The role of volatile compounds on aroma and flavour perception in coloured raw carrot genotypes

Quantitative analyses of volatile compounds isolated from raw carrots were combined with sensory analysis in order to identify the role of these compounds on aroma and flavour perception in coloured carrots. A sensory map of carrots with different colours was developed, the content of the isolated volatiles was determined and the role of these compounds for harsh flavour perception in raw coloured carrots was evaluated using multivariate data analysis. The sensory map showed that the coloured carrots formed distinct groups within the sensory profile. The orange genotypes were characterised by having significantly higher intensities in carrot flavour and aroma, while the reverse was true for the yellow genotypes. The purple genotype was characterised by having significantly higher intensity in sickenly sweet flavour and nutty flavour, and the red genotype was characterised by having significantly higher intensities in green aroma and flavour, bitterness and burning aftertaste. From the multivariate data analysis it was concluded that the isolated terpenes do correlate to the harsh flavour attributes.     

Water Blanching Effects on Headspace Volatiles and Sensory Attributes of Carrots

Carrots blanched in water for 0 to 300 sec were analyzed for flavor volatiles by dynamic headspace analysis, the volatiles identified by gas chromatography/mass spectrometry, and the sensory attributes evaluated by a trained panel to determine quality changes as related to blanching times. Most volatiles, in particular terpenoids (sabinene, β-pinene, β-myrcene, limonene, trans-caryophyllene, α-humulene, β-bisabolene and α-farnesene) decreased by at least 50% within 60 sec of blanching. Ratings on quality attributes of color, texture, raw carrot aroma, sweetness, flavor and overall impression decreased with blanching time, while cooked carrot aroma increased. There were correlations (p < 0.05) between blanching times, flavor volatiles and sensory attributes.     

外源可发酵糖对葡萄酒挥发性化合物的影响

通过气相色谱-质谱法对4 种外源可发酵糖葡萄酒中的挥发性化合物进行定性定量分析。结果表明：添加外源可发酵糖,影响葡萄酒挥发性物质的特征;添加麦芽糖,葡萄酒中醇类、酮类、酸类、醛类、酚类和萜烯类的含量较高,酯类含量较低,而醇类和酯类的总含量在添加果糖和葡萄糖的条件下达到最大值。通过计算挥发性物质的香气活性值,确定20 种挥发性化合物为葡萄酒的关键香气物质。主成分分析和感官分析显示添加不同可发酵糖发酵葡萄酒的关键香气物质有显著差别,添加葡萄糖改善了葡萄酒的植物香和果香,风味强度最大,添加果糖和蔗糖改善了葡萄酒的青草香、花香、甜香和果香,添加麦芽糖改善了葡萄酒的花香、酯香、果香和甜香。     

Aroma Changes in Fresh Bell Peppers (Capsicum annuum) after Hot-air Drying

The aroma of fresh and hot-air dried bell peppers (Capsicum annuum) was evaluated by sensory and instrumental methods. Hot-air drying decreased levels of the odor compounds (Z)-3-hexenal, 2-heptanone, (Z)-2-hexenal, (E)-2-hexenal, hexanol, (Z)-3-hexanol, (E)-2-hexenol, and linalool, which have green, vegetable-like, fruity, and floral notes, while intensity scores of corresponding sensory aroma attributes also decreased. The aroma of rehydrated dried samples was mainly characterized as savory, rancid/sweaty, sweet/sickly, hay-like, cacao, caramel, and nutty. Drying increased the levels of 2-methylpropanal, 2-and 3-methylbutanal, which have cacao, spicy, and rancid/sweaty odor notes; these volatiles may be correlated with the corresponding aroma attributes in the dried fruits. Principal component analysis demonstrated relationships between instrumental and sensory data for fresh samples, whereas they were more complex for dried fruits.     

GC-O-MS法分析野生刺梨汁游离态和O-糖苷键合态香气活性物质

采用顶空-固相微萃取法提取刺梨汁中游离态挥发性物质和酶法释放刺梨汁中O-糖苷键合态挥发性物质,结合气相色谱-嗅觉探测-质谱技术,对野生种刺梨汁中游离态和O-糖苷键合态香气活性物质进行分析。结果表明,刺梨汁中游离态和O-糖苷键合态香气活性物质分别有23 种和17 种。构成刺梨汁游离态香气活性物质主要有丁酸乙酯（青草）、正己醇（酒香）、正辛醇（甜香）、异戊酸乙酯（菠萝香）、叶醇（茶香）、苯乙烯（果香）、月桂烯（甜香脂）和芳樟醇（柠檬香）等。而构成刺梨汁O-糖苷键合态香气活性物质有3-羟基己酸乙酯（水果香）、2-庚醇（柠檬香）、3-羟基丁酸乙酯（果香）、叶醇（茶香）、正辛醇（甜香）、苯乙醇（玫瑰香）和2’-羟基-4’,5’-二甲基苯乙酮（花香、甜香）等。叶醇、正辛醇和辛酸为刺梨汁中以游离态和O-糖苷键合态共存的香气活性成分。刺梨中游离态和O-糖苷键合态香气活性物质均以果香/甜香味为主,但O-糖苷键合态香气活性物质的香气总强度较游离态的弱。     

