Effect of Fermentation Time on Cyanide Content and Nutritional Composition of Manihot esculenta (Cassava) Flakes Produced in Khana Local Area of Rivers State, Nigeria
Felicia Nmeazi Okwakpam *
Department of Biochemistry, Faculty of Science, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State, Nigeria.
Iniebiyo Felagha
Department of Chemical Sciences, Faculty of Basic and Applied Sciences, University of Africa, Toru-Orua, Bayelsa State, Nigeria.
Benjamin Achor Amadi
Department of Biochemistry, Faculty of Science, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State, Nigeria.
Dornubari Kukang
Department of Biochemistry, Faculty of Science, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background: Cassava (Manihot esculenta Crantz) is a major staple crop widely consumed across tropical regions, particularly in sub‑Saharan Africa. Despite its importance in food security, cassava roots contain cyanogenic glycosides that can release toxic hydrogen cyanide if not adequately processed. Fermentation is a traditional processing method that significantly reduces cyanide levels while improving the nutritional and sensory properties of cassava products. This study investigated the effect of fermentation duration on the proximate composition and cyanide content of cassava flakes (garri) produced in Khana Local Government Area of Rivers State, Nigeria.
Methods: Fresh cassava roots were processed into mash and fermented for 1, 3, 5, and 7 days before roasting into flakes. Proximate composition was determined using standard AOAC (Association of Official Analytical Chemists) analytical methods, while cyanide content was quantified using the alkaline titration method. All analyses were conducted in triplicate and statistical differences were evaluated using one‑way analysis of variance (ANOVA) at p < 0.05.
Results: Moisture content increased from 12.99% to 14.25% with increasing fermentation time, while ash content increased from 0.30% to 0.55%. Conversely, crude fat and crude fiber decreased during fermentation. Cyanide concentration decreased significantly from 2.95 mg on day 1 to 0.80 mg on day 7, demonstrating progressive detoxification during fermentation.
Conclusion: The results indicate that fermentation duration significantly influences both the nutritional composition and detoxification of cassava flakes. Extended fermentation therefore enhances the safety and nutritional quality of cassava‑based foods intended for human consumption.
Keywords: Cassava flakes, fermentation, cyanide detoxification, proximate composition, food safety