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Background and Aims Reliable malolactic fermentation (MLF) is essential for process efficiency and spoilage prevention in wine. This study extends previous research in our laboratory, aimed at the development and selection of new bacterial strains for reliable MLF in wine, focusing on ethanol‐tolerant lactic acid bacteria (LAB) strains. Sensory differences of seven LAB strains were assessed, including two commercial strains, two ethanol‐tolerant strains derived from directed evolution and three isolates from a high ethanol Grenache. Methods and Results In this study, the performance of 30 LAB strains was first assessed in fermented chemically defined grape juice media. Seven of the best performing strains were then tested in small‐scale (5 L) fermentations in Shiraz and Shiraz‐Grenache blend wines. All wines were evaluated with a sensory panel using free choice profiling. Conclusions Despite significantly different MLF kinetics between the strains there were no strain‐specific differences on the final wines. The choice of LAB strain did not adversely change the sensory properties of either wine. Significance of the Study These findings provide reassurance that the efficient LAB strains (G71 and G55) and the modified directed evolution strains do not compromise the sensory properties of wines despite their marked MLF benefits.

The fundamental purpose of wine consumption is for enjoyment. There are deep emotional connections between consumers and wine, and it is usually imbibed in social settings. Consumers’ emotions evoked by wine, as well as from external factors during wine consumption, have valuable implications for consumer science and industry. Current perspectives on emotions and wine research are examined with a focus on the role of wine intrinsic and extrinsic factors on consumers’ wine-evoked emotions. Future directions of where wine emotions research may head will be explored.

The sensory profiles of Cabernet Sauvignon and Chardonnay research wines were determined and analysed together with wine quality scores of expert judges. Research Cabernet Sauvignon and Chardonnay wines from three and two vintages, respectively, were evaluated. Wines of both varieties were produced with grapes harvested from across South Australian wine making regions throughout 2013–2016 vintages. Wines within varieties were vinified identically across samples and also across vintages. Wines were profiled in triplicate using descriptive analysis with a panel of trained assessors (n = 9–11) and graded for quality in triplicate by winemakers (n = 6–9) using a sorting task based on similarity of quality and with the aid of definitions formed by the winemakers prior to sorting. The data sets were analysed using canonical variate analysis (CVA) and multidimensional scaling (MDS). The scores from CVA and MDS per variety per vintage were analysed using Generalised Procrustes Analysis (GPA). Differences in Cabernet Sauvignon samples by provenance were determined, where associations with regions by sensory attributes were observed in all vintages. These wines were consistently sorted based on quality by the winemakers, evident from GPA. Chardonnay in comparison were poorly discriminated in both sensory profiles and quality. The combination of descriptive sensory analysis with sorting was complimentary to each other and was able to uncover additional information about the sensory properties of wines when the two methods were used in concert, such as balance and complexity. However the red wine variety had more intrinsic characteristics that lead to better discrimination based on sensory properties and hence quality than the white wine variety.

Formal or informal sensory analyses of grapes are often used to determine when a parcel of fruit should be harvested to produce a certain wine style. This study investigated whether relationships exist between sensory perceptions and basic chemical measures of Chardonnay grape berries and the corresponding wines. Chardonnay grape parcels were harvested at commercial maturity from across South Australia in vintages 2015 and 2016, yielding a total of 25 and 24 samples, respectively. Grapes were evaluated using berry sensory assessment (BSA) and vinified identically using small-scale winemaking, and the resulting wines were evaluated with descriptive sensory analysis. Sensory assessors were trained in the respective sensory evaluation methods. Chardonnay grape and wine samples were discriminated by the panel according to sensory attributes, and the fruit could also be discriminated by basic chemistry measures. However, differences in Chardonnay wines were subtle compared with those in grapes, as indicated by low effect sizes. Moderate validation models (R2Val = 0.53 to 0.81) of partial least squares regression (PLSR) 1 were determined in the 2015 vintage, using BSA attributes as x-variables and wine sensory attributes as y-variables, but poor models were obtained with the 2016 vintage (R2Val

