Comparison of hardaliye produced by different starters: Back-slopping and kombucha

Abstract

During traditional hardaliye production by fermentation from grape juice, mustard seeds are insufficient to inhibit yeast activities and alcohol formation. Chemical preservatives are used for the production of hardaliye of standard quality in traditional and industrial production. Today, consumers prefer natural products that do not contain chemical preservatives and additives. For this reason, in this study, considering that different production techniques should be tried in order to prevent alcohol formation, hardaliye production was carried out with two different methods as back-slopping (BH) and addition of kombucha mushrooms (KH). These methods were tried for the first time on hardaliye. Fermentation continued for 7 days (d) and storage for 14 d. During fermentation, pH and reducing sugar, L* and a* values of samples decreased, while phenolic compounds’ concentration, viscosity, and b* values increased. The pH continued to drop during storage. No significant changes were observed in reducing sugar contents. During storage, phenolic content of KH sample decreased and viscosity and L* values increased. The titratable acidity increase was greater in BH sample compared to the KH sample. While 5.5% alcohol formation was observed in the BH sample on the 7th day of fermentation, no alcohol formation was detected in the KH sample At the end of fermentation and storage, Total mesophilic aerobic bacteria (TMAB), yeast, Lactobacillus spp. and lactic streptococci numbers were found to be higher in BH sample than in KH sample. According to the results of the research, thanks to the metabolic activities of the kombucha mushroom microorganisms and their symbiotic association, natural fermentation takes place without any preservative chemicals in KH and more durable hardaliye production is provided compared to BH.