不同食用油氧化稳定性比较研究

为了比较不同食用油的氧化稳定性,选取紫苏油、亚麻籽油、核桃油、菜籽油和芝麻油5种食用油为原料,以烘箱法为对照,分别采用涂膜法和模拟法以过氧化值和酸值为考察指标对其氧化稳定性进行评价,并对其氧化过程中的脂肪酸组成变化进行探讨。结果表明:5种食用油氧化稳定性从高到低依次为:芝麻油菜籽油核桃油亚麻籽油紫苏油;在氧化初期,多不饱和脂肪酸含量减少,单不饱和脂肪酸含量和饱和脂肪酸含量有不同程度的增加,多不饱和脂肪酸含量对食用油氧化稳定性具有明显的影响,特别是亚麻酸含量;在评价氧化稳定性的方法中,烘箱法操作简便但无法反映氧化实际情况,涂膜法检测过程高效且实时,模拟法可反映食用油在使用中的实际氧化过程。     

马泡瓜籽油成分分析及氧化稳定性研究北大核心CSCD

采用溶剂浸出法提取马泡瓜籽油,对马泡瓜籽油的理化性质和营养组分进行了分析,通过Rancimat加速氧化实验对其氧化稳定性进行测定。结果表明:马泡瓜籽的粗脂肪含量为(27.96±2.15)%;马泡瓜籽油的酸值(KOH)(0.24 mg/g)、过氧化值(0.036 g/100 g)均达到了食品安全国家标准;马泡瓜籽油中共检测出8种脂肪酸和7种甘油三酯,主要是亚油酸(68.56%)和三不饱和甘油三酯(66.50%);马泡瓜籽油中植物甾醇(总含量619.21 mg/100 g,其中粘霉烯醇140.83 mg/100 g)、角鲨烯(38.01 mg/100 g)和生育酚(546.60 mg/kg)的含量较高;马泡瓜籽油的氧化稳定性优于葵花籽油,运用外推法计算出25℃条件下马泡瓜籽油的氧化诱导时间为582.43 h。研究证明马泡瓜籽油具有很好的应用前景。     

玉米油中主要营养因子在精炼与储存过程中的变化

分析了国内主要市售品牌玉米油中主要营养因子的含量,探讨了精炼工艺和储藏时间对玉米油中主要营养因子的影响。结果显示:不同品牌市售玉米油中脂肪酸含量差别较小,而生育酚和植物甾醇含量差别较大,其中生育酚含量范围为56.2~98.3 mg/100 g,植物甾醇含量范围为105.8~216.4 mg/100 g;精炼工艺脱臭对玉米油中亚油酸、α-亚麻酸、生育酚和植物甾醇含量有显著降低的效果(P0.05),脱皂能显著降低植物甾醇含量(P0.05),其他工艺均无显著影响(P0.05);精炼后常温储藏6个月后的玉米油中除油酸含量显著降低外,其他脂肪酸含量无显著变化(P0.05),生育酚和植物甾醇含量均显著减少(P0.05);复配添加维生素E和迷迭香提取物对玉米油的氧化稳定性具有显著的提升作用(P0.05)。     

植物油脱臭馏出物生物活性成分提取与纯化技术研究进展

油脂脱臭馏出物是植物油精炼脱臭时副产品,含有生育酚、甾醇、角鲨烯等生物活性成分,提取和纯化这些活性成分已成为研究热点;该文综述植物油脱臭馏出物生物活性成分提取与纯化技术研究进展。     

食用油使用过程中存贮条件对其氧化稳定性的影响研究

研究了大豆油、菜籽油、棕榈油等几种食用油在使用过程中不同存贮条件下的氧化稳定性。将食用油启封,放置在不同的环境里,检测其过氧化值和酸值的变化。结果表明:避光存贮31 d,食用油的过氧化值均低于8 mmol/kg,酸值(KOH)达到0.26~0.35 mg/g;而在室内日光直接照射的条件下存贮31 d,各食用油的过氧化值均高于10 mmol/kg,酸值(KOH)达到0.35~0.45 mg/g。实验表明,启封后的食用油,存贮于避光处可以连续使用30 d以上,而置于室内日光直接照射条件下,其连续使用期只有3周。对比实验中,棕榈油氧化稳定性优于其他油脂。     

