Characterization of tomato processing by-product for use as a potential functional food ingredient: nutritional composition, antioxidant activity and bioactive compounds

Abstract

Tomato pomace, a by-product generated during tomato processing, was collected at a large tomato processing industry. The by-product was mainly constituted of tomato skin (61.5%), and presented high moisture content (66.58 g.100g⁻¹ wet basis). Among the nutrients, the highest content was of dietary fibre, followed by proteins and fat (50.74, 20.91, 14.14 g.100g⁻¹ d.w., respectively). The pomace has high in vitro antioxidation capacity, especially when measured with the TEAC assay (224.81 μmol Trolox equivalent 100g⁻¹ d.w.). This is due especially to the high amount of lycopene remaining in the by-product after processing (446.9 μg.g⁻¹ d.w). The waste was fractioned into skin and seed fractions by sedimentation, resulting in the increase of lycopene yield by 55%, when using skin fraction as the source material in place of the whole pomace. This by-product shows great potential for being used as a source of the ingredients of high nutritional value, especially dietary fibre and lycopene.

Keywords:

• Solanum lycopersium
• pomace
• dietary fibre
• lycopene
• sedimentation

Acknowledgments

The authors would like to thank the processing company, for providing the materials used in the study, and Professor Flávio Alves da Silva for his remarks on methodology and the interpretation of the results obtained.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES/Brazil), the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq/Brazil), and the Fundação de Amparo à Pesquisa do Estado de Goiás (FAPEG/Brazil).