The influence of Harmonia axyridis morbidity on 2-Isopropyl-3-methoxypyrazine in 'Cabernet Sauvignon' wine

Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae; the Multicolored Asian Lady Beetle; MALB) is a vineyard pest in many winemaking regions of the world due to its ability to taint juice and wine (‘ladybug taint’) through excretion or extraction of 2-isopropyl-3-methoxypyrazine (IPMP) when the beetles are incorporated with the grapes at harvest. A common vineyard intervention is the use of insecticidal sprays and the resulting dead beetles are often incorporated in with the harvested fruit. The main objective of this study was to quantify the impact of dead MALB on IPMP concentrations in red wine. Duplicate 'Cabernet Sauvignon' wines were produced with the addition of 10 beetles·l-1 juice, added either live or at 1, 3, 7, or 60-days postmortem. A control wine with no added beetles was included. IPMP concentration was substantially higher in live-beetle wines, and decreased to base-line levels at approximately 6.5 days post-mortem. These results should assist in decisions on viticultural interventions, such as timing of insecticidal sprays, as well as the establishment of grape quality parameters.

Impact of Leaf Removal, Applied Before and After Flowering, on Anthocyanin, Tannin, and Methoxypyrazine Concentrations in ‘Merlot’ (Vitis viniferaL.) Grapes and Wines

7siThe development and accumulation of secondary metabolites in grapes determine wine color, taste, and aroma. This study aimed to investigate the effect of leaf removal before flowering, a practice recently introduced to reduce cluster compactness and Botrytis rot, on anthocyanin, tannin, and methoxypyrazine concentrations in Merlot' grapes and wines. Leaf removal before flowering was compared with leaf removal after flowering and an untreated control. No effects on tannin and anthocyanin concentrations in grapes were observed. Both treatments reduced levels of 3-isobutyl-2-methoxypyrazine (IBMP) in the grapes and the derived wines, although the after-flowering treatment did so to a greater degree in the fruit specifically. Leaf removal before flowering can be used to reduce cluster compactness, Botrytis rot, and grape and wine IBMP concentration and to improve wine color intensity but at the expense of cluster weight and vine yield. Leaf removal after flowering accomplishes essentially the same results without loss of yield. © 2016 American Chemical Society.reservedmixedSivilotti, Paolo; Herrera, Jose Carlos; Lisjak, Klemen; Baša Česnik, Helena; Sabbatini, Paolo; Peterlunger, Enrico; Castellarin, Simone DiegoSivilotti, Paolo; Herrera, Jose Carlos; Lisjak, Klemen; Baša Česnik, Helena; Sabbatini, Paolo; Peterlunger, Enrico; Castellarin, Simone Dieg

Vinegar production from fruit concentrates: effect on volatile composition and antioxidant activity

Vinegar stands as a highly appreciated fermented food product due to several functional properties and multiple applications. This work focuses on vinegar production from fruit wines derived from fruit concentrates, to attain a food product with nutritional added value. Four fruit vinegars (orange, mango, cherry and banana), were produced and characterized, with total acidities of 5.3 ± 0.3% for orange, 5.6 ± 0.2% for mango, 4.9 ± 0.4% for cherry and 5.4 ± 0.4% for banana. Acetification showed impact on aroma volatiles, mainly related to oxidative reactions. Minor volatiles associated with varietal aroma were identified, monoterpenic alcohols in orange vinegar, esters in banana vinegar, C13-norisoprenoids in cherry vinegar and lactones in mango vinegar, indicating fruit vinegars differentiated sensory quality. Total antioxidant activity analysis by FRAP, revealed fruit vinegars potential to preserve and deliver fruit functional properties. Antioxidant activity of fruit vinegars, expressed as equivalents of Fe2SO4, was of 11.0 ± 1.67 mmol L1 for orange, 4.8 ± 0.5 mmol L1 for mango, 18.6 ± 2.33 mmol L1 for cherry and 3.7 ± 0.3 mmol L1 for banana. Therefore, fruit vinegars presented antioxidant activity close to the reported for the corresponding fruit, and between 8 and 40 folds higher than the one found in commercial cider vinegar, demonstrating the high functional potential of these novel vinegar products.Authors would like to acknowledge the financial funding of: FruitVinegarDRINK QREN Project (Ref. 23209), Project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028" Co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER and the FCT Strategic Project Pest OE/EQB/LA0023/2013. Authors would also like to acknowledge the participation of Mendes Goncalves S.A. and Frulact S.A. staff, for the active input, which led to the work basis and rationale.info:eu-repo/semantics/publishedVersio

