Post-harvest control of wine-grape mycobiota using electrolyzed water. (June 2016)

• Record Type: Journal Article
• Authors: Cravero, Francesco; Englezos, Vasileios; Torchio, Fabrizio; Giacosa, Simone; Río Segade, Susana; Gerbi, Vincenzo; Rantsiou, Kalliopi; Rolle, Luca; Cocolin, Luca
• Is Part Of: Innovative food science & emerging technologies. Volume 35(2016)
• Page Start: 21
• Page End: 28
• Publication Date: 2016-06
• Subjects: Electrolyzed water -- Grape -- Wine -- Yeast dynamics -- Sanitization -- Innovative treatment; Food -- Biotechnology -- Periodicals; Food industry and trade -- Technological innovations -- Periodicals; Aliments -- Biotechnologie -- Périodiques; Food -- Biotechnology; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.ifset.2016.03.010
• Languages: English
• ISSNs: 1466-8564

Abstract

Abstract: Electrolyzed water (EW) has recently attracted much attention due to its efficacy against a broad spectrum of microorganisms. In this study, we investigated the impact of two EW treatments (40 and 400 mg/L free chlorine) on grape mycobiota using culture-dependent and -independent approaches. Moreover, the effect of yeast inoculation on treated and non-treated grapes was also considered. At the end of the fermentation, the wines produced were subjected to chemical and aroma analyses. The results revealed a decrease of about 0.5 log CFU/mL of the total yeast population on grapes surface independently of the dose of EW applied. Yeast inoculation and EW treatments shortened the time needed by Saccharomyces cerevisiae to dominate apiculate yeasts, particularly, 2 days for inoculated and 7 days for spontaneous fermentations. A decrease of acetic acid (about 55%) was also observed compared to untreated spontaneous fermentation. In addition, aroma analysis highlighted a positive contribution of inoculated yeast on the wine aromas, since they had approximately 50 % higher pleasant esters compared to spontaneous fermented wines. Industrial Relevance: Sulfur dioxide is widely used in crushed grapes prior to fermentation due to its antimicrobial and antioxidant activity. However, legislative rules, health risks and negative consumer perception related to its presence and use have resulted in a need to find new sanitizers able to reduce its use. The effectiveness of EW to reduce yeast species able to produce high levels of undesirable compounds was demonstrated. This research introduced an innovative antimicrobial agent, which could assist in the first step of wine production to reduce the use of SO2 . Highlights: Grapes were treated with electrolyzed water (EW) to sanitize the surface before wine making. A negligible reduction (0.5 log) in the yeast counts was obtained after EW treatment. Interestingly a strong impact on the yeast ecology by EW treatment was determined. Reduction of apiculate yeasts by EW limited the acetic acid production in wines,