Variation in HSYA and Carthamin Contents Across Developmental Stages of Flowers and Different Petal Colours in Safflower (Carthamus Tinctorius L.): Relationship With CIELAB Colour Space Parameters

Abstract

This study investigates the variation in hydroxysafflor yellow A (HSYA) and carthamin contents in safflower (Carthamus tinctorius L.) petals across different developmental stages and petal colours (white (W), yellow (Y), orange-red (O-R), and yellow-orange-red (Y-O-R)). Safflower is a multipurpose crop valued for its natural pigments, which are used in food colouring, fabric dyes, cosmetics and medicine. The research aims to determine the optimal harvest time for maximizing pigment yield and to explore the relationship between pigment content and flower colour parameters. The findings reveal that HSYA and carthamin contents vary significantly depending on petal colour and developmental stage. O-R petals exhibited the highest levels of both pigments, particularly during the initial flowering stage (IFS), while white petals had the lowest pigment content. Yellow petals showed an increase in HSYA content during later stages, but carthamin levels decreased. Although the PCA results indicate that the 'c' (chroma) parameter is strongly associated with the pigments, correlation analysis did not reveal a statistically significant relationship between the 'c' value and HSYA or carthamin. This suggests that, while chroma may contribute to overall colour variation in the multivariate context, its direct association with these specific pigments is not statistically supported. The results suggest that harvesting safflowers at the IFS stage, especially in genotypes with O-R petals, is optimal for maximizing pigment yield. These findings provide valuable insights for the agricultural and industrial applications of safflower pigments.