Effects of Yeast Product Addition and Fermentation Temperature on Lipid Composition, Taste and Mouthfeel Characteristics of Pinot Noir Wine

Lipids have important impacts on wine sensory. By targeting the lipid sources in wine, mainly from grape tissues and yeast cell walls, it was possible to alter the wine lipid profile thus potentially changing the final product quality. This research examined the changes of wine total lipids, lipid composition and sensory characteristics of Pinot noir wines in response to the winemaking factors, fermentation temperature and yeast product addition. Pinot noir grapes were fermented at 16 °C and 27 °C. After fermentation, Oenolees® yeast product was added to the wines at three levels (0 g/L, 0.5 g/L and 1.0 g/L). The six wine treatments were subjected to chemical analyses measuring total lipids and an untargeted lipidomic approach analyzing lipid composition. High temperature fermentation wines had significantly higher total lipid content. Random forest analysis distinguished the wine groups based on the 25 main lipids, including free fatty acids, acylcarnitines, diglycerides, triglycerides and phospholipids. Taste and mouthfeel characteristics of each treatment were assessed using descriptive analysis and check-all-that-apply (CATA) techniques. Multivariate analyses showed that changing fermentation temperature significantly impacted sweetness and drying perception in Pinot noir wines. Yeast product addition had nuanced effects on wine lipid profiles and sensory perception.

Characterization of Musts, Wines, and Sparkling Wines Based on Their Elemental Composition Determined by ICP-OES and ICP-MS

Samples from the different processing stages in the elaboration of sparkling wine (cava)—including must, base wine, and sparkling wine—of Pinot Noir and Xarel·lo grape varieties from different vineyard qualities (A, B, C, D) have been analyzed by inductively coupled plasma (ICP) techniques to determine their elemental composition. The resulting data has been used to characterize these products according to oenological features and product qualities. For this purpose, box plot diagrams, bar charts, and principal components analysis (PCA) have been used. The study of the behavior of each given species has pointed out the relevance of some elements as markers or descriptors of winemaking processes. Among others, Cu and K are abundant in musts and their concentrations progressively decrease through the cava production process. S levels suddenly increase at the base wine step (and further decay) due to the addition of sulfites as preserving agents. Finally, concentrations of Na, Ca, Fe, and Mg increase from the first fermentation due to the addition of clarifying agents such as bentonite. PCA has been applied to try to extract solid and global conclusions on trends and chemical markers within the groups of samples more easily and efficiently than more conventional approaches.

Non-Conventional Grape Varieties and Yeast Starters for First and Second Fermentation in Sparkling Wine Production Using the Traditional Method

Sparkling wine production using the traditional method involves a second fermentation of still wines in bottles, followed by prolonged aging on lees. The key factors affecting the organoleptic profiles of these wines are the grape varieties, the chemical and sensory attributes of the base wines elaborated, the yeast strains used for first and second fermentation, and the winery practices. While Chardonnay and Pinot noir are gold standard grape varieties in sparkling wine production, other valuable grape cultivars are used worldwide to elaborate highly reputable sparkling wines. Fundamental research on the chemical and sensory profiles of innovative sparkling wines produced by the traditional method, using non-conventional grape varieties and novel yeast strains for first and/or second fermentation, is accompanying their market diversification. In this review, we summarize relevant aspects of sparkling wine production using the traditional method and non-conventional grape varieties and yeast starters.

‘Pinore’: The New Red Wine Variety Cross-Bred between ‘Pinot Noir’ and ‘Regent’ Vines

Renewed interest in varieties that are more tolerant to diseases has emerged, which is mainly due to increased awareness by producers and consumers regarding the impact of phytochemicals in the environment. This paper describes the first Slovenian grapevine variety ‘Pinore’ crossed between the Vitis vinifera L. ‘Pinot Noir’ clone Mf and ‘Regent’ vines. The aim was to create an early ripening grape cultivar that has a good tolerance to biotic stress (e.g., downy and powdery mildew, botrytis) combined with the benefits of established cultivars and their intense wine colors. Some ampelographic characteristics of young shoots, mature leaves, bunches, and berries are presented, and its major agronomic traits, ripening time, grape yield, quality performances, and disease resistance were evaluated over a three-year period (2014–2017). Wine sensory analyses were performed and compared with the international variety ‘Pinot Noir’. The examined genotype showed good agronomic performance and a high wine quality as far as the content of polyphenols is concerned, especially in terms of anthocyanins and tolerance to diseases (Ren3/9 and Rpv3.1); it is significantly different compared to the reference variety ‘Pinot Noir’. In terms of ampelographic characteristics, the main differences are in the number of leaf lobes, the depth of the lateral sinuses, and the content of anthocyanins in its flesh. The investigated genotype has been proposed to the Committee of new varieties in Slovenia for the variety recognition procedure, and completion of the procedure planned for the end of 2023.

