Tomato waste: Carotenoids content, antioxidant and cell growth activities

•Waste from tomato juice processing was evaluated as a potential source of carotenoids.•Lycopene and β-carotene were identified and quantified by HPLC.•Tomato waste extracts rich in carotenoids exhibited good antioxidant properties.•Cell growth of tomato waste extracts rich in carotenoids depend on cell lines and dose.•Tomato waste should be regarded as a good source of carotenoids. The carotenoid content, antioxidant and cell growth activities of tomato waste extracts, obtained from five different tomato genotypes, was investigated. High performance liquid chromatography was used to identify and quantify the main carotenoids present in tomato waste extracts. The antioxidant activity of tomato waste extracts was tested using spectrophotometric methods, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and reducing power assay. The highest DPPH scavenging activity (IC50=0.057mg/ml) was obtained for Bačka extract. The Knjaz extract showed the best reducing power (IC50=2.12mg/ml). Cell growth effects were determined in HeLa, MCF7 and MRC-5 cell lines by sulforhodamine B test. Anti-proliferative effects were observed in all cell lines at higher concentrations (⩾0.125mg/ml). The carotenoid contents exhibited a strong correlation with antioxidant and anti-proliferation activity. The results obtained indicated that tomato waste should be regarded as potential nutraceutic resource and may be used as a functional food ingredient.