The objective of the present study determined cross-modal sensory interactions between volatile stimuli elicited by 3-isobutyl-2-methoxypyrazine (IBMP) and orange extract, and the astringent stimulus aluminium ammonium sulphate dodecahydrate (alum). Three concentration levels of each volatile stimulus was individually combined with three levels of alum in aqueous solutions, giving a 32 full factorial design per alum-volatile combination. A panel of 12 assessors participated in the study; they were familiarised with the perceptual characters of the stimuli individually, as well as practise on scale usage for rating attribute intensities. Three sensory attributes (flavour, astringency and sourness intensity) were evaluated for each alum-volatile mixture in aqueous solutions, in duplicate. Orange flavour intensities were significantly (p = 0.016) enhanced by the addition of alum, specifically at 700 mg/L alum when compared from the control of no added alum. Astringency of alum was significantly (p = 0.014) enhanced by IBMP, in particular at 4 ng/L but not at 14 ng/L. The mechanisms behind orange flavour enhancement may stem from the sourness of alum as opposed to its astringency, but this requires further confirmatory tests. Astringency enhancement by IBMP on the other hand may have occurred either from previous learning, from an innate biological mechanism, or a combination of both. All cross-modal interaction effects were repeatable and quantified enhancement of astringency by aroma has been demonstrated in the current study for the first time.

The use of vegetable proteins to fine astringent compounds in wine has gained increased interest due to the pressure of consumer demand. The objective of this study was to compare the ability of alternative vegetable proteins (derived from rice, soy, pea, or potato) to reduce tannin and thereby astringency, relative to that of traditional fining agents (gelatin and polyvinylpolypyrrolidone [PVPP]) in a commercial wine with added grape seed extract. Total tannin and phenolics, SO2-resistant pigments, pH, and color of the treated wines were determined, and astringency intensity perception was evaluated by a trained sensory panel (n = 9). Potato, pea, soy, and gelatin proteins similarly reduced total tannin concentration. Similar to PVPP, addition of rice or soy protein reduced total phenolics. These alternative vegetable proteins also influenced the chroma, which may change the depth of wine color. Furthermore, this study was the first to evaluate the change in astringency sensation resulting from the use of rice and soy proteins as alternative fining agents. The type of vegetable proteins used appeared to fine different types of polyphenolic compounds, an observation that was reflected on astringency perception and requires further investigation. The chemical and sensory measures showed that rice and potato proteins have the potential to replace PVPP and gelatin, respectively.

It is conventional wine industry practice for winemakers and grapegrowers to taste winegrapes to determine their fitness for producing various wine styles of different quality. However, the ability to predict wine style from tasting grapes is unverified, and the relationship among the sensory characters of grapes and wine is poorly understood. The objective of the study was to investigate the sensory properties of Cabernet Sauvignon grapes and the corresponding wines, and to determine the relationships between the two data sets. Grapes were harvested between 23 and 25 Brix from eight locations across the state of South Australia over two vintages and vinified using a standardized protocol. A total of 25 samples from across the eight locations were harvested for each vintage. The grapes and wines were evaluated by a sensory panel trained in descriptive analysis. Grapes were evaluated using the berry sensory assessment (BSA) methodology previously described in the literature, and the basic chemical parameters of the grapes and wines were measured. Samples were consistently discriminated by their chemical and sensory properties within the grape and by wine data sets across the vintages. Five sensory attributes of wine were consistently modeled with moderate to high regressions using BSA attributes and berry-chemical measures. Finding berry sensory attributes that consistently relate to wine style and profile remains challenging. The basic chemical measures, including Brix, anthocyanins, and chroma of grape homogenates, were reliable contributors to wine sensory attributes for both vintages.