Inter-species horizontal toxicity: Experimental control of Argentine ants and their citrophilus mealybug mutualists in a viticultural system

<p>The invasive Argentine ant, Linepithema humile, is known to form a trophobiotic association with honeydew excreting homopterans Pseudococcus sp. providing protection from natural enemies in exchange for the honeydew they excrete. The vine mealybug Pseudococcus calceolariae, can transmit Grapevine leafroll- associated virus 3 (GLRaV-3) between vines as it travels and feeds with the ensuing leafroll disease negatively impacting on vine health and wine quality. Therefore, if an effective chemical control method targeting incursions of Argentine ants in vineyards contributes to the dissociation of this invasive ant species with its citrophilus mealybug mutualist, then in theory the spread of GLRaV-3 in vineyards by its mealybug vector can be stemmed. Three insecticidal treatments targeting Argentine ants in the canopy of potted Pinot Noir grapevines inoculated with citrophilus mealybugs were trialled at a field site established in Nelson during the summer of 2016/2017. Bifenthrin (1200ppm) was sprayed on vine trunks and the low- toxicity baits, thiamethoxam (0.0006%) or boric acid (0.5%) carried in polyacrylamide gel with 25% sucrose and 0.15% citric acid solution, were placed at the base of vines. A significant decline in ant activity (p < 0.001) and citrophilus mealybugs was observed for the bifenthrin treatment. A follow-on bioassay was conducted at Mt. Albert Plant and Food Research, in the absence of P. calceolariae’s natural enemies to test the hypothesis that the decline in citrophilus mealybugs in response to vines treated with bifenthrin, could in fact be due to inter-species horizontal toxicity because of Argentine ants transferring the toxicant bifenthrin to citrophilus mealybugs while tending them or contaminating the substrate that they fed on. The significant decrease in average citrophilus mealybug activity rate (p < 0.001) for bifenthrin treatments compared with the controls provides evidence for inter-species horizontal toxicity. Bifenthrin sprayed on grapevine trunks may be suitable to control Argentine ants in the vine canopy and indirectly control P. calceolariae, a known vector of GLRaV-3 between grapevine hosts. The concept of inter-species horizontal toxicity could become a model for targeted pest management by exploiting different insect mutualisms in various horticultural cropping systems.</p>

Inter-species horizontal toxicity: Experimental control of Argentine ants and their citrophilus mealybug mutualists in a viticultural system

<p>The invasive Argentine ant, Linepithema humile, is known to form a trophobiotic association with honeydew excreting homopterans Pseudococcus sp. providing protection from natural enemies in exchange for the honeydew they excrete. The vine mealybug Pseudococcus calceolariae, can transmit Grapevine leafroll- associated virus 3 (GLRaV-3) between vines as it travels and feeds with the ensuing leafroll disease negatively impacting on vine health and wine quality. Therefore, if an effective chemical control method targeting incursions of Argentine ants in vineyards contributes to the dissociation of this invasive ant species with its citrophilus mealybug mutualist, then in theory the spread of GLRaV-3 in vineyards by its mealybug vector can be stemmed. Three insecticidal treatments targeting Argentine ants in the canopy of potted Pinot Noir grapevines inoculated with citrophilus mealybugs were trialled at a field site established in Nelson during the summer of 2016/2017. Bifenthrin (1200ppm) was sprayed on vine trunks and the low- toxicity baits, thiamethoxam (0.0006%) or boric acid (0.5%) carried in polyacrylamide gel with 25% sucrose and 0.15% citric acid solution, were placed at the base of vines. A significant decline in ant activity (p < 0.001) and citrophilus mealybugs was observed for the bifenthrin treatment. A follow-on bioassay was conducted at Mt. Albert Plant and Food Research, in the absence of P. calceolariae’s natural enemies to test the hypothesis that the decline in citrophilus mealybugs in response to vines treated with bifenthrin, could in fact be due to inter-species horizontal toxicity because of Argentine ants transferring the toxicant bifenthrin to citrophilus mealybugs while tending them or contaminating the substrate that they fed on. The significant decrease in average citrophilus mealybug activity rate (p < 0.001) for bifenthrin treatments compared with the controls provides evidence for inter-species horizontal toxicity. Bifenthrin sprayed on grapevine trunks may be suitable to control Argentine ants in the vine canopy and indirectly control P. calceolariae, a known vector of GLRaV-3 between grapevine hosts. The concept of inter-species horizontal toxicity could become a model for targeted pest management by exploiting different insect mutualisms in various horticultural cropping systems.</p>

Natural and Artificial Oxidation of Grape Seed Phenolics are Influenced by Extractability and Galloylation Pattern

In cool-climate viticulture, the short growing season can influence grape seed maturation by reducing the apparent oxidation of flavan-3-ols and associated increase in seed browning. A reduction in seed maturation increases the potential extraction of flavan-3-ols into wine during maceration operations, heightening bitterness. Here, we carried out a 2x2 factorial experiment to test the ability of freezing and heating treatments to artificially “ripen” seeds (decrease flavan-3-ols, improve browning) of (Vitis vinifera L.) Pinot noir and Cabernet Sauvignon over a 24-hour incubation period. Only freezing significantly increased seed browning in both cultivars. Subsequent correlations with seed flavan-3-ols concentrations suggest that freezing enhanced the oxidation of these compounds. Interestingly, natural ripening and freezing reduced galloylated flavan-3-ols to a greater extent than non-galloylated ones. This study provides new information regarding the susceptibility of flavan-3-ols to freezing and heating, and also suggests that freezing can artificially ripen the seeds of under-ripe red vinifera grapes.