Browsing by Author "Dupas de Matos A"

Now showing 1 - 6 of 6
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    Chemosensory Profile of South Tyrolean Pinot Blanc Wines: A Multivariate Regression Approach
    (MDPI (Basel, Switzerland), 15/10/2021) Poggesi S; Dupas de Matos A; Longo E; Chiotti D; Pedri U; Eisenstecken D; Robatscher P; Boselli E
    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.
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    Effects of Long-Term Bottle Storage on Red and Rosé Wines Sealed with Different Types of Closures
    (MDPI (Basel, Switzerland), 2021-12) Tchouakeu Betnga PF; Longo E; Merkytė V; Dupas de Matos A; Rossetti F; Boselli E; Câmara JS; Teixeira JAC; Perestrelo RM
    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.
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    Exploring Consumer and Producer Views of Verjuice: A Grape-Based Product Made from Viticultural Waste
    (John Wiley & Sons, Inc on behalf of The Australian Society of Viticulture and Oenology, 2023) Dupas de Matos A; Robyn M; Joanne H; Francis IL
    The wine sector is actively working to add value, increase sustainability, and reduce waste streams. One great example is to use thinned grapes, that are usually left to rot, to make verjuice. As verjuice has no identity standard, there is a wide scope for producers to innovate. Decisions regarding sensory characteristics and packaging are currently made by the verjuice producers, mainly winegrowers and winemakers but also chefs, without fully understanding the needs and wants of consumers. Using discussion groups and interviews, this study explored both consumer and producer views towards commercial verjuice regarding perceived sensory characteristics, possible end-uses, packaging, and desirable label elements. Similarities and differences were discovered between consumer views and verjuice producer practices. Consumers reported a diverse range of attributes beyond the sourness and sweetness that was the focus of producers, indicating potential for a broader range of applications of verjuice than currently considered. Sweeter variants were generally preferred for drinking, while sourer ones were favoured for cooking, although exceptions to this trend existed across consumers. Additionally, a mismatch between producer packaging choices and consumer preferences was identified, highlighting potential for producers to optimise packaging to better cater to consumer needs. This research explored an opportunity to create verjuice with desirable sensory characteristics for specific end-uses, providing product diversification for the wine industry’s revenue stream. Uncovering these consumer insights is key to better inform promotion of verjuice by producers and the agrifood sector seeking to enhance the value of their by-products
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    Sensory characteristics of plant-based milk alternatives: Product characterisation by consumers and drivers of liking
    (Elsevier Ltd, 2024-03) Jaeger SR; Dupas de Matos A; Frempomaa Oduro A; Hort J
    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.
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    Understanding consumer acceptability of verjuice, its potential applications and sensory and chemical drivers of liking
    (Elsevier Ltd, 2024-07) Dupas de Matos A; Reis MG; Maggs R; Hort J
    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.