Evaluation of safety and quality parameters of persimmon balsamic-type vinegar during multistarter culture fermentation and accelerated aging with oak chips

The present study explores for the first time, the feasibility of using concentrated persimmon juice (CPJ) as a starting material for high-quality balsamic-type vinegar (cv. Jiro, Northern Greece) via a two-stage fermentation process (alcoholic fermentation and then acetification). The best-performing wild type osmophilic strains of Hanseniaspora uvarum and Saccharomyces cerevisiae and acetic acid bacteria isolated from concentrated grape must and varietal vinegar (cv. Xinomavro, Northen Greece), respectively, were used as multistarters. The objective was to produce persimmon balsamic vinegar (PBV) that could be subsequently aged using oak chips as an accelerating agent under conditions that promote its quality attributes. A Taguchi design was applied to reveal the most influential combination of process factors (oak chips amount and pretreatment, aging time) as to the desired sensorial and physicochemical characteristics of the aged PBV (saturated and clear red-orange color, balanced ratio of sugars/organic acids, low 5-hydroxymethyl furfural (HMF) content, high antioxidant activity). Notably, adding even very low amounts (1% w/v) of oak chips significantly affected the quality profile of PBV within a very short aging time (10 days). After 30 days, PBV presented distinct, attractive color characteristics regardless of the amount or pretreatment of oak chips. The HMF content remained constantly low during all treatments while the redox potential increased on intensification of conditions. Implications for the role of phenolic compounds and/or other component interactions with oak chips are discussed. Our approach and outcomes contribute to the innovative valorization of persimmon fruits and the development of aged persimmon balsamic vinegar.