Consumer acceptability,sensory properties and expert quality judgements of Australian Cabernet Sauvignon and Shiraz wines

Background and Aims: This study aimed to determine what sensory attributes most drive consumer and expert acceptance for Cabernet Sauvignon and Shiraz wines. Methods and Results: The sensory attributes of a set of commercial wines were quantified by a trained panel. A subset was assessed blind for liking by 203 consumers and for quality by 67 winemakers. For the total group of consumers, wines with low levels of ‘bitterness’, ‘hotness’, ‘metallic’, ‘smoky’ and ‘pepper’ were preferred. In addition, four consumer clusters were identified, each with different sensory drivers of preference, with the attributes ‘red berry’, ‘floral’, ‘caramel’ and ‘vanilla’ aroma, ‘acidity’, ‘green’ flavour and astringency being of importance in distinguishing the different clusters' acceptance scores. The winemakers' quality scores had little relationship with consumer response, although both groups gave low ratings to wines with Brettanomyces-related flavour. Conclusions: A relatively small set of sensory attributes were of greatest importance to consumer liking, and these generally dominate varietal differences. Winemakers' quality concepts do not closely align with those of the consumers. Significance of the Study: This study identifies sensory properties of red wines which could be maximised as well as those which should be reduced, allowing producers to better meet consumers' preferences.     

An assessment of the effects of wine volatiles on the perception of taste and astringency in wine

The objective of this work is measuring the effect of different volatile extract compositions on the perception of taste, astringency, global intensity and persistence of wine. Six Spanish wines, two from Chardonnay and four from Tempranillo grapes, all of them showing different chemical and sensory characteristics, were selected. Wines were separated into volatile and non-volatile fractions by solid phase extraction and lyophilisation and further liquid extraction, respectively. Eighteen “reconstituted wines” were prepared, combining different volatile extracts and different non-volatile matrices and adjusting ethanol content to 12% (v/v), and were further described by a specifically trained sensory panel. Taste attributes (sweetness, acidity, bitterness), astringency, aroma intensity, global intensity and persistence were assessed in both, original and “reconstituted” wines by using a numerical category scale. The sensory properties of the original wines were retained by their corresponding “reconstituted samples”. The sensory assessment of the “reconstituted wines” showed that the addition of volatile fruity extracts from white wines brought about a decrease in astringency and bitterness and an increase in sweet perception in all cases. While global intensity and persistence of white wine matrices were also increased, they did not change in red wine matrices, which suggests that the volatile fraction plays only a secondary role in these attributes of red wines. Similarly, the effects of replacing the volatile fraction of a red wine by volatile extracts from other red wines were small and inconsistent, which confirms that taste and astringency are primarily driven by non-volatile molecules in these wines.     

Sensory attribute evolution in bottled young red wines from Rioja Alavesa

The evolution of 19 bottled young red wines from Rioja Alavesa was studied through 9 months. Twenty-four sensory attributes (including appearance, aroma, flavor, taste and mouth-feel) were evaluated at four times (at 1, 3, 5 and 9 months after bottling) by a ten-member panel. Fifteen physicochemical parameters were also analyzed at these four times. Effect of winemaking process (carbonic maceration vs. destemming), and grape variety (only Tempranillo vs. Tempranillo with a white variety) on wine evolution was considered too. Data were analyzed by analysis of variance. Nine sensory attributes changed significantly through the time: red berry aroma and flavor, body, balance, purple hue and color intensity increased, whereas alcoholic aroma and flavor, and astringency decreased. Almost all the physicochemical parameters changed significantly through the time. The winemaking process and the addition of white grapes did not influence sensory and physicochemical evolution.     

基于品评小组可靠性筛选葡萄酒的香气描述符

利用定量描述性分析（0～5标度法）评价9 款国产‘赤霞珠’干红葡萄酒的香气特性,结合方差分析和多元统计分析方法,评估品评小组可靠性和规范葡萄酒香气特性感官描述符的筛选方法。结果表明,利用平均重现性指数Ri、检验统计量F值、均方误差（mean-square error,MSE）值和Manhattan图等能够有效评估品评员的重现性、辨别能力、可重复性以及品评小组的一致性。以可靠品评小组的感官数据为原始变量,通过几何平均值（M值）计算和排序,结合主成分分析（principal component analysis,PCA）和聚类分析（cluster analysis,CA）,规范了葡萄酒特征香气描述符的科学筛选方法,明确了实验‘赤霞珠’干红葡萄酒的香气特征：以黑醋栗、红醋栗等果香为主,有突出的焦糖、烟熏等焙烤类香气,兼有胡椒等佐料香气。     

Impact of Multicolored Asian Lady Beetles on the Sensory Properties of Concord and Niagara Grape Juice

