Research Journal of Chemical Sciences ______________________________________________ ISSN 2231-606X Vol. 2(12), 78-80, December (2012) Res.J.Chem. Sci. International Science Congress Association 78 Short Communication Determination of Residual Hydrocyanic Acid (HCN) in White and Yellow Garri Flour Processed from Cassava (Manihot Esculata Crantz) Emoyan O.O., Agbaire P.O and Peretieo-Clarke B.O. Department of Chemistry, Delta State University, P.M.B. 1 Abraka, NIGERIAAvailable online at: www.isca.in Received 28th July 2012, revised 14th August 2012, accepted 24th August 2012Abstract Twenty samples of white and yellow garri flour produced from cassava (Manihot esculenta Crantz) that were processed for 0, 24, 48, 72 and 96 hours using the combination methods of grating, dewatering, fermentation and frying were analysed for residual hydrocyanic acid concentration using the Spectrophotometeric alkaline Picrate method, (AOAC, 2000). Analysis of results showed that the mean concentration and percentage of HCN concentration lost to processing from 0 to 96 hours in white and yellow garri flour are not significantly different. Therefore, the length of processing time and the combination of grating, dewatering, fermentation and frying methods are responsible for the removal of HCN in both white and yellow garri flour. Keywords: Cassava, Garri Flour and Residual HCN. Introduction Manihot esculenta Crantz is widespread in the tropical world, and commonly known as manioc, cassava, tapioca, mandioca. Its primary attraction is that in its tuberous root, it is the highest yielding starchy staple where yields are as high as 50 to 82 metric tones per hectare have been recorded. Albeit with lesser yield, it can be grown on marginal soils where economic yield cannot be obtained from other crops, also, it is attacked by few pests other than rodents . The major deterrent to its cultivation is that is known to reduce K in soil which is probably due to its high yields. Cassava is believed to have originated from Brazil and was introduced into West Africa. Cassava product such as garri flour is a major staple food in most African and Latin American countries. The proximate nutritive value of cassava tuber was expressed as: moisture (59.4g.kg-1), total carbohydrate (38.1g.kg-1), lipid (0.2 g.kg-1), protein (0.7 g.kg-1), Ca (50 mg.kg-1), P (40 mg.kg-1), Fe (0.9 mg.kg-1), niacin (0.3 mg.kg-1), vitamin C (25 mg.kg-1), thamin (0.05 mg. kg-1) and riboflavin (0.1 mg.kg-1. Cassava tubers are traditionally processed by a range of multistage processes of grating, dewatering, and fermentation and frying, which reduces their toxicity, improve palatability and convert the perishable fresh root into stable products such as garri flour, tapioca etc6-8. Several authors have reported the toxicity caused by consuming improperly processed cassava products with respect to hydrocyanic acid. Acute toxicity of cyanohydrin causes calcific pancreatitis, apnea and cardiac arrest with death following in a matter of minutes. While chronic toxicity could result in weakness and a variety of symptoms including permanent paralysis, goiter, with tropical ataxic neuropathy10-13. A number of processing steps involved in the production of garri influenced the levels of residual hydro- cyanide6.7. In this research, the concentration of residual hydrocyanic acid was studied at different fermentation time and treatment in red and white garri flour. Material and MethodsTwenty samples of white and yellow garri flour produced from fifteen months old white and bitter cassava tubers harvested in Aragba-Orogun Delta State, Nigeria were used for the analysis. Each grated species were divided into ten: five portions were mixed with red palm oil (yellow garri). The twenty samples were packed separately into twenty jute bags and dewatered using a locally fabricated hydraulic press. The cassava pulps in each bag were separated into five groups and left to ferment for 0, 24, 48, 72 and 96 hours respectively. After sieving and subsequent frying (120-200C) in rectangular frying pan (1.5/.7m), the garri was cooled, packed labeled and sealed. Residual hydrocyanic acid was determined in white (ten) and yellow (ten) garri flour samples14. Results and Discussion Concentrations of residual hydrocyanic before and after fermentation are presented in table 1. The concentration of residual