Characterization of β-carotene Extracted from Orange Peels and its Use as a Natural Colorant and Antioxidant in Ice Cream

Abstract

The orange manufacturing sector produces great quantities of waste, mostly orange peels that generate environmental issues. These residues are rich sources of pigments and bioactive chemicals. β-carotene is one of the carotenoids, an antioxidant fat-soluble pigment. This study was performed to extract β-carotene from orange peels and investigate its stability to some treatments, including temperature, storage, light, pH and its antioxidant characteristics. Carotenoids were determined and identified using high performance liquid chromatography. The total content of phenolic compounds and flavonoids in the dried orange peels were found to be 16.12 and 2.06 mg / g, and β-carotene 14.51 mg/100 g, respectively. Additionally, antioxidant activity of orange peels powder was found to be 88.65% based on DPPH assay. As storage duration and the exposure to high temperature and light increased, beta-carotene degradation increased, while it was more stable in the alkaline medium. The antioxidant activity of β-carotene extract was found to be comparable to that of industrial BHT based on oil oxidation stability assay. In the sensory evaluation, panelists preferred ice cream incorporated with 1% β-carotene extract. During storage of ice cream for 21 days at -18˚C, the β-carotene content decreased by about 5%.