Rheological, Storage Stability and Sensory Profiling of Low-Fat Yoghurt Fortified with Red Capsicum Carotenoids and Inulin

Abstract

Inulin and color imparting carotenoid pigments are candidate functional ingredients for development of a low-fat functional yoghurt. The study evaluates the potential of carotenoid-rich extract from red-capsicum (5%) and different levels of inulin (4, 6 and 8%) on functional and structural properties of low-fat set-yoghurt. Changes in pH, syneresis, sensory and rheological parameters were monitored for 14 days at 6 ± 2C. The variations in sensory acceptability and syneresis were related to rheological properties. Hysteresis area in the flow curve (shear stress–shear rate) increased until 10th day of storage. Inulin fortification significantly reduced syneresis by 59% over control. The time sweep and frequency sweep experiments confirmed stability of protein networks in yoghurt fortified with inulin at high levels. Consistency index of yoghurts was higher for inulin-fortified yoghurts and kept increasing up to 10 days. Results suggest promising applications of natural carotenoids in conjunction with inulin for improving quality of low-fat yoghurt. Practical Applications Development of low-fat functional yoghurt enriched with carotenoids from red capsicum. Addition of carotenoid extract had structural destabilizing effect. The effect was mitigated by addition of inulin. Functional yoghurt showed improved sensory profile and storage stability.