MICROENCAPSULATED LYCOPENE FOR PRE‐EXTRUSION COLORING OF FOODS

ABSTRACT The effect of extrusion conditions on the retention of lycopene during extrusion of rice flour, chosen as a model, was evaluated as a function of moisture content, screw speed and die temperature by response surface methodology using central composite rotatable design (CCRD). Experiments were carried out by extrusion of rice flour containing 1% lycopene microcapsules and free lycopene equivalent to that present in the microcapsules, using a single‐screw extruder at a constant feed rate of 55 g/min. At all conditions of extrusion, the microencapsulated lycopene gave better retention of color in the extrudates than the free lycopene. The quadratic model developed by CCRD showed a good agreement between the experimental and predicted values of color. The storage stability of microencapsulated lycopene increased twofold as compared to free lycopene over a period of 96 h. PRACTICAL APPLICATIONS This work evaluates the potential of free lycopene in comparison with microencapsulated lycopene in a 1:3 blend of gum Arabic and a modified starch (n‐octenyl succinic anhydride or n‐OSA), as pre‐extrusion coloring of rice flour extrudate.