Genomics and Applied Biology, 2017, Vol.8, No.3, 17-25
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3.7 Glucoside cyanogen’s (Linamarin) determination
From the extract
,
0.1 ml pippeted and added to 0.4 ml of phosphate buffer (pH 7.0) in a stoppered test tube. Then
0.1 ml of linamarase enzyme was added and incubated for 15 min. at 30°C. Thereafter 0.6ml of 0.2 M NaOH was
added and left for 5 min. after which, 2.5 ml of phosphate buffer (pH 6.0) was added. Subsequently, 0.2 ml of
chloroamine T was added to the test tube already containing 4.0 ml of buffered extract to stabilize the colour
formation. One mililitre of the mixture was introduced into the curvet of the spectrophotometer and ninhydrin of
0.5 ml was added to the mixture and the absorbance was immediately measured in the uv-photospectometer
(UV-1100 Spectrophotometer Mapada model) at 590 nm wavelength (Mihaescu, 2009). The values were then
calculated using the formula for calculating cyanide content described above.
3.8 Determination of residual cyanide
From the extract, 0.1 ml was pipetted and mixed with 3.9 ml of phosphate buffer (pH 4.0). Then the colorimetric
procedure was used to determine the free cyanide content.
3.9 Determination titratable acidity
Ten grams of sample was homogenized in 200 ml of distilled water and filtered using Whatman filter paper.
Eighty mililitre of filtrate was titrated with 0.1 M NaOH using 1% phenolphthalein as indicator (Obilie et al
.
,
2004). The formula used in determining the Total Titratable Acidity is given as:
Where V is the volume of 0.1 M NaOH used.
3.10 Determination of daily pH
Ten grams of the fermented peels was added to 20 ml of distilled water. Then the mixtures were stirred for 1
minute and the setups was left for 30 minutes, after which the pH of fermented peels were determined by dipping
the tip of Jenway 3015 pH-meter into the suspension and the pH value of the fermented cassava read on the digital
scale of the instrument.
Proximate Analysis was determined using AOAC (1990).
All the experimental set up were replicated three times. The data collected were subject to analysis of variances
(ANOVA) and means were separated using Turkey Mean Simultaneous Test.
Authors' contributions
Akomolafe, Olatunji Modupe helped in the planning of the project and interpretation of the analyzed data, Salami, Olufemi Samson
fine tuned the planed project, executed the project, collected data, analysed the data and drafted the manuscript. Olufemi-salami,
Folasade Kemisola helped in data collection and editing the drafted manuscript.
Acknowledgments
My sincere gratitude goes to Mrs Alade Oluwatoyin, the chief Technologist of Biology department for making most of the material
available for the research. I also appreciate Dr. Ogungbite Olaniyi for his encouragement during the drafting of this manuscript.
References
Abba-Kareem V.N., and Okagbue R.N., 1999, Studies on the microbiology of cassava flour. Nigerian Food Journal 9:85-91
Achinewhu, S.C., and Owuamanam, C.I., 2001, Garification of five improved cassava cultivars, physicochemical and sensory properties of gari yield, African
Journal Root Tuber Crops, 4(2): 18 – 21
Ahaotu I., Ogueke C.C., Owuamanam C.I., Ahaotu, N.N., and Nwosu, J.N., 2013, Fermentation of undewatered cassava pulp by linamarase producing
microorganisms: effect on nutritional composition and residual cyanide, American Journal of Food and Nutrition, 3(1):1-8
Amoa-Awua, W.K.A., Appoh, F., and Jaobsen, M., 1996, Lactic acid fermentation of cassava into 'Agbelima', International Journal of Food Microbiology, 31:
87-98
