茶儿茶素类物质对大豆脂肪氧化酶活性的影响

油脂和含油脂的食品在贮存和加工期间会发生酸败而产生醇、醛、酮、酸类物质,使食品的色、香、味发生劣变。酸败主要是因有脂肪的存在而发生自动氧化、酶促氧化和脂肪分解。自动氧化反应的最初引发,如形成氢过氧化物,涉及光、γ射线和χ射线,光敏染料,过渡金属离子和游离基等,因此冷藏、避光、添加抗氧化剂有利于食品保存。由于抗氧化剂可以抑制油脂的自动氧化,延缓氧化物的生成而被广泛应用于食品行业。然而,自动氧化并不是油脂和含油脂食物变质的唯一原因,解脂变质也     

茶叶中天然抗氧化剂研究初报

油脂自动氧化引起的劣变,不仅有损于油脂食品的风味和品质,而且食用劣变的油脂食品有加快体细胞衰老的进程,甚至中毒的危险。抗氧化剂是一种能够阻止或延缓油脂自动氧化的物质,从而提高油脂食品的稳定度和贮存性,由此,抗氧化剂广泛应用于食品、化妆品和肥皂工业。抗氧化剂有人工合成和天然的两大类,一般多是酚性成分。目前用于油脂及油脂食品工业的抗氧化剂BHA(丁基羟基茴香醚)     

茶多酚抗氧化剂在食品上的研究与应用综述

氧化是导致食品品质变劣的重要因素之一，特别是对于油脂或含油食品来说更是如此，抗氧化剂是一种能够阻止或延缓油脂自动氧化的物质。茶多酚是一种天然抗氧化剂。茶多酚与油脂中脂肪酸的结合达到抗氧化作用。茶多酚可作为油脂食品抗氧化剂，也可作为功能食品的添加剂。     

武夷岩茶茶多酚对油脂的抗氧化效果

在猪油中分别添加0．4％的V、VE和武夷岩茶TP，85℃下进行抗氧化试验14d，间日取样测定油脂POV和AV。结果：Vc、VE和TP对油脂氧化的抑制率分别达到31．7％、4．8％、92．5％（P〈0．05或0．01）；对照组和添加VE、Vc的油脂AV分别升高280％、274％、11％，而TP使油脂AV降低27％。结果说明TP对油脂有显著的抗氧化效果，其作用优于Vc和VE。     

固态发酵大豆制备的抗氧化肽的活性分析

综合评价用固态发酵法制备的大豆抗氧化肽的抗氧化活性.通过T-AOC方法测定总抗氧化能力、通过水杨酸法测定·OH、通过邻苯三酚法测定O2ˉ、通过卵磷脂法测定脂质体过氧化、通过POV值法测定抗油脂自氧化.大豆抗氧化肽的总抗氧化能力为50.07 U、对羟基自由基的清除率达到85.68%、抑制邻苯三酚自氧化能力达到23.61 U/mL、抑制脂质体过氧化率为34.58%、对油脂过氧化抑制抑制率为30%.用固态发酵法制备出的大豆抗氧化肽具有较强的还原能力、能清除羟基自由基、抑制邻苯三酚自氧化,并能够对脂质体过氧化和油脂过氧化具有一定的清除作用能力.     

制茶专用油脂对龙井茶品质及脂肪酸组分的影响

本文针对不同用量的制茶专用油脂对龙井茶的感官品质、物理性质及化学成分进行研究。结果表明:制茶专用油脂在茶叶炒制过程中对降低成茶碎裂程度有一定作用,添加量在0.3%时具有较好效果;处理组感官审评表现为外形色泽较绿润,香气高爽,略带花香,汤色嫩绿明亮,滋味较醇,表明制茶油能够提高茶叶内在品质,但过量使用使茶叶表面油脂氧化程度加重,不利于茶叶贮藏保鲜;制茶油的应用不会影响茶叶主要脂肪酸的组成,但能够影响成茶脂肪酸含量分布,尤其是棕榈酸、硬脂酸、油酸等含量的增加,推测与成茶内质提高有关。     

儿茶素在食用植物油中的抗氧化应用效果

采用一种食用有机溶剂溶解儿茶素,而后添加到新鲜的植物油中,比较儿茶素与几种常用的合成抗氧化剂在植物油中的抗氧化效果,并用ＮＤ－１００１ＤＰ测色色差计测定儿茶素的氧化产物对油脂色泽及清亮度的影响。结果显示,儿茶素的抗氧化效力强于ＢＨＴ、ＴＢＨＱ和维生素Ｅ等合成抗氧化剂。不过,儿茶素氧化后对油脂的色泽及清亮度有一定影响,但可通过添加某些有机酸（如柠檬酸等）增效剂加以改善。文中还对儿茶素在植物油中的抗氧化机理和中介物质进行了讨论。     

