Understanding consumer acceptability of verjuice, its potential applications and sensory and chemical drivers of liking.

The wine sector is working to add value, enhance sustainability and reduce waste, yet often creating new products with unknown consumer acceptance. Verjuice, juice made from discarded unripe thinned grapes, is an example. Whilst verjuice has various culinary uses, its versatility in beverages continues to expand. However, its sensory drivers of liking when consumed as a drink, and their potential impact on its application remain unclear. Chemical drivers of sensory characteristics are also unknown representing a critical knowledge gap needed to guide product innovation. This study aimed to provide new knowledge regarding consumer acceptability of verjuice by identifying its sensory drivers of liking as a beverage, evaluating its potential use in different applications and identifying chemical drivers of its sensory characteristics. New Zealand consumers (n = 93) evaluated 13 verjuice samples from different countries. Furthermore, verjuice familiarity and its influence on emotional response was investigated to determine likely future consumer engagement. Sweetness was the most positive driver of liking in verjuice overall, followed by fruity and floral notes, smoothness, and to a lesser extent citrus flavour. Consumers expressed varied preferences for verjuice's sensory profile, with fruity, floral, and honey flavours driving beverage application, whilst winey and green apple notes were more associated with culinary scenarios. Some association between chemical parameters and sensory attributes were evident (e.g. sugars were highly associated with perceived sweetness, fruity, and floral attributes; these attributes also shared proximity with 1-hexanol and cyclohexanol). The general idea of verjuice elicited positive valence emotions, but consumers who were 'not familiar' felt more curious, and those 'familiar' felt happier and more satisfied. Findings highlight the potential to tailor verjuice for specific applications by understanding desired sensory profiles and related chemical parameters. Recognising the interplay between familiarity level and emotional response is crucial for positioning the product in the marketplace and fostering consumer engagement. Marketing initiatives are needed to increase verjuice familiarity and support product innovation, leading to increased product appeal.

Sensory characteristics of plant-based milk alternatives: Product characterisation by consumers and drivers of liking.

Like other plant-based (PB) product categories, PB milk alternatives (PBMA) are in ascendency as part of the green consumer transition and a greater focus on personal health. However, consumption remains far below that for cow's milk, and among multiple barriers to uptake, inferior sensory properties is one problem, nutritional inadequacies another. While exceptions exist in both instances, a general need for improved products remains. The present research is situated in this nexus, and its primary aim was to contribute new consumer-centric insight regarding the sensory drivers of liking/disliking in the PBMA category. This was achieved through a central location study with adult New Zealanders (n = 143, not regular PBMA consumers) who tasted 18 different PBMA samples spanning a broad range of PB ingredients (soy, oat, coconut, almond, rice, cashew, peanut, macadamia, lentil, hemp, sesame) in different product types (single PB source, blends, barista style) with varying nutritional profiles. The most liked sample (6.5/9), which was made from soy, had the nutritional profile that most approximated cow's milk (3 g/100 mL protein), as well as a milky appearance and taste. Its mouthfeel was smooth, and this sensory characteristic was also paramount for barista-style PBMAs being well-liked (>5.9/9) regardless of their constituent PB ingredient (oat, almond, coconut). Opportunities for product innovation within this type of PBMA was identified including for using barista-style beyond hot beverages, as these samples received positive liking scores on average. The same applied to blends as multiple-source PBMAs can facilitate improved nutritional composition, and significant scope seemed to exist to identify more liked vs less liked PB ingredient combinations (e.g., almond/rice vs coconut/sesame). By identifying, through penalty/lift analysis that positive sensory drivers of PBMA liking span all sensory modalities (appearance, taste, flavour, texture and mouthfeel), it becomes easier to appreciate that products in this category are complex and challenging to optimise. A second minor research aim was focused on the modulating influence of PBMA consumption frequency on product liking and the sensory drivers of liking. The key result was a positive association between liking and higher consumption frequency, and greater appreciation of sweet, coconut, nutty and cereal/oaty characteristics of PBMAs.

