Production of milk-based drink enriched by dietary fiber using carrot pomace: Physicochemical and organoleptic properties during storage

Abstract

The utilization of fruit and vegetable wastes in the production of functional dairy beverages is one of the effective ways to enhance fiber intake in a diet. In this study, the production of milk-based drinks containing carrot pomace (CP), as a dietary fiber source, was evaluated. CP was added into low-fat sterilized milk to create 2, 4, and 6 % (w/w) CP-fortified milk drink using high methoxyl pectin (0, 0.05, 0.1, and 0.15 % w/w) as a stabilizer. Our results implied that CP altered the color of milk, making it darker and more red/yellow, increased its apparent viscosity from 11.6 to 16.15 m Pa.s, acidity (from 0.17 to 0.19 %), soluble solids (from 8.25 to 9.90° BX), and promoted sedimentation, while, significantly reduced negative charges from −42.45 to −21.45 mV. It observed that 0.1 % of pectin has the potential to stabilize the carrot pomace-milk drink and reduce the sedimentation of particles, which made the drinks a vehicle for delivering a higher level of dietary fiber and phytochemicals (carotenoids and vitamins). Afterward, the effect of pectin (0 and 0.1 %) on drink stability containing CP (4 %) during 8 days of cold storage was investigated at regular intervals. No significant changes were observed in the physicochemical properties of treatments, concerning the acidity, turbidity, color, physical stability, and ζ-potential over time. The results indicated that a reversible phase separation occurred in the beverage samples, induced by decreased ζ-potential during the period. Also, a slight loss in total carotenoid content of samples from 31.20 to 23.18 mg ß-carotene l −1 was found with the prolonged storage time. Sensory analysis revealed a similar consumer preference in terms of sensory attributes (color, flavor, aroma, and mouthfeel) for both treatments. Therefore, producing a stable functional milk drink containing 4 % CP could be feasible and applicable in food industry.