茶叶抗氧化剂对花生系列产品的抗氧化效应

花生仁含有45％左右的油脂,其油脂主要由不饱和的脂肪酸和甘油组成,不饱和的脂肪酸与空气接触后易发生自动氧化作用,这种自动氧化是油脂酸败,花生仁及其制品变质的最主要原因。1988年,上海油脂五厂开始采用中国农业科学院茶叶研究所提取的安全无毒的1号和2号茶叶天然抗氧化剂,作了花生系列制品的抗氧化试验,现将     

新型木本油料树种光皮树研究进展

光皮树是我国重要的新型木本油料树种,其深度开发对我国油脂安全具有重要意义。近年来我国在光皮树基础研究及产业化利用等方面取得了丰硕成果,显著推进了光皮树生长发育、遗传背景、油脂合成与调控、油脂提取与分析、油脂工业转化等的研究进程。本文从农艺性状、组织结构、生理生化、分子遗传、果实发育、内含物累积、油脂提取、油脂成分、油脂应用等方面对我国光皮树研究进展进行总结,以期为后续研究应用提供参考。     

基于热诱导的绿咖啡油氧化过程解析及活性成分变化规律研究

绿咖啡油是一种富含生物活性成分的功能性油脂,贮藏过程中极易氧化酸败影响产品品质。本文以海南地区兴隆咖啡为原料提取绿咖啡油,系统研究在60 ℃加速贮藏36 d内氧化指标、生物活性成分及表征氧化的光谱特征峰变化。结果表明：过氧化值、茴香胺值、硫代巴比妥酸、总氧化值初始值分别为0.97±0.04 meq/kg、4.19±0.14、55.08± 1.98 nmol/mL、8.05±0.06,经过36 d的氧化分别显著升高到28.56±0.15 meq/kg、19.19±0.13、102.38±2.18 nmol/mL、133.43± 0.45。本研究中共鉴定出11种脂肪酸,在绿咖啡油氧化过程中,饱和脂肪酸与不饱和脂肪酸比值由1.14上升至1.49。利用高效液相色谱测定绿咖啡油中的二萜类物质和生育酚,咖啡豆醇、咖啡醇的初始含量分别为21.01±0.31 mg/g、23.44±0.52 mg/g,在氧化24 d后升高至8.21±0.10 mg/g、8.99±0.02 mg/g,随后含量趋于稳定。共定性出α、δ和γ-生育酚,总生育酚含量由初始的49.75±0.88 mg/100 g在氧化18 d达到最大值53.70±1.72 mg/100 g,在氧化结束时降至34.58± 0.05 mg/100 g。利用傅里叶变换红外光谱（FTIR）从特征官能团的角度分析绿咖啡油的氧化过程,油脂在3008、2927、2854、1745、1461、1375、1238、1164、721 cm^-1处有特征吸收峰。采用拉曼光谱技术表征绿咖啡油加速贮藏中的氧化变质,在1000~1800 cm^-1波段的峰强度有明显减弱趋势。本研究表明绿咖啡油在热诱导下的贮藏过程中发生了明显的氧化反应,可为提升绿咖啡油贮藏稳定性提供理论参考。     

Synthesis of a new thiophosphorylated compound derived from cashew nut shell liquid and study of its antioxidant activity

This work describes the synthesis and study of the antioxidant activity in mineral oils of new thiophosphorylated compound derived from cashew nut shell liquid (CNSL), a by-product of the process of improvement of cashew nuts. This study was conducted through the thermal analysis observing the T_onset variations and the accelerated oxidation experiments observing the induction time variations. The results of thermogravimetric and acceleration oxidative experiments showed a significant improvement in the oxidative stability of the doped oils. These results suggest that this new compound acts efficiently in the stabilization of the naphthenic mineral oils.     

