Phenolic profiles and antioxidant activity of Crataegus pinnatifida fruit infusion and decoction and influence of in vitro gastrointestinal digestion on their digestive recovery

Abstract

In this work, phenolics and antioxidant activity (AOA) of Chinese organic hawthorn berry (Crataegus pinnatifida) infusion (OHBI, brewed at 100 °C for 5/10/15 min) and decoction (OHBD, kept boiling for 5/10/15/30 min) were investigated and their digestive fate was further assessed by in vitro gastrointestinal model (VGIM). Nine phenolic acids, six flavonoids and two procyanidins were detected by HPLC-ESI-MS/MS with the most abundant being procyanidins (1275 ± 9–1531 ± 2 μg/g). Hawthorn berry was a great food matrix for phenolics extraction by infusion (52.7–58.8%)/decoction (62.8–64.3%), and OHBD10 presented the highest amount of phenolics (4148 ± 20 μg/g). OHBD kept boiling for 5–15 min exhibited higher AOA than OHBD30 as longer boiling resulted in a greater loss of phenolics. Digestive stability of phenolics varied depending on their structure (phenolic acids > others), digestive phase (small intestinal > gastric) and existing form (bound > free). Overall, 28.2% of phenolics became available for absorption after VGIM, and chlorogenic acid, epicatechin and procyanidin B2 were still the predominant antioxidant contributors. Catechin displayed the highest digestive recovery (244.7%) whereas only 24.4–27.9% were found in the mentioned predominant contributors. Although phenolics decreased after VGIM, relevant AOA (66.5 ± 1.9–132 ± 4 μmol Trolox/g) was observed. OHBI and OHBD could be regarded as bio-accessible sources of antioxidant phenolics for the dietary supplement as well as potential applications in food/pharmaceutical/nutraceutical industries.