Ultrasound-Assisted Extraction and Optimization of Zeaxanthin Dipalmitate, Total Carotenoids, Phenolics, and...

Goji berry is a rich source of carotenoids, particularly zeaxanthin dipalmitate (ZDP), a bioactive compound linked to antioxidant and eye-health benefits. This study presents a green ultrasound-assisted extraction (UAE) approach for the efficient extraction and optimization of ZDP, total carotenoids, phenolics, and antioxidant compounds from goji berry. A Box-Behnken design within the response surface methodology (RSM) was employed to optimize three key variables-ultrasound amplitude, extraction time, and solvent-to-solid ratio-under mild conditions (40% ethanol, room temperature). Quadratic models best described the responses for total carotenoids, ZDP, and total phenolic content (TPC), whereas a two-factor interaction (2FI) model provided the best fit for total antioxidant compounds. The optimal UAE conditions (25% amplitude, 2 min, and 3.27:1 g/g ratio) significantly enhanced the extraction efficiency of carotenoids and phenolics, while also improving mineral content (phosphorus, copper, selenium) and color quality, indicating improved nutritional and sensory properties of the extract. These findings highlight the potential of UAE as a sustainable technique for producing carotenoid- and phenolic-rich goji berry extracts that can serve as natural colorants and antioxidant ingredients in functional foods and nutraceutical formulations. PRACTICAL APPLICATIONS: This study demonstrates that UAE can efficiently recover ZDP and phenolic compounds from goji berry within a short time, enhancing both nutritional and color properties. The resulting extracts can be applied in foods, beverages, and nutraceuticals as natural colorants and antioxidant-rich ingredients, offering a sustainable alternative to synthetic additives and supporting the development of functional products with added health benefits.