Effects of Long-Term Bottle Storage on Red and Rosé Wines Sealed with Different Types of Closures.

Volatile and non-volatile chemical profiles, free and total SO2 and dissolved oxygen content were studied in three red (Merlot, Lagrein red, St. Magdalener) and one rosé (Lagrein rosé) wine after 30 months of storage in bottles. Each wine was sealed with closures made of a 'blend' (B) of natural cork microgranules and polymers without glue and was compared with wines closed with other types of corks (C; a technical cork 1 + 1, or an agglomerated natural cork or a natural one-piece cork). Glutathionyl caftaric acid (GRP) was inversely correlated with total SO2 content and was higher in all three red wines closed with B compared to C, whereas epicatechin was higher in three wines closed with C compared to B. Three volatile compounds formed by fermentation (ethyl butanoate, isoamyl lactate, and octanol) were inversely correlated with both free and total SO2. In terms of their volatile profiles, ethyl octanoate and 2,3-butanediol were significantly higher in the Lagrein red wines closed with C closures, whereas no significant difference was observed in Merlot, Lagrein rosé and St. Magdalener wines. Small differences in some phenolic compounds due to the type of closure were found: GRP, syringic acid, (+)-catechin, and (-)-epicatechin differentiated the Merlot wines closed with B from the C closures. Protocatechuic acid and GRP levels differentiated the Lagrein red wines according to their closure type, whereas only (-)-epicatechin differentiated the Lagrein rosé wines. GRP, caffeic acid, (-)-epicatechin, and anthocyanin content differentiated the St. Magdalener wines according to their closure type. Even though St. Magdalener and Lagrein rosé closed with C could be distinguished from those closed with B by using the (sensory) triangle test (α = 0.05), these differences appeared to be relative as it did not include all the wines in a systematic manner.

Chemosensory Profile of South Tyrolean Pinot Blanc Wines: A Multivariate Regression Approach.

A multivariate regression approach based on sensory data and chemical compositions has been applied to study the correlation between the sensory and chemical properties of Pinot Blanc wines from South Tyrol. The sensory properties were identified by descriptive analysis and the chemical profile was obtained by HS-SPME-GC/MS and HPLC. The profiles of the most influencing (positively or negatively) chemical components have been presented for each sensory descriptor. Partial Least Square Regression (PLS) and Principal Component Regression (PCR) models have been tested and applied. Visual (clarity, yellow colour), gustatory (sweetness, sourness, saltiness, bitterness, astringency, and warmness) and olfactory (overall intensity, floral, apple, pear, tropical fruit, dried fruit, fresh vegetative, spicy, cleanness, and off-odours) descriptors have been correlated with the volatile and phenolic profiles, respectively. Each olfactory descriptor was correlated via a PCR model to the volatile compounds, whereas a comprehensive PLS2 regression model was built for the correlation between visual/gustatory descriptors and the phenolic fingerprint. "Apple" was the olfactory descriptor best modelled by PCR, with an adjusted R2 of 0.72, with only 20% of the validation samples falling out of the confidence interval (α = 95%). A PLS2 with 6 factors was chosen as the best model for gustatory and visual descriptors related to the phenolic compounds. Finally, the overall quality judgment could be explained by a combination of the calibrated sensory descriptors through a PLS model. This allowed the identification of sensory descriptors such as "olfactory intensity", "warmness", "apple", "saltiness", "astringency", "cleanness", "clarity" and "pear", which relevantly contributed to the overall quality of Pinot Blanc wines from South Tyrol, obtained with two different winemaking processes and aged in bottle for 18 months.

Exploring young consumers' attitudes and emotions to sensory and physicochemical properties of different red wines.

