2种油脂与氯化钠热反应模型中氯丙醇的生成

以猪脂和鸡脂为原料,分别建立了不同的油脂与NaCl热反应模型,并结合气质联机对模型热反应中生成的氯丙醇进行了分析。通过正交试验,考察了不同油脂用量、NaCl用量、反应温度、反应时间等因素对氯丙醇生成量的影响,并探究了氯丙醇的生成机理。研究表明:温度对氯丙醇的产生影响较大,当高于140℃时可以极大地促进氯丙醇的生成;NaCl的浓度足够大时会使氯丙醇的生成量下降而生成二氯衍生物;随油脂用量的增加,氯丙醇的产生呈下降趋势;随反应时间的延长,氯丙醇的产生呈上升趋势。     

食用油中3-氯丙醇酯的研究进展

氯丙醇酯污染是近年来国际上出现的食品安全热点问题之一,尤其是3-氯丙醇酯污染更为突出,各种食用油或油脂食品中都含有一定量的3-氯丙醇酯。总结了国内外对3-氯丙醇酯的研究现状,介绍了3-氯丙醇酯来源、毒理和安全性、可能的形成机制、检测方法、污染水平、控制措施和精炼过程中形成的影响因素等方面的内容,并提出了目前急需解决的问题。旨在推动我国油脂食品行业的健康发展。     

氯丙醇酯——油脂食品中新的潜在危害因子

氯丙醇酯是油脂食品中新近发现的一个潜在危害因子,日本Econa烹调油因高含量3-氯丙醇酯而被迫停止销售的事实表明氯丙醇酯问题已开始对油脂行业产生实质性影响,本文总结了当前国际学术界和业界对氯丙醇酯类物质的研究现状,对氯丙醇酯进行了较为明确的定义和初步的分类,分析了氯丙醇酯可能产生的潜在毒性,介绍了油脂食品中氯丙醇酯的来源、形成途径和控制措施。最后建议我国相关部门应积极介入,主动应对挑战,开展对氯丙醇酯安全问题的研究,以指导油脂食品的生产和消费,推动我国油脂食品行业的健康发展。     

氯丙醇酯类化合物的风险评估与应对措施研究进展

氯丙醇酯类化合物是含油脂类食品中对人体健康具有危害性的污染物质,具有肾脏、生殖毒性及潜在的致癌性。氯丙醇酯是当前油脂中污染物领域的研究热点。氯丙醇酯主要产生于精制过程的脱臭步骤,目前对于其具体的反应机制研究尚不完全。针对国内外食品中氯丙醇酯的暴露情况、形成与降解机制、影响因素等关键点进行了的综述,总结归纳了现行有效的应对措施,为我国食品中该类污染物的监管措施提供理论基础。     

微生物油脂中氯丙醇酯的形成及应对措施综述

氯丙醇及其酯类是国际社会广泛关注的食品污染物之一,近年来发现氯丙醇酯广泛存在于各种食用油脂及含油脂食品中,而引起油脂行业的广泛关注。本文较为详细的总结了目前国内外对油脂中氯丙醇酯的毒性、检测方法、形成机制及控制方式等的研究现状,并对微生物油脂中可能的产生机制和应对措施进行了概述,以指导微生物油脂及食品的生产和消费,推动我国微生物油脂食品的健康发展。     

植物甾醇的研究进展

研究发现,植物甾醇能同时降低血清中总胆固醇含量和低密度脂蛋白胆固醇水平,并在2010年被我国批准为新资源食品。文中简要介绍了植物甾醇的性质、来源及生理功能,总结了典型的植物甾醇分离提取工艺,并综述了植物甾醇的改性研究和甾醇氧化产物研究进展,重点阐述了天然植物甾醇及其氧化物的安全性问题,为甾醇的工业应用提供一定的借鉴作用。     

植物甾醇制取及应用研究进展

油脂中植物甾醇含量较少,但是却有着重要的生理功能。主要围绕国内外近年来植物甾醇的制取及应用方面的研究进展进行综述。介绍了油脂精炼过程中植物甾醇在各工段的损失情况;对脱臭馏出物(DD油)、酸化油、渣油为原料的植物甾醇制取工艺及甾醇酯的合成工艺发展现状进行论述;对植物甾醇的应用进行了介绍。以期为植物甾醇的生产及应用提供技术参考。     

