Sunflower seeds as a promising raw material resource for the processing industry

Abstract

Goal. To form the concept of integrated processing of sunflower seeds and demonstrate its prospects; to show the potential of sunflower seeds as a source of valuable substances; to carry out search and analysis of data for obtaining reliable quantitative characteristics of contents of such classes of substances as unstructured carbohydrates, phenolic compounds, phospholipids, and wax esters, taking into account morphology of seeds, and also information about basic characteristics of botanical material which were studied before. Methods. At the theoretical level, methods such as generalization, comparison, and analysis were used: system, bibliometric, and content analysis. For auxiliary operations with data, calculation methods were used: dimension analysis, and material balance method. Results. Water-alcohol soluble carbohydrates in the kernel of sunflower seeds can reach 12% (of the defatted dry matter), and the use of alkaline solvents increases their yield. The content of phenolic compounds in defatted nuclei varies mainly in the range of 1.5–4.2%. The amount of phenolic compounds that can be classified into subclasses after separation by modern chromatographic methods is more than 30, and chlorogenic acid remains dominant (70–85% of the total content of phenolic compounds). Phospholipids during seed maturation show a stable content of about 1%, and phosphatidylcholines make up 34–39% of the phospholipid fraction. The content of waxes in the husk reaches 0.10–0.15%, and in the oil from the husk — 1.5–4.0% and their composition and waxes of the seed nucleus differ significantly. Conclusions. The vision of the innovative technological process of processing sunflower seeds as a complex task to obtain the maximum number of valuable products in accordance with the composition of its main morphological parts: shell and core is presented. The content and detailed composition of carbohydrates, phenolic compounds, phospholipids, and waxes are summarized and updated. The dependence of the output of non-structural carbohydrates on the choice of solvent is established and it is revealed that their composition requires further clarification. The study significantly expanded information on isolated and identified phenolic compounds. The composition of the phospholipid fraction is analyzed, where phosphati­dylcholines remain the main component, and the correspondence between the composition of commercial lecithins and the composition of seed phospholipids is investigated. Information on the content and distribution of fractions of waxes from husks and kernels, which is important for their further use, is summarized. The obtained results allow for improving the technology of sunflower seed processing with the maximum extraction of valuable components.