Study of a process of obtaining of protein preparation from sunflower seeds for application in food industry

Abstract

The article deals with a study of processing methods of obtaining protein preparations from sunflower seeds. For obtaining of food-grade protein preparations from the defatted sunflower kernels phenolic compounds were additionally removed. Modern Russian and foreign literature sources devoted to the isolation of phenolic compounds from vegetable protein raw materials were analyzed. The objective of obtaining a light-colored food-grade protein preparation from sunflower seeds was solved through developing of a multi-stage extraction process with removal of various groups of non-protein compounds, including the stage of aqueous ethanol extraction and removal of phenolic compounds. Parameters of different stages of obtaining of protein substances from defatted sunflower seed kernels after removal of phenolic compounds were studied. These stages included alkaline extraction of protein and nitrogen-free extractives (NFE), separation of the insoluble residue, isoelectric precipitation of protein compounds from the clarified extract, neutralization of the protein suspension. Drying of the protein suspension was carried out on a laboratory spray installation Buchi Mini Spray Dryer with a temperature at the entrance of the dryer 180–190 ℃ and at the exit – up to 90 ℃. Protein preparations of light gray color were obtained with a crude protein content of 75,72% and 87,15% on dry matter basis, which corresponds to the crude protein content of commercial sunflower and soy protein concentrates. Solubility pattern of proteins and functional characteristics of finished protein preparations after spray drying have been analyzed. Based on the high fat-holding capacity and moderate fat-emulsifying properties of the obtained protein preparations it’s possible to recommend the obtained sunflower protein preparation for usage as a vegetable protein enricher and functional additive in food industry.