甾醇氧化物分析方法研究进展

该文介绍甾醇氧化物种类,综述目前国内外对甾醇氧化物检测方法;包括油脂提取、甾醇氧化物纯化、富集,及色谱、色谱质谱联用对其定性、定量分析方法。     

油脂中氯丙醇形成机制及控制研究进展

食品中的氯丙醇污染是目前国际上广为关注的食品安全问题之一, 最初在酸水解植物蛋白加工中被检出, 近年来发现氯丙醇及其酯类化合物广泛存在于油脂及其加工品中, 成为危害消费者身体健康的又一隐性因素, 从而引起人们的再次高度关注。本文较为全面地介绍了氯丙醇的定义、分类, 分析了氯丙醇的潜在毒性及在食品中的污染现状, 总结了氯丙醇特别是3-氯-l,2-丙二醇(3-monochloropropanol-l,2-diol, 3-MCPD)的可能形成途径, 并归纳了油脂加工过程中可行的控制方法。     

甾醇组成分析结合化学计量学识别8种植物油脂北大核心CSCD

探讨了甾醇组成分析结合化学计量学识别植物油脂种类的可行性。从植物油脂中提取不皂化物,并经液相色谱分离,再经衍生化后通过气相色谱测定了8种植物油脂共21批样品的甾醇组成,并以15种甾醇组分的含量作为基础数据,进行聚类分析与主成分分析。结果表明,2种化学计量学方式对甾醇组成的分析结果基本一致,都可以对植物油脂进行识别分析。因此,化学计量学是植物油脂中的甾醇组成分析的有效方法,甾醇组成可作为植物油脂种类识别的测量指标之一。     

Phytosterol Oxidation Products: Their Formation,Occurrence, and Biological Effects

Phytosterols or plant sterols are integral natural components of plant cell membranes that are abundant in vegetable oils, nuts, seeds, and grains; as well as added components in various functional foods. Due to their chemical structure, phytosterols are susceptible to oxidation under certain conditions giving rise to a family of compounds known as phytosterol oxidation products (POPs). The following review gives an in-depth account on the formation and occurrence of POPs in foodstuffs. The metabolism and biological effects of these oxides is also discussed in detail.     

植物甾醇氧化物的形成、摄入及健康相关效应

植物甾醇（phytosterol,PS）是一类重要的生物活性物质,具有降低胆固醇、预防心血管疾病、抗癌、抗炎等生理功能,但由于其自身结构不稳定,易被氧化形成植物甾醇氧化物（phytosterol oxidation products,POPs）,POPs包括酮基类、羟基类和环氧氧化物。随着越来越多的PS强化食品进入人们的日常生活,PS的氧化、POPs的机体摄入及可能存在的危害已引起了消费者的广泛关注。本文查阅国内外有关POPs的最新研究成果,从POPs的形成、种类与结构、膳食暴露情况、机体吸收及健康相关效应等方面进行系统分析论述,以期为PS的氧化控制,特别是POPs的膳食摄入和风险评估提供科学参考。     

植物甾醇的提取、生理功能及在食品中的 应用综述

本文主要介绍了植物甾醇的相关性质、功能及在食品中的应用等。综述了在油脂加工副产物中甾醇的含量与提取：包括在副产物油脚中甾醇的含量与提取率;不同来源的副产物脱臭馏出物中甾醇的含量、主要甾醇成分及提取工艺等。介绍了植物甾醇的特殊功能（如降低胆固醇、减少冠心病发生、抗氧化等）及在食品中的广泛应用。天然植物甾醇常在食品体系中添加时出现结晶现象,且在水相和油相中溶解度低,为能在食品中广泛应用,常采用植物甾醇改性将其转变成甾醇酯的方式添加到食品中。文中介绍了植物甾醇改性的不同工艺并得到了较好的效果。在特殊的环境条件下,天然甾醇会发生氧化产生甾醇氧化产物。文中介绍了不同储藏条件甾醇氧化产物的含量及主要成分、甾醇氧化稳定性与结构的关系以及对主要慢性病的发生和发展的促进作用等。     

Pan-frying may induce phytosterol oxidation

The oxidative stability of different phytosterol compounds during pan-frying was evaluated. Rapeseed oil, rapeseed oil-based liquid margarine and butter oil were used as lipid matrices. Gas chromatographic–mass spectrometric analyses indicated that pan-frying may induce phytosterol oxidation but has no marked effect on phytostanol oxidation; up to 5.1% of original sitosterol and 0.1% of original sitostanol were found as oxides. High-performance size-exclusion chromatographic determinations also revealed a moderate degree of polymerization of lipid matrices. The extents of these deteriorative reactions were determined by frying temperature and time, but also by unsaturation degree and water content of the lipid matrix as well as by structure of the phytosterol compound added. The highest phytosterol oxide content was measured in saturated butter oil enriched with free phytosterols, whereas the highest matrix dimer and polymer contents were found in free phytosterol-enriched liquid margarine, which contained 20% of water.     

