This study aimed to compare the functional compounds, physicochemical properties of passion fruit juices from Guangdong, Fujian, Yunnan and Guangxi Province of China, and investigate the change of phenolic compounds and bioactivities after in vitro digestion. All passion fruit juices had citric acid as the main organic acid, and neochlorogenic acid was the richest phenolic compounds except YNP. GXY and GDY showed the highest ascorbic acid content (8.76 mg/100 ml), and β‐carotene were found in YNP and GXP. After in vitro digestion, the TPC and TFC of all passion fruit juices were increased, while neochlorogenic acid and cyanidin‐3‐O‐glucoside were decreased. Accordingly, the bioactivity of all passion fruit juices showed different variation. The YNY and GXY showed enhanced antioxidant activity. The YNY showed the highest DPPH scavenging ability of 1354.86 μmol TE/L FJ, and GXY with the highest ORAC value of 14.31 μmol TE/L FJ. All passion fruit juices showed enhanced α‐glucosidase inhibitory effect. And, the GXP showed the strongest inhibitory effect with 83.11% as the existence of vitexin which was 3.7‐fold than that of acarbose. Molecular docking displayed that vitexin bond with active sites of α‐glucosidase resulting in the inhibition on catalytic action. The results showed that the passion fruit juices exhibited more beneficial effect on human health after consumption.
Practical applications
This study compared the physicochemical properties of passion fruit juices, and evaluate the change of bioactivity and bioactive compound in vitro digestion. Passion fruits were often used to produce concentrated juice, beverage, frozen pulp, and preserved fruit in industry. The data about physicochemical properties and bioactive compounds of passion fruit juice could provide guidance for the screen of passion fruits in industry, and it also could make a reference for the improvement of quality standards in passion fruit juice. GXY had high sweetness and low acidity, which also showed high total phenolics and flavonoids content, as well as excellent antioxidant activity after in vitro digestion. GXY could be regarded as raw material to develop new beverages with good tasty and nutrition values. GXP had strong α‐glucosidase inhibitory after in vitro digestion, and it could be used to invent healthy beverages suited for people with high blood sugar.