Impact of starch morphology on the stability and color of paprika red

The impact of starch granules from different sources on the stability and color of paprika red pigments was investigated. The results indicated that pigment color and stability were not affected by starch composition (moisture and amylose content) but were strongly dependent on starch morphology. The color on potato starch was much redder and darker with a ΔE value of 8.41 compared to maize starch, which was attributed to its large diameter (29.94 ± 0.08 μm), leading to low diffuse reflectance and facilitating the formation of J-type aggregates of pigment molecules. In addition, the porous structure of starch was recognized as a critical factor in determining the pigment stability during light irradiation or thermal treatment. The porous maize starch provided good protection for paprika red, showing higher pigment retention (87.23%) during storage (15000 lx, 10 days). The hemispherical modified cassava starch provided moderate protection (84.35%), while the potato starch with smooth surface resulted in a rapid pigment degradation, with only 80.44% remaining under the same storage conditions. FTIR spectra indicated that the paprika red molecules interacted with the starch mainly by hydrogen bonding.