Determination of nutritional value and the effect of strain, inoculum size, temperature, and incubation period on pH fermentation of Ipomoea batatas

Abstract

Ipomoea batatas, also known as sweet potato, belongs to the Convolculaceae family, and serves as one of the most important food crops worldwide. In the present work, the nutritional values and physicochemical properties of selected sweet potato varieties, namely VitAto (orange), Gendut (yellow), and Anggun (purple) were evaluated. Results indicated that VitAto had the highest content of crude fibre (2.02%), ash (0.65%), and carbohydrate (25%) as compared to Gendut and Anggun. The high carbohydrate content of VitAto makes this variety suitable as a substrate in the development of high nutrition products through food bioprocessing. The combination of parameters studied, such as strain type (Amylomyces rouxii F0050), inoculum size (0.4%), incubation temperature (30°C), and fermentation period (36 h) was found to not only affect the growth of microorganisms, but also improved the pH of culture fermentation. This demonstrated that to obtain the required products or metabolites, proper use of microorganisms to hydrolyse carbohydrates or starches into simpler sugars is very important as a source of carbon to grow the microorganisms.