Producing wines within an acceptable range of astringency is important for quality and consumer acceptance. Astringency can be modified by fining during the winemaking process and the use of vegetable proteins (especially potato proteins) as fining agents has gained increasing interest due to consumers&rsquo, requirements. The research presented was the first to investigate the effect of a potato protein dose on the kinetics of tannin and phenolic removal compared to gelatin for two unfined Cabernet Sauvignon wines. To further understand the results, the influence of the wine matrix and fining parameters (including pH, ethanol concentration, sugar concentration, temperature, and agitation) were tested according to a fractional 25-1 factorial design on one of the Cabernet Sauvignon wines using potato proteins. The results from the factorial design indicate that potato protein fining was significantly influenced by wine pH, ethanol concentration, fining temperature as well as an interaction (pH &times, ethanol) but not by sugar content or agitation. Insights into the steps required for the optimisation of fining were gained from the study, revealing that potato protein fining efficiency could be increased by treating wines at higher temperatures (20 &deg, C, rather than the conventional 10&ndash, 15 &deg, C), and at both a lower pH and/or alcohol concentration.

Food studies have shown that emotional responses can be influenced by food alone and by its environmental context. The influence of context on perception and liking of red wine flavors and on the emotions evoked is poorly understood. The primary aim of this research was to examine the effect of wine flavors and context by immersive environment on consumer-perceived intensities of green and floral flavors, liking, and emotions elicited during wine consumption. Red wine consumers (n = 105) tasted three Cabernet Sauvignon wines: an unaltered control wine (CW), green wine (GW; control wine spiked with 3-isobutyl-2-methoxypyrazine), and floral wine (FW; control wine spiked with rose water), in both a “floral” room (FR) and a “green” room (GR). The wine consumers were asked to taste and rate the intensity of green and floral flavors, hedonic liking, and the emotions elicited. The results showed that in both rooms, FW was rated consistently higher in floral flavor and GW was rated higher in green flavor. CW and FW were significantly (p

The effect of cross-modal sensory interactions between cheese aroma and cheese taste on both cheese flavour intensity and cheese flavour character were investigated. Cheese aroma consisted of a mixture of ten aroma compounds, whilst cheese taste was constructed with the five basic tastes in water solution. Interactions were investigated using a combination of a high resolution design (HRD) and central composite design (CCD). The HRD was 2 aroma × 5 NaCl × 5 lactic acid levels. The CCD was constructed based on a 23 factorial design that covered the HRD space. Both HRD and CCD gave a total of 57 samples. A panel of experienced assessors (n = 8–10) evaluated cheese flavour intensity relative to reference. In addition, samples were sorted based on similarity of flavour character. Fourteen samples were selected for free choice profiling and analysed using generalised procrustes analysis (GPA). Cheese flavour intensity was non-linear and dependent on both taste level and aroma level. The status of flavour character being cheese-like was dependent on taste levels, where either NaCl or lactic acid at a high or low level altered the flavour character to being atypical of cheese. A cheese-like flavour character was maintained across a wide range of NaCl concentrations, but only across a narrow range of lactic acid concentrations. Aroma level changed the character of cheese flavour. Overall, the balance in concentration of both tastes and aroma levels was important in maintaining cheese flavour character as cheese flavour intensity was modified.

Odour active compounds (OACs) from the headspace of yellow and black plum wines (Prunus domestica L.) were analysed using gas chromatography-mass spectrometry-olfactometry (GC-MS-O). Olfactometry was conducted using aroma extract dilution assay, through varying split ratios during injection. A total of 18 OACs were determined in the wine headspace including esters, ketones, sulfur containing compounds, alcohols, a terpene, and phenolic compounds. Thirteen of volatile compounds differed significantly (p

