基于电子鼻检测鸭梨新鲜度及损伤程度

目的 探究鸭梨果实流通过程中新鲜度变化及损伤程度。方法 以不同跌落角度处理（0°、20°、40°、60°）的鸭梨为试材,测定鸭梨果实呼吸速率、乙烯释放速率的变化,同时利用电子鼻结合主成分分析（principal components analysis,PCA）、线性判别分析（linear discriminant analysis,LDA）和载荷分析（loading analysis,LA）研究不同贮藏时间和不同损伤程度下果实的挥发性气体变化。结果 完好果实在贮藏4 d时出现呼吸高峰和乙烯释放高峰;与完好果实相比,机械伤处理提高了呼吸速率和乙烯释放速率,并且损伤越严重,变化趋势越明显。电子鼻的10个传感器对不同贮藏期和损伤程度的响应值有显著性差异(P<0.05)。LDA可明显区分不同贮藏点和不同损伤程度鸭梨挥发性气体。LA表明果实成熟和受损时,传感器W1S、W5S、W1W、W2W、W2S的响应值变化较为明显,意味着刺激了甲烷、氮氧化合物、硫化物和萜烯类、有机硫化物和芳香族化合物、醇类和部分芳香族化合物类物质的生成。结论 传感器W1S、W5S、W1W、W2W、W2S可反映鸭梨的挥发性气体变化情况,其中W2S传感器响应值可区分果实损伤程度,这对于实时监测果实品质具有重要意义。     

基于电子鼻检测香红梨腐烂程度

目的 为监测贮藏、运输过程中香红梨（Pyrus communis L. cv. Xianghong）的腐烂情况,确定腐烂果的特征传感器。方法 利用电子鼻技术对按腐烂点直径划分的3个等级香红梨的挥发性气体进行测定,同时比较了贮藏初期和后期果实挥发性气体的差异。采用主成分分析（PCA,principal components analysis）、线性判别分析（LDA,linear discriminant analysis）和载荷分析（LA,loading analysis）对电子鼻响应信号值进行分析。结果 电子鼻传感器W5S、W1S、W1W、W2S、W2W是检测香红梨挥发性气体的特征传感器。贮藏期间,氮氧化合物、甲烷、硫化物和萜烯类、醇类和部分芳香族化合物释放量逐渐增加。果实腐烂使硫化物和萜烯类（W1W）、甲烷（W1S）、氮氧化合物（W5S）挥发性物质进一步积累释放,传感器响应值比贮藏初期（P）分别提高了7.7、4.6、4.5 倍。通过监测W5S传感器响应值变化可判断果实的腐烂情况。LDA分析对不同贮藏时期和不同腐烂程度香红梨的区分能力更好。结论 电子鼻传感器W5S、W1S、W1W、W2S、W2W可灵敏反应香红梨的挥发性气体,其中W5S、W1S、W1W为果实腐烂特征性传感器,其响应值可区分果实腐烂程度。本结果为果实采后贮藏保鲜的无损检测技术及果实品质评价提供理论参考。     

基于电子鼻分析1-MCP对‘香红’梨后熟进程的影响

香红’梨经1-甲基环丙烯（1-Methylcyclopropene,1-MCP）（1.0 μL·L-1）处理后,测定贮藏期（10 d）内果实的呼吸强度、乙烯释放速率变化,同时利用电子鼻对贮藏期内的果实挥发性气体变化进行分析。结果表明:与对照组相比,1-MCP处理抑制果实的呼吸强度和乙烯释放速率。电子鼻能区分对照组不同贮藏时期的果实挥发性气体,其中6、10 d的果实挥发性气体分别有明显变化。1-MCP处理组0、2、6、8 d的果实挥发性气体的响应值分布存在部分交叉,而4、10 d的挥发性气体分布区域相对独立。线性判别分析（linear discriminant analysis,LDA）结果中果实挥发性气体的分布区域更加集中,更能说明不同贮藏时期果实挥发性气体的分布情况。载荷（Loading）分析表明W5S、W2W和W2S三个传感器对区别不同处理的果实挥发性气体发挥了关键作用,1-MCP处理明显减少氮氧化合物（W5S）、有机硫化物和芳香族化合物（W2W）、醇类和部分芳香族化合物（W2S）三类物质的生成。总之,结合电子鼻分析,证明1-MCP明显抑制香红梨果实乙烯和部分挥发性气体的生成,因而延缓果实后熟进程。     

