亚临界萃取结合分子蒸馏提取甜橙油的研究

采用亚临界萃取制备甜橙油,并利用分子蒸馏降低柠檬烯含量、富集特征香气成分。通过正交试验优化甜橙油亚临界萃取和分子蒸馏工艺条件,并采用气相色谱-质谱(GC-MS)对所制备的甜橙油进行香气成分检测。结果表明:最佳的亚临界萃取工艺条件为:萃取压力1.0 MPa、萃取温度45℃、萃取90 min、萃取2次。精油得率为9.21%。最优的分子蒸馏工艺条件为:蒸馏温度50℃、蒸馏压力150 Pa、进料速度1.5 mL/min、刮板转速200 r/min。萜烯去除率为60.36%。经亚临界萃取和分子蒸馏分离后,最终甜橙油的得率为3.25%,其主要成分为柠檬烯、桧烯、香叶烯、癸醛、芳樟醇、莰烯、松油烯、香叶醇、石竹烯。     

气相色谱/质谱法结合保留指数分析甜橙油中香味成分

利用GC/MS联用技术检测,通过质谱库检索,保留指数比对,分析并确定了60个化合物,并用峰面积归一化法计算各成分相对含量,占甜橙油香味成分98.69%,结合香气评价,确定了甜橙油中关键致香成分为柠檬烯,月桂烯,芳樟醇,癸醛,α-蒎烯,桧烯,辛醛,α-松油醇,丁酸乙酯,香茅醛,壬醛,正壬醇等。     

GC-MS法分析三种柑橘皮精油成分

采用水蒸气蒸馏法提取酸橙、甜橙、柠檬三种柑橘皮精油,运用GC-MS法分析其香气成分,分别检出68、68、58种香气成分,各占总峰面积的98.69%,99.53%,99.58%.3种柑橘有32种相同的香气成分,并分别有20、16、15种独有的香气成分.3种柑橘皮精油化学成分的种类和含量的差异构成了其特有的香气,对酸橙特征香气贡献较大的成分有芳樟醇、3-蒈烯、β-蒎烯等;对甜橙特征香气贡献较大的成分有[1R-(1α,7β,8Aα)]-1,2,3,5,6,7,8,8A-八氢-1,8 A-二甲基-7-(1-甲基乙烯基)-萘等;对柠檬特征香气贡献较大的成分有3-蒈烯、β-水芹烯、香叶醇等.     

水蒸气蒸馏甜橙油的工艺优化、分析及应用

采用水蒸气蒸馏法制备甜橙油,研究了物料比、提取温度、提取时间等因素对甜橙油得率的影响,进行最佳工艺优化,并以气相色谱-质谱法(GC-MS)对其化学成分进行分离和鉴定。结果表明,其最佳工艺条件为:物料比1/8、提取温度130℃、提取时间8 h,精油得率为0.495%;甜橙油主要成分为柠檬油精(93.00%)、芳樟醇(1.52%)、月桂烯(1.49%)、辛醛(0.42%)、α-蒎烯(0.39%)等物质;将该香料用于卷烟加香,能够明显丰富烟香,减轻刺激,甜润烟气,改善卷烟余味。     

不同品种甜橙芳香物质的SPME分析

采用固相微萃取（SPME）技术分析了不同品种甜橙的挥发性芳香物质。结果表明，50／30μm DVB／CAR／PDMs纤维头在0．3g／mL的饱和NaCl新鲜橙汁溶液中40℃顶空吸附30min的条件下吸附效果最好。利用毛细管气相色谱-质谱法（GC—MS）分离鉴定了不同品种甜橙的挥发性芳香物质，共检出47种物质，其中15个碳氢化合物。10个醇类物质，9种醛类物质，9个酯类物质以及4个酮类物质。其中，丁酸乙酯、d-柠檬烯、β-月桂烯、辛醛、癸醛、α-蒎烯、柠檬醛和芳樟醇构成了甜橙的主要特征致香成分。     

固相微萃取-气质联用分析塔罗科血橙汁香气成分

采用顶空固相微萃取对塔罗科血橙汁的香气成分进行提取,用气相色谱-质谱对香气化合物进行分析,结合谱库检索技术和保留指数对化合物进行鉴定,应用峰面积归一化法测定各成分的相对含量,共鉴定出39种香气成分,相对总量为87.23%。主要香气成分为烃类(55.13%),酯类(13.67%)、醇类(13.17%)、醛类(4.59%),还有2种酮类(0.67%)。其中相对含量最高的是柠檬烯(50.40%),其次是丁酸乙酯(7.67%)、乙醇(5.38%)、3-羟基己酸乙酯(3.92%)、己醛(3.73%)、芳樟醇(3.32%)、β-月桂烯(1.87%)、α-松油醇(1.50%)、巴伦西亚桔烯(1.50%)、己酸乙酯(1.07%)。     

