Microbial Quality and Sensory Assessment of Vinegar from Date Palm and Apple Fruits: Implications for Consumer Preference

Abstract

Studies have shown that variations in production methods, raw materials quality and storage conditions may affect the sensory attributes and microbial safety of vinegar produced from fruit extracts. This study was carried out to evaluate the sensory and microbial quality of vinegar produced from date palm and apple fruits, exploring the implications for consumer preference and acceptance. Yeast and acetic acid bacterium were isolated from spoilt fruits and characterized using appropriate microbiological techniques. Vinegar production was carried out using submerged fermentation of must extracted from Phoenix dactylifera (PD) and Malus sylvestris (MS) fruits. Instrumentation and in vivo techniques were employed for the determination of acetic acid content and toxicity of the fruit vinegar. The data generated from this study were analyzed at 95% confidence level using Analysis of Variance (ANOVA), and post-hoc analysis using Turkey’s test. Yeast and acetic acid bacterium were isolated from spoilt fruits and characterized using appropriate microbiological techniques. Vinegar production was carried out using submerged fermentation of must extracted from Phoenix dactylifera (PD) and Malus sylvestris (MS) fruits. Standard plate technique was employed for the microbial qualities of the vinegar samples. The sensory evaluation and acceptability of the vinegar samples were carried out among validated participants and analyzed using 9-point hedonic scale. The data generated from this study were analyzed at 95% confidence level using Analysis of Variance (ANOVA), and post-hoc analysis using Turkey’s test. There were variations in microbial loads of the vinegar produced from MS and PD using Saccharomyces cerevisiae strain SR 128 (CS 128) and Acetobacter aceti strain WI (AAWI), but these were statistically non-significant (P > 0.05) and conform to the stipulated standard. The samples were well rated in terms of colour, taste and odour, and generally acceptable. Therefore, the prepared vinegar samples from MS and PD had microbial qualities that conformed with the stipulated standard, preferred and acceptable, and the sample prepared from PD was slightly better.