VIJAYALXMI, K GLAIKHURAM, SARDA DEVI2023-01-042023-01-042022-12-19Th-13420https://krishikosh.egranth.ac.in/handle/1/5810191150Roselle (Hibiscus sabdariffa L.) calyces is an underutilized crop with potent source of bioactive components having antioxidant and antimicrobial properties. Therefore, a study was undertaken to utilize roselle calyces to formulate into functional fermented beverages. Tray drying of calyces at 50°C was standardized through colour and total antioxidant activity. Fresh and dried roselle calyces had pH, titrable acidity, TSS and brix:acid ratio as 1.06, 2.54 %, 0.63°Bx, 2.46 and 1.92, 4.13%, 3.60°Bx and 0.87 respectively. Drying reduced the moisture content from 84 to 11.08 percent. There was an increase in crude protein (7.87 %), ash (5.27 %), total energy content (316 Kcal/100g), total sugar content (54.23%), ascorbic content 15.00mg/100g, total polyphenol 562.89mg and flavanoid content 841.87mg respectively. The anthocyanin compound, Delphinidin-3- sambubioside was predominant in both fresh (13.03mg/g) and dried (39.62mg/g) calyces. Dried calyces exhibited higher antibacterial (2.57mm) and antifungal (98.66%) activities. Fermentation conditions were standardized for honey (5%), sugar (15%) and inoculum concentration, (8%) for yeast and (10%) for Lactobacillus strains. The dried calyces were inoculated with two yeast strains (Saccharomyces ellipsoideus and S. boulardii) and two Lactobacillus strains (Lactobacillus plantarum and L. acidophilus) and fermentation was done for 12 days with 7days interval. The yeast inoculated samples RET and RBT showed a highest total viable population of 7.35 and 2.81 CFU/mL respectively. Fermented beverages with yeast strains showed better microbial populations as well as sensorial characteristics compared to Lactobacillus strains. Thus, exploitation of roselle calyces as a beneficial substrate for microorganisms could be a substitute to dairy based products.EnglishThesis