Characterization of Bioactive Compounds from Monovarietal Virgin Olive Oils: Relationship Between Phenolic Compounds-Antioxidant Capacities

The characterization of bioactive components of virgin olive oil from nine varieties (Cuquillo, Empeltre, Manzanilla, Cornicabra, Picual, Arbequina, Lechin, Picudo, and Hojiblanca) has been carried out. Carotenoids, chlorophylls, α-tocopherol, fatty acids, total phenols, and individual phenols were determined. The antioxidant capacity was evaluated by 2,2′-diphenyl-1-picrylhydrazyl and 2,2′-azinobis (3-ethylbenzothiaziline-6-sulfonate) radical scavenging capacity assay, ferric reducing antioxidant potential assay, and oxygen radical absorbance capacity assay. Twelve phenolic compounds were detected and quantified by high-performance liquid chromatography with diode-array detection. Dialdehydic form of elenolic acid linked to tyrosol and hydroxytyrosol, oleuropein, and ligstroside aglycones were the major components in all the samples. Principal component analysis confirmed that Manzanilla, Lechin, Cuquillo, and Hojiblanca var. were the most similar. Furthermore, these results showed that the antioxidant capacity measured by different assays was highly influenced by the phenolic content, especially the dialdehydic form of elenolic acid linked to tyrosol and hydroxytyrosol.     

Fatty Acids,Sterols, Polyphenols,and Chlorophylls of Olive Oils Obtained from Tunisian Wild Olive Trees (Olea europaea L. Var. Sylvestris)

Olive (Olea europaea L.) includes cultivated olive trees (var. europaea) and wild olive trees or oleaster (var. sylvestris) as two botanical varieties. These olive varieties were widely spread in the Mediterranean Region. The aim of this study was to determine fatty acid compositions, sterols, polyphenols, and chlorophylls of oils obtained from 12 wild olive trees from Northern Tunisia. Two dominated oil cultivars in Tunisia (Chétoui and Chemlali) were also used to compare results. The fatty acid methyl ester and the sterol compositions were analyzed using gas-liquid chromatography and thin layer chromatography methods, respectively. The polyphenols and chlorophylls were determined using the calorimetrical method. Results indicated that oils extracted from wild olives displayed good balanced fatty acid compositions, sterols, polyphenols, and chlorophylls. Qualitatively, for wild and cultivated olive oils, the oil has an identical composition, whereas the quantitative variation showed that some wild trees seem to be interesting oil sources as two Tunisian dominated cultivars. The highest oleic acid and polyphenol contents were 71.55% and 537.6 mg/kg of oil found in wild olives (OIch2, OIch1). The β-sitosterol was the major sterolic fraction and ranged from 84.72 to 75.70% according to the wild olives. Consequently, wild olives would be a new future edible olive oil source, as well as commonly cultivated ones.     

Differences in fatty acid composition of fish faeces as determined by two extraction methods

Chloroform-methanol, a supposedly efficient solvent system for lipid extraction, was applied to heterogeneous samples, respectively fish diets and fish faeces. Comparisons were made of the compositions of the fatty acids prepared from solvent-recovered lipids with those obtained by total saponification. These show that solvent extraction, followed by saponification prior to fatty acid methyl ester preparation, gives differences attributable to incomplete extraction. Direct sample saponification in ethanolic alkali is recommended if all fatty acids in the diet are of interest.     

Fatty Acids Composition of Apple and Pear Seed Oils

In this study, oil content and fatty acid composition of apple and pear seeds were analyzed. Apple (cv. red Fuji) seeds and pear (cv. Dangshan Suli) seeds contained a large quantity of oils (apple seed oil, 291 g/kg seed; pear seed oil, 179 g/kg seed). Eleven types of fatty acids were identified in apple and pear seed oil; c16:0, c16:1, c18:0, c18:1, c18:2, c18:3, c20:0, c20:1, c20:2, c22:0, and c24:0. The dominant fatty acids in apple seed oil were c18:1 (43.03 g/100g oil), c18:0 (26.47 g/100g oil), and c16:0 (5.60 g/100g oil). The same three fatty acids were also dominant in pear oil (c18:1, 56.80 g/100g oil; c18:0, 20.28 g/100g oil; and c16:0, 6.39 g/100g oil). Compared with previous research, an additional six fatty acids were found in apple seed oil (c16:1, c18:3, c20:1, c20:2, c22:0, and c24:0). Unsaturated fatty acids comprised 70.598 g/100g oil of apple seed oil and 77.846 g/100g oil of pear seed oil. In conclusion, apple seeds and pear seeds contain a large quantity of oil comprised of many fatty acids, especially unsaturated fatty acids. These data suggest that apple and pear seeds could be new sources of edible oils.     

