中提取维生素E的进展,对开发我国维生素E生产的前景进行了探讨。     

油脂和机体的最佳抗氧化剂——维生素E

介绍了有关维生素E生理功能的近期研究结果,维生素E同系物的8种结构及其在有机体内的活性等;α-维生素E是最佳氧自由基清除剂,摄取正常膳食即可保证维生素E的供应.     

天然维生素E提取工艺研究进展

天然维生素E是一种具有良好生理功能和药理价值的抗氧化剂,具有广阔的开发前景和市场需求。综述了天然维生素E的性质、应用及提取方法,重点介绍了国内外提取天然维生素E的生产工艺,进展情况,对今后开展天然维生素E的进一步深入研究具有一定参考价值。     

糙米中的维生素E有抑制癌细胞作用

粗米胚芽中含有维生素E,维生素E为脂溶性的。众所周知,如果缺乏维生素E,妇女就患不孕症,此外维生素E可防止人体老化,为了维持人体细胞膜的正常机能,维生素E是一不可少的有效成份。     

维生素E对猪肉品质的影响

主要介绍维生素E独特的抗氧化作用,以及维生素E是如何支持肉类的稳定性。此外,还介绍了维生素E的作用方式,添加要求和功效。     

天然维生素E琥珀酸酯的制备

维生素E琥珀酸酯有比维生素E更强的化学稳定性,同时其还有抗癌功效,是水溶性维生素E--TPGS的基本原料.介绍了用天然维生素E酯化制备维生素E琥珀酸酯的方法,选用三乙胺作为催化剂制备维生素E琥珀酸酯.通过实验优化后得到优化的工艺条件为(原料50 g):反应时间为4.0 h、琥珀酸酐用量为原料维生素E的150%(W/W)、催化剂用量为5.0 mL、反应温度为55℃.在优化的工艺条件下,维生素E酯化率为93.91%.     

Effect of Cooking Method,Distiller's Grains,and Vitamin E Supplementation on the Vitamin Content of Value Cuts from Beef Steers Fed Wet Distiller's Grains and Solubles and Supplemental Vitamin E

ABSTRACT: Vitamin E, thiamin, riboflavin, niacin, vitamin B₆, and vitamin B₁₂ concentrations of flat iron steaks and petite tenders from steers fed finishing rations containing 0% and 40% corn wet distiller's grains and solubles (WDGS) with and without supplemental vitamin E were determined. Feeding treatment groups were: 0% WDGS with basal vitamin E, 0% WDGS with supplemental vitamin E (500 IU daily), 40% WDGS with basal vitamin E, and 40% WDGS and supplemental vitamin E. Cattle can be fed 40% WDGS diets more economically than corn diets. The incorporation of 40% WDGS, with and without vitamin E, was hypothesized to have little effect on the vitamin concentrations of these value meat cuts. Flat iron steaks and petite tenders were broiled and/or grilled to 70 °C internal temperature. Mean cooking yields ranged from 68.7% to 78.2%. The majority of the vitamin concentrations of broiled and of grilled meat were significantly different (P < 0.05) from that of raw meat. Vitamin E concentrations of raw and cooked meat from steers that received supplemental vitamin E were significantly higher (P < 0.05) than those fed basal vitamin E. Significant differences in thiamin, riboflavin, vitamin B₆, and vitamin B₁₂ concentrations in raw flat iron steaks and in vitamin B₆ in raw petite tenders were observed by WDGS. Thiamin, vitamin B₆, and vitamin B₁₂ concentrations of broiled flat iron steaks were significantly different (P < 0.05) than grilled. A few differences in vitamin concentrations of the flat iron steaks and petite tenders were observed by WDGS, vitamin E supplementation, and cooking treatments, but most of the vitamin concentrations were statistically similar.     

