LAUSR

Abstract Lemon (Citrus limon) flavedo, an outer green layer of lemon peel, is used in the bakery for its good smell and attractive color. However, most of the research has been focused lemon peel bioactivities. Currently, there are no data exist on flavedo individual bioactive compounds. Therefore, we compared three extraction processes (ultrasound-assisted extraction (UAE; 20 min), high-pressure processing (HPP; 400 MPa/10 min), and enzymatic hydrolysis (EH)) on two dried samples (oven-dried (OD); essential oil residues (EOR)) to understand the effect of flavedo extracts on the inhibition of carbohydrate hydrolyzing enzymes and their bioactive compounds. EH-treated samples exhibited higher carbohydrate hydrolyzing enzymes inhibition compared to UAE and HPP-treated samples (α-amylase inhibition of 25.83-93.77 % for UAE and EH-treated OD samples, respectively). The phenolics in OD-EH was higher than EOR samples (3688 mg GAE/100 g and 2306 mg GAE/100 g) and SOD-like activity (3505 U/g and 2815 U/g). Moreover, sinapic acid (47.33 % and 59.59 %) and esculetin (16.85 % and 18.31 %) were the major compounds of the total phenolics in OD and EOR samples that may regulate obesity and blood sugar, respectively. Therefore, lemon flavedo might be considered as a potential source in the development of functional foods.