Phenolic Compounds in Virgin Olive Oils: Fractionation by Solid Phase Extraction and Antioxidant Activity Assessment

The polar fraction of virgin olive oil was separated into two main parts (A and B) using solid phase extraction. Analysis of individual components by RP-HPLC indicated that the part (A) contained only simple phenols and phenolic acids. Part (B) had a complex nature. The two parts tested for their antioxidant activity showed relatively high protection factors in safflower oil stored at 80°C. Part B was found to contribute more than part A to the stability of the oil. The antioxidant activity of both fractions was related to their content of total polyphenols and o-diphenols. Acidic and alkaline hydrolysis showed significant quantitative changes in the HPLC profiles indicating the presence of ether and ester bonds while high-performance anion exchange chromatography of sugars after hydrolysis gave evidence for the presence of only traces of glycosides. A first attempt to identify a characteristic chromatographic peak of part B by HPLC fractionation and mass spectrometry showed the presence of an ester of tyrosol most probably with a dicarboxylic acid. © 1997 SCI.     

Extraction Methods of Citrus Peel Phenolic Compounds

Several extraction methods have been reported in the literature for the extraction of phenols from citrus peel. Extraction methods may cause a degradation of phenolic compounds due to high applied temperature and pressure or long extraction times (conventional solvent extraction, high-pressure extraction). However, other extraction methods are limited by the polarity of phenolic compounds (supercritical CO₂ extraction). Novel techniques of extraction of bioactive compounds have been developed in order to shorten the extraction time, increase the extraction yield, and prevent the degradation of the phenolic compounds. This review provides a critical comparison of the different extraction methods of citrus peel phenolic compounds. The review compiles valuable data that could be useful for the choice of an appropriate extraction method for bioactive compounds from vegetables sources. The main parameters influencing the extraction yield are also discussed.     

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.     

苦杏仁油不同提取方法的比较研究

研究了杏仁油热回流提取、冷浸法提取、热榨法提取及超临界二氧化碳4种提取方法。从油脂的得率、油脂的品质及理化性质几个因素综合考虑,热榨法和超临界二氧化碳萃取法是比较理想的两种提取方法。     

Evaluation of Functional Phytochemicals in Destoned Virgin Olive Oil

Processing destoned olives by means of extracting adjuvants micronised food talc and depolymerising Cytolase 0 enzyme complex have been studied in the present work. This innovative processing technology increased the plant efficiency (amounts of olives processed per hour) by 20%, as well as the nutritional quality of the end product with respect to functional compounds. The oils showed higher contents of biophenols, aromas, and tocopherols. An intense and balanced flavor and a potentially higher stability and endurance to oxidation (shelf-life) was found. Contents of chloroplast pigments (chlorophylls, pheophytins, carotenes, and xanthophylls) appeared to be lower in comparison to conventional processing. The processing aids allowed to increase significantly the oil yields and to reduce the oil percentage in the byproducts. Traceability of the new products was still possible applying chemometric data analysis for discriminating between cultivars.     

亚临界萃取回收橄榄果渣油的工艺研究

以1,1,1,2-四氟乙烷作萃取溶剂,利用亚临界萃取技术,考察了提取橄榄果渣油提取回收最佳实验条件.采取单因素和三因素三水平正交实验,研究了不同原料粒度、萃取温度和时间对提取率的影响.结果表明当原料粒度为60目,温度为30℃,时间为45 min时萃取效果最好,提取率为93.75％.     

A Comparative Study of Stability of Extra Virgin Olive Oil,Virgin Coconut Oil and Grape Seed Oil against Domestic Deep Frying

The aim of this study was to evaluate the relative stability of extra virgin olive oil （EVOO）, virgin coconut oil （VCO） and grape seed oil （GSO） against domestic deep frying. Oil samples were subjected to deep frying at 190 ℃ for 30, 60, and 90 min and then compared with fresh oil samples in terms of fatty acid composition, peroxide value （PV）, p-anisidine value （p-AV）, total oxidation value （TOTOX）, iodine value （IV）, free fatty acid content （%FFA） and total phenolic content （TPC）. Experimental results showed that the changes in the fatty acid composition, p-AV and TOTOX were in the order, GSO 〉 EVOO 〉 VCO throughout the experiment, while PV was in the order, VCO 〉 EVO0 〉 GSO. Meanwhile, the reduction in the IV was in the order, GSO 〉 VCO 〉 EVOO throughout the experiment. On the other hand, the changes in the %FFA were in the order, VCO 〉 GSO 〉 EVO0 throughout the experiment. VCO had the greatest stability against domestic deep frying, followed by EVO0 and GSO had the least stability against domestics deep frying.     