In an investigation of objective measures that link grape composition to wine quality, this study sought to identify Cabernet Sauvignon grape parameters that predict the sensory properties of the corresponding wines. Eleven chemical measures comprising volatile and non-volatile compounds, enzyme activity plus standard industry harvest measurements were applied to grape samples obtained from different regions throughout South Eastern Australia over three vintages. Grapes underwent controlled vinification and the resulting wines evaluated with sensory descriptive analysis. The entire multi-vintage data sets were combined and modelled using a combination of partial least squares (PLS) and sequential and orthogonalised (SO) -PLS regression techniques. Optimal models were obtained with single sensory attributes rather than global modelling with the entire sensory profile. Five grape chemical measures, which in the main were harvest parameters, were used along with colour, total phenolics and tannin, targeted volatiles, and flavonols, and orthogonalised to model 14 sensory attributes of the Cabernet Sauvignon wines. The seven remaining measures were not used due to their poor ability to model wine sensory attributes, with enzyme activity and tannin by HPLC explaining the least. The study revealed new insights into the relationship between grape chemistry and wine sensory characters, which has implications for developing an objective measurement system for determining grape quality.

Wine astringency is important for quality and consumer acceptance. Perception of this mouthfeel is temporal and can be separated further into unique textural sub-qualities. Quantitative data on these astringent sub-qualities in wine however are poorly understood. The aim of this study was to characterize the dynamic astringency profiles of 13 Australian commercial red wines and 2 roses made from 11 grape varieties using modified progressive profiling by a trained sensory panel (n = 8). Seven attributes generated and defined by the panel (overall astringent intensity and 6 sub-qualities: pucker, mouth coat, dry, grippy, adhesive and graininess) were scored at six time periods (each lasting 10 s), with 20 s gap between each time period. Attributes were rated on 15 cm scales with anchors at 10 and 90% and samples were evaluated in duplicate. The wine composition as well as phenolic profiles were determined. Intensities of astringent sub-qualities were correlated with overall intensity, but the sub-quality profiles at a specific evaluation period and the progression of an attribute varied differently depending on the wine. The discrimination of wines at each time interval was dependent on attribute, and the relative importance of each astringent sub-quality varied at different evaluation periods. Correlations between mouthfeel attributes and chemical measures were established. This study demonstrated the utilisation of modified progressive profiling for wine astringency evaluation, providing a tool to capture quantitative data on astringent sub-qualities in wine.

The current study determined the applicability of sequential and orthogonalised-partial least squares (SO-PLS) regression to relate Cabernet Sauvignon grape chemical composition to the sensory perception of the corresponding wines. Grape samples (n = 25) were harvested at a similar maturity and vinified identically in 2013. Twelve measures using various (bio)chemical methods were made on grapes. Wines were evaluated using descriptive analysis with a trained panel (n = 10) for sensory profiling. Data was analysed globally using SO-PLS for the entire sensory profiles (SO-PLS2), as well as for single sensory attributes (SO-PLS1). SO-PLS1 models were superior in validated explained variances than SO-PLS2. SO-PLS provided a structured approach in the selection of predictor chemical data sets that best contributed to the correlation of important sensory attributes. This new approach presents great potential for application in other explorative metabolomics studies of food and beverages to address factors such as quality and regional influences.

Wine mouthfeel is considered important for wine quality by experts, while consumers understanding of mouthfeel and the role of wine body in their wine choice is unknown. One experiment determined the influence of intrinsic wine mouthfeel on consumers' wine liking and emotions, and the other, how consumers understand the term wine body. The first experiment used a 2 astringency level×2 body level experimental design. The samples were base wine with; nothing added (control), added xanthan gum (for increased body), added grape seed extract (GSE, for increased astringency), and with both added xanthan gum and GSE. The consumer taste trial (n=112) indicated that wine with increased body did not influence wine liking and emotions; while increased astringency decreased liking and elicited more intense negative emotions. The second experiment examined consumers' knowledge of wine body through an online survey (n=136). Consumers described wine body most frequently using words such as flavour, fullness, and strength. Wine body was therefore understood by consumers predominantly as a holistic multi-sensory perception of flavour. Wine flavour was indicated by consumers to be the most important factor driving purchase decisions followed by balance of flavours and wine body. It is crucial that wine professionals carefully communicate wine characteristics to consumers to prevent possible misunderstandings such as the meaning of wine body and as a result better meet consumer expectations. In future, the term body may benefit from a clearer definition for academic research as well as industry.