Metabolite profiling of phenolic and carotenoid contents in tomatoes after moderate-intensity pulsed electric field treatments

Abstract

A metabolite profiling approach was used to study the effect of moderate-intensity pulsed electric field (MIPEF) treatments on the individual polyphenol and carotenoid contents of tomato fruit after refrigeration at 4 °C for 24 h. The MIPEF processing variables studied were electric field strength (from 0.4 to 2.0 kV/cm) and number of pulses (from 5 to 30). Twenty four hours after MIPEF treatments, an increase was observed in hydroxycinnamic acids and flavanones, whereas flavonols, coumaric and ferulic acid-O-glucoside were not affected. Major changes were also observed for carotenoids, except for the 5-cis-lycopene isomer, which remain unchanged after 24 h of MIPEF treatments. MIPEF treatments, conducted at 1.2 kV/cm and 30 pulses, led to the greatest increases in chlorogenic (152%), caffeic acid-O-glucoside (170%) and caffeic (140%) acids. On the other hand, treatments at 1.2 kV/cm and 5 pulses led to maximum increases of α-carotene, 9- and 13-cis-lycopene, which increased by 93%, 94% and 140%, respectively. Therefore, MIPEF could stimulate synthesis of secondary metabolites and contribute to production of tomatoes with high individual polyphenol and carotenoid contents.

The authors express their gratitude to CICYT’s (AGL2010-22319-C03), RETICS RD06/0045/0003 from the Spanish Ministry of Science and Innovation (MICINN) for financial support. The CIBERobn CB06/03 is an initiative from the Instituto de Salud Carlos III, Spain. The authors also acknowledge the financial support of the Spanish Institute of Agricultural and Food Research and Technology (INIA) through the project RTA2010-00079-C02-02. ICREA Academia Award is also acknowledged by O. M.-B. A.V.-Q. received support from MEC for the training of researchers.