Biodiversity of Indigenous Saccharomyces Populations from Old Wineries of South-Eastern Sicily (Italy): Preservation and Economic Potential

In recent years, the preservation of biodiversity has become an important issue. Despite much public discussion, however, current practices in the food industry seldom take account of its potential economic importance: on the contrary, the introduction of industrialized agriculture practices over large areas has often resulted in a dramatic reduction in biodiversity

Quantitative determination of free and hydrolytically liberated beta-damascenone in red grapes and wines using a stable isotope dilution assay

International audienc

Quantitative determination of 2-methoxy-3-isobutylpyrazine in red wines and grapes of Bordeaux using a stable isotope dilution assay

International audienc

Quantitative determination of beta-ionone in red wines and grapes of Bordeaux using a stable isotope dilution assay

International audienc

Addition of carbon dioxide and ascorbic acid in white wines: effects on browning development and antioxidant activity

White wines contain low concentrations of antioxidant compounds, which make them sensitive to the oxidation and the development of brown colour. Browning is a serious problem which affects the quality and the sensory attributes of white wines. It is well known that it is associated with polyphenol oxidation, and therefore it may be accompanied by changes in the antioxidant capacity. The addition of different amounts of carbon dioxide (C1:0.535g/L, C2:0.9g/L, C3:1.1g/L) and ascorbic acid (As1:100mg/L, As2:150mg/L, As3:200mg/L) before bottling and the effect in browning capacity and antioxidant protection of white wines was investigated in this work. Browning was approached from a kinetic point of view by the accelerated browning test and antioxidant activity was evaluated by the 2,2-diphenyl-1- picrylhydrazyl (DPPH•) assay. The results showed that the percentage change in browning (%ΔA420) and the antioxidant activity (AR) were significantly affected by the addition of carbon dioxide and ascorbic acid. Antioxidant activity enhancement was observed after the addition of CO2 and ascorbic acid in all samples

Evaluation of

Enhancing flavors and/or improving fermentation parameters through the use of different species of yeast strains is nowadays a frequent challenge in winemaking research, especially for aromatic varieties such as Sauvignon Blanc. In this work, the aim was to focus on the impact of a species not already studied in wine: Saccharomyces pastorianus. Twenty-two fermentations were conducted on a Sauvignon Blanc must by addition of different strains and mixtures of them by using two different inoculation temperatures. The must was inoculated in cold condition with two similar mixtures of S. pastorianus 1 or 2 (70%) and S. bayanus(30%), with S. pastorianus 1 or 2 alone, with the correspondent S. bayanusalone and with two other S. cerevisiae1 and 2 alone as well. For classic condition, the must was inoculated with only one mixture S. pastorianus1 (70%) / S. bayanus(30%), and respectively with S. pastorianus1, S. bayanus and S. cerevisiae 2 alone. Samples were taken all along the fermentations for both conditions in order to check chemical and microbial analyses as well as yeast implantations. The final wines were analysed for alcohol, glucose, fructose, all other classical wine analysis as well as for acetate esters, and higher alcohols. The results underlined that for both S. pastorianus 1 and S. pastorianus 2 strains, the production of acetic acid was zero in cold condition and really low (0.09 g/l) for classic condition regarding S. pastorianus 1. As a consequence, Saccharomyces pastorianus seems to be highly interesting for winemaking, alone or in co-inoculation with S. bayanus

Effets de certains facteurs viticoles et oenologiques sur les teneurs en 2-méthoxy-3-isobutylpyrazine

National audienc