A normalization strategy of cyanidin-3-diglucoside-5-glucoside recovery from red cabbage byproduct

The chemical synthesis and microbial production of anthocyanin monomers are often hindered by various challenges and limitations, making plant-based extraction a preferred approach. However, the complex composition of anthocyanins in plants complicates the isolation of specific monomers. In this study, we present an innovative enzyme-catalyzed strategy to produce high-purity anthocyanin monomer using agri-food waste as a sustainable resource. Initially, anthocyanins-rich water extracts were prepared, with acylated anthocyanins accounting for 80% of the total content. By employing the recombinant carboxylesterase estbH, four acylated anthocyanins were selectively converted into cyanidin-3-diglucoside-5-glucoside (Cy3diG5G). Consequently, the proportion of Cy3diG5G increased to 79.0%, yielding 137.68 mg per 100 g of fresh weight, which was 2.6 times than its native content in raw red cabbage byproducts. The efficient enrichment of Cy3diG5G was successfully achieved through the utilization of red cabbage byproducts. This method simplifies production and enhances both the yield and purity of target anthocyanins, offering an eco-friendly solution by integrating enzymatic technology with agricultural waste. This study underscores a normalization strategy for monomers production, particularly for compounds with a "core" structure.