Antioxidant Protection of Edible Oils

The ability of different cooking oils to withstand oxidation was investigated in relation to their native antioxidant capacity [measured as the Ferric Reducing/Antioxidant Power (FRAP) value]. The antiperoxidation effect of the presence of the Chinese herbs, du-zhong (Cortex Eucommia ulmoides) and ginseng (Panax ginseng C.A. Mayer) in corn oil was also investigated over 26 days’ storage at 55°C. Results showed that sesame oil had the highest FRAP value (803 μM), followed by canola oil (400 μM), and sunflower, peanut, corn and olive oils (100–153 μM). Oils with higher intrinsic antioxidant content showed higher resistance to oxidation, although this was not statistically significant. Corn oil to which was added the herbs du-zhong, ginseng or both had increased resistance to oxidation (conjugated diene level and lipid peroxide formation) over 26 days. FRAP values of the oil/herb mixtures decreased during this time, implying utilisation of herbal antioxidants. Results have implications for increasing the shelf-life and usage time of cooking oils by addition of herbs which can increase resistance of the oil to oxidation. Results have implications also for health, as it is possible that ingestion of these herbs could increase resistance of polyunsaturated fatty acids of cell membranes and lipoproteins to oxidation within the body.     

Epoxidized soybean oil as a potential source of high-temperature lubricants

Development and application of biocompatible lubricants are increasing daily as a result of stringent regulations imposed on mineral oil-based lubricants with their non-biodegradable toxic wastes. Before consumer acceptance of vegetable oil-based lubricants, they must overcome certain poor performance characteristics such as thermal and oxidative instabilities. This work demonstrates the improved performance of epoxidized soybean oil (ESBO) over soybean oil (SBO) and genetically modified high oleic soybean oil (HOSBO) in certain high temperature lubricant application. We validated the thermal and deposit forming tendencies of these oils using micro-oxidation and differential scanning calorimetry in conjunction with identification of oxidized products by infrared spectroscopy and also discussed the function of a phenolic antioxidant in these oils. Boundary lubrication properties under high load and low speed were determined and the variations explained based on the structural differences of these vegetable oils.     

Research progress on the origin traceability of edible oils

The origin traceability of edible oil is an effective way to protect the legitimate rights and interests of producers and consumers. This review briefly summarizes research progress on origin traceability technologies for edible oils including stable isotope ratio mass spectrometry, mineral element fingerprint analysis, organic component fingerprint analysis, near-infrared spectroscopy, nuclear magnetic resonance technology and biochemical analysis. Moreover, the development trends in edible oil origin traceability technology were proposed.     

Influence of palm oil ( Elaesis guineensis) on health

In recent times there has been a growing research interest in palm oil, one of the major edible plant oils in the tropical countries, because of the link between dietary fats and coronary heart disease. Obtained from a tropical plant, Elaesis guineensis, it has a polyunsaturated fatty acid/saturated fatty acid ratio close to unity and a high amount of antioxidant vitamin A precursors and vitamin E. Palm oil is consumed in the fresh state and/or at various levels of oxidation. Feeding experiments in various animal species and humans have highlighted the beneficial role of fresh palm oil to health. These benefits include reduction in the risk of arterial thrombosis and atherosclerosis, inhibition of cholesterol biosynthesis and platelet aggregation, and reduction in blood pressure. However, a considerable amount of the commonly used palm oil is in the oxidized state which possesses potential dangers to the physiological and biochemical functions of the body. Oxidation is as a result of processing the oil for various culinary purposes. Studies have revealed that relative to fresh palm oil, oxidized palm oil induces an adverse plasma lipid profile, free fatty acids, phospholipids and cerebrosides. Additionally, oxidized palm oil induces reproductive toxicity and organotoxicity particularly of the kidneys, lungs, liver and heart. Available evidence suggests that at least part of the oxidized oil impact on health reflects generation of toxicants due to oxidation. The reduction of the dietary level of oxidized oil and/or the level of oxidation may reduce the health risk associated with consumption of oxidized fats.     

蔗糖脂肪酸三酯在菜籽油脱磷工艺中的应用及蔗糖酯磷脂复合物的制备

本文以蔗糖脂肪酸三酯（sucrose fatty acid triester，STE）和磷脂酰胆碱（phosphatidylcholine，PC）为原料制备蔗糖酯磷脂复合物，并通过傅里叶红外光谱分析（Fourier infrared spectrum，FT-IR）、热重分析（thermogravimetric analysis，TGA）和差示扫描量热分析（differential scanning calorimetry，DSC）对制备的蔗糖酯磷脂复合物进行表征分析；以STE为吸附脱磷剂，考察STE在菜籽油脱磷工艺中的应用。研究结果表明，STE与PC在无水乙醇体系中形成了新型的STE-PC复合物，与STE和PC相比，STE-PC复合物具有更低的相变熔融温度；另外，STE对菜籽油中的磷脂有一定的吸附脱除作用，在脱磷温度为55oC、STE添加量为3.5%、脱磷时间为30min条件下，脱磷率可达37.2%。     

大豆种子脂肪酸组分的研究进展

随着社会的进步和人们生活水平的提高,人们越来越重视自身的健康状况.大豆油的饱和脂肪酸与不饱和脂肪酸的比例相对其它的植物油(如菜籽油、花生油等)较为合理,其消费量和食用量也已经逐步超过了其它植物油,成为人们日常饮食重要的营养来源之一.本文在脂肪酸组成、脂肪酸组分形成与地理纬度、气象因素的关系、及发育种子脂肪酸组分的形成等方面综述了大豆种子脂肪酸组分的研究进展,并指出了该领域目前存在的主要问题和发展的前景.     