Effects of emulsifier type on physical and oxidative stabilities of algae oil-in-water emulsions

Algae oil-in-water emulsions were prepared using sodium caseinate (SC, 0.5%), whey protein concentrate (WPC, 0.5%), and a mixture of TWEEN80 (T80, 0.5%), and SPAN80 (SP80, 0.6%), and their emulsification and oxidative stabilities during storage were compared. Oil droplet sizes of SC- and T80+SP80-emulsions were smaller than that of WPC-emulsion. Serum layer appeared in all emulsions from day 15, and serum layer thicknesses were higher in WPC-emulsion than SC- and T80+SP80-emulsions, but an excess layer oil was observed only at the top of T80+SP80-emulsion until day 36. According to conjugated dienes, aldehydes, hydroperoxide and TBARS values, the oxidative stability of SC-emulsion was better than those of WPC- and T80+SP80-emulsions. This trend was also observed in fatty acid profiles of the emulsions showing the largest DHA reduction and palmitic acid increase in T80+SP80-emulsion, followed by WPC- and SC-emulsions. In present study, sodium caseinate formed stable algae oil-in-water emulsions with excellent antioxidative activity.     

Evaluation of Fatty Acid Composition,Tocols Profile,and Oxidative Stability of Some Fully Refined Edible Oils

Present study includes evaluation of fatty acid composition, tocols profile, and oxidative stability of some fully refined edible oils. Fully refined sunflower, soybean, corn, hazelnut, peanut, and canola oils were analyzed for fatty acids by capillary gas liquid chromatography, tocols by normal phase-high performance liquid chromatography and oxidative stability by rancimat. Free fatty acid, peroxide value, and iodine value of investigated oils were determined by titrimetric methods. Saturated, mono-, and polyunsaturated fatty acids were found to be in the ranges between 2.03–18.58, 23.39–77.26, and 14.39–58.52%, respectively. Tocols and oxidative stability of the investigated oils were found to be in the ranges between 488.88–913.51 mg kg^?1 and 3.05–4.99 h, respectively.     

Effect of plant phenolics,tocopherol and ascorbic acid on oxidative stability of pork patties

BACKGROUND: There is great interest in the use of naturally occurring antioxidants to delay oxidation in meat products. The effect of rosemary extract (RE), green tea extract (TE), tocopherol, trolox, ascorbic acid (AA) and ascorbyl palmitate (AP), at levels of 50–200 ppm of antioxidant components, on colour (CIE L*a*b*), lipid (TBARS) and protein oxidation (thiol groups) in fresh, frozen and cooked pork patties during illuminated chill storage was investigated. Individual components of RE and TE were also tested. RESULTS: RE, TE, AP, tocopherol and trolox equally inhibited lipid oxidation in fresh and frozen patties, whereas for cooked patties RE was most effective. AA stimulated lipid oxidation. No dose effect in the range of 50–200 ppm was found for fresh and frozen patties, whereas for cooked patties higher doses of RE and TE more efficiently prevented lipid oxidation. Protein oxidation was hardly influenced by antioxidant treatment. Colour stability decreased as follows: tocopherol, AA and AP > RE and TE > trolox. Antioxidant properties of the extracts and their major antioxidant components were comparable. CONCLUSION: The relative effect of the antioxidants depends on the oxidation parameter assessed, the applied dose and the hydrophilic/lipophilic character. Copyright © 2009 Society of Chemical Industry     

Characterisation of oil oxidation,fatty acid,carotenoid, squalene and tocopherol components of hazelnut oils obtained from three varieties undergoing oxidation

