Pesticides' Influence on Wine Fermentation

Residual behavior of dinotefuran and its metabolites during Huangjiu fermentation and their effects on flavor

Yellow rice wine (Huangjiu) is a traditional Chinese alcoholic beverage. However, there is a risk of pesticide residues in Huangjiu due to pesticide indiscriminate use. In this study, the residues of dinotefuran and its metabolites during Huangjiu fermentation and their effects on flavor substances were studied. The initial concentrations of dinotefuran ranged from 856.3 to 1874.9 μg/L, and its half-life was no more than 3.65 d. At 24 d of Huangjiu fermentation, the terminal residues of dinotefuran, 1-methyl-3-(tetrahydro-3-furylmethyl)urea (UF) and 1-methyl-3-(tetrahydro-3-furylmethyl)guanidine (DN) were 195.1-535.3 μg/L, 38.33-48.70 μg/L and 37.8-74.1 μg/L, respectively. Twenty potential degradation compounds were identified by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS), and their toxicity was evaluated. Finally, the effect of dinotefuran on physicochemical properties and total phenol content of Huangjiu were analyzed. The risk of rancidity was significantly increased and bitter amino acids were formed. These findings provide a guidance and the safe production of Huangjiu.

Occurrence and impact of carbendazim and hymexazol residues on yeast growth and ochratoxin A contamination during wine production

BACKGROUND

Grapes are highly vulnerable to infection by carbon black aspergilli, which produce ochratoxin A (OTA), a mycotoxin. Carbendazim and hymexazol are widely applied to control grape diseases. Howerver, fungicides, toxigenic fungi, and OTA can be transferred from grapes to wine causing potential safety issues. The impact of these residues on fungal populations and OTA during vinification are currently unclear. Here we investigated the effects of carbendazim and hymexazol on the viability of Aspergillus carbonarius and OTA contamination during an indoor wine-processing experiment.

RESULTS

The population size of A. carbonarius substantially increased at 24 h followed by a significantly decreased at 72 h after destemming and crushing. However, carbendazim and hymexazol notably inhibited the growth of A. carbonarius in must samples. In addition, yeast growth was substantially deleyed by carbendazim, hymexazol, and OTA during the first 3 days in compared with the control. Carbendazim, hymexazol, and OTA residues declined over time, and the processing factors (PFs) for carbendazim and hymexazol throughout vinification were 0.164, 0.074, and 0.185-0.476, respectively. Carbendazim and hymexazol each reduced OTA concentrations. However, there was no significant difference after 48 h. Addition of carbendazim or hymexazol significantly reduced the level of A. carbonarius but had no significant effect on the final concentration of OTA in mature wine.

CONCLUSION

The wine-making process can reduce the residues of OTA, carbendazim, and hymexazol in grapes, but it is recommended that grapes chosen to make wine should be free of A. carbonarius contamination. © 2023 Society of Chemical Industry.

Drinking alcohol in moderation is associated with lower rate of all-cause mortality in individuals with higher rather than lower educational level: findings from the MORGAM project

The association between socioeconomic status (SES) and alcohol-related diseases has been widely explored. Less is known, however, on whether the association of moderate drinking with all-cause mortality is modified by educational level (EL). Using harmonized data from 16 cohorts in the MORGAM Project (N = 142,066) the association of pattern of alcohol intake with hazard of all-cause mortality across EL (lower = primary-school; middle = secondary-school; higher = university/college degree) was assessed using multivariable Cox-regression and spline curves. A total of 16,695 deaths occurred in 11.8 years (median). In comparison with life-long abstainers, participants drinking 0.1-10 g/d of ethanol had 13% (HR = 0.87; 95%CI: 0.74-1.02), 11% (HR = 0.89; 0.84-0.95) and 5% (HR = 0.95; 0.89-1.02) lower rate of death in higher, middle and lower EL, respectively. Conversely, drinkers > 20 g/d had 1% (HR = 1.01; 0.82-1.25), 10% (HR = 1.10; 1.02-1.19) and 17% (HR = 1.17; 1.09-1.26) higher rate of death. The association of alcohol consumption with all-cause mortality was nonlinear, with a different J-shape by EL levels. It was consistent across both sexes and in various approaches of measuring alcohol consumption, including combining quantity and frequency and it was more evident when the beverage of preference was wine. We observed that drinking in moderation (≤ 10 g/d) is associated with lower mortality rate more evidently in individuals with higher EL than in people with lower EL, while heavy drinking is associated with higher mortality rate more evidently in individuals with lower EL than in people with higher EL, suggesting that advice on reducing alcohol intake should especially target individuals of low EL.

