Extrusion of mixtures of starch and d-limonene encapsulated with β-cyclodextrin: Flavour retention and physical properties

d-Limonene was encapsulated with β-cyclodextrin to improve its retention during pre-added flavour starch extrusion. The objective of this work was to determine the effect of processing condition on the flavour retention and extrudate properties. Corn starch containing five levels of β-cyclodextrin-d-limonene capsules (0–5%) were extruded at five different maximum barrel temperatures (133–167 °C) and screw speeds (158–242 rpm) using a twin screw extruder. The effect of these parameters on the flavour retention, expansion, texture, colour difference (ΔE), Water Absorption Index, Water Solubility Index, and residence time distribution (RTD) were investigated. Barrel temperature and capsule level predominantly influenced flavour retention and extrudate properties, while screw speed primarily affected extruder performances such as torque, die pressure, specific mechanical energy and RTD.