High Power Ultrasound: Impact on Olive Paste Temperature,Malaxation Time,Extraction Efficiency,and Characteristics of Extra Virgin Olive Oil

High power ultrasound (HPU) provides rapid heating of olive paste and disrupts cell walls, helping small oil droplets exit tissue and coalesce. This has been shown to improve oil yield and reduce malaxation time without affecting oil quality. Indirect and direct HPU at different treatment times were examined on Arbequina and Frantoio olive pastes. Olive pastes were mixed at four different malaxation times to evaluate extraction efficiency. Additionally, oil yield and different quality parameters were observed. HPU increased olive paste temperature from 20?±?0.5 to 25.5 °C, achieving the optimum kneading temperature of 29?±?1 °C in less mixing time. HPU significantly (P?<?0.05) improved oil yield by 1% for both varieties. There were no significant differences (P?>?0.05) in oil yield between 35 and 45 min malaxation time, suggesting the possibility to reduce malaxation by 10 min with HPU. No significant differences (P?>?0.05) were observed in any quality parameters observed, except peroxide value, which increased slightly. Significant increases (P?<?0.05) in total tocopherol and pigments with increasing HPU treatment time occurred, while a decrease in total polyphenol and oxidative stability index resulted after 8 min treatment. HPU influenced L, a, and b values causing the oil to become darker. Sensory results showed no differences between commercially available and HPU-treated samples. These results suggest the possibility of using HPU treatment to increase oil extraction capacity and yield without loss of product quality.     

Potential Use of FTIR-ATR Spectroscopic Method for Determination of Virgin Coconut Oil and Extra Virgin Olive Oil in Ternary Mixture Systems

The aim of this study was to investigate the feasibility of Fourier-transform infrared (FTIR) spectroscopy combined with multivariate calibrations of partial least square (PLS) and principle component regression (PCR) for analysis of virgin coconut oil (VCO) in the ternary mixture with palm oil (PO) and olive oil, and for analysis of extra virgin olive oil (EVOO) mixed with soybean oil (SO) and corn oil (CO). The spectra of individual oils and their blends with certain concentrations were scanned using horizontal attenuated total reflectance accessory at mid-infrared region of 4,000–650 cm⁻¹. The optimal frequency regions selected for calibration models were based on its ability to give the highest values of coefficient of determination (R ²) and the lowest values of root mean standard error of calibration (RMSEC). PLS was slightly better for quantitative analysis of VCO and EVOO compared with PCR. VCO in ternary mixtures is successfully determined at frequency region of 1,200–1,000 using second derivative FTIR spectra with R ² and RMSEC values of 0.999 and 0.200, respectively. Meanwhile, EVOO is best determined at 1,200–1,000 using first derivative FTIR spectra with R ² and RMSEC values of 0.999 and 0.975, respectively. The results showed that FTIR spectroscopy offers accurate and reliable technique for quantitative analysis of VCO and EVOO in ternary systems. In addition, the developed method can be used for the monitoring of VCO and EVOO adulteration with cheaper oils like PO in VCO as well as SO and CO in EVOO.     

Authentication of Extra Virgin Olive Oil from Sesame Oil Using FTIR Spectroscopy and Gas Chromatography

The presence of sesame oil in extra virgin olive oil has been investigated using Fourier transform infrared spectroscopy and gas chromatography. Frequencies of 1207–1018, 1517–1222, and 3050–2927 cm^?1 were chosen for quantification of sesame oil in extra virgin olive oil. Using Fourier transform infrared normal spectra coupled with a partial least square model, the root mean standard error of calibration and root mean standard error of prediction obtained were relatively low, i.e., 0.331 and 1.01% (vol/vol), respectively. Using fatty acid profiles as determined by gas chromatography, the levels of palmitic and oleic acids were decreased linearly with R² of 0.969 and 0.934, meanwhile the levels of stearic and linoleic acids were increased with R² of 0.930 and 0.959, respectively, with the increasing levels of sesame oil. From level 10% sesame oil (vol/vol), all these fatty acids are significantly different (p < 0.05).     

荔枝果肉多酚的提取与分离

以荔枝果肉为试验材料,以多酚含量为评定参数,提取分离其中的多酚物质。以乙醇溶液为提取溶剂,通过单因素试验和正交试验,考察了浓度、提取时间、料液比、提取温度、浸提次数等影响提取率的几个重要因素,得出影响果肉中多酚提取的因素由大到小依次为,提取时间料液比乙醇浓度提取温度,最佳工艺条件为,乙醇浓度70%,料液比1∶11,浸提时间6 h,浸提温度40℃,浸提2次,而且荔枝果肉多酚主要以多酚的多聚体为主,其次是低聚体和单体。     