Monitoring of mycotoxins and pesticides in winemaking

This study monitored concentrations of both pesticides 2,4-dichlorophenoxyacetic acid (2,4-D) and procymidone, and mycotoxin ochratoxin A (OTA) in stages of the winemaking process. Sampling was carried out in the usual vinification process of red wine in a winery between the steps to obtain must and alcoholic fermentation. The highest transference of contaminants in the process occurred in the crushing step to 2,4-D (100%) and maceration to OTA and procymidone (100%). Removal of contaminants in the winemaking process corresponded to 100%, with a half-life (T1/2) longer for procymidone (216.5 h) and shorter for 2,4-D (38.5 h) and OTA (96 h). The processing factors (PFs) (0) for the contaminants, together with the data obtained, characterize winemaking as a process of reducing mycotoxin and pesticides. Results highlight the importance of fermentation to reduce contaminants and that yeasts promote detoxification

Biodiversity and oenological attitude of Saccharomyces cerevisiae strains isolated in the Montalcino district: biodiversity of S. cerevisiae strains of Montalcino wines

The biodiversity of Saccharomyces cerevisiae was studied in the Montalcino area (Italy). Two wineries were involved in the study, which compared the genotypic and oenological characteristics of the S. cerevisiae strains isolated in spontaneous fermentations. After isolation yeasts were identified by 26S rRNA gene sequence analysis, and S. cerevisiae strains were characterized through interdelta sequence analysis (ISA). Oenological tests were performed in synthetic grape must by varying the magnitude of the main wine-imiting factors. The evolution of alcoholic fermentation was monitored by measuring sugar consumption and flow cytometry. The results revealed the prevalence of S. cerevisiae from the third day of fermentation and the presence of a wide range of S. cerevisiae strains having ISA profiles characteristic of each winery. From an oenological point of view, the features of such strains, in terms of resistance to wine-limiting factors, seemed to be linked to the main oenological variables applied in the production process of each winery. Extreme fermentation temperatures and copper residues are the variables that mostly depress the yeast population, in terms of fermentation rate and cell viability. Flow cytometry revealed the different impact of limiting factors on the viability of yeast by the quantification of the ratio between live/dead yeast cells of each strain, suggesting different mechanisms of inhibition, for instance stuck of cell growth or cell killing, in response to the different stress factors.

Effect of the Technological Process from Vine to Wine on Pesticide Residues in Vernaccia di Oristano Cultivar

Vernaccia is a white grape mostly used to produce a distinct wine protected by the controlled designation of origin (DOC) recognition. It is very susceptible to fungal disease, and it is subjected to a defined management protocol in the field. Winemaking could influence pesticide residues through different mechanisms. This work investigated the influence on pesticide residues of the winemaking process at the industrial level of the wine Vernaccia di Oristano. Thirty-five samples of grapes, two musts, and two vines (both liquid fraction and pellets) were analyzed by using a validated multiresidue LC-MS/MS (Liquid Chromatography with tandem mass spectrometry) method. Data obtained showed the presence in grapes juice of 16 pesticides (8 not allowed in the EU) with mandipropamid and mepanipyrim, the only ones with values higher than their MRL (maximum residue level). Pesticide residues decrease in must was related to the dilution effect due to mixing the grape samples. However, pellets analysis also confirmed the high affinity of pesticides for the suspended material (fenhexamid), whereas the increase in wine to a re-solubilization process from the lees during the fermentation step. The present paper highlighted the effectiveness of the technological process of winemaking to decrease pesticide residues compared to the raw material.

Occurrence and impact of fungicides residues on fermentation during wine production- A review

Continuous fungicide spraying is required to eliminate fungal pathogens on grapes. However, this practice is associated with several risks, including contamination and environmental imbalance, as well as toxicity to operators and the induction of resistance in pathogens. In addition, a strong correlation has been reported between the presence of fungicides and the occurrence of issues during alcoholic fermentation, resulting in negative impacts on the sensory quality of the final products. Numerous studies have evaluated residue concentrations of phytosanitary products in grapes, juices, and wines, and a significant number of studies have assessed the impact of different agrochemicals on bioprocesses. However, a review compiling the key results of these studies is currently lacking. This review incorporates results obtained in the last decade from research on the presence of fungicide residues, including azoxystrobin, boscalid, captan, copper, fenhexamid, folpet, pyraclostrobin, pyrimethanil and tebuconazole, and their effects on fermentation kinetics. Practical solutions to mitigate these problems, both in vineyards and industry, are also presented and discussed. This review highlights the constant high fungicidal agent concentrations (greater than 1 or 2 mg L^-1) used throughout the winemaking process, with the impact of residues being of particular concern, especially with regard to their effect on yeast activity and the fermentation process. Thus, the adoption of methodologies that allow winemakers to control and trace these residues is an important step in avoiding or reducing fermentation problems throughout the winemaking process.[Figure: see text].