蒸青绿茶浓缩液加工过程中香气成分变化研究

目的探索蒸青绿茶浓缩液加工过程中各阶段香气成分变化,优化加工工艺。方法采用顶空固相微萃取法(headspace solid-phase microextraction, HS-SPME)提取各加工阶段试样的香气成分,并用气相色谱-质谱联用法(gas chromatography-mass spectrometry,GC-MS)对其进行分析,同时对各试样进行感官评定。结果经分析鉴定,各阶段共鉴定出25种香气成分,其中醇类3种、醛类11种、酮类5种、烯类2种、其他类4种。原茶叶的香气组分以β-紫罗酮、二甲硫、D-柠檬烯、癸醛、β-环柠檬醛、己醛等为主,香气青香带栗香。浓缩灭菌后浓缩液的香气组分以芳樟醇、D-柠檬烯、癸醛、β-环柠檬醛、二甲硫、σ-杜松烯等为主,香气栗香为主带花香和青香。醇类和烯类相对含量增加,醛类、酮类和其他类香气组分相对含量降低,其中醇类增幅最大25.89%,醛类降幅最大,降低18.09%。在各香气组分中芳樟醇相对含量增加最多25.41%,其次σ-杜松烯、癸醛等,β-紫罗酮的相对含量降低最多,下降9.85%,二甲硫其次,下降5.42%。结论由原茶叶到浓缩液香气类型由青香带栗香变为栗香带青香花香,香气强度减弱,香气持久性增强。在加工过程中对浓缩液香气变化影响最显著的工艺是提取和浓缩,各香气组分相对含量的变化是浓缩液与原茶叶香气差异的主要原因。     

玫瑰茄中增甜香气成分分析及含量测定

以玫瑰茄的花萼为原料,通过气相色谱嗅闻技术筛选出11种可能呈现与甜味感知相关的挥发性香气成分,包括己醛、糠醛、苯甲醛、1-辛烯-3-醇、辛醛、芳樟醇、壬醛、α-松油醇、癸醛、香叶基丙酮和橙花叔醇。由感官描述筛选出6种甜味感知相关的香气成分,分别为糠醛、苯甲醛、芳樟醇、癸醛、香叶基丙酮和橙花叔醇,且除癸醛以外的5种香气成分在30 g/L蔗糖溶液中均有显著增甜作用,其中芳樟醇的增甜效果最佳。通过气相色谱-质谱联用技术对玫瑰茄中香气成分进行定性定量分析。结果表明,玫瑰茄样品中香气成分达56种,占峰面积的95.51%,其中醛类17种、碳氢化合物10种、醇类10种、酯类8种、酸类3种、酮类4种和其他化合物4种。糠醛（12.64%）、苯甲醛（1.69%）、芳樟醇（1.75%）、癸醛（4.10%）、香叶基丙酮（1.36%）以及橙花叔醇（1.01%）的相对含量均高于1%。     

不同品种荔枝香气成分的SPME/GC-MS分析

以五个荔枝品种为试材,采用SPME/GC-MS方法对其香气成分进行了分析鉴定。结果表明,不同品种荔枝在香气组成和含量上差异显著,妃子笑、黑叶、白蜡、荔枝王、玉荷包中分别含有58、57、47、28、39种香气成分;五种荔枝共有的主要香气成分有1-甲氧基-2-丙醇、乙偶姻、3-甲基-2-庚醇、1-庚烯-3-醇、芳樟醇、2-乙基-2-丁烯醛、β-蒎烯、柠檬烯、巴伦西亚桔烯等,但其相对含量差异很大;此外,各品种也具有自己独特的香气成分。     

