米糠油及其脱臭馏出物中生育酚和生育三烯酚的分析检测

对米糠油及其脱臭馏出物中生育酚及生育三烯酚含量进行检测分析,结果表明,米糠来源和米糠油精炼工艺对米糠油及其脱臭馏出物中α、β、γ、δ-生育酚和生育三烯酚的含量有显著影响。米糠毛油中生育三烯酚占维生素E总量的60%～70%,脱臭馏出物中生育三烯酚占维生素E总量的25%～40%,米糠油脱臭馏出物维生素E总量中生育三烯酚的含量较米糠毛油有较大的损失。通过对米糠油脱臭馏出物不皂化物的分析检测可知,米糠油脱臭馏出物中主要甾醇的种类为豆甾醇、菜油甾醇、谷甾醇,总甾醇含量很少,仅为0.32%;除此之外,还有少量日耳曼甾醇、羊毛甾醇、3,5-二烯豆甾烷等。     

精炼过程对大豆油回色的影响

从大豆油精炼生产工艺出发,考察γ-生育酚、磷、金属离子等影响大豆油回色的微量成分在精炼过程中的含量变化及其与辅料添加量、脱臭条件对储存期成品大豆油回色的影响。结果表明：γ-生育酚在脱臭工段损失最大,建议脱臭温度在250 ℃以下,而辅料和汽提蒸汽压力的微调对其影响不大;水化磷脂基本在脱胶工段可以彻底脱除,酸炼脱胶主要脱除非水化磷脂,建议将磷含量控制的关键环节设置在脱胶工段,以降低脱色工段白土吸附除磷的压力和生产成本;金属离子基本可以在正常的脱酸、脱色工段利用皂脚和脱色剂吸附脱除;γ-生育酚损失率、脱臭油的磷含量与储存期成品大豆油的回色呈正相关,而金属离子与回色无相关性;脱色剂种类配比对不同产地大豆油的回色无显著影响;而高柠檬酸添加量对储存1个月的大豆油回色有抑制作用,但随储存时间的延长,抑制作用不明显;脱臭温度、汽提蒸汽压力对美国大豆油的回色影响不大,但对巴西大豆油回色影响较明显。     

气相色谱法同时快速测定大豆油脱臭馏出物中的生育酚、植物甾醇和角鲨烯含量

摘要：建立了可以同时定量分析大豆油脱臭馏出物中生育酚（α-生育酚、(β+γ)-生育酚、δ-生育酚）、植物甾醇（菜籽甾醇、菜油甾醇、豆甾醇、β-谷甾醇）和角鲨烯含量的气相色谱检测方法。以十六酸十六醇酯为内标物质,样品直接溶解在内标溶液中,采用HP-1色谱柱分离,以内标法定量。结果表明：各组分之间分离度良好,生育酚、植物甾醇和角鲨烯分别在0.4~6.4 mg/mL、0.5~8.0 mg/mL、0.4~4.0 mg/mL范围内呈现良好的线性关系,R2均大于等于0.999,平均加标回收率分别为95.38%~102.78%、96.40%~101.24%、96.14%~104.43%,相对标准偏差均小于10%,检出限分别为0.08、0.15、0.05 mg/L。该方法前处理简单、重复性好、灵敏度高、结果准确可靠,可应用于大豆油脱臭馏出物中生育酚、植物甾醇、角鲨烯含量的同时测定。     

大豆油脱臭馏出物中α、β、γ、δ-生育酚4种异构体的HPLC测定

建立了大豆油脱臭馏出物中α、β、γ、δ-生育酚4种异构体的简便、准确、快速的HPLC分析方法。选用NucleosilNH2柱正相分离,以正己烷-异丙醇(98∶2)为流动相,在280nm波长进行检测,获得了较理想的分离效果。该方法线性范围宽(0.015～1.7μg),回收率范围为99%～103%,信噪比(S/N)为3时最低检测限为3.5×10-5μg。     

大豆油精炼过程中生育酚的损失

以国内21家大型油脂精炼厂生产的大豆油为对象,研究了精炼过程中生育酚总量和各单体含量的变化,重点考察了不同脱臭塔设备及脱臭条件与生育酚损失率之间的关系.结果表明,在油厂现有通用精炼条件下,整个精炼过程中生育酚总损失率不超过33%,4种生育酚单体(α,β,γ,δ)的相对比例几乎没有变化.影响生育酚保留率的关键因素为脱臭阶段塔的结构、温度及搅拌蒸汽用量.     

