香橼精油体外抗氧化及其抑菌活性研究

为了研究香橼精油的抗氧化性及对细菌、酵母和霉菌的抑菌活性,本文采用体外抗氧化法和琼脂平板扩散法,研究香橼精油总还原力,清除DPPH自由基、·OH自由基和H2O2能力,以及对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、酿酒酵母、黑曲霉的抑制作用。结果表明:香橼精油的抗氧化能力与质量浓度呈正相关,对DPPH自由基、·OH自由基(IC50值为0.32 mg/m L)和H2O2(IC50值为148μg/m L)均有一定的清除能力。香橼精油对霉菌的抑制作用明显强于酵母与细菌,其中对黑曲霉的抑制效果最显著(25.39±1.12)mm,对金黄色葡萄球菌抑制最弱(14.04±1.35)mm。最小抑菌浓度在0.31~1.25 mg/m L,且在p H5~7范围内、温度80、115、121℃及一定时间紫外线照射(20、40 min)影响下,对大肠杆菌和酿酒酵母仍保持较强的抑制作用。      

青柠果皮精油蒸馏工艺优化及香气成分分析

目的:研究青柠果皮精油提取工艺及性质,为青柠果皮的综合利用提供数据。方法:以青柠果皮为原料,通过压榨法提取其精油粗产品,后经分子蒸馏技术对其进行分离纯化,以总轻馏分得率为指标,考察蒸馏温度、刮板转速、进料速度、蒸馏压力4个单因素对青柠果皮精油提取的影响,通过正交实验优化青柠果皮精油提取工艺,并用气质联用仪(GC/MS)分析青柠果皮精油香气成分组成。结果:青柠果皮精油的最佳提取工艺:蒸馏温度30℃,刮板转速400 r/min,进料速度0.25 L/h,蒸馏压力15 Pa,其总轻馏分得率为76.10%±0.29%;GC/MS结合保留指数对纯化青柠果皮精油进行香气成分分析,共鉴定55种化合物,主要包括柠檬烯(36.585%)、γ-松油烯(12.077%)、α-松油醇(8.407%)、萜品油烯(7.867%)、α-松油烯(5.777%)等。结论:优化了分子蒸馏提取青柠果皮精油工艺,并从香气成分中鉴定出55种化合物。     

国产玫瑰精油的化学成分及香气特征

对玫瑰精油制备方法进行了综述。按照化学物种类归纳了国产玫瑰精油的化学成分并对其香气特征进行了分析。     

GC-MS-O结合OAV鉴定花生油特征香气成分

该研究利用气相色谱-质谱联用（GC-MS）、气相色谱-嗅闻（GC-O）、气味活性值（OAV）和香气重组对花生油的特征香气成分进行评价分析。得到顶空固相微萃取最优条件为DVB/CAR/PDMS萃取头、萃取温度50℃、萃取时间60 min。在此条件上,在花生油中共检测出89种挥发性化合物,包括吡嗪、呋喃、醛、酚、吡咯、吡啶、酮、醇、酸、酯类等化合物。其中GC-O确定的香气活性化合物32种,结合OAV分析得到特征香气成分27种。热榨花生油和冷榨花生油中的特征香气成分分别有22、8种,共有成分为己醛、乙酸和苯甲醛。热榨花生油的特征香气成分主要为2,6-二甲基吡嗪、2,3-二甲基吡嗪、2-乙基-6-甲基吡嗪、2-乙基-5-甲基吡嗪、2,3,5-三甲基吡嗪、3-乙基-2,5-二甲基吡嗪、2-乙基-3,5-二甲基吡嗪、苯甲醛、乙酰基吡嗪、2,4-癸二烯醛、麦芽酚、甲基环戊烯醇酮、2-乙酰基吡咯、吡咯-2-甲醛、2-甲氧基-4-乙烯基苯酚。冷榨花生油特征香气成分主要为己醛、D-柠檬烯等物质。结果预期对评价花生油的品质及优化其加工工艺具有重要意义。     

新疆玫瑰精油与保加利亚玫瑰精油化学成分及香气比较

用GC/MS方法,定性定量地分析了保加利亚玫瑰油、新疆玫瑰油的化学成分,分别鉴定了29,25种成分.保加利亚玫瑰油的主要成分为β-香茅醇、反式-香叶醇、橙花醇、芳樟醇、β-苯乙醇、甲基丁子香酚;新疆玫瑰油的主要成分为β-香茅醇、反式-香叶醇、β-苯乙醇、7-辛烯酸乙酯、乙酸香叶酯、金合欢醇.由于两种玫瑰油的化学成分和含量的差异,使得两种玫瑰油的香气有微妙的差异.同时初步讨论了这两种玫瑰油成分与它们香气之间的关系.     

