Development of optimal method of obtaining pea isolated proteins for use in breeding for quality

The article provides the results of the experiments on determination of optimal parameters for obtaining isolated proteins from grains of cultivated and wild pea for use in breeding for quality. The flour of pea varieties Sophia, Rodnik and wild accession k-3370 (Pisum sativum L. ssp. Elatius) were used in the experiment. Isolated pea proteins were obtained based on alkaline extraction and isoelectric precipitation. The experiments were carried out with the use of complete and fractional factorial plans with two levels of factors. Extraction and precipitation of protein were conducted in two stages. One hundred grams of flour were used for extraction. Influence of factors (variety, pH, duration of extraction) on the yield of isolated protein, extraction efficiency, crude protein and fat content in protein isolates was studied. All isolates were characterized by high content of crude protein (90.2-93.1 %). It was determined that increase of pH higher than eight led to enhancement of protein yield and decrease of crude protein content. The results obtained raise the possibility of effective extraction at decreased level of pH that prevents the formation of toxic chemicals. Increase of pH promoted fat accumulation in protein isolate especially at the second stage of extraction. Thus, obtaining protein isolates for evaluation of pea genetic resources should be conducted during a single cycle of extraction and precipitation. The experiments have not revealed significant differences between cultivated and wild pea as to the technology of extraction. The results of the studies are important for evaluation of pea genetic resources according to functional properties of protein isolates.