Composition and physical properties of cress (Lepidium sativum L.) and field pennycress (Thlaspi arvense L.) oils

The fatty acid profiles and tocopherol and phytosterol contents of crude oils of cress (Lepidium sativum L.) and field pennycress (Thlaspi arvense L.) are reported, along with yields from the corresponding seeds. The physical properties of these oils were also determined, which included oxidative stability, kinematic viscosity, viscosity index, low temperature fluidity, specific gravity, acid value, lubricity, and iodine value. The oil content of dried cress and field pennycress seeds was 22.7 and 29.0 wt%, respectively. The primary fatty acids found in cress oil were oleic (30.6 wt%) and linolenic acids (29.3 wt%), whereas field pennycress oil was principally composed of erucic (32.8 wt%) and linoleic (22.4 wt%) acids. Cress oil contained high concentrations of γ- (1422 ppm) and δ- (356 ppm) tocopherols, whereas α-tocopherol (714 ppm) was the primary tocopherol discovered in field pennycress oil. The overall tocopherol concentrations of cress and field pennycress oils were 1799 and 851 ppm, respectively. The primary phytosterols elucidated in cress and field pennycress oils were sitosterol and campesterol, with avenasterol also present in significant quantity in cress oil. The total phytosterol concentration in cress oil (14.41 mg/g) was greater than that in field pennycress (8.55 mg/g) oil. Field pennycress oil exhibited excellent low temperature fluidity, whereas cress oil was more stable to oxidation and over a range of temperatures displayed lower kinematic viscosities as well as a higher viscosity index. The acid and iodine values of field pennycress oil were lower than those for cress oil, but both oils had excellent lubrication properties.     

Effect of ageing on quality of jojoba oil from Indian locations

Jojoba oil is a source of specialty chemicals and its uses for industrial application are gaining in adaptability and importance. For prolong use of jojoba oil, the details of its storage behaviour are required. This information is scarce for the products obtained from Indian locations. In this study, the ageing effect on the quality of oils was studied for oils from five locations of Rajasthan (India). The oils were extracted/expelled from the seeds that contained 2.5–3.9 wt.% moisture and 42–50 wt.% oil.Physico-chemical properties were determined by standard analytical test methods. Effect of storage time on quality of solvent extracted oil samples with respect to acid value, iodine value, saponification value and peroxide value were determined. The samples were stored for 18 months in the laboratory under climatic condition prevailing in Dehradun (India) during study period. The analysis of samples was done at an interval of 3 months. The properties of jojoba oils compare well with the International Jojoba Expert Council (IJEC) specifications. During storage, acid values, iodine values and peroxide values of the oil increase with time while saponification values remain almost unchanged.     

The development and comparison of bio-thermoset plastics from epoxidized plant oils

This study investigates the development of thermoset plastics from plant-based oils (e.g., linseed, soybean, cottonseed, oilseed radish, and peanut oils) using an optimal process of solvent-free epoxidation. The epoxidation of plant oils can be accomplished economically by reacting the double bonds of fatty-acids with hydrogen peroxide. During the solvent-free process catalyzed by the ion-exchange resin, we observed that the influence of several variables was important: the molar ratio of hydrogen peroxide to unsaturation, acetic acid to unsaturation, and temperature. The epoxidation of plant oils was determined from the liquid mixture and the composite matrix by thermal and spectroscopic analyses. Compounds with a higher double-bond (iodine) value showed higher oxirane oxygen percent and selectivity, and a higher hydroxyl value because of a greater possibility of attack by solutions causing side reactions. Lower iodine values indicated fewer epoxy groups and selectivity, and a lower hydroxyl value. Benzyl pyrazinium hexafluoroantimonate (BPH) yielded good thermal curing properties; as little as 1% added to the plastics produced light-weight composites. Epoxidized linseed oil promises the highest modulus and impact resistance due to the largest number of double bonds to contribute more epoxy groups and the large proportion of linolenic acids to produce epoxy groups rapidly.