花椒精油及其水提物的香气活性成分分析

本研究通过水蒸气蒸馏法提取汉源青花椒、金阳青花椒、汉源红花椒、武都红花椒的挥发性油,采用直接进样法分析花椒精油,采用溶剂辅助蒸发（solvent-assisted flavor evaporation, SAFE）分离花椒水提物中的挥发性成分,结合气相色谱-质谱联用仪（gas chromatography-mass spectrometry, GC-MS）和气相-嗅闻仪（gas chromatography-olfactometry, GC-O）对两者的香气活性成分进行分析。结果显示,在精油和水提物中分别鉴定出99种和153种挥发性成分,仅水提物中含内酯类和酸类物质;青花椒精油及水提物中相对含量最高的物质为芳樟醇、D-柠檬烯、桧烯、萜品烯-4-醇;红花椒精油及水提物中相对含量最高的物质为芳樟醇、D-柠檬烯、乙酸芳樟酯、α-月桂烯;酯类物质含量的差异可能是造成红花椒与青花椒的精油和水提物香气差异的原因。感官评价结果显示,精油的青香、椒麻和油脂味比水提物更强,水提物的甜香、酸味和哈喇味比精油更突出。通过GC-O分析,在精油中和水提物中分别鉴定出57种和68种香气活性物质,经偏最小二乘法（partial least squares regression, PLSR）进行香气属性和化合物的相关性分析,确定了对精油和水提物香气轮廓影响较大的29种物质。     

GC—MS分析柠檬不同品种果皮精油成分

以云南德宏地区栽培的不同柠檬品种为试材,利用气质联用技术（GC-MS）分析果皮精油挥发性成分种类及相对含量,比较不同品种挥发性成分差异。结果表明,费米耐劳、云柠1号、艾伦尤力克柠檬果皮精油中分别检测到23、20、27种挥发性成分,烯烃类、醇类、醛类、酯类和酮类是3个品种共有组分。烯烃类物质是主要组分,其中特征香气成分D-柠檬烯含量最高,β-蒎烯、γ-萜品烯次之。艾伦尤力克柠檬中挥发性物质的种类和含量均高于费米耐劳和云柠1号柠檬,主要特征香气成分含量也最高。     

三种晚熟甜橙冷磨精油挥发性及主体香气成分的比较分析

为研究重庆主栽晚熟甜橙精油的挥发性及主体香气物质的组成含量特点,采用顶空固相微萃取-气质联用技术和香气活度值(odor activity values,OAV)分析奥林达夏橙、五月红甜橙和晚熟血橙的果皮冷磨精油(cold-pressed oil,CPO)。3个品种中分别鉴定出53、54和52个挥发性物质,其中D-柠檬烯含量普遍较低;奥林达CPO醇酚类、醛酮类含量更高,五月红和晚熟血橙CPO含较高的萜类物质。OAV分析表明,3种CPO的主体香气贡献物质包括对伞花烃、癸醛、己醛、壬醛和芳樟醇等30个成分,体现柑橘香、花香、油脂香等8类主要香气属性;奥林达CPO中花香、脂香和甜香类物质OAV较高,晚熟血橙CPO中松香和木香类物质OAV较高。本地区3个晚熟甜橙冷磨油的主体香气属性各具特点,适合加工不同类型的低萜精油,提升晚熟甜橙的产品附加值。     

4种兰花精油的提取及其成分分析

以建兰、企黑、白墨、金咀4种兰花为原料,使用超声波法和索氏提取法提取兰花精油,并通过GC-MS分析其成分。结果表明：在4种兰花精油中,企黑精油含化合物最多,为48种;在4种兰花精油中均含有棕榈酸、亚油酸、亚麻酸甲酯、5-羟甲基糠醛和α-亚麻酸5种组成成分,且含量均在1%以上;4种兰花精油均含有环氧芳樟醇、α-红没药醇和α-金合欢烯3种香气成分,其中企黑精油中的香气成分含量最高。     

