Green Approaches to Enhance Bioactive Compounds in Goji Berry (Lycium Barbarum) Fruits: Comparative Optimization of Pressurized Water, Microwave-Assisted, and Ultrasound-Assisted Extraction Technologies by Using Response Surface Methodology

Abstract

Goji berries (Lycium barbarum L.), a superfruit with a long history of usage in Asian medicine, are gaining recognition for their potential as functional foods because of their high levels of antioxidants, flavonoids, anthocyanins, and phenolic acids. With the growing demand from consumers for clean-label and naturally sourced ingredients, environmentally friendly extraction technologies are now crucial to creating bioactive-rich extracts appropriate for food and nutraceutical applications. Three eco-friendly extraction methods-pressurized water extraction (PWE), microwave-assisted extraction (MAE), and ultrasound-assisted extraction (UAE)-are thoroughly evaluated in this study to maximize the bioactive compounds' recovery from Goji berry fruits. Water was the only solvent used in all extraction processes, guaranteeing environmental sustainability and food-grade compliance. The solid/liquid ratio, temperature, duration, pressure, and power were all optimized using response surface methodology (RSM). The total phenolic content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC), and antioxidant activity (DPPH inhibition) of the extracted materials were assessed. Under ideal circumstances, the extracts' rutin contents were ascertained by HPLC analysis. According to the findings, MAE had the highest DPPH inhibition rate (75.942%), whereas PWE had the most TPC (17.753 mg GAE/g extract). The flavonoid content of both techniques was comparable. The UAE produced the best energy-to-bioactivity ratio and the most anthocyanin-rich extracts (3.607 mg C3G/g). UAE is the most ecologically friendly option among the techniques, as evidenced by its highest overall efficiency in terms of bioactive recovery and antioxidant capacity. This is the first study to employ a combined approach of RSM and bioactivity-energy efficiency assessment to optimize and compare water-based PWE, MAE, and UAE methods for Goji berries. These results demonstrate that green extraction technologies can be leveraged to sustainably produce bioactive compounds from functional foods like Goji berries, which have significant applications in food, nutraceuticals, and cosmetics.