甜橙果肉粉对橙油风味物质的吸附性能研究

为探究柑橘果肉在风味吸附方面的机制,测定了甜橙果肉粉的成分构成、氮气吸附-脱附等温线,采用扫描电子显微镜（scanning electron microscope, SEM）观察了其微观结构,采用气相色谱-质谱法（gas chromatography-mass spectrometry, GC-MS）测试分析了其对橙油风味物质的吸附性能。成分分析结果表明甜橙果肉粉主要由膳食纤维（51.87%±3.12%）、蛋白质（20.47%±0.58%）、脂肪（11.33%±1.60%）、淀粉（4.06%±0.59%）构成。SEM观察结果及氮气吸附-脱附等温线分析结果表明,甜橙果肉粉复合物中存在丰富的褶皱和缝隙等不规则结构,比表面积达2.98 m2/g。GC-MS测试分析结果表明,甜橙果肉粉对橙油典型香气成分例如柠檬烯、γ-萜品烯、β-月桂烯、β-水芹烯、芳樟醇、辛醛、壬醛等有明显的吸附作用,尤其与直链脂肪醛、含氧萜类衍生物的相互作用较明显,而对α-蒎烯、桧烯等双环单萜类成分的吸附作用相对较弱。综上,甜橙果肉粉中各组成成分交联而成的褶皱和缝隙结构是其发挥风味吸附作用的重要基础,研究结果可为进一步开发利用甜橙果肉提供参考。     

Isolation and Biological Activities of Decanal,Linalool, Valencene,and Octanal from Sweet Orange Oil

Abstract: Product 1 (82.25% valencene), product 2 (73.36% decanal), product 3 (78.12% octanal), and product 4 (90.61% linalool) were isolated from sweet orange oil by combined usage of molecular distillation and column chromatography. The antioxidant activity of sweet orange oil and these products was investigated using 2,2‐diphenyl‐1‐picrylhydrazyl and reducing power assays. In this test, product 1 (82.25% valencene), product 2 (73.36% decanal), and product 4 (90.61% linalool) had antioxidant activity, but lower than sweet orange oil. The antimicrobial activity was investigated in order to evaluate their efficacy against 5 microorganisms. The results showed that sweet orange oil, product 2 (73.36% decanal), product 3 (78.12% octanal), and product 4 (90.61% linalool) had inhibitory and bactericidal effect on the test microorganisms (except Penicillium citrinum). Valencene did not show any inhibitory effect. Saccharomyces cerivisiae was more susceptible, especially to the crude sweet orange oil (minimal inhibitory concentration 6.25 μL/mL). The cytotoxicity was evaluated on Hela cells using the 3‐(4,5‐dimethyl‐thiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay. All test samples showed significant cytotoxicity on the cell lines with IC₅₀ values much less than 20 μg/mL.     

白芽奇兰茶叶特征风味成分的分析鉴定

本论文的主要目标是分析鉴定白芽奇兰茶叶的关键香气成分。通过顶空固相微萃取结合气相色谱质谱联用技术分析白芽奇兰茶叶,从白芽奇兰茶叶中鉴定出36种挥发性成分,包括烯烃类9种,醛类7种,酯类5种,醇类4种,酮类4种,氧化物3种及其它类4种。其中,1-乙基-1氢-吡咯(753.60μg/L)、壬醇(430.57μg/L)、2-乙基呋喃(170.21μg/L)、己醛(147.14μg/L)、2-甲基丁醛(148.49μg/L)、2-甲基丙醛(86.48μg/L)和3-甲基丁醛(73.53μg/L)含量较高。相对气味活度值分析及风味重构实验表明,1-乙基-1-氢-吡咯、壬醇、3-甲基丁醛、2-甲基丁醛、癸醛、2-乙基呋喃、辛醛、己醛、丁酸己酯、2-甲基丙醛、芳樟醇、庚醛、芳樟醇氧化物和柠檬烯是白芽奇兰茶叶的主要呈香化合物。本研究阐明了白芽奇兰茶叶的特征香气成分,为制定白芽奇兰茶叶香气品质的量化标准及品质管理提供了参考数据。     

Flavor Losses in Orange Juice during Ultrafiltration and Subsequent Evaporation

Losses of volatile compounds in orange juice during ultrafiltration and subsequent evaporation were studied. Alcohols and esters predominated in the permeate, while terpenes (d-limonene and valencene) and nonpolar aldehydes (octanal and decanal) were distributed in the retentate from the ultrafiltration (UF) system. Fractions of some flavor compounds were lost during ultrafiltration process. An aqueous phase essence was recovered from the permeate during evaporative concentration. No oil phase was observed. When whole juice was concentrated, both oil and aqueous phases were recovered. Essence recovery efficiency of individual compounds was 3 to 13% when concentrating permeate and <5% when concentrating whole juice.     