To gain deeper understanding on young consumers' attitudes and preferences to wines is needed to connect wine industry with the youth. The aims of the present study were (i) to define 'trendy wine' for young consumers and (ii) to identify chemical drivers of liking in red wines for the youth. The study was divided in two phases: phase I explored young consumers' attitudes towards wines using an online survey, and phase II studied the relationship between hedonic and emotional responses elicited by 12 red wine samples and their physico-chemical characteristics. Consumers' responses and physico-chemical data were related using Principal Component Analysis (PCA). Results of the online survey showed that trendy wines were associated to: sparkling, soft, fresh, fruity, sweet, light, and balanced wines. Also, young consumers reported that, although flavor was considered the most important attribute, price and Protected Designation of Origin could be valuable attributes. PCA results of phase II showed that wines with a lower ratio [total polyphenol index/polysaccharides] were more liked and elicited more positive emotions than wines with higher total polyphenol index, color intensity, volatile acidity, and alcohol content. Liking and positive emotions were positively related to higher Odor Activity Values of the volatile compounds from the organic acids group. The presence of benzenoids and lactones, and the lower presence of terpenoids & norisoprenoids were associated with negative emotions. In conclusion, red wines should be soft (described as lower ratio [total polyphenol index/polysaccharides]), and have floral, and fruity aromas to better connect with young consumers.

Pinot Blanc: Impact of the Winemaking Variables on the Evolution of the Phenolic, Volatile and Sensory Profiles.

The impact of two different winemaking practices on the chemical and sensory complexity of Pinot Blanc wines from South Tyrol (Italy), from grape pressing to the bottled wine stored for nine months, was studied. New chemical markers of Pinot blanc were identified: astilbin and trans-caftaric acid differentiated the wines according to the vinification; S-glutathionylcaftaric acid correlated with the temporal trends. Fluorescence analysis displayed strong time-evolution and differentiation of the two wines for gallocatechin and epigallocatechin, respectively. After nine months of storage in bottle, the control wine showed higher amounts of most ethyl esters, acetate esters and octanoic acid, whereas higher alcohols characterized instead the wine obtained with prefermentative cold maceration. The sensory panel found notes of apple and tropical fruit in the control wine and attributed a higher overall quality judgement to it, whereas the cold-macerated wine was described by olfactory intensity, spicy and pear attributes.

Isolation of a tyrosinase inhibitor from unripe grapes juice: A spectrophotometric study.

Grapes are known to contain high quantity of polyphenolic compounds, including caffeic, coumaric and ferulic acids esterified with tartaric acid, to yield caftaric, coutaric and fertaric acids, respectively. These acids are more abundant in unripe grapes, which can be processed into verjuice, a product that shows intrinsic resistance against microbial growth and significant antioxidant activity. In the present work, the isolation of hydroxycinnamoyl tartaric acids from unripe grape juice by chromatographic techniques was described. Moreover, the capability of caftaric acid to inhibit tyrosinase activity was evaluated by spectrophotometric assays. According to the kinetics parameters calculated, caftaric acid was shown to be a competitive inhibitor of tyrosinase, more potent than the related caffeic and chlorogenic acids, suggesting that it can be used in cosmetic and food industries for the development of natural skin whitening formulations and as an agent able to counteract the enzymatic browning of food.

Sensory characterization of cucumbers pickled with verjuice as novel acidifying agent.

Verjuice is an acidic unfermented unripe grape juice that has recently been proposed as an alternative to vinegar in different food preparations. In this study, pickled cucumber preserves were industrially prepared using two dilutions of verjuice as acidifying agent and compared with the traditional vinegar-pickled samples. Samples were chemically characterized and subjected to sensory analyses using a trained panel and consumers. The different acidifying agents resulted in pickled cucumbers giving different olfactory and gustatory evaluations. No differences in appearance and texture were found. Despite showing chemical and sensory differences, pickles preserved with verjuice and vinegar had similar overall liking scores for visual, olfactory and gustatory aspects. A key feature of pickles prepared with verjuice is their lack of acetic acid potentially conferring them an additional value, suggesting that verjuice represents a viable alternative to vinegar for the production of pickles with distinctive sensorial properties.