Preliminary study on the stability of paprika red pigments

In this study,paprika red pigments were prepared from hot red peppers using the method of microwave-assisted organic solvent extraction.The variation degree and law for stability of paprika red pigments were studied under different treated conditions,which provided theoretical basis for further exploitation and application of paprika red pigments.The results showed that the method of microwave-assisted organic solvent extraction was an effective and practicable one for paprika red pigments extraction,and the spectral properties and main characteristic absorption peak of paprika red pigments were similar to that of standard compound.Paprika red pigments had higher thermal stability under 90 ℃,but its light resistance was not very good.Thus,it should be preserved in shadow or using opaque packaging in order to delay the discoloration of pigments.In addition,pH value had little effect on the stability of paprika red pigments.Ca2+,K+ and Na+ had function of fixing color of pigments,while Fe3+ showed the decreasing appearance significantly.Therefore,it was better to avoid Fe3+ intervention.