Detoxification of undecorticated cottonseed meal by various physical and chemical methods Nagalakshmi D.*, Sastry V.R.B., Agrawal D.K. Division of Animal Nutrition, Indian Veterinary Research Institute, Izatnagar-243 122, India *Reprint request: Dr. D. Nagalakshmi, Feed Technology Unit, Dept. of Animal Nutrition, College of Veterinary Science, ANGRAU, Rajendranagar, Hyderabad-500 030, India. Tel: +91-40-4017211; Fax: +91-40-4017002; E-mail: pdpoult@ap.nic.in
Abstract An attempt was made to develop feasible processing methods for detoxification of undecorticated cottonseed meal (CSM) so as to incorporate it safely in rations of livestock and poultry. The processing methods were cooking at 100°C for 30, 45 and 60 min; pressure cooking at 5, 10 and 15 min; calcium hydroxide Ca (OH)2 treatment in concentrations of 0.5, 1.0 and 2.0% (w/w) and iron treatment in ratio of 1 part free gossypol (FG) to 0.2, 0.3 and 0.4 parts iron. The raw CSM contained 2700 ppm FG and 5183 ppm total gossypol. The FG content was lowered (P<0.01) by 30 min. cooking and then with 45 min. cooking, but a further increase in cooking time (60 min) did not reduce the FG content. A linear reduction (P<0.01) of FG was observed as the time of pressure-cooking increased. Treatment with 0.5, 1.0 and 2.0% Ca (OH)2 resulted in reduction (P<0.01) of FG by 21.25, 28.15 and 40.52%, respectively. Treatment with iron in ratio of 1:0.2, 0.3 and 0.4 parts iron reduced (P<0.01) the FG content linearly by 7.8, 20 and 32% and increased the iron concentration of meal by 0.05, 0.81 and 0.108%, respectively. The crude protein content of meal was not affected due to processing. The result of this study suggested that 15min. pressure cooking and 2% Ca (OH)2 treatment of CSM significantly (P<0.01) reduced the FG content to lower (P<0.01) levels in comparison to other processing methods followed by iron treatment in ratio of 1:0.4. Top Key words Cottonseed meal, Gossypol, Cooking, Calcium hydroxide, Iron. Top |