Bioreactor-based vinegar production from parthenocarpic ‘assiane’ dates cv (Phoenix dactylifera L.): a sustainable valorization approach
摘要
Parthenocarpic ‘Assiane’ dates, often considered underutilized due to their low market value, were assessed as a viable substrate for the synthesis of vinegar. Their elevated dry matter content (90.5%), fermentable sugar concentration (42 g/100 g DW), and adequate levels of nitrogen (0.31% DW) and phosphorus (0.12% DW) facilitated the growth of yeast and acetic acid bacteria without the necessity for additional supplementation. The alcoholic fermentation conducted by Saccharomyces cerevisiae resulted in the depletion of sugars within a time frame of 96 h, culminating in the production of 10.2% (v/v) ethanol, whereas the subsequent acetic fermentation carried out by Acetobacter aceti transformed the ethanol into 62 g/L acetic acid over a span of 20 days. The bioreactor process yielded an impressive 155% vinegar, characterized by elevated acidity, reduced residual sugars and ethanol, enhanced microbiological safety, and a decreased processing duration in comparison to traditional method. These findings underscore the potential utility of parthenocarpic dates in the production of high-quality, functional vinegar.