Comparative Study of Pigment Content, Nutrient Composition and Antioxidant Capacity of Different Color Peppers at Different Maturity Stages

Pepper (Capsicum annuum L.), an annual herbaceous plant in the Solanaceae family, possesses significant edible and medicinal value. Studies have shown that there are significant differences in the plant chemical constituents and antioxidant activity among different colored peppers, but there have been fewer studies on the relationship between pigment content, plant chemical constituents and antioxidant activity in peppers. Therefore, this study divided twenty pepper accessions of pepper materials into four categories based on color changes and measured the bioactive compounds, pigment content and antioxidant activity of these four types of peppers at different maturity stages and conducted correlation analysis and principal component analysis (PCA). The results showed that yellow pepper cultivars had higher levels of vitamin C (Vc), and Class IV (purple-to-red transitioning pepper cultivars) had higher total phenolic content (TPC), total flavonoid content (TFC), and anthocyanin content in the early fruit stage. Correlation analysis showed that Class IV (purple-to-red transitioning pepper cultivars) had higher levels of bioactive compounds and antioxidant capacity. The antioxidant content in immature fruits was high, but decreased as the fruits matured. This study focuses on pepper-derived bioactive compounds and their antioxidant activity, providing a scientific basis for developing natural antioxidant products, expanding pepper resource utilization, and guiding pepper variety selection and cultivation management.