Chilling prior to low intensity pulsed electric field processing improved vitamin C stability of carrot purée ( Daucus carota cv. Nantes)

Summary Effects of chilling (5 °C) prior to low intensity pulsed electric fields ( PEF ) (0.1–1.1 kV cm −1 ) on vitamin C and activity of peroxidase ( POD ) and ascorbic acid oxidase ( AAO ) in carrot purée were studied. The effect of PEF on carotenoids extractability was evaluated and compared to that of purée pre‐conditioned at 20 °C (control). PEF enhanced carotenoids extractability for purée with and without pre‐chilling, up to 25% and 66%, respectively. Vitamin C content decreased after PEF but combined pre‐chilling and PEF maintained vitamin C stability and reduced AAO and POD activities. AAO and the heat‐stable POD fraction were found to be more thermolabile (i.e. higher k ref value) after PEF , particularly at 0.6 kV cm −1 , which implies elimination of their enzymatic action towards oxidation of bioactive compounds. It was suggested that chilling prior to low intensity PEF modified enzyme properties and secured the stability of vitamin C and carotenoids.