hydrocyanic acid in table 1 showed that there is a step wise reduction of HCN content in all samples (A-D) from 0 to 96 hours of processing. In sample A, 0 hours recorded 10.824 g.g-1 while 24 hours and 48 hours recorded 7.576 g.g-1 and 5.402 g.g-1 respectively. Similarly 72 hours and 96hrs processing hydrocyanic acid concentrations are 3.267 g.g-1 and 2.190 g.g-1 respectively. Results also showed that sample B Research Journal of Chemical Sciences ___________________________________________________________ ISSN 2231-606XVol. 2(12), 78-80, December (2012) Res. J. Chem. Sci. International Science Congress Association 79 HCN concentration ranged from 10.791 to 2.170 g.g-1. Similarly, in sample C the recorded residual hydrocyanic acid concentration ranged between 11.871 and 3.221 g.g-1. Analysis of results in sample D showed that the concentration of hydrocyanic acid ranges between 11.861 and 3.221 g.g-1. Also, the concentration of hydrocyanic acid lost to processing from 0 to 96 hours in sample A, B, C and D showed that the concentration of hydrocyanic acid in bitter cassava is higher than sweat cassava which is in agreement with other work 15. However, table 2 showed that there is no significant difference in the mean of the test samples. Analysis of results in table 1 and figure 1 showed that there is proportional reduction of residual hydrocyanic acid in both red and white garri samples from 0 to 96 hours of processing. The rate of hydrolysis of cyanogenic glucoside in cassava to produce the poisonous hydrogen cyanide was due to palm oil in garri4,16. However, the low level of cyanide in palm oil garri flour could be related to the sequestration of CN by palm oil components into a complex and therefore unavailable for quantitative measurement17. This could be responsible for the low concentration of hydrocyanic acid in the red garri flour. Therefore, fermentation and increase in fermentation time could be responsible for the removal of residual hydrocyanic acid in both red and white garri18-21. Secondly, the significant loss of residual hydrocyanic acid in the test samples from 0 to 96 hours of processing showed that the combination of grating (which allowed endogenous and microbial enzymes to hydrolyze cyanogenic glucoside by 95% within 3hours), hydraulic jack dewatering (which removed substantial amount of free cyanide from the cassava pulp), fermentation and frying (reduced the level of antinutrients and drive off the cyanide formed) processing methods are responsible21,6,7, 22. Therefore, the use of red oil in the production of garri flour is basically to protect it from mould attack, give appealing look and reduce vitamin A deficiency23. Table-1 Concentration of Residual Hydrocyanic Acid in Sample A –D (µg.g-1 dry matter) Sample Fermentation in hours Sweet Cassava Bitter cassava A % Loss B % Loss X C % Loss D % Loss 0 10.824+ 0.014 10.791+ 0.019 11.871+ 0.109 11.861+ 0.110 24 7.576+ 0.017 29.9 7.531+ 0.042 30.21 8.614+ 0.067 27.44 9.524+ 0.344 19.70 48 5.402+ 0.053 50.0 4.350+ 0.044 59.69 5.393+ 0.046 54.57 5.357+ 0.066 54.84 72 3.267+ 0.043 69.8 3.231+ 0.010 70.06 4.322+ 0.006 63.59 4.322+ 0.006 63.56 96 2.190+ 0.034 79.7 2.170+ 0.006 79.89 3.239+ 0.073 72.72 3.221+ 0.148 72.84 Results are expressed as means of quadruplet determination: A: yellow garri (addition of palm oil prior to fermentation), B: white garri, C: yellow garri, D : white garriTable-2 Significant Relationship between sample obtained by Pearson correlation n = 5, df==4 aa=0.05 Couph p�0.05 A – B 0.992 A – C 0.991 A – D 0.982 B – C 0.999 B – D 0.994 C – D 0.994 Figure-1 Hydrocyanic acid Concentration at Different Processing Time Research Journal of Chemical Sciences ___________________________________________________________ ISSN 2231-606XVol. 2(12), 78-80, December (2012) Res. J. Chem. Sci. International Science Congress Association 80 Conclusion The concentration of hydrocyanic acid and the percentage of hydrocyanic acid lost to multistage processing showed that fermentation and increase in fermentation time is responsible for the proportionate removal of hydrocyanic acid from white and red garri flour. Secondly, the combination of grating, dewatering, fermentation and frying processing methods contributed substantially to the removal of hydrocyanic acid from the test samples. Because of the acute and chronic toxic effects of