Hazelnut oils obtained from three varieties of Chinese hybrid hazelnuts (cv. ‘Liaozhen 3 (LZ)’, ‘Pingou 21’ (PG) and ‘Yuzhui’ (YZ)) were used to compare the lipid oxidation characteristics (peroxide value, p-anisidine value and conjugated diene value), fatty acid profiles and major active components (squalene, carotenoids and tocopherols) under oxidation condition at 60 °C for 40 days, in addition, the molecular structure changes in the three hazelnut oils were monitored by Raman spectroscopy. The lipid oxidation of the three hazelnut oils had similar tendencies, and the oxidation rate was slower in the early stage and faster in the later stage. Polyunsaturated fatty acids (PUFAs) tended to decrease mainly due to the decrease in linoleic acid. LZ had higher contents of tocopherol, carotenoids and PUFAs than the other varieties, while YZ owned the highest content of squalene. Tocopherol and carotenoids of the three hazelnut oils showed easy loss, while squalene was relatively stable. Raman spectroscopy can effectively indicate the degree of oxidation and carotenoid levels of hazelnut oil. This study can provide a scientific basis for variety selection in planting and utilisation of active ingredients for the hazelnut industry.     

Variations in the phytosterol and tocopherol compositions and the oxidative stability in seed oils from four safflower (Carthamus tinctorius L) varieties grown in north‐eastern Morocco

Phytosterol and tocopherol contents and oxidative stability were evaluated from seeds oils of four safflower (Carthamus tinctorius L) varieties originating from Spain (Rancho), India (Sharda) and Morocco (Cartamar and Cartafri), which were cultivated at the experimental station in Oujda (a semi‐arid region of eastern Morocco). Total phytosterols ranged from 3640 to 4140 mg kg^?1. GC analysis allowed the identification of nine compounds, of which β‐sitosterol was the major component. Total tocopherols ranged from 461.56 to 499.68 mg kg^?1. HPLC analysis allowed the identification of three compounds, α‐tocopherol (99.45%–98.84%), β‐tocopherol (0.94%–0.5%) and γ‐tocopherol (0.21%–0.01%). Oxidative stability study showed that Sharda had the lowest induction period of 2.3 h compared with 7.18, 7 and 6.67 h for Cartafri, Rancho and Cartamar, respectively. Likewise, we established a positive correlation between the oxidative stability and γ‐tocopherol; however, this difference was not significant.     

植物油中甾醇的高温稳定性研究

研究了6种植物油(玉米油、甾醇强化玉米油、大豆油、花生油、葵花籽油、橄榄油)中甾醇在高温条件下的热稳定性。使用气相色谱-质谱联用技术检测了植物油中3种主要甾醇(菜油甾醇、豆甾醇、β-谷甾醇)含量,并测定了油脂酸值随加热时间的变化。结果表明:总甾醇含量最高的是甾醇强化玉米油,达到7.82 mg/g,橄榄油中甾醇含量最低,为0.63 mg/g,β-谷甾醇在总甾醇中比例最高;高温加热(180℃)条件下,植物油中甾醇稳定性较强,但加热时间过长,仍会导致部分甾醇降解;加热过程中,植物油的酸值均呈上升趋势。因此,植物油中甾醇在高温条件下的降解应引起重视。     

不同产地核桃油理化性质、脂肪酸组成及氧化稳定性比较研究

测定了不同产地(云南、新疆、陕西、甘肃、山西、河北)核桃仁的理化性质和核桃油的理化性质、脂肪酸组成及含量,并进行了差异分析和变异分析;通过Rancimat法评估了6种核桃油的氧化稳定指数(OSI),利用回归分析研究了核桃油脂肪酸组成及其氧化稳定性之间的相关性。结果表明:6种核桃仁理化性质的差异程度依次为:水分含量蛋白质含量脂肪含量;6种核桃油理化性质的差异程度依次为:过氧化值酸值皂化值碘值相对密度折光指数;6种核桃油脂肪酸含量差异程度依次为:亚麻酸油酸硬脂酸棕榈酸亚油酸;脂肪酸组分对核桃油氧化稳定性的影响程度依次为:亚油酸硬脂酸棕榈酸油酸亚麻酸。     