HS-SPME-GC-MS分析小黄姜精油及油树脂挥发性香气成分

以西林小黄姜为原料,通过水蒸气蒸馏得精油(ginger essential oils,GEO)和石油醚、无水乙醇分别索氏提取得石油醚油树脂(oleoresin extracted by petroleum ether,PEEO)、无水乙醇油树脂(oleoresin extracted by absolute ethanol,AEEO)共3种姜油,采用顶空-固相微萃取(headspace solid phase micro-extraction,HS-SPME)结合气相色谱质谱(gas chromatography-mass spectrometer,GC-MS)对其挥发性香气成分进行分析,探讨萃取头、萃取时间和解析时间对萃取效果的影响,结果表明:采用100μm PDMS萃取头,精油萃取3.5 min,解析3 min,油树脂萃取7.5 min,解析2 min,效果最佳。在最佳条件下GEO、PEEO、AEEO分别鉴定出44、41、44种香气成分,组成和含量均具有一定差异,呈香各具特色。     

Composition and radical‐scavenging activity of Thymus glabrescens Willd. (Lamiaceae) essential oil

BACKGROUND: Knowledge about the chemical and therapeutic properties of Thymus glabrescens Willd. (Lamiaceae) is scarce and inconsistent. Therefore the main objectives of this study were to determine the yield and chemical composition of essential oils from wild‐growing T. glabrescens populations, to assess their radical scavenging activity and to correlate the results with published data in order to deduce which components are responsible for the activity. RESULTS: The plant material yielded between 4.0 and 8.0 mL kg^?1 of essential oil. All samples contained considerable but variable concentrations of thymol (22.3–55.1%), depending on the source. Radical‐scavenging activities of the oils were estimated by 1,1‐diphenyl‐2‐picrylhydrazyl free radical (DPPH) assay against butylated hydroxytoluene (BHT) and thymol as positive controls. The observed activities (IC₅₀ values ranged from 94 to 230 µg mL^?1) were strongly influenced by thymol concentration, as verified by rapid screening for DPPH radical‐scavenging activity on thin layer chromatography (TLC) plates and regression analysis. CONCLUSION: These results represent the first report on the free radical‐scavenging activity of T. glabrescens essential oil and one of the first comprehensive reports on its composition. Thymus glabrescens could be used in the food industry for seasoning purposes or for preserving processed foods from oxidative degradation. Copyright © 2008 Society of Chemical Industry     

甜橙精油的化学成分、抑菌和抗氧化活性研究

采用气相色谱-质谱法（GC-MS）对甜橙精油的挥发性成分进行分析,通过抑菌圈实验和试管二倍稀释法对其抑菌效果、最低抑菌浓度（MIC值）进行测定,采用3种方法（DPPH、ABTS和FRAP）对甜橙精油的抗氧化活性进行体外评价。结果表明:甜橙精油含有101种组分,鉴定出50种成分,主要为脂肪族（5.96%）和萜类化合物（78.39%）;甜橙精油对6种供试菌均有较明显的抑制作用,其中对枯草芽孢杆菌的抑制作用最强（MIC值7.5μL/m L）,绿色木霉最弱（MIC值15μL/m L）;甜橙精油对DPPH自由基和ABTS+自由基有明显的清除作用,样品量与清除率间呈量效关系。      

Detoxification of essential oil components (citral and menthol) by Aspergillus niger and Rhizopus stolonifer

The antifungal activity of two essential oil components (citral and menthol) towards Aspergillus niger and Rhizopus stolonifer was studied in shake culture. The activity was high with lower inoculum density (measured in terms of number of spores ml^?1), and it decreased as the inoculum density increased. Citral at 200 μg ml^?1 and menthol at 400 μg mh^?1 were lethal to the spores of A. niger and R. stolonifer, respectively, after a 48-h treatment. At lower concentrations both the compounds were only fungistatic: the growth of the fungi resumed after an initial delay or upon transfer to fresh medium. Periodic estimations of the essential oil components by gas-liquid chromatography showed a continuous decrease in their concentrations in the culture medium, indicating their removal tending to detoxification. The difference in the activity of the two compounds was related to the capacity of the fungi to detoxify the compounds.     

