Process optimization for extraction of protein from defatted safflower oil cake

Safflower (Carthamus tinctorius L.) is one of the oldest cultivated oilseed crops. Safflower meal is a source of high quality protein. Isolating safflower protein is one method of introducing this protein source into the human diet. Safflower meal protein was extracted with distilled water and the slurry was adjusted to pH 8, 9 or 10 with l.0 N NaOH. To study the effect of extraction process variables on protein isolate yield (% weight) and protein content, five levels of pH (7-11), extraction temperature (10-50 °C), extraction time (10-50 mins) and ratio of safflower meal to solvent (7-11w/v) using Design expert software were selected and evaluated. The moisture content and fat content of defatted safflower meal was 5.3 % fat content and moisture 12.74 % respectively. Extracted protein was precipitated at pH 5 with l.0 NHCl, and collected by centrifugation at 2000 rpm for 20 mins. Protein isolate yield and its protein content were estimated. In conclusion, response surface methodology technique was found to be very useful in determining the optimization conditions for extraction of protein isolate. The optimum extraction was achieved by extracting the meal at pH -9, temperature 30 °C, time 32mins and meal to solvent ratio 1: 9 w/v.