Oxidative stability of phytosterols in some food applications

The oxidative stability of phytosterols as lipid compounds can be defined as their resistance to oxidation and thus the formation of phytosterol oxidation products. We studied the oxidative stability of phytosterols during processing and long-term storage in phytosterol-enriched milk powder and heat-treated milk, and in microcrystalline phytosterol suspensions in different fats and oils. All of these food applications were observed to be stable despite the heat treatments used in their processing and the long-term storage even at slightly elevated temperatures. The largest change in the phytosterol oxide content was determined for phytosterol-enriched milk powder stored at 38°C for 12 months. During this period the percentage of phytosterol oxidation grew from 0.03 to 0.07%. Based on our observations, we concluded that food applications tested here were unlikely to represent an important source of phytosterol oxides. Furthermore, the formation of phytosterol oxides did not seem to be limiting factor for manufacture and subsequent storage of these products.     

Phytosterol oxides content in selected thermally processed products

Heat treatments are very popular methods of food preparation in European countries. Phytosterol present in foodstuffs undergoes oxidative changes during heat treatment, and phytosterol oxides (e.g., 7α-, 7β-hydroxysterol, 5α,6α-, 5β,6β-epoxysterol, 7-ketosterol and triol) are formed. Phytosterol oxidation products (POPs) have been associated with cytotoxic and pro-apoptotic effects in humans. On the other hand, several studies conducted on animals revealed that some phytosterol oxides lower serum triacyglycerol and blood glucose levels. The aim of this study was to evaluate the effect of heat treatment on formation of phytosterol oxidation products in selected foodstuffs. The following products were taken into considerations: minced meat (pork and beef), frozen French fries, frozen fish fillets, frozen fish products (e.g., fish sticks), wheat and egg noodles. Sterols and POPs content was evaluated by GC–MS working in total and selected ion monitoring modes. The phytosterol oxidation rate was higher in French fries and fish fillets (0.20–1.69% of total phytosterol content) than in noodles, minced meats and readymade fish products (in 0.04–0.36% range). Method of POPs determination using GC–MS is reported in this study. Results of this study show also that products of the animal origin might be considered as sources of the phytosterol oxides in the human diet.     

抗坏血酸棕榈酸酯对玉米油储藏稳定性的影响

采用Rancimat法测定不同抗坏血酸棕榈酸酯（AP）添加量下玉米油的氧化诱导时间,筛选出与添加50 mg/kg特丁基对苯二酚(TBHQ)玉米油氧化诱导时间相近的150 mg/kg AP添加量作为玉米油中AP目标添加量,开展6周玉米油储藏加速试验,每7 d取样检测酸值、过氧化值、回色（红值）、植物甾醇含量和维生素E含量,同时与TBHQ组（添加量50 mg/kg）、充氮组及空白组样品进行比较,分析AP对玉米油储藏稳定性的影响。结果表明：在玉米油储藏过程中,AP组样品与TBHQ组、充氮组样品在酸值、过氧化值、回色（红值）及植物甾醇含量方面无明显差别;但添加AP对玉米油中维生素E的保留作用明显优于添加TBHQ及充氮。     

甾醇氧化特性及其在食品中应用研究进展

植物甾醇具有降低胆固醇等生物学效应。本文在概述植物甾醇的功能特性和食用安全性的基础上,对其氧化产物的形成机制及特性、检测方法研究进展以及功能性甾醇食品的开发现状进行综述,针对中餐食用油以高温煎炸为主的食用习惯,对我国功能性甾醇食品的研究与开发提出建议。     

Comparative study of crude and refined kenaf (<Emphasis Type="Italic">Hibiscus cannabinus</Emphasis> L.) seed oil during accelerated storage

This study assessed the changes of antioxidant activity and bioactive compounds of crude and refined kenaf seed oil during accelerated storage at 65°C for 24 days. 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assays were used to determine their antioxidant activity. The changes of phenolic, tocopherol, and phytosterol contents during the storage were also studied. The phenolic content and antioxidant activity of refined oil were significantly lower than those of crude oil after the accelerated storage. There was a decrease of 72.5% tocopherol content and 31.1% phytosterol content in the crude oil and a decrease of 67% tocopherol content and 12.1% phytosterol content in the refined oil during the accelerated storage. There was no significant difference in tocopherol and phytosterol contents for crude and refined oils after the storage. The rate of degradation of tocopherol and phytosterol contents in refined oil was slower than that in crude oil during the storage.