Türkçe

Abstract

The aim of this study was to ferment beet extract with water kefir and to determine the chemical and microbiological properties of the resulting product over a 15-day shelf life. Beet peels were extracted after undergoing specific pretreatments, and the resulting liquid was sterilized by adding 0.5% ginger and garlic. A 5% water kefir grain culture was added at 25°C, and the mixture was left to ferment at this temperature for 36 hours.

The pH, dry matter, ash, lactic acid, and acetic acid content of the organic acids in the pre- and post-fermentation samples were determined by liquid chromatography; additionally, the contents of Lactobacilli spp., Lactococci spp., and yeast were detected. The product’s dry matter content was found to be 2%. The initial pH value decreased significantly from 6.36 to 4.23 by the end of fermentation. Correspondingly, an increase in lactic acid bacteria was observed. The Lactococcus spp. content was determined to be 7.3 log CFU/mL on day 1 and 7.26 log CFU/mL on day 15. The lactic acid content of the kefir derived from beet extract was determined to be 1.880 g/L, and the acetic acid content was determined to be 1.636 g/L; a microbial identification analysis of the kefir was also conducted. Additionally, as part of sensory analysis studies, panelists evaluated the product’s appearance, odor, and taste characteristics, and it was determined that the overall acceptability level was appropriate.

The results obtained indicate that agricultural food industry waste, such as beet peel, can be considered a potential raw material for the production of functional and fermented beverages. It has been determined that fermentation using water kefir contributes positively to the production of microbiologically safe and sensorially acceptable products.