钙和磷对小麦胚芽愈伤组织维生素E积累的影响

考查培养基中钙元素和磷元素的含量对小麦胚芽愈伤组织维生素E积累的影响,建立维生素E积累和细胞生长的动力学模型.以次生代谢产物维生素E积累最多为目标,通过实验优化确定钙磷含量的最佳组合.结果表明,当B5培养基中CaCl_2·2H_2O为150mg/L,NaH_2PO_4·H_2O为300mg/L时,有利于维生素E积累.维生素E积累的动力学模型的拟合度为97.96%,细胞干重的动力学模型拟合度为95.57%,非线性关系良好.大量元素钙和磷对小麦胚芽愈伤组织维生素E积累有影响,磷元素较钙元素的影响显著.     

Vitamin E and its anticancer effects

Abstract

Vitamin E is a lipid soluble vitamin comprising of eight natural isoforms, namely, α, β, δ, γ isoforms of tocopherol and α, β, δ, γ isoforms of tocotrienol. Many studies have been performed to elucidate its role in cancer. Until last decade, major focus was on alpha tocopherol and its anticancer effects. However, major clinical trials using alpha-tocopherol like SELECT trial and ATBC trial did not yield meaningful results. Hence there was a shift of focus to gamma-tocopherol, delta-tocopherol and tocotrienol. Unlike alpha-tocopherol, gamma-tocopherol and delta-tocopherol can scavenge reactive nitrogen species in addition to reactive oxygen species. Antiangiogenic effect, inhibition of HMG CoA reductase enzyme and inhibition of NF-κB pathway make the anti-cancer effects of tocotrienols unique compared to other vitamin E isoforms. Preclinical research on non-alpha tocopherol isoforms of vitamin E showed promising data on their anticancer effects. In this review, we deal with the current understanding on the potential mechanisms involved in the anticancer effects of vitamin E and the controversies in this field over last three decades. We also highlight the need to conduct further research on the anticancer effects of non-alpha-tocopherol isoforms in larger population and clinical setting.     

Mammary transfer of vitamin E in cows treated with vitamin A or linoleic acid

The effect of an intravenous injection of vitamin A alcohol and subcutaneous injections of linoleic acid on the mammary transfer of an intravenous injection of vitamin E acetate was studied with 15 Holstein cows. The cows received either an intravenous injection of 3 g vitamin E acetate (controls), intravenous injections of 3 g vitamin E acetate and 1 million IU vitamin A alcohol, or an intravenous injection of 3 g vitamin E acetate and subcutaneous injections totaling 40 g of linoleic acid. Milk samples were at 12-h intervals, two prior to and six following treatment. The main influence of vitamin A alcohol and linoleic acid on mammary transfer of vitamin E was to delay secretion of vitamin E in milk. However, total secretion of vitamin E was not reduced by injection of either vitamin A alcohol or linoleic acid. Vitamin E injection produced substantial increases in vitamin E in milk, but less than 1% of the dose could be accounted for in the milk.     

我国天然维生素E产业化前景初探

为了探讨我国天然维生素E产业化的前景，基于国内外天然维生素E生产现状与市场前景，提出我国天然维生素E产业化发展建议，不断完善和提高工艺技术、提高多品种开发能力，对发展我国天然维生素E产业具有重要的促进作用。     

Bovine neutrophil responses to parenteral vitamin E.

Twenty-eight Holsteins were tested to determine effects of dietary and parenteral vitamin E supplementation during the dry period on plasma alpha-tocopherol and in vitro neutrophil functions at calving. Cows were assigned to one of four experimental groups receiving either supplemental dietary vitamin E, injections of vitamin E, both dietary and injections of vitamin E, or neither source of supplemental vitamin E during the dry period in a 2 x 2 factorial arrangement. Cows receiving parenteral vitamin E were injected subcutaneously with 3000 IU of vitamin E (dl-alpha-tocopherol) at 10 and 5 d prior to anticipated calving. Cows not receiving parenteral vitamin E were injected with a placebo. Experimental groups receiving dietary vitamin E during the dry period were supplemented with 1040 IU/d compared with none for controls. Cows injected with vitamin E had greater plasma alpha-tocopherol concentration 5 d after the first injection, at calving, and 1 wk after calving than did cows injected with placebo. Plasma alpha-tocopherol concentrations did not differ between dietary vitamin E treatment groups from calving through 4 wk postpartum. No interaction was found between dietary and parenteral supplementation of vitamin E on plasma alpha-tocopherol concentration. Neutrophils from cows injected with vitamin E had greater intracellular kill of bacteria at calving than did neutrophils from placebo-injected cows. Neither phagocytic index nor percentage of neutrophils phagocytizing differed between vitamin E-injected and placebo-injected cows. Dietary vitamin E during the dry period had no effect on neutrophil function at calving. Intracellular kill and plasma alpha-tocopherol were correlated at calving.     

