Physico-chemical and microbiological properties of water kefir produced from carob (Ceratonia siliqua L.) sherbet

In this study, sugar-free (A) and sugar-added (B) formulations of carob sherbet were fermented with water kefir grains. After 48 h of fermentation, the pH and total soluble solid content level (TSS) of A and B decreased, while the titratable acidity (TA) value increased. At the end of fermentation, Ave B formulations were stored at 4 °C for 28 days. Fermented sherbets’ 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity decreased with storage. A had 75.3% DPPH radical scavenging activity on day 0th, whereas B had 77.0%. B had less total phenolic content (TPC) than fermented A on day 0. TPC values decreased significantly, notably on days 21st and 28th of storage. After fermentation, A had more gallic acid, hesperidin, p-coumaric acid, rosmarinic acid, and syringic acid than B. A had 2.21% sucrose before fermentation and 0.95% after. On 14th days of storage, potassium and calcium had the greatest mineral levels. Compared to A, B gave higher microbial count values (Lactobacillus sp., Lactococcus sp. total mesophilic aerobic bacteria, and yeast) in the microbiological analysis results at the end of fermentation and during storage.