基于电子鼻和HS-SPME-GC-MS技术分析9种新疆石榴果实挥发性成分

本研究采用电子鼻（Electronic Nose）与顶空固相微萃取-气相色谱-质谱联用（headspace solid-phase microextraction gas chromatography-mass spectrometer,HS-SPME-GC-MS）技术相结合对新疆南部地区9个不同石榴品种的果实挥发性成分进行比较分析,并对固相微萃取的条件进行了优化。结果表明：顶空固相微萃取的较优条件为：加盐量0.3 g/mL,萃取时间45 min,萃取温度45℃。电子鼻结果表明不同品种石榴果实之间的整体挥发性成分之间存在差异性。HS-SPME-GC-MS从9个石榴果实样品中共检测出73种化合物,其中萜烯类物质23种,醇类物质16种,酯类物质3种,醛类物质15种,酮类物质5种,酸类物质8种,其它3种。不同石榴品种之间果实的共有挥发性成分有6种,相对含量为63.11%～92.32%,它们构成了新疆石榴果实挥发性成分的主体特征,特有挥发成分分别有2、6、0、1、3、3、3、3、3种,赋予了不同品种石榴果实各自特有的风味特点,该研究结果可为新疆地区部分石榴品种的品质评价和综合利用提供参考依据。     

大果山楂酒发酵过程中抗氧化活性和香气成分分析

该文围绕大果山楂酒的开发,通过分析不同发酵时段样品的总酚含量、自由基清除能力,并采用顶空固相微萃取(head-space solid-phase micro extraction,HS-SPME)结合气相色谱-质谱联用(gas chromatography-mass spectrometry,GC-MS)对不同发酵时段的样品香气成分进行检测,探讨发酵过程中果酒发酵特性。结果表明,经酶解的大果山楂原浆,拥有良好的酒精发酵营养环境,72 h~96 h可完成干型果酒发酵;果酒总酚含量保存率高于80%,果酒拥有优良的DPPH·、ABTS+·清除能力,果酒中总酚含量与两种自由基清除能力高度关联;香气成分以发酵过程产生的代谢性酯类和醇类香气成分为主,同时保留了较多的原果芳香成分,总含量为163.63 mg/100 m L,共同构成大果山楂酒类似于香槟特征的淡雅清香。产量大、生物活性成分丰富的大果山楂具备开发高品质果酒可行性。     

GC-MS结合GC-O、电子鼻评价不同预处理方式对沙枣风味的影响

采用顶空固相微萃取结合气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）、气相色谱-嗅闻（gas chromatography-olfactometry,GC-O）及电子鼻方法,探究原果、烘焙、干燥及蒸、煮共5种不同预处理方式对新疆大果沙枣挥发性风味的影响。结果表明：通过GC-MS从5组不同处理后的沙枣中检测出69种化合物,通过GC-O分析结合香气活力值进一步分析,确定沙枣的特征香气成分有14种挥发性物质,发现(E,E)-2,4-癸二烯醛、壬醛、(E,E)-2,4-壬二烯醛、β-紫罗兰酮等是对沙枣具有关键香气贡献最大的物质。经过不同预处理后,样品的多个感官属性的香气强度存在显著差异,电子鼻可以有效区分各样品组之间的香气强度,通过偏最小二乘回归法进一步验证、解释不同处理下的沙枣中的特征香气强度与感官属性之间的相关性。综合分析可知,烘焙处理后的沙枣感官品质相对较好。     

