Chemical Composition and Functional Properties of Prickly Pear (Opuntia ficus indica) Seeds Flour and Protein Concentrate

Proximate composition and functional properties of prickly pear seed flour (PPS); protein concentrate and the effect of pH on these properties were investigated. The protein content, crude fat and crude fiberof PPS flour and protein concentrate averaged 13.62 and 62.41, 10.43 and 3.57 and 9.23 and 5.31%, respectively. The minimum protein solubility was observed at pH 4.5, as 16. and 15% while maximum protein solubility was observed at pH 11 which as 85 and 92%, repectively. Measurement of emulsion and foaming properties of PPS flour and protein concentrate showed that they are greatly affected by pH levels. The minimum values of both emulsion and foam properties were obtained at pH 4.5 which was the isoelectric point of the protein. The maximum values were obtained at pH 10. PPS flour and its protein concentrate had high water and oil absorption (4.71 and 3.16g water/g flour; 2.43 and 3.26 g oil/g flour, respectively) and protein concentrate tended to have higher values than those of PPS flour.