Abstract
Grape pomace is the main by-product of wine production that concentrates bioactive metabolites of polyphenolic nature with antibacterial activity. Since grape pomace composition varied depending on grape variety, climate, vineyard location, and winemaking technology, it is important to study the composition and antibacterial activity of each variety separately. In this study, antibacterial activity against different food pathogens was evaluated and its relation with polyphenols content was determined. Grape pomace from Cabernet Sauvignon and Syrah varieties was extracted with methanol/HCl 1% (v/v), followed by sequential extractions with hexane, chloroform and ethyl acetate. Ethyl acetate fraction had the highest antibacterial activity determined through the microdilution method, reaching over 90% of inhibition at 500 μg·ml-1 with the exception of Salmonella Typhi (70% of inhibition). Staphylococcus aureus and Escherichia coli were the most susceptible strains, exceeding 50% of inhibition at 62.5 μg·ml-1. Ethyl acetate fraction contains the highest phenolic concentration in both Cabernet Sauvignon (132.2 mg of GAE g-1) and Syrah (102.6 mg of GAE g-1) pomace, as determined by the Folin-Ciocalteau method. Antibacterial activity present in grape pomace extracts is in direct relation to the polar phenolic content, in particular that from Cabernet Sauvignon.
Highlights
Contamination of food by multiresistant infectious bacteria has become a serious problem, because they limit the treatment and effectiveness of the antibiotics currently in clinical use
Highest total phenolic content (TPC) were obtained with the more polar solvent, reaching the ethyl acetate fraction 132.229 and 102.592 mg GAE g−1 extract for Cabernet Sauvignon and Syrah, respectively
The fractions obtained with hexane, chloroform and ethyl acetate from the Cabernet Sauvignon variety showed significant higher (P < 0.001) TPC concentrations compared to the Syrah variety
Summary
Contamination of food by multiresistant infectious bacteria has become a serious problem, because they limit the treatment and effectiveness of the antibiotics currently in clinical use This has stimulated the search for compounds with antibacterial activity from natural sources. The main organic waste produced in wine industries is grape pomace [3], representing 13% to 25% of the total weight of processed fruit [1]-[8]. This waste is produced after pressing the crushed grapes in white wine processing or after fermentation in red wine production. Anthocyanins, catechins, flavonol glycosides, phenolic acids, alcohols and stilbenes have been identified among the compounds present in grape pomace [8] [13]-[15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
