Biophysical and Morphometric Characteristics of Sunflower Achenes: Implications for Industrial Processing and Byproduct Utilization

The main focus of industrial sunflower processing is oil production, in which the pericarp is most often treated as a byproduct or biological waste. However, sunflower pericarps have shown significant potential for alternative applications. Bridging the gaps in knowledge of the properties of achenes and their byproducts would improve the efficiency of industrial processes and open new possibilities for utilizing the pericarp as a biological resource. In this work, we analyzed biophysical and morphometric properties of the achenes of eight sunflower genotypes. Their byproducts indicate a complex interrelationship among the analyzed traits. The basic achene color of the tested genotypes was gray, with dark to light shades. Larger achenes had larger seeds and a higher weight, while more spherical achenes had a higher proportion of pericarp. Additionally, achenes with a smaller cavity between the seed and the pericarp had a higher germination percentage. Genotypes with a thinner and softer pericarp had higher oil content, while greater thickness contributed to its reduction. Pericarp hardness was proportional to the number of sclerenchyma layers, not to the percentage of sclerenchyma. These findings suggest that pericarp structure can be a key determinant for both oil yield and byproduct valorization, enabling the selection of genotypes for specific industrial applications.