3 个菠萝品种果实香气成分分析

研究“巴厘”、“卡因”和“台农11 号”3 种菠萝果实的香气成分及其差异。采用顶空固相微萃取技术- 气质联用技术(HS-SPME-GC-MS)对3 种菠萝成熟果实香气成分进行分析测定。从 “巴厘”、“卡因”和“台农11 号”3 种果实中分别检测出46、40 和29 种香气成分,各占总峰面积的99.04%、84.11%、92.43%。主要成分为酯类、烃类、苯类、萘类化合物。酯类物质在“巴厘”“卡因”“台农11 号”测试品种中含量最高,分别达90.87%、59.92% 和82.54%;烃类次之,苯类和萘类物质含量较小。3 种果实有11 种相同的香气成分,独有的香气成分为：“巴厘”16 种,“卡因”16 种,“台农11 号”7 种。3 种菠萝果实香气成分的种类和含量之间存在差异,“巴厘”的重要特征香气成分为癸酸乙酯、己酸乙酯和2- 甲基丁酸乙酯;“卡因”的重要特征香气成分为己酸乙酯、辛酸乙酯和乙酸异戊酯;“台农11 号”的重要特征香气成分为己酸乙酯、辛酸乙酯和2-甲基丁酸乙酯。     

Aroma volatile compositions of high- and low-aromatic guava varieties

BACKGROUND: The traditional guava variety cultivated in Israel, ‘Ben Dov’, emits a very strong odour, whereas some newly bred varieties have a mild odour. In this study the aroma profile composition of the high‐aromatic ‘Ben Dov’ variety was compared with those of four new low‐aromatic varieties. RESULTS: Overall, using gas chromatography/mass spectrometry, a total of 30 aroma volatiles were detected in fresh ripe guava fruit: 15 of them were specifically detected only in the high‐aromatic ‘Ben Dov’ variety, 13 were detected in both the high‐ and low‐aromatic varieties and two were detected only in the new low‐aromatic varieties. Interestingly, 11 out of the 15 volatiles specifically detected in ‘Ben Dov’ were esters that contribute sweet, tropical and fruity notes. In contrast, ten out of 13 detected terpenes and two detected aldehydes, contributing green, spicy, herbal and woody notes, were common to both the high‐ and low‐aromatic varieties. CONCLUSION: Based on these findings, it is concluded that accumulation of esters is the main reason why the traditional ‘Ben Dov’ guava variety emits such a strong tropical fruity odour. In contrast, the newly bred low‐aromatic guava varieties did not synthesise esters at all and thus lacked fruity aromatic notes. Overall, the results of this study point out the important role of esters in forming tropical fruity guava odours. Copyright © 2011 Society of Chemical Industry     

Fruit physical,chemical and aromatic attributes of early,intermediate and late apricot cultivars

BACKGROUND: In order to reach good fruit quality, apricots require a balance of sugars and acids as well as a strong apricot aroma. In this study, fruit quality of early, intermediate and late apricot cultivars was evaluated by measuring physical, chemical and olfactory attributes. Multivariate analysis of quality and aroma attributes was used to identify groups of similar cultivars and association with ripening season. RESULTS: Physical, chemical and aromatic attributes showed great variation among cultivars but no relation to ripening season. Aromatic profiles (34 volatiles) of fruit tissues indicated qualitative and quantitative differences among cultivars. Ninfa and Mandorlon were richest in aroma, with a prevailing fruity component; Goldrich and Orange Red were also highly aromatic, with all odour components well represented; Pinkot, Alba and Pellecchiella were lowest in aroma, with a prevailing grassy component. Linear functions including five volatiles (concentrations) and fruit diameter or six aromatic compounds (odour units) and peel colour were found to discriminate cultivars by ripening season. Principal component analysis individuated three groups of cultivars: Ninfa and Mandorlon with sweet and fruity‐flavoured fruits; Bulida, Alba, Goldrich, Ouardy and Silvercot with large, acidic and well‐coloured fruits; and Fracasso, Pellecchiella, Palummella and Pinkot with small and floral/grassy‐flavoured fruits. CONCLUSION: In apricot, detailed analysis of the aromatic profile may represent an efficient tool for classification of genotypes by ripening season, and volatiles with relevant odour contribution may serve as quality markers for selecting towards an extended ripening season of best quality apricots. Copyright © 2010 Society of Chemical Industry     