天然调味香料月桂精油化学成分的研究

采用水蒸气蒸馏法提取了调味香料月桂的精油,并利用气相色谱/质谱(GC/MS)联用技术和保留指数比较法分析了该精油的化学成分.从月桂的精油中鉴定了44种化合物,占精油总量的99.97％.主要成分为α-乙酸松油酯(19.52％)、肉桂醛(8.00％)、β-按叶油醇(6.18％)、β-石竹烯(5.72％)和丁香酚甲醚(5.25％).     

水蒸气蒸馏法提取柚子花精油工艺研究及其成分分析

以冻干柚子花为原料,采用单因素、响应面实验方法优化水蒸气蒸馏提取柚子花精油工艺,建立二次多项数学模型,得到水蒸气蒸馏法提取柚子花精油最优工艺参数:液料比16∶1、盐水浓度3.51%、蒸馏时间8.15 h,柚子花精油提取得率为0.3856%。采用GC-MS对水蒸气蒸馏法提取所得柚子花精油进行成分分析,共分离鉴定出50种化合物,占总萃取物的87.60%,其中主要成分为法呢醇、亚油酸乙酯、亚麻酸乙酯、棕榈酸乙酯、橙花叔醇等化合物。      

不同工艺市售芝麻油的气味活性成分和感官品质差异分析

旨在为芝麻油企业提高其产品的香气品质提供参考,以我国市场上不同工艺的13个品牌畅销芝麻油产品为实验材料,利用溶剂辅助蒸发(SAFE)法萃取挥发性物质,气相色谱-嗅闻-质谱(GC-O-MS)法和感官评价比较其气味活性成分和感官品质差异。结果表明:低温压榨芝麻油的气味活性成分以醛类、烯烃和醇类为主,生芝麻味最强;石磨水代和高温压榨芝麻油的气味活性成分以美拉德反应杂环类产物为主,具有较强的炒芝麻味、炒坚果味和焦香味;石磨水代芝麻油的苯酚类物质含量最高,烟熏味最强;高温压榨芝麻油的苦味最强。综上,不同工艺的市售芝麻油气味活性成分和感官品质具有显著差异。     

SDE-GC-O-MS鉴定浓香葵花籽油香气活性物质

采用同时蒸馏萃取法(SDE)萃取浓香葵花籽油中的挥发性风味物质,利用气相色谱-质谱-嗅闻技术(GC-O-MS)对香气活性物质进行分离鉴定.SDE的最佳萃取条件为:二氯甲烷40 mL,加油量40g,水添加量200 mL,萃取时间3 h.经GC-MS分析共鉴定出96种挥发性风味物质,主要为醛类(29.29％)、杂环类(29...     

Chemical composition, antioxidant, and antimicrobial activities of essential oil from pine needle (Cedrus deodara)

The chemical composition of essential oil from pine needles (Cedrus deodara) was determined, and its antioxidant and antimicrobial activities were evaluated. Twenty-three components, representing 95.79% of the oil, were identified by gas chromatography mass spectrometry. The main components include α-terpineol (30.2%), linalool (24.47%), limonene (17.01%), anethole (14.57%), caryophyllene (3.14%), and eugenol (2.14%). Pine needle essential oil showed remarkable antioxidant activity in scavenging free radicals, in lipid peroxidation, and in reducing power assays. Moreover, the essential oil revealed strong antimicrobial activity against typical food-borne microorganisms, with minimum inhibitory concentration and minimum bactericidal concentration values of 0.2 to 1.56 and 0.39 to 6.25 μg/mL, respectively. Transmission electron microscope observation ascertained that the bactericidal mechanism of pine needle essential oil may be the induction of cytoplasmic outflow and plasmolysis. These results suggest that the essential oil from pine needles has potential to be used as a natural antioxidant and antimicrobial agent in food processing. PRACTICAL APPLICATION: The present study provides a theoretical basis for the potential application of essential oil from pine needles (C. deodara) to be used as a natural resource of antioxidant and antimicrobial agents in food industry.