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

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