Effect of high-oleic sunflower seed on the carotenoid stability of ground pepper

Mixtures of dehydrated pepper fruit (Capsicum annuum L.) with pepper seed (PS) and with high-oleic sunflower seed (SFS) in proportions of 0, 20, 30, and 40% (w/w) were subjected to heat degradation to compare the effect of a polyunsaturated medium (PS mixtures) and a monounsaturated medium (SFS mixtures) on the carotenoid fraction. The kinetic study carried out indicates that the carotenoid degradation, in both types of mixture and for all the proportions, fits a first-order mathematical model. The values of the kinetic constant k in each case and for the stage of commercial usefulness of the paprika, which ends when 50% of its initial coloring power has been lost, indicate that the presence of a higher percentage of seed, either pepper or high-oleic sunflower, in the mixture means a greater stability of the carotenoid fraction. However the presence of a lipid medium less sensitive to oxidation (SFS mixtures) strengthens this effect, prolonging the stage of practical usefulness of the product, so manufacture of paprika by grinding dehydrated pepper fruit with high-oleic SFS will provide a product with a longer shelf life. Also the improvement of the natural lipid substrate of the pepper fruit, to delay carotenoid degradation in the end product, is a possible line of investigation.