Transformation of Gardenia Yellow Waste Production into Gardenia Blue Pigment by Leifsonia sp. ZF2019 and Evaluation of Its Physicochemical Stability

Abstract

To produce gardenia blue pigment (GBP) by natural fermentation, a novel bacteria, Leifsonia sp. ZF2019, was isolated from the larvae of a pest of Gardenia jasminoides Ellis fruits and shown to be able to convert gardenia yellow waste production (GYWP) into GBP. The fermentation medium and growth conditions were screened, and the GBP yield, color value, and stability were compared to those of Aspergillus niger fermentation. Leifsonia sp. ZF2019 was shown to effectively produce GBP in medium containing GYWP and leucine (Leu). A temperature of 35 °C, 0.8% leu content, a fermentation period of 72 h, and a pH value of 7.0 were shown to be optimal culture conditions. GBP produced by Leifsonia sp. ZF2019 was of higher yield and quality than that produced by Aspergillus niger fermentation. GBP was purified by D4020 macroporous adsorbent resin, and the effects of pH, temperature, light, oxidant and reductant, conventional food additives, and metal ions on its stability were evaluated. GBP produced by Leifsonia sp. ZF2019 fermentation was as stable as GBP generated directly by pure genipin. LC-MS revealed that the molecular formula of GBP was C37H45N2O8. Our results provide a reference for the preparation of efficient, stable, reliable, and high-quality gardenia blue pigments.