橄榄油中角鲨烯的提取与检测

本文建立了橄榄油中角鲨烯的提取及检测方法。研究形成以橄榄油为原料,利用酯化分离得到橄榄油中的不可皂化物经柱层析吸附分离纯化得到角鲨烯,并对该角鲨烯进行HPLC分析。结果显示:该橄榄油中角鲨烯的含量为569.21mg/100g,且提取所得角鲨烯纯度为84.33%,对高纯度角鲨烯的生产有着重要指导作用;该HPLC检测方法在0.2-1.8mg/mL范围内线性关系良好,相关系数为0.9970,相对标准偏差为1.04%,方法回收率较高,定量准确,灵敏度高,可用于角鲨烯的定量分析。     

蜡含量法鉴别初榨橄榄油的方法研究

研究了蜡含量法鉴别(特级和中级)初榨橄榄油的方法。采用色谱分离技术,通过柱色谱,洗脱出橄榄油中的蜡组分,再进行气相色谱分析,用内标法测得C40酯至C46酯总的蜡含量。结果表明:该方法C40酯检出限为0.106μg/mL,线性范围为0.001 06～0.106 mg/mL,加标回收率为98.8%～107.1%,试验过程中相对标准偏差(RSD)分别为3.7%和0.8%。该方法具有重复性好,回收率高等特点。通过测定橄榄油中蜡的含量,可用于鉴别(特级和中级)初榨橄榄油。     

两种抽吸模式下卷烟主流烟气中主要酚类的释放量比较

为了解不同抽吸方式对卷烟主流烟气中主要酚类化合物释放量的影响,建立了一种利用超高效液相色谱(UPLC)快速分析卷烟主流烟气中邻-苯二酚、对-苯二酚、间-苯二酚、苯酚、邻-甲酚、间+对-甲酚的方法,并采用该方法测定了ISO模式和加拿大卫生部(Health Canada)深度抽吸模式下38个卷烟样品烟气中这7种主要酚类的释放量。结果表明:①方法检测限为16～43 ng/支,回收率94%～102%,RSD4%;②与ISO抽吸模式相比,在HC深度抽吸模式条件下卷烟主流烟气中主要酚类化合物释放量显著提高。     

超声辅助提取瑭溪蜜柚皮中酚酸的研究

利用20kHz的超声波辅助提取琯溪蜜柚皮中的酚酸,主要研究了超声参数(超声时间、温度、超声功率)对琯溪蜜柚皮中的7种酚酸(咖啡酸、对香豆酸、阿魏酸、芥子酸、原儿茶酸、对羟基苯甲酸、香草酸)和黄酮糖苷(柚皮苷)的影响。结果表明:柚皮苷和酚酸的含量都随着超声时间和温度的增加而增加。超声功率对柚皮苷含量的影响较小,但对7种酚酸有不同程度的影响。确定了超声提取琯溪蜜柚皮中柚皮苷和酚酸的最佳提取条件:柚皮苷,超声30 min、超声温度40℃、超声功率8 W;酚酸,超声30 min、超声温度30℃、超声功率30 W。     

Comparative Study and Quality Evaluation of Italian Focaccias Seasoned with Extra Virgin Olive Oil

An extra virgin olive oil was used as seasoning for three different types of focaccia produced on an industrial scale. This oil and samples of the oil extracted from the focaccias after baking were submitted to routine analyses and to silica gel column chromatography to separate polar compounds. These were then subjected to high performance size-exclusion chromatographic (HPSEC) analysis and it allowed to determine oxidative and hydrolytic degradation products. The results were compared with those obtained from artisan focaccias, seasoned with the same oil and toppings, by statistical analyses. The different technologies and the toppings employed directed in different ways the oxidative and hydrolytic processes in the oil.     

从颗粒污泥中提取DNA的几种不同方法比较

为了从颗粒污泥中提取出DNA,分别采用CTAB法、TENPC法、Takara试剂盒三种方法提取总DNA,通过提取的核酸总量、纯度、片段分布情况指标来评价不同的提取方法对颗粒污泥总DNA质量的影响,并考察了三种不同的溶液洗涤样品以及三种不同的细胞破壁方法对提取的DNA质量的影响.结果表明:采用脱腐缓冲液、PBSbuffer、EDTA buffer洗涤,液氮研磨破壁后TENPC法提取DNA的效果最好,提取的总量最多,大片段提取效果好,这种方法较适合从颗粒污泥中提取DNA.     

花椒风味物质不同提取方法的比较

研究了花椒风味的索氏提取法、水蒸气蒸馏法和同时蒸馏法三种提取方法.对比了花椒油树脂得率、提取时间、试剂用量和感官品质,结果表明:同时蒸馏萃取法是最好的提取方法.     

两种硫酸根含量测定方法的比较

为了更快更准确地测定出卤水中硫酸根离子的含量,参照国家标准方法,我们对两种硫酸根含量的测定方法——分光光度法和容量滴定法进行了比较。