肉桂精油香氛抗菌活性及成分分析

为提高气相熏蒸肉桂精油的抗菌能力,对四种肉桂精油香氛方式对白色葡萄球菌的抑杀效果进行了研究。研究发现香氛方式对抗菌效果的影响呈现出一定规律。其中,最低抑菌浓度（MIC）大小规律为：喷雾雾化>水浴加热>自然挥发>燃烧;最低杀菌浓度（MBC）大小规律为：水浴加热>喷雾雾化>自然挥发>燃烧。采用电子鼻对四种香氛方式最低杀菌浓度下的气体成分进行大类区分,并进一步利用顶空固相微萃取（Headspace Solid Phase Microextraction,HS-SPME）结合气相色谱-质谱联用技术（Gas Chromatography-Mass Spectrometry,GC-MS）对其进行成分构成分析。结果表明不同香氛方式检测到的成分相对含量具有很大差异。其中水浴加热方式检测到的相对含量大于1%的成分种类数为15种,各萜烯类相对含量占比达到了29.76%;喷雾雾化强制性地雾化出相对含量更多的肉桂醛,其相对含量占比达到74.26%。由此可见：肉桂精油香氛方式改变时,香氛气体的成分构成会发生变化,进而影响对白色葡萄球菌的抗菌效果。其中喷雾雾化具有最佳的抑菌效果,水浴加热具有最佳的杀菌效果。     

不同品种芒果果脯和果干的品质比较分析

以金煌芒、桂七、台农和玉芒等四种不同品种的芒果为原料,采用色差计、电子舌、电子鼻及气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）等仪器,分别从色泽、滋味、气味及挥发性风味物质四方面评价不同芒果品种对果脯和果干原果风味及品质的影响。结果表明：金煌芒果脯、台农果脯、玉芒果脯较好地保留了原果色泽;金煌芒果干、桂七果脯、桂七果干、台农果干、玉芒果脯、玉芒果干较好地保留了原果滋味;基于电子鼻的PCA分析发现,台农果脯、台农果干较好地保留了原果的气味,其次是玉芒果脯、玉芒果干;不同品种芒果鲜果、果脯和果干鉴定出的主要挥发性风味成分有醇类、酯类、酮类、烷烃、烯烃、芳香烃及其他物质,其中烯烃类是主要的挥发性风味化合物,玉芒果脯、玉芒果干的烯烃相对含量均较高,分别为81.09%、77.52%。金煌芒果脯、金煌芒果干、桂七果干、玉芒果脯、玉芒果干较好地保留了原果的挥发性风味物质。综合考量,认为玉芒芒果最适合开发原果风味芒果果脯及果干。     

不同品种猕猴桃制汁适应性评价

为了研究不同品种猕猴桃果实制汁的品质特性,选取了全国5个地区,3个种系,12个品种猕猴桃,对其理化品质、营养成分、加工性能等22项指标进行测定,对测定结果进行描述性评价和相关性分析,运用主成分分析对不同品种猕猴桃汁进行综合评价,建立了猕猴桃制汁品质评价模型,得出12个品种综合评分值排列顺序,筛选出适宜加工制汁的品种;并用电子鼻对猕猴桃汁香气进行测定和分析,得出不同品种果实香气成分之间的差异。结果表明:软枣猕猴桃中绿迷、益玉,中华猕猴桃中脐红、华优制汁品质较好,经主成分综合得分模型计算,综合得分 F均大于0,适合做为果汁类产品的加工原料。东红、海沃德不适宜作为制汁品种,F均小于-1。12种猕猴桃果汁主要的挥发性物质为甲基类、无机硫化物、氮氧化物和芳香醇类,响应值G/G0分别为20.43、19.90、17.95、8.06。研究结果为猕猴桃果汁等加工企业选择适宜的制汁品种提供了科学依据。     

Ethyl alcohol levels in apples after deprivation of oxygen and the detection of alcohol vapour in controlled atmosphere stores using indicator tubes

Accidental deprivation of oxygen during controlled atmosphere storage of apples leads to the formation of ethyl alcohol in the fruit tissues and according to Fidler² if the fruit alcohol can be detected before it has reached 120 mg/100 g, measures can be taken to disperse it and to restore fruit quality. These experiments were designed to show that in apple stores equipped with lime scrubbers alcohol vapour in the storage atmosphere is roughly proportional to the level of alcohol in the fruit. Low levels of alcohol vapour were detected by passing measured amounts of the storage atmosphere through indicator tubes during routine monitoring of gas conditions. The method was found to be unsuitable for stores equipped with activated charcoal scrubbers.     

