Effect of Grinding on the Physicochemical and Functional Properties of the Passion Fruit Peel Residue

In the food industry, different particle size of dietary fiber will directly affect the quality of products. To study the physicochemical properties and functional activities of dietary fiber with different particle size could expand its application. Pigments were removed from passion fruit peel by 70% ethanol, and the passion fruit peel residue(PFPR) were prepared. The physicochemical properties and functional activities of PFPR were studied by 6 kinds of powder with particle sizes ranging from 217.00 to 20.23 μm. With the decreasing of powder particle size, the volume density, bulk density and the physical and swelling capacity, water holding capacity, oil holding capacity, water combining capacity, cation exchange capacity and viscosity of different fractions of PFER powder, increased first and then decreased, while the angle of repose increased gradually. The particle size of 145.67 μm powder at the dialysis time of 30 min was the best effect and the glucose dialysis retardation index value was 30.55%. Antioxidant results showed that 20.23 μm powder at the concentration of 80 mg/mL, had the best DPPH·(60.28%) and ABTS⁺·(23.04%) scavenging effects. There was a significant correlation between polyphenol content of PFER and antioxidant capacity. The theoretical reference for the application of PFPR was provided.