Effects of Various Physical Field–Assisted Techniques and Combination Methods on Extraction of Flavonoids and Polyphenols From <i>Angelica keiskei</i>

ABSTRACT Angelica keiskei has been well documented as a promising resource rich in bioactive chemicals, especially flavonoids. Field‐assisted extraction and their hybrids have been proved to be advanced approaches for the efficient utilization of flavonoids compared to conventional extraction methods. The current study aims to optimize the extraction conditions of the flavonoids from A. keiskei through high‐pressure processing, ultrasound‐assisted extraction, and microwave‐assisted extraction. Furthermore, taking total flavonoid content, total phenolic content, and antioxidant activity as indexes, three combination methods, high‐pressure processing combined with ultrasound‐assisted extraction, high‐pressure processing combined with microwave‐assisted extraction, and ultrasound‐assisted extraction combined with microwave‐assisted extraction, were further investigated and compared to enhance the extraction efficiency. The results indicate that the A. keiskei extracts obtained by ultrasound‐assisted extraction combined with microwave‐assisted extraction have the optimal total flavonoid content (41.671 mg/g) and total phenolic content (12.071 mg/g), as well as the strongest antioxidant activity. Scanning electron microscopy analyses reflect that the ultrasound‐assisted extraction combined with microwave‐assisted extraction treatment imposed the most pronounced damage to A. keiskei , in which the particles were changed into the smaller size. In vitro experiments for A. keiskei extracts demonstrate that it can effectively inhibit α‐amylase and tyrosinase, suggesting its potential hypoglycemic and whitening activity. This study demonstrates that A. keiskei extracts may serve as a possible source of antioxidants, whereas ultrasound‐assisted extraction combined with microwave‐assisted extraction might represent an innovative and advantageous method for flavonoid extraction from A. keiskei .