基于电子鼻与气相色谱-质谱法探究小麦与碎麦挥发性香气成分差异

目的 解析小麦与碎麦挥发性香气成分差异。方法 采用顶空固相微萃取(headspace solid-phase microextraction, HS-SPME)技术联用电子鼻(electronic nose, E-Nose)与气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)分析小麦与碎麦香气成分, 通过多元统计分析正交偏最小二乘法(orthogonal partial least squares-discriminant analysis, OPLS-DA)挖掘小麦与碎麦差异挥发物。结果 小麦与碎麦的香气成分存在显著差异, 整体上小麦挥发物响应强度高于碎麦, 小麦变成碎麦后部分香气值损失, 氧化分子和芳香化合物显著降低, 脂肪酸类化合物变化不明显, 酮类和胺类化合响应值较为接近。通过GC-MS共鉴定出42种化合物, 10种挥发物组分在小麦和碎麦共同检出, 小麦和碎麦中烷烃类化合物较多, 小麦主要挥发物为柠檬烯、十五烯和壬醛; 碎麦的主要挥发物是苯乙烯, 柠檬烯和间乙基甲苯。基于小麦和碎麦挥发组分建立了OPLS-DA评估模型, 共筛选出7种差异挥发物判别小麦品质。结论 本研究成功建立了区别小麦和碎麦的方法, 分析了小麦与碎麦香气成分差异, 为小麦品质判别提供了科学依据。     

Aromatic Compounds and Soluble Carbohydrate Profiles of Different Varieties of Tunisian Raisin (Vitis Vinifera L.)

This study analyzed the aromatic composition and established the soluble carbohydrate profiles of the Chriha, Razeki, Assli, and Meski varieties of Tunisian raisin (Vitis vinifera L.). A total of 80 compounds obtained by headspace solid phase micro-extraction were detected by gas chromatography-mass spectrometry. Non-terpene hydrocarbon derivatives were the major compounds of the Chriha and Assli varieties (35.8 and 26.3%, respectively). The Razeki variety accumulated 25.5%. apocarotenoids. Oxygenated non-terpene derivatives, including esters, alcohols, aldehydes, acids, ketones, and others were the most abundant (57.5%) in the Assli variety. The presence and amounts of volatiles were different among varieties and might be responsible, in part, for the aroma and taste of raisins. The concentration of total sugars was highest in the Razeki variety and lowest in the Chriha variety. The content of individual sugars differed quantitatively among the varieties in this study. The Razeki variety had the best fruit quality with higher contents of individual and total sugars compared to the other three varieties.     

基于仿生学技术不同发酵方式酸浆水品质评价

为比较研究纯种发酵与加引子发酵酸浆水品质差异,本研究分别采用发酵乳杆菌纯种发酵和以老卤水为引子发酵两种方式制作酸浆水,并使用电子舌、电子鼻和色度仪等仿生学设备对其感官品质进行检测。结果显示,发酵乳杆菌纯种发酵的酸浆水鲜味明显高于加引子发酵,而酸味和涩味呈现相反的趋势;挥发性风味方面,乳酸菌纯种发酵的酸浆水中芳香类物质的强度显著高于加引子发酵（P<0.05）;经色度仪检测发现,乳酸菌纯种发酵酸浆水明亮度及绿度较引子发酵酸浆水高,二者色差显著（P<0.05）。多元统计学分析结果显示不同发酵方式制作的酸浆水品质整体存在显著性差异,导致差异的主要指标为鲜味、芳香类以及烷烃类挥发性风味物质。综上,乳酸菌纯种发酵的酸浆水品质更优。     

