Improvement of antioxidant content and color stability in spice paprika powder by rosemary extract supplementation

This study investigated the impact of rosemary extract on the endogenous antioxidants and color characteristics of spice paprika powders with regard to origin and processing method. The shorter over ripening period and industrial drying was advantageous for the retention of phytochemicals, in contrast with sun drying. Rosemary extract supplementation up to 0.25% reduced the color loss from 23%–36% to 14%–27% after a 12‐month storage period. The surface color (L*, hab∘, Cab∗) of milled paprika was strongly influenced by the origin and the processing method applied to dehydrate paprika pods. The color difference parameters showed that the perceptibility of color change did not occur during more than 9 months with 0.25% rosemary extract. The extract competed actively with α‐tocopherol in the anti‐oxidation process in the presence of oil from paprika seeds. The low level of ascorbic acid gave the chance for the antioxidants from rosemary to dominate and prevent the whole system. Practical application Spice paprika powder is a color‐improving ingredient in several dehydrated foods, in which improved color retention is a reasonable expressed or latent demand. The study demonstrated that the shorter over ripening period and industrial drying is advantageous for the retention of phytochemicals. The antioxidant supplementation improves the color retention of paprika powder products and compensates the adverse effects of post‐harvest factors. Therefore, the loss of quality and commercial value can be moderated. The rosemary extract contributes to the reduction of color loss more effectively in the presence of paprika seeds as a source of higher oil content. Besides the extractable color stabilization, the perceptibility of color change can be avoided for several months. This is an important result from the point of view of consumer opinion, as generally the visual color of spice paprika products is associated with the quality and coloring power.