Influence of flavour absorption by food-packaging materials (low-density polyethylene, polycarbonate and polyethylene terephthalate) on taste perception of a model solution and orange juice

The influence of flavour absorption by low-density polyethylene (LDPE), polycarbonate (PC) and polyethylene terephthalate (PET) on taste perception of a model solution containing seven flavour compounds and orange juice in glass bottles was studied with and without pieces of the respective plastic films after dark storage at 20°C. Owing to absorption, the amount of flavour compounds in the model solution exposed to LDPE decreased substantially. From the model flavour solution valencene was almost completely absorbed by LDPE, followed to a lesser extent by decanal, hexyl acetate, octanal and nonanone. Less flavour compounds were absorbed from the model solution by PC and PET. In contrast to LDPE, valencene was absorbed in the lowest amounts and decanal in the highest. Limonene was readily absorbed from orange juice by LDPE, while myrcene, valencene, pinene and decanal were absorbed in smaller quantities. Only three flavour compounds were absorbed from orange juice by PC and PET in very small amounts: limonene, myrcene and decanal. Although the flavour content between controls and polymer-treated samples differed substantially, the loss of flavour compounds due to absorption by LDPE, PC and PET did not influence taste perception of a model solution and orange juice significantly up to 29 days of dark storage at 20°C as determined by triangular taste panel tests.     

无菌真空包装酱羊肉特征性挥发性风味成分分析

为明确无菌真空包装酱羊肉的特征性香气,采用固相微萃取和气相色谱-质谱联用技术对无菌真空包装酱羊肉进行挥发性成分分析,并结合感觉阈值和相对气味活度值（relative odor activity value,ROAV）确定其特征香气物质。结果表明：无菌真空包装酱羊肉中共检出67 种挥发性物质,包括醇类14 种、醛类17 种、酸类8 种、酮类7 种、酯类3 种、烷烃类10 种和其他类化合物8 种;采用ROAV评价各香气成分对酱羊肉总体风味的贡献,确定出14 种关键挥发性成分,分别为正辛醇、1-辛烯-3-醇、芳樟醇、4-萜烯醇、(E)-2-壬烯醛、(E)-2-辛烯醛、苯丙醛、癸醛、庚醛、己醛、壬醛、辛醛、2-十一烷酮和6-甲基-5-庚烯-2-酮,这些物质是无菌真空包装酱羊肉香气成分的重要贡献者。     

香橼精油的组成及香气活性成分的GC-MS-O分析

采用水蒸气蒸馏法提取香橼皮精油,运用气相色谱-质谱-嗅辨仪联机技术(GC-MS-O)对其成分组成及香气活性成分进行了研究。结果显示:香橼精油中柠檬烯的含量最高,为精油的50.53%,其次为对伞花烃(16.40%),其他含量较高的成分还有γ-萜品烯(8.70%)、罗勒烯(5.03%)、β-蒎烯(3.35%),α-蒎烯(2.66%)和β-月桂烯(2.30%)。另外,检测出11种香气活性成分,其中已鉴定的9种为α-蒎烯、β-蒎烯、对伞花烃、柠檬烯氧化物、里那醇、4-萜品醇、反-对-薄荷-2,8-二烯醇、丙酸松油酯、乙酸橙花酯、巴伦西亚橘烯。嗅闻结果显示,伞花烃和丙酸松油酯可能对香橼的特征香气起重要作用。     

分子蒸馏纯化薰衣草精油主要成分的HSSPMEGC分析

目的:采用分子蒸馏法纯化薰衣草精油(LO)的挥发性成分,HS-SPME-GC法分析其化学成分。方法:在单因素的基础上,通过星点设计效应面法的设计原理,以提取物质的色谱图总峰面积为考察指标,对顶空固相微萃取的萃取温度、平衡时间、萃取时间和解吸时间进行4因素3水平响应面分析;通过正交实验,以薰衣草精油中主要组分的纯度为考察指标,对分子蒸馏的蒸馏温度、蒸馏压力和刮膜转速进行3因素3水平分析。结果:顶空固相微萃取的最佳萃取条件为萃取温度70℃、萃取时间41 min、平衡时间10 min、解吸时间6 min,在最优条件下的峰面积平均值为7750;分子蒸馏的最佳条件为蒸馏温度55℃,蒸馏压力0.6 kPa,刮膜转速320 r·min-1,在最优条件下薰衣草精油中乙酸芳樟酯、芳樟醇、乙酸薰衣草酯的纯度分别为45.11%、25.52%、14.27%。结论:HS-SPME技术和分子蒸馏技术适用于薰衣草精油挥发性成分的富集纯化。     