Influence of Triazole Pesticides on Wine Flavor and Quality Based on Multidimensional Analysis Technology

Triazole pesticides are widely used to control grapevine diseases. In this study, we investigated the impact of three triazole pesticides-triadimefon, tebuconazole, and paclobutrazol-on the concentrations of wine aroma compounds. All three triazole pesticides significantly affected the ester and acid aroma components. Among them, paclobutrazol exhibited the greatest negative influence on the wine aroma quality through its effect on the ester and acid aroma substances, followed by tebuconazole and triadimefon. Qualitative and quantitative analysis by solid-phase micro-extraction gas chromatography coupled with mass spectrometry revealed that the triazole pesticides also changed the flower and fruit flavor component contents of the wines. This was attributed to changes in the yeast fermentation activity caused by the pesticide residues. The study reveals that triazole pesticides negatively impact on the volatile composition of wines with a potential undesirable effect on wine quality, underlining the desirability of stricter control by the food industry over pesticide residues in winemaking.

Trichoderma atroviride P1 Colonization of Tomato Plants Enhances Both Direct and Indirect Defense Barriers Against Insects

Numerous microbial root symbionts are known to induce different levels of enhanced plant protection against a variety of pathogens. However, more recent studies have demonstrated that beneficial microbes are able to induce plant systemic resistance that confers some degree of protection against insects. Here, we report how treatments with the fungal biocontrol agent Trichoderma atroviride strain P1 in tomato plants induce responses that affect pest insects with different feeding habits: the noctuid moth Spodoptera littoralis (Boisduval) and the aphid Macrosiphum euphorbiae (Thomas). We observed that the tomato plant-Trichoderma P1 interaction had a negative impact on the development of moth larvae and on aphid longevity. These effects were attributed to a plant response induced by Trichoderma that was associated with transcriptional changes of a wide array of defense-related genes. While the impact on aphids could be related to the up-regulation of genes involved in the oxidative burst reaction, which occur early in the defense reaction, the negative performance of moth larvae was associated with the enhanced expression of genes encoding for protective enzymes (i.e., Proteinase inhibitor I (PI), Threonine deaminase, Leucine aminopeptidase A1, Arginase 2, and Polyphenol oxidase) that are activated downstream in the defense cascade. In addition, Trichoderma P1 produced alterations in plant metabolic pathways leading to the production and release of volatile organic compounds (VOCs) that are involved in the attraction of the aphid parasitoid Aphidius ervi, thus reinforcing the indirect plant defense barriers. Our findings, along with the evidence available in the literature, indicate that the outcome of the tripartite interaction among plant, Trichoderma, and pests is highly specific and only a comprehensive approach, integrating both insect phenotypic changes and plant transcriptomic alterations, can allow a reliable prediction of its potential for plant protection.

Evaluating a preventive biological control agent applied on grapevines against Botrytis cinerea and its influence on winemaking

BACKGROUND

This research was aimed to study the influence on grape and wine quality and on the fermentation processes of the application of a preventive biological treatment against Botrytis cinerea in Tempranillo Rioja grapevines. For this purpose, a biofungicide containing Bacillus subtilis QST713 was applied twice to the vineyard.

RESULTS

Results were compared with non-treated samples from the same vineyard and with samples treated with a chemical fungicide composed of fenhexamid. Data showed that general grape quality and spontaneous alcoholic fermentation performance were not influenced by either fungicide application. The chemical fungicide had a considerable influence on the clonal diversity of Saccharomyces cerevisiae species, which led to the alcoholic fermentation. Furthermore, it caused longer malolactic fermentation than with the biological fungicide and in the control. The biofungicide made malolactic fermentation 1 day shorter because the establishment of the commercial lactic acid bacteria used as a starter culture was total. After malolactic fermentation, the wines did not show significant differences in general oenological parameters.

CONCLUSION

Preventive biofungicide treatment against B. cinerea did not negatively influence the quality of grapes and wines and the fermentation processes. Therefore, biological control of B. cinerea with B. subtilis applied on grapevines could be advisable in oenological terms. © 2018 Society of Chemical Industry.