Functional Component Variation and Antioxidant Potential of Safflower Seeds as a Food Resource

Safflower (Carthamus tinctorius L.) is an important oilseed crop used traditionally for edible oil production and is increasingly recognized as a functional food resource because of its bioactive compounds.In this study, the phenotypic diversity in fatty acid composition, functional components, and antioxidant activity was comprehensively evaluated across a diverse safflower germplasm.The fatty acid profiles were dominated by unsaturated fatty acids, particularly oleic and linoleic acids, with moderate variations observed across accessions.Antioxidant-related traits, including total polyphenol content, ABTS and DPPH radical scavenging activities, and serotonin-related compounds N-(p-coumaroyl) serotonin and N-feruloyl serotonin, exhibited wide and continuous variation, highlighting substantial diversity in the functional properties.Correlation analysis revealed strong positive relationships between total polyphenol content and antioxidant activities, whereas the fatty acid composition showed relatively weak associations with antioxidant traits.Principal component analysis suggested that the antioxidant and functional components were the major contributors to the overall phenotypic variations, followed by specific fatty acid traits.Nonlinear dimensionality reduction using Uniform Manifold Approximation and Projection and a Self-Organizing Map analysis showed that the phenotypic diversity was structured along continuous gradients rather than discrete clusters, with antioxidant-related traits displaying coordinated patterns.Eta-squared analysis showed that seed coat color partially explained the variation in antioxidant activity and functional components but had limited explanatory power for fatty acid composition.These results suggest that antioxidant and phenolic compounds are the primary determinants of functional variation in safflower seeds, while external morphological traits serve as supplementary indicators.This study provides a quantitative basis for selecting safflower germplasm with enhanced functional food potential.