天然维生素E的开发及应用前景

<正> 维生素E又名生育酚,是脂溶性维生素之一,有天然产品和合成产品2种。天然维生素E主要来自植物油精炼过程中产生的副产物——脱臭馏出物之中。自然界中存在的天然V_E为α、β、γ、δ体生育酚和α、β、γ、δ三烯生育酚这8种生育酚同族体的混合体,其中以d-α-生育酚的生物活性最强,其生物活性由强到弱的顺序为α>β>γ>δ;而d-δ-生育酚的抗氧化性最强,其由强到弱的顺序为δ>γ>β>α。     

皂化工艺对生育酚含量及其异构体变化影响研究

采用皂化工艺对从大豆油脱臭馏出物中脂肪酸进行脱除,研究不同相中皂化过程对生育酚含 量影响,分析生育酚各异构体在皂化过程中损失。     

大豆油脱臭馏出物中同时提取角鲨烯、生育酚和植物甾醇的工艺研究

采用酯化—高真空蒸馏工艺路线,从大豆油脱臭馏出物中同时提取角鲨烯、生育酚及植物甾醇。考察酯化条件(甲醇、催化剂浓硫酸用量及反应时间)对酯化率、角鲨烯和生育酚含量的影响。优化得到的最佳工艺为:催化剂浓硫酸添加量0.5%,醇油摩尔比10∶1,反应温度70℃,反应时间120 min,大豆油脱臭馏出物酯化率达到98.2%,生育酚和角鲨烯保留率分别为97.7%和97.5%。酯化后的物料通过冷析结晶,抽滤得到植物甾醇粗品,滤液高真空蒸馏,初步分离得到脂肪酸甲酯、角鲨烯、生育酚等组分。各组分中角鲨烯富集到12.2%,生育酚富集到28.6%,植物甾醇富集到60%左右,初步实现了大豆油脱臭馏出物中角鲨烯、生育酚、植物甾醇的同时提取,为角鲨烯、生育酚及植物甾醇的进一步富集提供了参考依据。     

分子蒸馏法浓缩α-生育酚的工艺研究

采用三级分子蒸馏,从大豆油脱臭馏出物中浓缩α-生育酚.一、二级分子蒸馏通过单因素试验确定优选工艺;三级分子蒸馏采用响应曲面法对操作条件进行优化.试验结果表明,将大豆油脱臭馏出物进行甲酯化预处理后,再通过3次分子蒸馏,并结合两次脱除甾醇,可明显提高生育酚质量分数,α-生育酚质量分数从0.48％提高至3.59％.     

食用植物油中生育酚含量测定方法优化及分析

采用高效液相色谱法测定了8种24个植物油样本中生育酚的含量,并对生育酚的提取条件进行优化。在室温下,以甲醇为溶剂,采用超声法进行提取,料液比为1∶1.25,提取3次,每次20min,采用液相色谱方法进行分析。结果表明:该方法在生育酚质量浓度为0.05~1.00 g/L时,相关系数R2可达到0.999 2~0.999 4,线性关系良好;检出限分别为α-生育酚0.5 mg/L,γ-生育酚2.0mg/L,δ-生育酚1.2 mg/L;三水平加标样品的平均回收率为92.1%~99.8%,相对标准偏差(RSD,n=3)为2.5%~8.5%。在8种植物油中,葵花籽油中α-生育酚的质量分数较高,可达4.234 9×10-4,大豆油的β/γ-生育酚、δ-生育酚及总生育酚的质量分数较高,分别为7.371 3×10-4,1.621 5×10-4,9.883 6×10-4。     

生育酚单体的功效、应用及分离技术研究进展

综述了生育酚单体在食品、医药、饲料、化妆品等领域的应用,对不同生育酚单体在食品、医药、饲料行业的生理学功效和抗氧化特性进行了详细阐述,并对生育酚单体的分离技术(色谱分离法、化学反应法和离子液体萃取法)进行了归纳整理,以期为高端生育酚产品的开发、生产、应用提供参考。     

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.     

从脱臭馏出物提取天然生育酚研究进展

天然维生素E(生育酚)是一种优良生理活性物质和良好抗氧化剂,具有广阔开发前景和市场需求。该文介绍植物油精炼加工副产物脱臭馏出物主要成分及天然维生素E生物活性,重点综述从不同植物油脱臭馏出物中提取生育酚方法,为扩大天然生育酚制备途径和提高油脂加工业经济效益提供参考。     

Effects of mixed tocopherols added to milk replacer and calf starter on intake,growth, and indices of stress