超临界CO2和微波辅助萃取佩兰挥发油工艺的研究

本文通过超临界CO2萃取均匀设计实验和微波诱导萃取佩兰挥发油的正交实验比较,考察影响提取的主要因素,寻求最佳萃取工艺。超临界CO2萃取最佳工艺条件为萃取压力15MPa,萃取温度32℃,CO2流量20kg/h和时间80min,得率2.71%;微波萃取最佳工艺条件为辐射功率720W,辐射时间160s,溶剂量300ml,洗涤剂量30ml,得率3.76%。水蒸馏法提取率为0.76%。结果表明超临界CO2和水蒸馏法萃取佩兰挥发油品质最好;微波萃取收率最高,但品质较差。     

不同树龄侧柏木精油差异的研究

本文采用超临界流体法提取三种不同树龄的侧柏木精油,并研究了三种侧柏精油在提取率、感官性状、精油组成和抑菌功效等方面的差异。研究结果表明,树龄越老的侧柏木的精油提取率越高,最高可达到9.98%,精油的芳香气味也更浓郁醇正;采用GC-MS法分析精油成分,发现树龄越老的侧柏木的精油其主要成分罗汉柏烯、雪松醇、花侧柏烯等含量也越高;采用最低抑菌浓度(MIC)法比较了三种精油的抑菌功能,发现树龄越老的侧柏木精油其MIC也越低,对四种细菌(金黄色葡萄球菌、乳酸菌、大肠杆菌和沙门氏菌)的MIC均可低至0.05 mg/m L,说明其具有高效的抑菌效果。本文研究结果表明,侧柏木的陈化时间对其精油的风味、含量、组成和功能等方面均具有重要影响,树龄越老的侧柏木精油利用价值越高。     

两种溶剂萃取黑比诺葡萄酒香气成分的比较

采用二氯甲烷和乙醚:正己烷(1:1)两种不同溶剂提取黑比诺干红葡萄酒中的香气成分,并用GC-MS进行分析比较.结果表明,用二氯甲烷提取的葡萄酒香气成分总收量高于乙醚:正己烷(1:1),且各类香气成分的组成比例有很大差异.用二氯甲烷提取得到的香气成分为34种,其中醇类12种、酯类10种、烷烃类4种、酸类4种,总量为441.73 mg/L;而用乙醚:正己烷(1:1)提取得到的香气成分只有25种,醇类6种、酯类5种、烷烃类5种、苯环类3种,总量为186.93 mg/L;两者相同的成分有11种,多为醇类、酯类,不同的成分有34种.     

Comparison of Oxidative Stability among Edible Oils under Continuous Frying Conditions

The stability of camellia oil (saturated fatty acid: monounsaturated fatty acid: polyunsaturated fatty acid = 1:7:1) after frying potatoes was compared with palm oil (saturated fatty acid: monounsaturated fatty acid: polyunsaturated fatty acid = 4:4:1) and peanut oil (saturated fatty acid: monounsaturated fatty acid: polyunsaturated fatty acid = 2:4:4). Oil samples were evaluated for acid value, iodine value, peroxide value, p-anisidine value, total oxidation value, tocopherols content, and fatty acids composition. There was the least change in fatty acid composition in camellia oil among the three edible oils. The α-tocopherol was more vulnerable to heat degradation than γ-tocopherol and δ-tocopherol, and α-tocopherol was completely degraded before the whole frying process was done for palm and peanut oils. The oxidative stabilities of the three edible oils were in the order of camellia oil > palm oil > peanut oil. The oxidative stability was mainly determined by the calculated oxidizability value related to fatty acid composition, and when calculated oxidizability values were similar, the tocopherol contents of edible oils would be a key factor in affecting their oxidative stabilities.     

