Natural Dyes and Antioxidant Compounds from Safflower (Carthamus tinctorius L.) Florets: The Effects of Genotype and Sowing Time

TL;DR

This study shows how different safflower genotypes and sowing times affect the production of natural dyes and antioxidants, offering insights for sustainable agriculture in the Mediterranean.

Contribution

The study identifies optimal genotypes and sowing times for maximizing safflower's bioactive compound yields.

Findings

The Pieve genotype produced the highest floret yield and heads per plant.

Autumn sowing increased bioactive pigment and antioxidant levels compared to spring sowing.

Montola 2000 had the highest polyphenol concentration and antioxidant activity.

Abstract

Safflower (Carthamus tinctorius L.) is increasingly attracting the attention of Mediterranean farmers due to its broad environmental adaptability and low input requirements. Although still relatively underexplored, this species holds remarkable potential as a source of natural dyes and bioactive phytochemicals with recognized health-promoting and phytotherapeutic properties. In this study, the effects of genotype and sowing time on safflower’s productive and qualitative traits were investigated by testing six genotypes and two sowing times (autumn and spring) in an open-field trial conducted in central Tuscany. The Pieve genotype achieved the highest floret dry yield per head, number of heads per plant, and total floret yield per plant, whereas the Montola 2000 genotype was distinguished by its elevated polyphenol concentration and pronounced antioxidant activity. Autumn sowing resulted in higher yields of bioactive pigments, including carthamin and yellow quinochalcones, alongside greater total phenolic content and antioxidant capacity. Conversely, spring sowing appeared to limit pigment biosynthesis, likely due to environmental stressors such as elevated temperature and excessive light exposure. Overall, these findings highlight the strong influence of genotype and sowing time on the accumulation of health-beneficial compounds in safflower. By optimizing these factors, safflower can be strategically valorized as a multipurpose crop in the Mediterranean region, combining economic and environmental sustainability with the production of natural compounds of high nutraceutical and phytotherapeutic value.

Figures