Black Pea Protein Extraction and Investigation of Physicochemical Characteristics

An extraction process was used to obtain a protein isolate from black peas through alkaline solubilization, followed by acid precipitation at the isoelectric point. Zeta potential measurement showed that the isoelectric point of the black pea protein isolate (BPPI) was within the range of 4.3–4.5 mV. The protein content of the obtained isolate was determined to be 88.59%. Further analysis of the extracted protein was conducted to evaluate its physicochemical characteristics, selected functional properties, and amino acid composition, aiming to explore its potential applications in food systems. The obtained isolate exhibited a well-balanced combination of essential amino acids in accordance with the Food and Agriculture Organization (FAO) pattern. The primary elements of BPPI were determined as the 7S and 11S globulins. Differential scanning calorimetry (DSC) measurement showed a slightly lower T_d value (61.5°C) for the obtained isolate. Circular dichroism (CD) spectroscopy results revealed that the unordered structures (Unordered coil+Turn) were the main secondary structure of BPPI. The chosen functional properties related to emulsification and foaming were also evaluated.