The format of β-carotene delivery affects its stability during extrusion

This study examined the retention of β-carotene in extruded corn-based formulations, as influenced by the delivery format of β-carotene and the die temperature (140, 160 or 170 °C) during twin-screw extrusion. The β-carotene was delivered via the liquid feed as (i) an oil-in-water emulsion stabilized by a heated protein-carbohydrate matrix; (ii) an oil-in-water emulsion stabilized by Tween 80 or (iii) solubilized in oil. Up to 90% of β-carotene was retained during extrusion when β-carotene was delivered as an oil-in-water emulsion stabilized by a heated protein-carbohydrate matrix regardless of the die temperature. When β-carotene was delivered as an oil-in-water emulsion stabilized by Tween 80 or solubilized in oil, the β-carotene retention was 70-85% and 65-80%, respectively, with lower β-carotene retention being obtained as the die temperature was increased. This study has shown that the stabilization of β-carotene within a heated protein-carbohydrate matrix enhanced the retention and stability of β-carotene in the extruded product. A heated protein-carbohydrate matrix may have the potential to protect and enable improved delivery of other oil soluble bioactives into extruded food products.