Efficacy of olive oil mill extract in replacing sulfur dioxide in wine model

Abstract

Olive oil industry produces high amounts of olive mill solid waste. These have been described as natural source of hydroxytyrosol, which shows high antioxidant and antimicrobial properties joint to health-promoting effects. In the present work, an olive mill solid waste extract dissolved in model wine was evaluated to determine its potential capacity to replace and/or reduce sulfur dioxide in winemaking. Olive oil mill extract is a potent antioxidant of biological origin. The extract resulted in 4 and 40 mmol/L Trolox/mg extract by DPPH and ORAC respectively. Its antimicrobial activity was approaching to that of SO2 for Hanseniaspora uvarum, Candida stellata, Lactobacillus plantarum, Pediococcus damnosus and Acetobacter aceti, higher for Oenococcus oeni and lower for Dekkera bruxellensis and Botryotinia fuckeliana.Additionally, GC-olfactometry analysis showed that the most important odorants from the extract are naturally present in wines. However, some odorant zones might be significantly increased in wine after extract addition.It can be concluded that olive mill solid waste extracts is a source of bioactive compounds of low cost, with high antioxidant activity and good antimicrobial properties.