Effects of Various Cooking Methods on Content, Oxygen Radical Absorbance Capacity, and Bioaccessibility of Caffeoylquinic Acids in Ligularia fischeri (Ledeb.) Turcz, Gom-Chi

Abstract

We hypothesized that cooking methods generally applied to Gom-chi preparation such as blanching, pan frying, and microwaving could change content, oxygen radical absorbance capacity (ORAC), and bioaccessibility of caffeoylquinic acids (CQAs). Mono-, di-, and tri-CQAs were identified and quantified by using an ultra-performance liquid chromatograph-photodiode array detector. In vitro biomimick system was performed for assessing the bioaccessibility of CQAs. The free radical scavenging capacity was measured by ORAC assay, expressed as trolox equivalents (TE). The amount of 5-CQA, 4-CQA, 3-CQA, and 3,4-di-CQA were 136.72, 2144.44, 16.81, and 421.93 μg, respectively, in g of fresh Gom-chi. The highest amount of CQAs and TE was observed in microwaving for 3 min and pan frying for 3 min, respectively. The ranking of total CQAs were found in the order of microwaving 3 min (239.96 μg/g) > microwaving for 2 min (206.11 μg/g) > blanching for 3 min (191.94 μg/g) > blanching for 5 min (180.32 μg/g) > pan for frying 5 min (161.20 μg/g) > pan frying for 3 min (115.83 μg/g). The bioaccessibility of total CQAs were 16.42, 17.64, 14.39, 13.29, and 12.43 (%) in fresh, blanching for 3 min, blanching for 5 min, pan frying for 3 min, and pan frying for 5 min, respectively. Among the cooking methods, blanching for 3 min had the highest amount of CQAs after digestion. Our results suggest that blanching 3 min could be a suggested optimal cooking method for Gom-chi to improve CQAs absorption.