Physical Interactions between Tomato and Dried Carrot Pomace Components in a Novel Ketchup Formulation

Dried carrot pomace (DCP) may be used as a thickening, coloring agent and also a carotenoid-fiber enriched component in food products formulations. The main objective of this study to investigate the effect of DCP from juice industries waste material on the physicochemical, rheological, nutritional properties of ketchup by partial replacement (0.7-3.5%) of tomato paste and the carboxy methyl cellulose. The physicochemical parameters of DCP, including: the moisture, fat, protein, ash, crude fiber, pectin, phenolic compounds content, water holding capacity and color properties were first analyzed. Then, different ketchup samples, based on DCP content variations, were formulated. The physicochemical properties of the formulations as well as the tomato lycopene and DCP β-carotene synergistic effect were studied. Based on the analytical data obtained, the samples with highest viscosity, lowest syneresis and the best color index with (0-2.1%) carrot pomace powder were selected for more detailed investigations to perform carotenoids measurements, color parameters specifications, rheological properties. Finally the formulation with 28% tomato paste, 3% glucose syrup, 0.4% carboxymethyl cellulose and 0.7% DCP was assigned as the best carotenoid-fiber enriched and healthy ketchup product.