Safflower petal composition: Impact of sowing time and plant density on proximate, antioxidant, and colorant properties

Valeria Cafaro¹Cristina Patanè^1*Vivienne Panebianco²Silvio Calcagno²Paolo Caruso²GIORGIO TESTA²

• ¹National Research Council, Institute for the BioEconomy, Catania, Italy
• ²Universita degli Studi di Catania Dipartimento di Agricoltura Alimentazione e Ambiente, Catania, Italy

Safflower (Carthamus tinctorius L.) has recently attracted renewed interest as a natural source of antioxidant compounds and pigments from petals. In a split-plot experimental design, the effects of three winter sowings (December, January, February), and two plant densities (D1, 25 plants m-2; D2, 50 plants m-2) on petals production and composition in nutrients and antioxidants, including colorants, were examined in safflower (cv. Catima) in a semi-arid Mediterranean environment. Petals were harvested twice, at the flowering of the main shoots (early harvest) and a week later, at the flowering of lateral shoots (late harvest). Petals production was reduced as sowing was shifted from December to February. The increase in plant density did not affect petals produced per single plant but resulted in greater productions per unit area. Crude protein was the highest (up to 17.2%) and oil content was the lowest (down to 3.72%) with sowing in January. Carthamidin (yellow pigment) was higher at the 1st harvest (up to 8.39%) probably because its content is maximized at the start of flowering and decreases thereafter, as carthamin (red pigment) is synthesized. Both pigments tended to decrease with the shift of sowing time and were lower in D1. The nutritional value was positively associated with that nutraceutical. Greater content in phenols, flavonoids, and carthamidin, with minor changes in proximate composition of petals, can be achieved with sowings in late fall-early winter. Harvest at late flowering (~ 90% flowers open on lateral shoots) resulted in greater yields and carthamin content but lower petal quality, suggesting that the choice of harvest time of petals strictly depends on the specific trait desired.