Effect of pH on protein extraction from sour cherry kernels and functional properties of resulting protein concentrate

Abstract

The aims of this research were to examine the effect of pH on extraction of proteins from sour cherry (Prunus cerasus L.) kernels, and to investigate the functional properties of the resulting protein concentrate. The optimum pH values for the protein extraction and isoelectric precipitation were determined as 10.0 and 4.5, respectively. The protein concentrate contained 4.03 +/- 0.16% moisture, 3.31 +/- 0.17% ash, 2.94 +/- 0.36% carbohydrate, 1.93 +/- 0.16% lipid, and 80.48 +/- 2.38% protein. Water holding capacity, oil holding capacity and the least gelling concentration of the protein concentrate were 2.42 +/- 0.09g water/g, 1.73 +/- 0.17g oil/g and 8%, respectively. Results showed that emulsifying activity and stability indices, foaming capacity and stability of protein concentrate were 38.91 +/- 2.50m(2)/g, 37.49 +/- 2.41min, 35.00 +/- 3.54% and 71.80 +/- 7.25% (after 30min), respectively. The functional and chemical properties of the protein concentrate indicate that it may find application as functional ingredient for various food products.