两种不同南瓜籽油中脂肪酸的GC/MS分析

采用超声波提取辽宁产普通南瓜籽和黑籽南瓜籽油，用氢氧化钾－甲醇法酯化后，对其进行GC／MS分析，从普通南瓜籽油中检测出8种脂肪酸，黑籽南瓜籽油中检测出15种脂肪酸，其中人体必需的不饱和脂肪酸含量较高。     

两种提取方式的燕麦油成分的GC-MS分析

为了研究不同提取方法对燕麦油中化学成分的影响,本实验采用常规提取和超临界CO2流体提取两种方法提取燕麦油中的成分,并结合气相色谱-质谱联用(GC-MS)对燕麦油的成分进行检测和分析。GC-MS分析结果显示,燕麦油常规提取物中,通过人工解析结合标准图谱数据库(NIST)检索定性确认,共鉴定出6种成分,从常规提取燕麦油脂肪酸酯化产物中共鉴定出13种成分;采用超临界CO2流体提取方法提取的燕麦油中共鉴定出16种成分,从超临界流体提取燕麦油脂肪酸酯化产物中共鉴定出10种成分。采用峰面积归一化法计算各化合物的相对百分含量,4种样品化学成分含量分别占总面积的82.7%、99.65%、64.26%和99.71%,其中含量较高的有N-(2-羟乙基)癸酰胺、顺式-十八烷酸、亚油酸、油酸和棕榈酸等。本研究旨在今后为燕麦油的进一步食用或药用研究开发提供参考。     

五种方法提取的牡丹皮挥发油成分比较

本研究通过采用气相色谱-质谱联用（GC-MS）法结合保留指数（RI）对牡丹皮蒸馏法、水蒸气蒸馏法、水蒸气加酒精灯加热蒸馏法、乙醚超声波萃取法和超临界CO2萃取法这五种提取方法所制备的挥发油进行分析,通过比较挥发油得油率、化合物成分和丹皮酚提取率,选出最佳提取方法。五种方法的得油率分别为：1.03%、2.97%、4.45%、2.85%、0.63%,确定所得化合物的种类依次为21、22、22、23和22种,主要包括酚、烷烃、酸、酯、酮、醇和醛类等成分。五种方法获得的丹皮酚含量分别为：76.34%、72.49%、91.54%、60.04%和75.90%。以得油率和丹皮酚提取率为指标,水蒸气加酒精灯加热蒸馏法提取牡丹皮挥发油的提取率最高,可用于牡丹皮挥发油的提取;以化合物成分为指标,则超临界CO2萃取法和乙醚超声波萃取法,鉴别出的成分更全面。     

不同方法萃取的燕麦油脂肪酸组成及清除DPPH 自由基活性研究

对以正已烷、甲醇为溶剂和不添加与添加乙醇为夹带剂的超临界CO2(SCF-CO2)萃取的燕麦油的脂肪酸组成与清除DPPH 自由基活性进行研究,气相色谱分析结果显示,对于SCF-CO2、添加夹带剂的SCF-CO2、正己烷、甲醇4 种方法萃取的燕麦油中：脂肪酸主要由棕榈酸、反式油酸、亚油酸构成,三者相对含量的总和在燕麦油的脂肪酸总量中都占93%;不饱和脂肪酸相对含量依次为79.41%、77.86%、77.56% 与76.51%,饱和脂肪酸、单不饱和脂肪酸与多不饱和脂肪酸的比例依次为1:2.74:1.85、1:2.08:1.71、1:2.21:1.60 与1:1.74:1.73。DPPH自由基清除实验结果显示：SCF-CO2 萃取的燕麦油能有效清除DPPH 自由基,清除能力由强到弱依次为：VC ＞甲醇提取燕麦油＞添加夹带剂的SCF-CO2 提取燕麦油＞ VE ＞正己烷提取燕麦油＞无夹带剂的SCF-CO2 提取燕麦油。     

酶法提取植物油的工艺方法及特点

介绍了酶法提取植物油的多种工艺方法，讨论了有关工艺的影响因素，总结了酶法提油工艺的特点，对现有文献报道的工艺方法的优缺点进行了评述。从植物油提取工艺应用的要参出发，提出了酶法提油需进一步研究的问题。应用生产量大、价格低廉的酶是该方法工业化的基础，进一步提高得油率及研究提油后油料蛋白利用的技术，是酶法提油工艺发展的根本。     

改进型Clevenger装置提取柠檬果皮精油及成分分析

研究Clevenger装置改进前后对尤力克柠檬精油提取率和精油成分的影响;采用改进型Clevenger装置分别提取了青柠、尤力克、艾伦尤力克、费米耐劳、无籽里斯本5个不同柠檬品种的果皮精油,通过气相色谱-质谱法对其进行成分分析和结构鉴定,得到不同品种的柠檬果皮精油成分的指纹图谱。结果表明,Clevenger装置改进后尤力克柠檬精油的提取率增加了63.37%,且对精油挥发性成分种类无显著影响;5个柠檬品种中分别检测到51、50、41、43种和42种挥发性成分,主要为烯烃类、醇类、醛类、酯类以及少量的酸类和酮类。烯烃类物质是各个品种精油成分中最主要的组分,其中特征香气成分D-柠檬烯相对含量最高,β-蒎烯、γ-松油烯次之。品种间差异较大,除了含有32个共有成分之外,每个品种都存在自身特有的挥发性成分。     