糖基化修饰对油茶油脂体界面结构及稳定性的影响

油脂体是植物种子储油细胞器,由单层磷脂与界面蛋白共同稳定。为增加油脂体的pH稳定性,选用葡萄糖和乳糖为羰基供体,通过糖基化修饰油茶油脂体的界面结构。通过粒径及Zeta-电位的变化综合评估油脂体物理稳定性,采用聚丙烯酰胺凝胶电泳考察油脂体膜蛋白分子质量变化,采用Thermo Scientific Pierce BCA试剂盒分析油脂体膜蛋白溶解度的变化,并利用拉曼共聚焦显微镜观察油脂体界面结构的变化。结果表明：糖基化反应增大了油茶油脂体粒径,但粒径分布更均一,而Zeta-电位未发生显著变化（p>0.05）;葡萄糖和乳糖与油脂体质量比分别为2∶ 1和5∶ 1时糖基化油脂体膜蛋白溶解度最高,分别比对照组（未糖基化油脂体）提升了26.8倍和16.1倍。糖基化后油脂体膜蛋白分子质量小幅增大;拉曼光谱分析表明糖与油脂体膜蛋白成功接枝。综上,糖基化有利于提高油茶油脂体稳定性。     

磷脂与游离脂肪酸对油脂烟点和氧化稳定性的影响

考察了磷脂含量、游离脂肪酸含量、游离脂肪酸碳原子数和不饱和度对花生油和山茶油烟点和氧化稳定性的影响。结果表明:磷脂含量对油脂烟点影响很大,含量越高,烟点越低,对油脂氧化稳定性表现出不同规律,其对花生油氧化稳定性有一定的提高作用,而对山茶油则影响不大;游离脂肪酸含量越高、游离脂肪酸碳原子数越少和不饱和度越大,油脂的烟点越低、氧化稳定性越差,并且相对于氧化稳定性,对烟点的影响要大得多。     

Endogenous biophenol, fatty acid and volatile profiles of selected oils

Fatty acid composition, total phenols, phenolic and volatile profile data are presented for cold-pressed and refined camellia oil, in comparison to other commercially available oils – avocado, pumpkin, sesame and soybean – representing a cross-section of bulk, “bland” oils (e.g., soybean) through to more boutique oils consumed primarily for taste (e.g., pumpkin). Camellia oil has a high oleic acid content, low polyunsaturated acid content, and levels of endogenous phenols comparable, in quantity and diversity, to cold-pressed oils. Volatile profiles of camellia oil are also comparable to cold-pressed oils, in that alkanals are the dominant headspace compounds, as measured by solid-phase microextraction gas chromatography. These factors suggest that camellia oil may find much wider commercial acceptance outside its current market range, southern China.     

不同种类榛子油脂脂肪酸组成及抗氧化活性

对欧洲榛巴塞罗那、平榛1#、平欧杂交榛辽榛3#和达维4个品种榛子油脂的基本理化性质、脂肪酸组成和抗氧化活性进行研究,并比较不同品种之间的差异。结果表明：不同品种榛子油脂的基本理化性质之间存在显著差异,碘值为137.15～147.50g I2/100g,皂化值为144.99～159.03mgKOH/g,平榛油脂具有较低的酸值和碘值,欧洲榛油脂的酸值较高,平欧杂交榛油脂具有较高的碘值,两个品种平欧杂交榛油脂的皂化值之间具有较大差异。榛子油脂中的脂肪酸组成以油酸含量最高,为67.69%～82.26%;其次是亚油酸,为11.37%～14.24%;不饱和脂肪酸含量为84.37%～94.31%,其中多不饱和脂肪酸含量为11.84%～16.39%。榛子的DPPH自由基半数清除质量浓度IC50在23.63～42.40mg/mL,抗氧化活性：辽榛3#＞平榛1#＞达维＞巴塞罗那。说明：我国平榛和平欧杂交榛相比于欧洲榛,在不饱和脂肪酸含量和抗氧化能力方面存在优势。     

