Effect of temperature on tuber starch (tacca leontopetaloides) pretreatment and incubation for glucose production from ragi tapai / Mohd Aliff Jamian

The high demands for sugars and the development of enzymatic technology have increased the production of sweeteners, especially for glucose. The aim of this work is to maximize the glucose production for the fermentation of Tacca leontopetaloides with ragi tapai by optimizing the temperature of the tuber starch processes. This research work describes the process of glucose production from tuber starch of Tacca leontopetaloides which is commonly found in tropical Africa, South Asia, Southeast Asia, Australia, Samoa, New Guinea and Fiji. In this research work, four different types of ragi tapai from Sabah, Johor, Perlis and Kelantan were obtained and used to identify the best ragi tapai in the production of glucose. The different types of ragi tapai were first undergo identification and characterization process in order to determine selection of ragi tapai. This study was conducted to achieve the objective of the research: (1) To study the effect of pretreatment temperature towards the production of glucose by ragi tapai. (2) To study the optimum incubation temperature of the ragi tapai in the glucose production from tuber starch. A series of fermentation process of tuber starch were performed by varying the pretreatment temperature at 30°C – 70°C at fixed incubation temperature of 30°C and incubation temperature at 30°C – 50°C at fixed pretreatment temperature of 70°C with constant 5% (w/v) of starch slurry and 10% (w/v) of ragi tapai concentration for 180 minutes. DNSA test were performed via spectrophotometer at 540nm to quantify the production of glucose. In the fermentation at various pretreatment temperature, the lowest glucose yield obtained was at 30°C (7.333 g/L) and the highest glucose yield was at 70°C (46.760 g/L). Meanwhile in the fermentation at various incubation temperature, the lowest glucose yield obtained was at 30°C (7.333 g/L) and the highest was at 50°C (62.764 g/L). When the temperature increases, the glucose yield increases. From the results studied shows that Tacca leontopetaloides starch is a promising feedstock to produce glucose.