Original Research Article

Production of Amylase Using Different Retting Methods during Retting of Cassava Tubers

Cletus Anes Ukwubile

Department of Basic and Applied Sciences, Federal Polytechnic Bali, Nigeria

E-mail: doccletus@yahoo.com

Accepted September 12, 2014

Abstract

This study looks into the possibility of using waste cassava retting water as a source of industrial amylase. It also compares the different amylase activity levels using four different retting methods. Different sizes of fresh cassava tubers were retted for fufu production. The sizes include unpeeled whole tubers (UPWT), peeled whole tubers (PWT), peeled sliced tubers (PST) and peeled grated tubers (PGT). Two retting methods were considered, the traditional method, in which the tubers were retted with tap water and the modified method, in which the tubers were retted in aseptic condition using sterile water and starter cultures. In the traditional method, amylase activity of the retting water increased daily reaching the peak of 2.75 µ /mol for UPWT, 4.53 µ /mol for the PWT, 4.60 µ /mol for PST, and 3.66 µ /mol for PGT on the fourth day. Microorganisms in the retting water were isolated daily and a total of nine organisms (Candida tropicalis, Aspergillus sp, Staphylococcus aureus, Enterobacter aerogenes, Lactobacillus coryneformis, Citrobacter aerogenes, Rhizopus stolonifer, Saccharomyces cerevisiae and Klebsiella aerogenes) were isolated. Five organisms were able to ret the tubers and yield considerable amount of amylase. These organisms were used as starter cultures to ret the peeled sliced tubers. They yield a greater amylase activity with the sample for Lactobacillus coryneformis yielding the highest amount of up to 7.34 µ /mol. Since cassava processing to fufu is usually accompanied with the production of stinking smelling waste water which constitute nuisance to humans, animals and aquatic life, the waste water can be utilized as a source of industrial amylase to save our environment.

Keywords: Amylase activity, Cassava tubers, fufu, industrial amylase, waste water