两种不同方法提取鲜橙皮中挥发油的比较研究

采用微波辅助水蒸气蒸馏(MAHD)法和水蒸气蒸馏(HD)法提取新鲜橙皮中的挥发油,并利用气质联用仪(GC-MS)对各成分的含量进行分析,用峰面积归一化法确定各组分的相对含量。结果表明:两种提取方法得到的挥发油组分基本一致,但相对含量不同。与HD法相比,MAHD法节省时间,总的提取率略高。对挥发油中的不同成分进行提取时,对于高温较易氧化的成分,选择HD法可能要优于MAHD法;对于对氧化时间敏感或高温比较稳定的成分,选择MAHD法可能更好。     

Evaluation of the quality of olive oil using fatty acid profiles by direct infusion electrospray ionization mass spectrometry

Electrospray ionization mass spectrometry is used to predict the olive oil quality according to European Union marketing standards. Samples were 1:50 diluted in an alkaline 85:15 (v/v) propanol/methanol mixture and directly infused into the electrospray ionization source of an ion trap mass spectrometer. The establishment of ratios of the peak abundances of the free fatty acids followed by linear discriminant analysis was employed to predict the olive oil quality grade. In addition, using multiple linear regression and partial least-squares regression, the percentages of extra virgin and virgin olive oils in binary mixtures were predicted with 5–11% average prediction errors.     

PCR法定性检测食用油脂中转基因成分

食用油脂（尤其是精炼油）被认为几乎不含DNA和蛋白质等生物大分子。针对食用油脂中DNA含量极低、破坏严重的特点，成功地建立了食用油脂中DNA提取方法，并从中检测出玉米、大豆内源基因（IVR、Lectin）以及外源抗虫基因[CryIA(b)]和抗除草剂基因（EPSPS），为油脂进行核酸类生物性检测提供了一种简捷有效的方法。     

不同方法提取山桐子油的品质及体外抗氧化活性研究

文章研究了压榨法、水酶法、有机溶剂浸提法提取山桐子油及对其品质的影响,结果表明,提取率分别为压榨法20.9％、水酶法20.54％、有机溶剂浸提法28.47％;浸提法的提取率最大,但耗时长,存在一定溶剂残留;水酶法过氧化值最低,但耗时长;压榨法不饱和脂肪酸高于水酶法及溶剂浸提法,且耗时短,操作简单.DPPH自由基清除能力...     

蒸馏法提取香根油成分的GC-MS分析

为研究蒸馏法香根油化学成分,以气相色谱-质谱联用仪检测水蒸馏法香根油,在香根油中鉴定发现异丁香酚等21种化学成分的化学结构,其中有5-甲基糠醛等12种化合物是香根油中首次发现的天然化合物,该发现对以香根油为原料的新食品添加剂研发及应用具有重要意义。     

不同方法制备的栀子果油的理化性质比较

本实验利用正己烷萃取技术、超临界CO2萃取技术和亚临界低温萃取技术三种方法制备得到了三种栀子果油,并对其主要理化指标、脂肪酸组成、植物甾醇含量、谷维素含量、维生素E含量及氧化酸败时间进行比较分析,以研究不同萃取方法对栀子果油品质的影响。结果表明三种栀子果油的过氧化值为9.38~17.30 mmol/kg,酸值为4.06~14.28 mg KOH/g,皂化值为186.07~198.91 mg KOH/g,碘值为116.43?10-2~130.16?10-2 g I2/g。气相色谱法测定其脂肪酸组成以油酸和亚油酸等不饱和脂肪酸为主,相对含量占76.04~78.00%。栀子果油中植物甾醇和维生素E的含量分别是0.85~3.48%和17.06?10-2~29.80?10-2 mg/g,谷维素含量极少。其中超临界栀子果油的色泽最好,溶剂残留量最少,但酸价最高;正己烷栀子果油中甾醇含量最高,氧化稳定性相对较好;亚临界栀子果油的酸值最低,维生素E含量最高。本文为栀子果油制备方法的选择和精炼提供了理论依据,具有一定的应用意义。