Response surface methodology for extraction optimization of pigeon pea protein

Optimisation for pigeon pea protein extraction (Y) (Cajanus cajan (L) Mills p from the new IAPAR 43-Arata variety) was investigated using response surf ace methodology. A compound central design was used with variables (X-1) Na Cl concentration (0.000; 0.025; 0.050; 0.075 and 0.100M); (X-2) pH (2.5; 4. 0; 5.5; 7.0 and 8.5) and (X-3) liquid:solid ratio (5:1; 10:1; 15:1; 20:1; a nd 25.1, v/w). A model of the second degree equation was used to create the surface responses and confirmative studies were carried out. The following equation: (Y) over cap = -19.3733 + 8.6004x(2)-0.50852x(2)(2) shows optimu m conditions for protein extraction of about 75% yield, at pH 8.5 without N aCl regardless of the liquid:solid ratio (v/w) under the experimental condi tions studied. (C) 2000 Elsevier Science Ltd. All rights reserved.