Study of Optimized Process Development of Fermented Ipomoea Batatas Leaves by Streptococcus Thermophiles

• Main Authors: Lin,Chien-Wen, 林千雯
• Other Authors: Wang,Shan-Shue
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/yjw5am

碩士 === 高苑科技大學 === 化妝品應用系碩士班 === 107 === The growth of Steptococcus thermophilus fermented with sweet potato leaf soaked in H2O was investigated in this study. The five factors considering to be affected the bacterial growth were selected as sweet potato leaves, time, bacteria number, carbon source and nitrogen source. The central composite design (CCD) and Design Expert software (Design Expert) were used to design a series of combinative formula in order to determine the optimal formula for growth. The bacteria growth and functionality of fermented sweet potato leaf broth were investigated. The results showed that S. thermophilus had the best bacterial count of 2.78×10^9 cells/mL in 4% sweet potato leaves and 5 fermented days. We have found that there were significant amount of functional molecules in sweet potato leaf fermentation broth at optimal formula condition during fermentation process. During this fermentation process, the total sugar was between 4.44 to 10.36 mg Glucose / mL, total polyphenols was between 0.56 to 0.66 mg Gallic acid / mL, DPPH radical scavenging capacity was between 0.52 to 0.63 mg Gallic acid / mL, flavonoids was between 0.03 to 0.22 mg Quercetin / mL, reducing power was between 0.56 to 1.13 mg BHT / mL, reducing sugar was between 14.0 to 205.1 mg Glucose / mL, amino acids was between 1.66 to 5.03 mg MSG / mL, protein was between 2.34 to 4.90 mg BSA / mL, protease activity was between 7.31 to 11.34 Unit / mL, amylases activity was between 21.81 to 41.42 Unit / mL, cellulase activity was between 3.85 to 5.25 Unit / mL, carotene was between 0.71 to 4.04 μg carotene / mL, and chlorogenic acid ranged from 39.03 to 52.12 μg chlorogenic acid / mL. In the sensory evaluation, the sweet potato leaves fermentation broth by Streptococcus thermophilus has a high acceptance. Based on the aforementioned information, the functional ability of No. 1 sweet potato leaf can be significantly improved while it was fermented with Streptococcus thermophilus. This fermented broth has potentially become an excellent health drink.