超临界CO2萃馏浓缩天然VE的国内外研究现状(1980～2002)

详细介绍了1980～2002年期间超临界CO2萃馏浓缩天然VE的相平衡基础研究概况以及萃馏工艺研究现状,指出了这一应用领域目前所存在的问题是缺乏VE相平衡热力学及萃取动力学方面的实测数据.其解决办法是加大前处理工艺的研究以及VE在超临界CO2中的相行为,以期为研究这一领域的科技工作者提供有价值的参考.     

Effect of different dietary levels of natural-source vitamin E in grow-finish pigs on pork quality and shelf life

Improving pork quality and shelf life is important in today’s swine industry because higher levels of DDGS are incorporated into pig diets. Relatively high level of poly-unsaturated fatty acids (PUFA) in DDGS may increase pork susceptibility to lipid oxidation and thus reduce pork shelf life. Antioxidants such as vitamin E may delay the onset of pork lipid oxidation when used as an ingredient in the diet. This experiment examined carcass characteristics, meat quality, shelf life, and color stability in pork from pigs (n = 150) fed five levels of a natural vitamin E (Nova-E) and one level of synthetic vitamin E. Natural vitamin E and synthetic vitamin E had no effect on carcass characteristics or meat quality. Increasing dietary natural vitamin E from 10 to 200 mg/kg decreased lipid oxidation. Lipid oxidation of pork chops and ground pork was similar between pigs fed 40 mg/kg and higher levels of natural vitamin E, indicating no additional benefits from supplementing beyond 40 mg/kg natural vitamin E. Supplementing 200 mg/kg synthetic vitamin E decreased pork lipid oxidation when compared to supplementing 10 mg/kg natural vitamin E. High levels of natural vitamin E or synthetic vitamin E, however, did not prevent discoloration of loin chops. These data indicate that natural vitamin E was effective to help reduce lipid oxidation and the effective minimal level of dietary supplementation appeared to be 40 mg/kg.     

Acute phase response elicited by experimental bovine diarrhea virus (BVDV) infection is associated with decreased vitamin D and E status of vitamin-replete preruminant calves

Studies in young animals have shown an association between vitamin deficiencies and increased risk of infectious disease; however, there is a paucity of information regarding the effect of acute infection on the vitamin status of the vitamin-replete neonate. To characterize the effects of acute infection on vitamin D and E status of the neonate, 6 vitamin-replete preruminant Holstein bull calves were experimentally infected with bovine viral diarrhea virus (BVDV; strain BVDV2-1373). Six mock-inoculated calves served as controls. Sustained pyrexia, leukopenia, and asynchronous increases in serum haptoglobin and serum amyloid A characterized the response of calves to infection with BVDV. Infection was also associated with increased serum IFN-γ, IL-2, and IL-6 concentrations. During the last 8 d of the 14-d postinoculation period, serum 25-hydroxyvitamin D and α-tocopherol concentrations in infected calves decreased by 51 and 82%, respectively. The observed inverse association between vitamin D and E status and serum amyloid A in infected calves suggests that the infection-induced acute phase response contributed to the reduced vitamin status of these animals. Additional studies are necessary to determine if the negative effect of infection on status are unique to this specific infection model or is representative of preruminant calf’s response to acute infection. Studies are also needed to characterize mechanisms underlying infection-related changes in vitamin D and E status and to determine whether additional vitamin D or E supplementation during an acute infection diminishes disease severity and duration in the young animal.