Effect of extrusion and enzyme modification on functional and structural properties of pea peel (Pisum sativum L.) insoluble dietary fibre and its effect on yogurt rheology

Abstract

SummaryThe enzyme and extrusion modifications of insoluble dietary fibre (IDF) of green pea peel were done to improve the functional and structural properties. The effect of the modified IDF on the yogurt rheology was also examined. The enzyme treatment was done with different concentrations of cellulase and xylanase, while the extrusion modification was done with different cooking temperatures. The typical honeycomb morphology of control IDF got changed after both modifications. Brunauer–Emmett–Teller (BET) surface area ranged from 11.892 to 15.358 m2 g−1 for enzyme‐modified sample. Enzyme‐modified IDF (M2) sample showed higher water retention capacity (3.25 g g−1), swelling capacity (8.89 mL g−1), oil absorption capacity (3.25 g g−1), cation exchange capacity (0.86 mmol g−1) and glucose adsorption capacity (4.73 mM) as compared to the extrusion‐modified samples. The glucose dialysis retardation index (GDRI) was significantly higher for enzyme‐modified samples (P < 0.05). The addition of modified IDF to yogurt changed oscillatory rheological and viscoelastic behaviour, which was linear and enhanced supramolecular interaction during gel formation. The results of the present investigation exhibited a method of customising IDF for food fortification.