cyanide in cassava by-products, increasing processing time and the combination of processing methods should be applied to enable maximum removal of cyanide in the production of garri flour. Further research on the effect of red palm oil on starch concentration in garri flour should be carried outAcknowledgmentThe authors are grateful to Education Trust fund (ETF2011) and Prof. E.O. Arubayi Education Research Foundation for providing grants to power this research work. References1.Jansz E.R. and Uluwaduge D.I., Biochemical Aspects of Cassava (Manihot Esculenta Crantz) with Special Emphasis on Cynogenic Glucosides, A Review, . Nutr. Sci. Coun. Sri Lanka.,25(1), 1-24 (1997)2.Centro International Agricultural Tropical Cassava Programmed Annual Report, (Cali, Colombia (CIAT) 5-87 (1979)3.Olsen K.M. and Schaal B.A., Evidence on the Origin of Cassava: Phylogeography of Manihot Spp. Proceedings of the National Academy of Sciences of the United States of America,96 (10), 5586–91 (1999)4.Odoemelam S.A., Studies on Residual Hydrocyanic Acid in Garri Flour Made from Cassava (Manihot spp.) Pak. J. of Nutri., 4(6), 376-378 (2005)5.Perera W.D.A., Jayasekera P.M. and Thaha S.Z., Table of Food Composition as Used in Sri Lanka Medical Research Institute. Sri Lanka (UNICEF) (1989) 6.Oke O.L., Eliminating Cyanogens from Cassava through Processing: Technology and Tradition, Acta. Hort (ISHS), 375, 165-174 (1994)7.Padmaja G. and Keith H.S., Cyanide Detoxifiation in Cassava for Food and Feed Uses, Critical Reviews in Food Sci and Nutr, 35(4), 299-339 (1995)8.Sohore D.A. and Nimlin G.J., Changes in BiochemicalProperties of Fresh Attiéké During its Storage, Food and Public Health 2(4), 99-103 (2012)9.Almazan M., Cyanide Concentration in Fried Cassava Chips and its Effect on Chip Test, Nig. Food J., 4, 65-74 (1986)10.Delenge F. and Ahluwalia R., Cassava Toxicity and Thyroid: Research and Public Health Issues, Proceedings of a Workshop held in Ottewa, Canada IDRC 207e 7-146 (1982)11.Geevargheese P.J., Cassava Diet, Tropical Calcifying Pancreatitis and Pancreatic Diabetics IDRC Oloe 11-162 (1982)12.Lagasse R., Luvivila K., Yung Y.M., Gerard M., Harrison A., Bourdoux P., Delenge F. and Thilly C.H., Endemic Goitre and Cretinism in Ubangi IDRC 136C 45-60 (1980)13.Akindahunsi A.A., Grissom F.E., Adewusi S.R., Afolabi O.A., Torimiro S.E. and Oke O.L., Parameters of Thyroid Function in the Endemic Goitre of Akungba and Oke-Agbe Villages of Akoko Area of Southwestern Nigeria, Afr. J. of Medc and Med. Scs.,27(3-4), 239–42 (1998)14.Knowles T. and Wathins M., Bitter and Sweet Cassava Hydrocyanic Acid Content trinadad and Tobego Bulletin, 14,52-56 (1990)15.Chiwona-Karltun L., Katundu C., Chipungu F., Mkumbira J., Simukoko S. and Jiggins J., Bitter Cassava and Women, An Intriguing Response to Food Security, LEISA Magazine 18(4)(2002)16.Fominyan R.T., Adegbola A.A. and Oke O.L., The Role of Palm oil in Cassava Based Ration, In: Tropical Root Crops: Research strategies for the 1980’s Eds Terry E.R., Oduro K.A. and Caveness F. Ottawa, Canada 152-153 (1981)17.Uvere P.O., Reactivity of Red Palms Oil and Cyanide ion: Implications for the Cyanogen Content of Palm oil-treated garri,Plant Foods for Human Nutr. 5(3), 249-253 (1999)18.Ukhun M.E. and Nkowocha F.O., The HCN Content of Garriflour made from Cassava, (manhot spp) and the Influence of Length of Fermentation and Location of Source, Food Chemistry,33, 107113 (1989)19.Otuya C.O. Ukpong E. and Adesina A.A., Modelling of the Rate Date from the Fermentation of Cassava Slurry, Letters in Applied Microbiology, 9, 1316 (1989)20.O’Brien G.M. and Mbome L., Variation in Cyanogen Content of Cassava during Village Processing in Camerouns, Food Chemistry,44, 131136 (1992)21.Milingi N.V., Assey V.D., Swai A.B.M., Mclaren D.G., Karlen H. and Rosling H., Determinants of Cyanide Exposure from Cassava in a known Afflicted Population in Northern Tanzania, Int. J. of food Sci. and Nutri.,44, 137-144 (1993)22.Oboh G. and Oladunmoye M.K., Biochemical Changes in Micro-Fungi Fermented Cassava Flour Produced from Low and medium-Cyanide Variety of Cassava Tubers Nutr. Health, 18(4) 355-367 (2007)23.Gouado I., Mawamba A.D., Ouambo R.S.M., Some I.T. and Félicité T.M., Provitamine A Carotenoid of Dried Fermented Cassava Flour: The Effect of Palm Oil Addition during Processing, Int. Jr. of Food Eng., 4(4), 1556-3758 (2008)