Genomics and Applied Biology, 2017, Vol.8, No.3, 17-25
17
Research Article Open Access
Fermentation: A Means of Treating and Improving the Nutrition Content of
Cassava (
Manihot esculenta
C.) Peels and Reducing Its Cyanide Content
Salami O.S.
, Akomolafe O.M., Olufemi-salami F.K.
Department of Biology, Federal University of Technology, Akure. P.M.B. 704, Akure Ondo state Nigeria
Corresponding author email
Genomics and Applied Biology, 2017, Vol.8, No.3 doi
Received: 01 Sep., 2016
Accepted: 14 Sep., 2016
Published: 30 Jun., 2017
Copyright
© 2017 Salami et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Salami O.S., Akomolafe O.M., and Olufemi-salami F.K, 2017, Fermentation: a means of treating and improving the nutrition content of cassava (
Manihot
esculenta
C.) peels and reducing its cyanide content, Genomics and Applied Biology, 8(3): 17-25 (doi:
Abstract
The capability of microorganisms involved in the fermentation and detoxification of cassava peels through the breaking
down of cyanogenic glucosides as well as improving protein and oil contents of fermented milled underwatered cassava peels were
studied at ambient temperature and relative humidity of 28 ±2°C and 75 ±5% respectively.
Corynebacterial manihot
,
Lactobacillus
plantarum
,
Sacharomyces exiguus
and
Geotrichum candidum
were isolated from cassava waste water. Standard analytical methods
were used to monitor the fermentation for linamarin breakdown and free (residual) cyanide production. Linamarin decreased with
increase in fermentation time and the lowest value of linamarin was observed at 96 hours by the mixed microbes of bacteria and
yeasts {20.11 mg HCN/kg}. Residual cyanide increased during fermentation; however, no ordered pattern in the increase. Total
titratable acidity increased with increase in time of fermentation. The mash fermented by
Lactobacillus plantarum
had the highest
values of titratable acidity of 2.23 % at the end of fermentation, while their pH values reduced with increase in fermentation period.
Protein content of mash fermented by
Lactobacillus plantarum
and naturally fermented peels had the highest value of 21.60 mg/g/dry
matter. The carbohydrate content of the
Lactobacillus plantarum
fermented mash was lower than the values (48.13 mg/g/dry matter)
obtained from the mashes fermented by other isolates. Fermentation reduced cyanide content of milled cassava peels and also
improve the protein and oil contents of it.
Keywords
Delayed transplanting; Aged seedlings; Yield reduction; Potential yield; Farmer’s field
Background
Cassava (
Manihot esculenta
Crantz) has been considered as a major staple food in the developing world,
providing a basic diet for about 500 million people. It is the fifth most cultivated and important plant in the world
(FAOSTAT, 2011) has been processed into different valuables such as garri, tapioca, starch, ethanol etc. (IITA,
1999). The major problem associated with cassava as food is it cyanide content which exists as cyanogenic
glycosides, primarily known as linamarin (Uyoh et al., 2007). More than 50% of the cyanide present in the root is
concentrated in the peels (Burns et al., 2012). Peeling is considered as one of the post harvest practices employed
in reducing cyanide in cassava roots (Okigbo et al., 2009). However, the peel of cassava which is usually peeled
off during processing to reduce the cyanide content of the tuber constitutes a huge of waste. Exploiting this waste
for other benefit is a major concern which has not been well scrutinized, although, several research works have
been done aimed at reducing cyanide in cassava, however, in this study, the cassava peels’ nutrients has been fully
investigated to understand how fermentation can be used to reduce the cyanide content as well as improving the
nutrient of the cassava peels.
1 Results
1.1 Identification of bacteria
The physiochemical test used for the identification of the bacteria isolated from the waste water of fermented
cassava is shown on Table 1. Although the two bacteria types;
Corynebacteria manihot
and
Lactobacillus
plantarum
isolated from the effluent were Gram positive and cocci-shaped bacteria, nevertheless,
L. plantarum
was differentiated form
C. manihot
by the inability of
C. manihot
to produce gas from these sugars: glucose,