Fatty acid composition,oxidative stability,antioxidant and antiproliferative properties of selected cold-pressed grape seed oils and flours

Cold-pressed chardonnay, muscadine, ruby red, and concord grape seed oils and their defatted flours were studied for their fatty acid composition, oxidative stability and antioxidant and antiproliferative activities. The phenolic profiles of the seed flours were also measured. The most abundant fatty acid in the oils was linoleic acid, ranging from 66.0 g/100 g of total fatty acids in ruby red seed oil to 75.3 g/100 g of total fatty acids in concord seed oil. The oils were also high in oleic acid and low in saturated fat. Ruby red grape seed oil recorded the highest oxidative stability index of 40 h under the accelerated conditions. Total phenolic content (TPC) was up to 100 times lower in the oils than in the flours. Lutein, zeaxanthin, cryptoxanthin, β-carotene, and α-tocopherol levels were also measured. DPPH radical-scavenging capacity ranged from 0.07 to 2.22 mmol trolox equivalents (TE)/g of oil and 11.8 to 15.0 mmol TE/g of flour. Oxidative stability of menhaden fish oil containing extracts of the seed flours was extended by up to 137%. HPLC analysis was conducted to determine the levels of free soluble, soluble conjugated and insoluble bound phenolics in the seed flours. The phenolic compounds analyzed included catechin, epicatechin, epicatechin gallate, quercetin, gallic acid, and procyanidins B1 and B2. Antiproliferative activity was tested against HT-29 colon cancer cells. All of the seed flours and muscadine seed oil registered significant (P < 0.05) inhibition of cancer cell growth. The results from this study demonstrate the potential of developing value-added uses for these seed oils and flours as dietary sources of natural antioxidants and antiproliferative agents for optimal health.     

Physical and oxidative stability of pre-emulsified oil bodies extracted from soybeans

Soybeans contain oil bodies that are coated by a layer of oleosin proteins. In nature, this protein coating protects the oil bodies from environmental stresses and might be utilised by food manufacturers for the same purpose. In this study, an aqueous extraction method was developed to increase the yield of oil bodies extracted from soybean. This method involved a two-step procedure: (i) blending, dispersion, and filtration of soybeans; (ii) homogenisation, suspension, and centrifugation of the filter cake. Using this extraction method about 65% of the oil bodies could be obtained. The mean particle diameter (d₄₃) and sedimentation of the resulting oil bodies increased during storage, suggesting they were prone to aggregation. Heat treatment (90 °C, 30 min) of the oil body suspensions immediately after extraction improved their storage stability, which was attributed to deactivation of endogenous enzymes such as lipase and lipoxygenase. Heat treatment did not adversely affect the oxidative stability of the oil body suspensions at pH 3 or 7 during storage at 37 °C. These results suggest that this aqueous extraction method can be used to prepare oil body suspensions with improved long-term stability.     

植物油氧化稳定性的研究进展

氧化稳定性是衡量植物油质量优劣的一个重要指标,而植物油的酸败变质严重降低了其氧化稳定性。抗氧化剂含量、脂肪酸组成、不同脂肪酸在甘油三酯中的位置分布以及甘油三酯结构等使不同植物油具有不同的氧化稳定性。氧化稳定性的差异取决于植物油氧化的程度,一级二级氧化产物的分析是对植物油氧化程度综合评价的良好指标。文章综述了国内外油脂氧化机理现状及氧化程度的分析方法,重点阐述油脂内外在氧化影响因素,为提高植物油在生产存储中的氧化稳定性及为预防植物油氧化产生的危害提供参考。