Effects of pulsed electric field processing and storage on the quality and stability of single-strength orange juice

The effects of pulsed electric field (PEF) processing on microorganisms in orange juice and on the flavor and color of the juice during storage for 112 days at 4 and 22 degrees C were investigated. Single-strength orange juice was PEF processed at an electric field strength of 35 kV/cm for 59 micros and placed into sterilized glass bottles in a sanitary glove box. PEF-processed orange juice was microbiologically stable at 4 and 22 degrees C for 112 days. PEF processing resulted in significant increases in the hydrocarbons D-limonene, alpha-pinene, myrecene, and valencene (P < or = 0.05) but did not have any effect on octanal, decanal, ethyl butyrate, and linalool. The levels of hydrocarbon compounds did not change at 4 and 22 degrees C in 112 days. Octanal, decanal, ethyl butyrate, and linalool levels significantly decreased in 14 days at 4 degrees C and in 2 days at 22 degrees C. The decrease in these compounds did not have a significant effect on the sensory quality of the orange juice (P > or = 0.05). The microorganisms in PEF-processed orange juice, along with the flavor and color of the juice, remained stable at 4 degrees C for 112 days.     

Hot and cold water infusion aroma profiles of Hibiscus sabdariffa: fresh compared with dried

Abstract: Calyxes from the Roselle plant (Hibiscus sabdariffa L.) were used to prepare cold (22 °C for 4 h) and hot (98 °C for 16 min) infusions/teas from both fresh and dried forms. Aroma volatiles were extracted using static headspace SPME and analyzed using GC‐MS and GC‐O with 2 different columns (DB‐5 and DB‐Wax). Totals of 28, 25, 17, and 16 volatiles were identified using GC‐MS in the dried hot extract (DHE), dried cold extract (DCE), fresh hot extract (FHE), and fresh cold extract (FCE) samples, respectively. In terms of total GC‐MS peak areas DHE ? DCE > FHE ? FCE. Nonanal, decanal, octanal, and 1‐octen‐3‐ol were among the major volatiles in all 4 beverage types. Thirteen volatiles were common to all 4 teas. Furfural and 5‐methyl furfural were detected only in dried hibiscus beverages whereas linalool and 2‐ethyl‐1‐hexanol were detected only in beverages from fresh hibiscus. In terms of aroma active volatiles, 17, 16, 13, and 10 aroma active volatiles were detected for DHE, DCE, FHE, and FCE samples, respectively. The most intense aroma volatiles were 1‐octen‐3‐one and nonanal with a group of 4 aldehydes and 3 ketones common to all samples. Dried samples contained dramatically higher levels of lipid oxidation products such as hexanal, nonanal, and decanal. In fresh hibiscus extracts, linalool (floral, citrus) and octanal (lemon, citrus) were among the highest intensity aroma compounds but linalool was not detected in any of the dried hibiscus extracts. Practical Application: Hibiscus teas/infusions are one of the highest volume specialty botanical products in international commerce. The beverage is consumed for both sensory pleasure and health attributes and is prepared a number of ways throughout the world. Although color and taste attributes have been examined, little information is known about its aroma volatiles and no other study has compared extractions from both fresh and dried as well as extraction temperature differences. This is also, apparently, the first study to identify the aroma active volatiles in hibiscus beverages using GC‐olfactometry. Manufacturers and consumers will now have a better understanding of why hibiscus teas prepared in different ways from either fresh or dried forms have a different flavor quality and intensity.     

Analysis of free and glycosidically bound compounds of ash gourd (Benincasa hispida): Identification of key odorants

Free and glycosidically bound aroma compounds of ash gourd were investigated. Gas chromatography–mass spectrometry (GC/MS) analysis of the free aroma compounds isolated by both steam distillation and high vacuum distillation revealed the presence of acetoin as the major constituent in both the oils. Acetoin was also identified as the major constituent existing as glycosidic conjugate. GC–olfactometry (GC–O) of the volatile oil based on detection frequency (olfactometry global analysis) was further used to characterise odour active compounds of the vegetable. Based on odour activity value (OAV) measurements the potent odorant among these were identified as acetoin (9522.5), octanal (8571) and nonanal (24,000). The region corresponding to the characteristic ash gourd aroma when collected by cryotrapping from a packed GC column and subsequently analysed by GC/MS was found to be mainly comprising of acetoin suggesting the role of this compound as the key odour active compound of this vegetable.