ABSTRACT: The presence of Multicolored Asian Lady Beetles (MALB) in grape juice is increasingly problematic. The overall objective of this study was to determine the specific sensory impacts of MALB on Concord and Niagara grape juice. The aroma threshold for MALB-taint in both juices was determined and expressed as the best estimate threshold (BET). The aroma BET for MALB-taint in Concord grape juice was 1.8 and 0.65 MALB/L Niagara grape juice. The specific sensory attributes of the grape juices influenced by the presence of MALB were then described. In Concord grape juice, trained panelists (n = 9) found significant increases in vegetal aroma and earthy flavor as MALB concentration increased from 0.45 to 7.2 MALB/L. In Niagara grape juice, with increasing MALB concentration, trained panelists (n = 8) indicated significant decreases in honey and sweetness with corresponding increases in sourness, astringency, and vegetal and earthy aromas and flavors (P < 0.05). For both aroma and flavor, consumer rejection studies were performed using paired preference comparisons of control juice to MALB-tainted grape juice. For Concord grape juice, consumers (n = 60) rejected the aroma of MALB-tainted juice at 1.8 MALB/L and the taste/flavor of the MALB-tainted juice at 3.6 MALB/L. For Niagara juice, consumers rejected the aroma of the juice at 3.6 MALB/L. This study demonstrated the presence of MALB negatively impacts the sensory properties of Concord and Niagara grape juice. Grape juice processors may use this research for quality control measures and for establishing tolerance limits. Practical Application: The Multicolored Asian Ladybeetle (MALB), initially used for biocontrol, has been shown in previous literature to impact the sensory properties of wines. The presence of MALB in grape juice is now becoming problematic; however, there is little research describing the specific sensory impacts of MALB on grape juice. This study examined the sensory impact of MALB on both Concord and Niagara grape juice. While the threshold and trained panel evaluations from this study provide valuable sensory profile information, grape juice processors may be particularly interested in the consumer rejection of MALB-tainted grape juice as they can use this research for quality control measures and for establishing tolerance limits.     

Influence of locally-selected yeast on the chemical and sensorial properties of Albariño white wines

The use of selected yeast strains with improved or novel properties may promote wines with special and original quality attributes. In this paper, changes in the chemical composition (aroma compounds and polyphenols) and sensorial properties of Albariño white wines elaborated with the same must and selected yeast (named as 1, 2 and 3) have been studied in comparison with wines subjected to non-inoculated fermentation (control wine). The results indicated that yeast strain can significantly influence the aroma and polyphenol composition of the wines. Wines elaborated with strain 1 had a higher concentration of terpenes and norisoprenoids, which are compounds closely associated with the fruity and fresh character of Albariño white wines. These same wines had a lower concentration of flavan-3-ols, closely associated with the astringency and bitterness of the wine and the lowest browning potential. The formal sensory analysis conducted by 8 trained judges showed that wines elaborated with strain 1 were preferred by the tasting panel. Therefore, the selection of yeast strains could offer the possibility to modulate sensorial attributes related with the aroma and phenol composition in Albariño white wines.     

INFLUENCE OF APPEARANCE ON THE ASSESSMENT OF AROMA IN BORDEAUX WINES BY TRAINED ASSESSORS

Similarity-scaling approaches and INDSCAL analysis were used to survey 1976 Bordeaux wines presented to trained assessors in four ways: (i) in clear (colourless) glasses with instructions to assess both appearance and aroma attributes; (ii) in clear glasses with instruction to assess aroma, ignoring visual cues; (iii) in clear glasses but under red illumination; and (iv) in coloured glasses, with instruction to assess similarities using aroma only. The results indicated that when instructed to ignore appearance, assessors as a whole succeeded in doing so, providing similar information to that which was obtained in red glasses or under red illumination. When differences in wines are assessed using both appearance and aroma, there is evidence to indicate that some aroma attributes are being assessed differently from when the assessors could not see the wine or were instructed to ignore its appearance.     

Sensory changes during bottle storage of Spanish red wines under different initial oxygen doses

Sixteen commercial Spanish red wines selected to cover a wide range of sensory properties were stored at 25 °C for 6 months in air-tight containers under different oxygen doses (0–30 mg L^− 1) mimicking real and extreme bottling situations. The 16 initial samples (before storage) and the 80 stored samples (16 wines × 5 oxygen doses) were submitted to sensory analysis. Sensory changes related to post-bottling storage and initial oxygen dose were evaluated by means of discriminant and characterisation sensory strategies.Significant increases in black fruits, dried fruits, woody, lactic and stronger increases in cooked vegetables and spicy notes reveal a general pattern of aroma evolution. Remarkable departures to this general pattern have been observed, which can be related to the initial sensory properties of the wines and to their basic polyphenolic composition. The effect of post-bottling storage in bitterness is wine dependent, while global decreases in both global intensity and persistence evaluated in mouth are observed. Discrete increases in astringency are observed for wines with the lowest initial astringent scores. Important sensory interactions between aroma attributes (herbal and spicy) and bitterness and between roasted and astringency perception are shown. Little impact of the initial oxygen dose in the in-mouth sensory properties is reported. These results are relevant for wine experts in that they help understanding the evolution of wine sensory properties in the bottling stage. This study may help them to develop strategies for managing this winemaking stage with objective criteria.