Vinegar production from red beet (Beta vulgaris L.) and some physicochemical and sensory properties of red beet vinegar

In this study, the physical, chemical, microbiological qualities together with sensory characteristics, especially on the basis of the consumer, of the vinegar produced from red beet, a root vegetable, having a remarkable level of antioxidant properties – mostly known containing betalain, a flavonoid – were evaluated. In the vinegar production process (N=2), which was carried out by the surface culture method, red beet juice (KPS0), vinegar samples after fermentation (KPS1 and KPS2) were sampled. The color values of red beet juice (KPS0) were L*: 25,30, a*: 2,70 and b*: -1,18. The mean pH, dry matter %, °Brix, ash %, density and conductivity, viscosity values of red beet juice samples were 6,1, 11,29, 9,60, 0,76, 0,977 g/cm3 and 2,43 μS/cm, 20,50 cP, respectively. DPPH free radical scavenging activity was determined as 59,46 % inhibition. The mean total acidity, total phenolic content, reducing sugar, monomeric anthocyanin, flavonoid values of 2,60 g/L, 897,00 mg GAE/L, 11,13 g/L, 151,29 mg/L (expressed as cyanidin-3-glucoside) and 14,25 µg catechin equivalents CE / mL, respectively. The mean acetic bacterial count in red beet juice was 1,05 log cfu/mL while the mean lactic acid bacterial count was 0,71 log cfu/mL, the mean yeast/mold count was 0,39 log cfu/mL, and the mean total aerobic mesophilic bacterial count was 2,36 log cfu/mL. The color values of red beet vinegars (KPS1 and KPS) were L*: 25,60 and 27,63, a*: 1.84 and 2,72, b*: -1,54 and -0,45. The mean pH, dry matter %, °Brix, ash %, density and conductivity, viscosity values of vinegar samples were 3,3 and 3,1, 2,44 and 2,10, 3,26 and 3,28, 0,10 and 0,47, 0,923 and 0,939 g/cm3, 6,67 and 6,65 μS/cm, 20,50 and 20,50 cP, respectively. DPPH free radical scavenging activity were determined as 39,89 and 36,67 % inhibition. The mean total acidity, total phenolic content, reducing sugar, monomeric anthocyanin, flavonoid values of red beet vinegar samples (KPS1 and KPS2) were 23,30 and 24,50 g/L, 417,00 and 462,50 mg GAE/L, 6,60 and 8,07 g/L, 24,38 and 22,47 mg/L (expressed as cyanidin-3-glucoside), 17,25 and 14,40 µg catechin equivalents CE/mL, respectively. Following the fermentation process, the mean acetic bacterial counts in vinegar samples (KPS1 and KPS2) were 3,07 and 3,21 log cfu/mL while the mean lactic acid bacterial counts were 2,20 and 2,75 log cfu/mL and the mean yeast/mold counts were 1,04 and 1,07 log cfu/mL and the mean total aerobic mesophilic bacterial counts were 3,14 and 3,32 log cfu/mL. According to the sensory analysis results, the highest scores were determined to be 6,2 and 6,4 in color score whereas the lowest scores were 5,4 in aroma and odor score (KPS1) and 5,6 in flavor and odor score (KPS2). The general appreciation score of the red beet vinegars were 6,4 and 6,6. The results of this study showed that the findings of red beet vinegar have a remarkably promising effect in terms of biochemical quality and consumer taste. As an additional result, it will be possible to evaluate red beet, which cannot be directly evaluated commercially or consumed on a limited basis, as a new and alternative biomaterial for vinegar production.