The concentration of sugars: sucrose, glucose, and fructose, as well as citric acid and other metabolic products: ethanol, acetic acid, and lactic acid; were measured by HPLC using Aminex-HPX-87H Biorad column and Refractive Index Detector, using sulfuric acid as the eluent. The fermentation index was measured by spectrophotometry following Gourieva and Tserrevitinov