Optimized preparation process for naringenin and evaluation of its antioxidant and α‐glucosidase inhibitory activities

Naringenin have attracted growing attention in food and medicine fields due to significant bioactivities. This study utilized response surface methodology to identify the optimal conditions for preparing naringenin via acid hydrolysis; Antioxidant and α-glucosidase inhibitory activities of naringenin were evaluated. A 33 Box–Behnken design, with extraction time, liquid–solid ratio, and acid concentration as independent variables, was employed for optimization. Naringenin was characterized with ultra-performance liquid chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) scavenging activities and α-glucosidase inhibitory activity of naringenin were considered. The conversion rate of naringin reached 97.2 ± 0.28% under optimized conditions (acid concentration: 3.0% (vol/vol); liquid–solid ratio: 50 ml/g; reaction time: 5 hr). Naringenin showed good antioxidant activity against ABTS and DPPH free radicals with half-maximal effective concentration values of 0.566 ± 0.098 and 18.406 ± 0.24 mg/ml. Naringenin showed better α-glucosidase inhibitory activity than naringin and acarbose. Practical applications Exocarpium Citri Grandis is rich in naringin, and naringenin can prepared from naringin by an acid hydrolysis method. However, the research in this field is not very thorough or comprehensive. The optimization of preparation process and antioxidant and α-glucosidase inhibitory activities of naringenin were investigated in this study, providing a theoretical basis for the application of naringin in functional foods, medicines or health products.