Physicochemical and descriptive sensory characterization of Spanish pomegranates: aptitudes for processing and fresh consumption

Pomegranate fruit and its products are being widely promoted to consumers as healthy alternatives for their daily diet. The aim was to study the main sensory differences among twenty pomegranate cultivars, determining which cultivars have particular flavour or texture notes that could make them more appropriate for fresh consumption or processing. Four clusters grouped all samples, two of them included sour cultivars and two of them included sweet and sweet‐sour cultivars. Cluster 1 (sour) was characterized by having floral, apple, and grape flavour notes and also producing a tongue numbing sensation. Cluster 2 (sour), which included the Wonderful cultivar, had samples with wine‐like attributes. Clusters 3 and 4 (sweet and sour‐sweet) were characterized by having overall sweet, pear and grape notes for cluster 3, and beet, fruity‐dark, fermented, musty and woody flavour for cluster 4.     

SENSORY AND PHYSIO‐CHEMICAL PROPERTIES OF MEMBRANE FILTERED APPLE JUICES1

Shelf‐stable apple juices were prepared using two ceramic and four polymeric tubular membranes of varying pore sizes and evaluated using color matching and triangle tests. Juices from 9 kDa and 20 kDa membranes were different in color and aroma/flavor from the other membranes, the characteristics of which did not differ from each other. A full sensory profile was obtained for experimental juices produced using a 0.02 μm ceramic membrane and from commercial pasteurized apple juice. Experimental juices were prepared from fresh and stored apples with and without ascorbic acid. Twelve judges evaluated color; cooked/caramelized, appley, fruity and green aromas and seven flavor attributes (cooked/caramelized, appley, fruity, green, sweet, sour, astringence). Analysis of variance and principal component analysis revealed that membrane filtered juices lacked the cooked/caramelized aroma and had a green flavor compared with the commercial apple juice. Membrane filtered juices prepared from freshly harvested apples had less appley and fruity aroma and flavor, but were more sour and astringent than juices prepared from stored apples. Ascorbic acid treatment significantly reduced the yellow color and increased the astringence of juices.     

戴尔有孢圆酵母与酿酒酵母混合发酵对猕猴桃酒香气的影响

用戴尔有孢圆酵母（Torulaspora delbrueckii SY-2-2）和酿酒酵母（Saccharomyces cerevisiae RV002）作为猕猴桃酒发酵菌株,以单接种酿酒酵母、单接种戴尔有孢圆酵母为对照组,同时接种戴尔有孢圆酵母和酿酒酵母、顺序接种戴尔有孢圆酵母和酿酒酵母为实验组,采用顶空固相微萃取法结合气相色谱-质谱技术测定猕猴桃汁发酵酒样产生的挥发性香气成分。结果表明,混菌发酵组获得的挥发性香气成分种类高于单菌发酵组,且顺序接种发酵组的香气成分种类（23 种）和质量浓度（336.95 mg/L）均最高。在顺序接种发酵组中,戴尔有孢圆酵母的参与提高了猕猴桃酒中挥发性物质的种类和含量,特别是苯乙酸乙酯、苯丙酸乙酯、苯乙醇、β-大马士酮、α-松油醇、桉树油醇等物质,赋予猕猴桃酒浓郁的花果香味,丰富了猕猴桃酒的香气成分。香气感官评价表明顺序接种发酵组的花香、草本香、甜香味更加浓郁,酒香和果香次之,整体评分最高。     

Sensory Attributes and Instrumental Analysis Relationships for Strained Processed Carrot Flavor

Regression models relating sensory attributes and composition of tin genotypes of processed strained carrots were developed. Fresh carrot-flavor, aroma, and aftertaste were associated with high total sugar to terpinolene ratios. Sweet taste and sweet aftertaste were associated with high levels of total sugar and high total sugar to terpinolene ratios. Cooked flavor and cooked aftertaste were associated with high terpinolene content. Selection of genotypes with high total sugar to terpinolene ratios should improve strained processed carrot sensory quality.     

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