The Research Of Yam Fermentation Beverage By Lactic Acid Bacteria

This reserarch studied on the yam fermented beverages used the yam as raw material and fermented by lactic acid, through the process of color-protecting, saccharification and fermentation, with good color and nutritional value. The study used the detection method of gas phase and liquid phase to detect its nutrient composition. Finally, the studying had made a further discussion on the various process conditions, the main results in the test is as the follow:(1) The optimum protective coloration technology conditions of yam beverage:citric acid of 0.2%, NaHSO3 of 0.06%, Vc of 0.5%, CaCl2 of 0.5%.(2) The best technology of yam saccharification as saccharifying enzyme 0.2%, and solid-liquid ratio of 1:3.5, pH value of 4, temperature of 60℃, time of 3h.(3) The rest used Thermophilic streptococcus, Bulgaria lactobacillus and L. lactis to fermente for yam saccharification liquid, the best strain formula is:Bulgaria lactobacillus:L. lactis:Bulgaria lactobacillus is 1:1.8:1.8. The best fermentation conditions is:temperature of 39℃, time of 14h, inoculated quantity of 5%.(4) The experiment chose the best factors and levels of sucrose, honey, citric acid,fermente broth to determine the best formula by orthogonal optimization test:honey of 3%, sugar of 0.2%, citric acid of 0.5%.(5) The test selected CMC-Na, sodium alginate, xanthan gum as stabilizer, optimized by orthogonal experiment to determine the yam lactic acid fermented beverage composite stabilizer best formula: CMC-Na of 0.04%, sodium alginate of 0.02%, xanthan gum of 0.08%.(6) The content of the main component of Yam fermented beverages:acetaldehyde of 17.04 mg/mL, diacetyl of 19.937mg/mL, oxalic acid of 0.132mg/mL, allantoin of 0.502mg/mL, succinic acid of 1.136mg/mL, citric acid of 2.472mg/mL, lactic acid of 16.826mg/mL.