Damage to intact fruit affects quality of slices from ripened tomatoes

Breaker stage fruit (cvs 901 and Bobcat) were subjected to different types of physical damage: 3 impacts of a steel ball (67 g) from a height of 33, 66 or 99 cm, 8 impacts of the ball from 99 cm, or dropping the fruit once 1 m onto a hard surface. Fruit were then held at 20 °C until full red, sanitized, sliced and stored at 5 °C. Damaged fruit were less firm than undamaged fruit when ripe. Slice quality (appearance, translucency, lycopene content, juice loss) and shelf-life were affected by damage to the fruit. Lycopene concentrations were higher in undamaged (4.0 mg/kg) than damaged fruit (3.5 and 2.7 mg/kg with 3 impacts from 99 cm and drop damage) and decreased during storage at 5 °C. Translucency increased with time and onset was more rapid in moderate to high damage fruit. Juice loss was higher in slices from undamaged (6–8 g/100 g FW) than damaged fruit (1–4 g/100 g). Severe damage resulted in collapse of locular tissue and moderate damage may have induced mealiness. PG activities differed little between slices from severely damaged and undamaged fruit and no differences in PME activities were found.     

胡柚汁益生菌发酵挥发性风味特征

利用筛选到的2株乳酸菌植物乳杆菌L1（Lactobacillus plantarum）和发酵乳杆菌L2（L. fermentum）对胡柚汁发酵,研究其挥发性风味成分及其变化特征。采用静态-顶空固相微萃取和气相色谱-质谱联用分析方法,测定胡柚汁经此2种乳酸菌发酵后挥发性风味物质组分和相对含量,运用主成分分析法对发酵胡柚汁样品挥发性风味成分进行分析,并采用电子鼻对乳酸菌发酵胡柚汁的香气进行检测。结果表明,胡柚汁经发酵后共鉴定出79种挥发性风味物质,其中醇类20种、烯烃类15种、烷烃类12种、酮类10种、醛类5种、酯类2种、其他类15种,挥发性风味物质分别为59、36种和35种。经乳酸菌发酵后,胡柚汁挥发性风味化合物种类均增加,并检测到了胡柚汁中未被检测到的酯类、醇类、酮类和烷烃类相对含量显著提高,醛类物质相对含量大量降低。主成分分析找出了影响4个样品特征风味组分在主成分中的差异,表明主成分分析法可实现对乳酸菌发酵胡柚汁特征风味差异性的评价。电子鼻分析表明胡柚汁经不同乳酸菌发酵后风味差异显著。研究结果揭示了胡柚汁乳酸菌饮料的风味特征并为产品质量评定等提供依据。     

贵长猕猴桃果醋风味分析及果醋饮料研发

本文以贵州修文贵长猕猴桃为原料,以感官评分为指标,采用气相色谱-质谱法分析了猕猴桃果醋饮料的风味性物质组成;研究了猕猴桃果醋饮料最佳配方,并且分析了猕猴桃果醋饮料在货架期内的品质变化情况;研究表明：检测出猕猴桃果醋饮料共有44种挥发性风味成分,其中主要风味物质为：醇类、酯类、酸类、醛酮类等;猕猴桃果醋饮料最优配方为：猕猴桃果醋原液10%、柠檬酸钠0.15%、乳酸钙0.1%、白砂糖4%;应用ALST 法通过研究猕猴桃果醋饮料的保质期再24个月以上,可以满足市场销售需求     

Development of Volatile Compounds during Fruit Maturation: Characterization of Apricot and Plum×Apricot Hybrids

Optimum fruit quality depends upon a number of factors, including fruit developmental stage at harvest. The volatile constituents present in apricot fruit and plumcot accession P251-002 during three different developmental stages have been studied, as well as some physical characteristics such as weight, firmness, °Brix, titratable acidity and flesh and skin colour. The volatile compounds behaved differently during the fruit maturation period, alcohols being the most important group, quantitatively, during the three developmental stages in apricot fruit. In plumcot, total volatiles obtained from fruit sample extractions were very similar in each developmental stage; however, the aromatic profile of constituents changed as fruit maturity progressed to a tree ripe stage. Important differences were found in the volatile constituents profile for both fruits; at the tree ripe stage, the concentration of lactones and terpenic alcohols, characteristic compounds of apricot aroma, were much higher in apricot than plumcot, the latter more resembling a plum aromatic profile. Even with the important presence of lactones that gives a very aromatic apricot when tree ripe, the low firmness at this point does not allow any commercial use of the fruit. © 1997 SCI