Vitamin E comprises 8 fat-soluble isoforms: α-, β-, γ-, and δ-tocopherol and α-, β-, γ-, and δ-tocotrienol. Yet the body preferentially uses α-tocopherol, and only α-tocopherol supplementation can reverse vitamin E deficiency symptoms. However, other isoforms influence many biological functions in the body, including inflammation and stress. Therefore, the study objective was to determine metabolic and performance responses in young calves fed diets containing a constant amount of α-tocopherol and increasing amounts of soybean oil-derived mixed γ- and δ-tocopherols. Holstein calves [n = 48; 2–3 d of age; 40.2 kg of initial body weight (BW), standard error = 0.54] were assigned to receive approximately 0, 5, 10, or 15 mg/kg of BW daily (treatments T0, T1, T2, and T3, respectively) of mixed tocopherols (TMIX) provided in milk replacer (MR) and calf starter. The TMIX liquid contained 86% γδ-tocopherols and 9% α-tocopherol. Milk replacers were formulated to contain approximately 0, 400, 800, or 1,200 mg of TMIX/kg for treatments T0, T1, T2, and T3, respectively. Calf starters were formulated to contain approximately 0, 250, 500, or 750 mg of TMIX/kg for treatments T0, T1, T2, and T3, respectively. Mean consumption of γδ-tocopherols was 0.0, 6.5, 14.3, and 20.5 mg/kg of BW, respectively. Milk replacer contained 24% crude protein (CP) and 20% fat on a dry matter (DM) basis. Calf starters were pelleted and offered for ad libitum consumption from 0 to 56 d. Starters contained 18 to 20% CP and 9 to 12% starch in the DM. On d 28, 4 calves per treatment were randomly selected for slaughter, and necropsy was performed. Samples of liver, duodenum, ileum, and trapezius muscle were collected and stored before analysis for α-, β-, γ-, and δ-tocopherols and δ-tocotrienol. Data were analyzed using a completely randomized design using mixed model ANOVA with orthogonal polynomials to determine linear and quadratic effects of TMIX. Repeated-measures analyses were performed for data collected over time. Increasing dietary TMIX increased or tended to increase change in hip width at 28 and 56 d, respectively, and improved average daily BW gain and gain-to-feed ratio at 56 d. Increasing TMIX reduced plasma xanthine oxidase at 0 h and tended to reduce concentrations at 24 h following vaccination with 2 commercial vaccines on d 28; however, we detected no effect of TMIX following vaccination on d 56. Concentration of α-tocopherol in skeletal muscle declined quadratically with increasing TMIX, whereas ileal and liver γ-tocopherol increased linearly with increasing TMIX. The number of mucin-2 cells in the ileum increased more than 2-fold in calves fed T3. Addition of mixed tocopherols to diets of young dairy calves improved animal growth and altered indices of antioxidant metabolism.     

高效液相色谱测定玉米油生育酚含量研究

该研究通过比较应用高效液相正相色谱和反相色谱两种方法对玉米油生育酚含量测定结果,以期建立更适于测定玉米油生育酚含量的高效液相方法。正相色谱法采用硅胶柱色谱柱,流动相为正己烷∶异丙醇=98∶2(V/V),流速为1.0 ml/min,紫外检测器波长为298 nm,平均回收率97.1%,变异系数为2.00%:反相色谱法采用C18色谱柱,流动相为甲醇∶水=90∶10(V/V),流速为0.8 ml/min,紫外检测器波长为298 nm,平均回收率84.9%,变异系数为2.29%。通过对两种方法比较可知,正相色谱法测定玉米油生育酚含量更为高效、稳定、省时,且成本较低。     

油脂脱臭馏出物的组成与市场前景

脱臭馏出物是脱臭工序的副产物 ,其中含有游离脂肪酸、甘油酯、臭味物质、氧化分解产物、生育酚、甾醇及甾醇酯等。目前 ,脱臭馏出物因其中富含生育酚和甾醇而具有很高的应用价值。优化脱臭系统和妥善处理收集脱臭馏出物是提高脱臭馏出物中生育酚含量的有效方法。     

以生育酚为目标的油脂脱臭馏出物的生产

近年来 ,富含生育酚的脱臭馏出物具有很高的应用价值。脱臭馏出物中生育酚的含量与油脂精炼工艺、脱臭时间、脱臭温度、捕集器温度、蒸汽用量和系统真空度等因素有关。提出一些建议以提高脱臭馏出物中生育酚的含量 ,但不影响精炼油的质量。     

Technical note: Development and validation of an HPLC method for the quantification of tocopherols in different types of commercial cow milk

In the present study, a methanol-fluorescence-based HPLC method was validated for its use to quantify α-tocopherol and γ-tocopherol in raw milk, whole UHT milk, partially skimmed UHT milk, whole pasteurized milk, and partially skimmed pasteurized milk. Repeatability and reproducibility, calculated as relative standard deviation of 10 measurements within the same day and 30 measurements across 3 d, respectively, were always below 5% for both tocopherols concentrations and retention times. Recovery was assessed through 3 spiking levels and it ranged from 89 to 107%. The method was able to detect the expected declines in tocopherols in milk exposed to UHT or skimming treatments. Vitamin E, calculated as the sum of α-tocopherol and γ-tocopherol, was similar in whole pasteurized and raw milk, averaging 1.57 and 1.56 mg/L, respectively, followed by whole UHT (1.33 mg/L), partially skimmed pasteurized (0.77 mg/L), and partially skimmed UHT milk (0.61 mg/L).     

Cholesterol Autoxidation Inhibition Varies Among Several Natural Antioxidants in an Aqueous Model System

Inhibition of cholesterol autoxidation by several natural materials was examined in an aqueous meat model system at pH 5.50 and 80°C. Antioxidant effectiveness was measured using the induction period for 7-ketocholesterol. An industrial rosemary oleoresin, quercetin, myr-icetin and BHA (included for comparison) had no antioxidant properties for cholesterol. All tocopherol treatments delayed cholesterol oxidation. The γ- and δ- treatments were most effective and α-toco-pherol was least effective. No synergistic effects were observed with tocopherol blends. Antioxidants effective against unsaturated fatty acid autoxidation may not inhibit cholesterol autoxidation.