Application of pulsed electric fields to tomato fruits for enhancing the bioaccessibility of carotenoids in derived products

Abstract

The application of pulsed electric fields (PEF) to whole tomatoes is proposed as a pre-processing treatment to obtain purees with high health-related properties. Tomato fruits were subjected to different electric field strengths (0.4, 1.2 and 2 kV cm-1) and number of pulses (5, 18 and 30 pulses). Tomatoes were stored at 4ºC for 24 h after PEF processing and then ground and mixed with 5% of olive oil. The resulting tomato-based product was subjected to an in vitro gastrointestinal digestion. PEF treatments significantly increased the amount and bioaccessible fraction of carotenoids in the derived product. Treatments conducted at 2 kV cm-1 and 30 pulses led to the greatest increase in the concentration of any of the carotenoids studied in the tomato-based products. The amount of carotenoids incorporated into the micellar phase was increased in those products made from PEF-treated tomatoes, especially after the application of 5 pulses at 2 kV cm-1. At such treatment conditions, the bioaccessibility of lycopene, δ-carotene, β-carotene, γ-carotene and lutein was increased by 132%, 2%, 53%, 527% and 125%, respectively. Therefore, the application of PEF as a pre-treatment could be considered as a promising technology to obtain tomato derivatives with high antioxidant potential.

This research was financed by the Ministerio de Economía y Competitividad (Spain) reference AGL2013-44851-R. S. G.-C. thanks the Agència de Gestió d ′ Ajuts Universitaris i de Recerca (AGAUR) for the predoctoral grant.