Extra virgin olive oil is frequently used in the preparation of vegetable canning and sauces. Several vegetables contain phenol oxidative enzymes, responsible of enzymatic browning. The activity of laccase from Trametes versicolor and that of a raw protein artichoke extract on the polyphenols of two extra virgin olive oils were investigated. In presence of laccase, already after an incubation of 1 hour at 60°C, total phenols and o-diphenols respectively decreased by 74 and 89% in respect to those of the fresh oil; loss of polyphenol caused a 62% reduction of oil rancimat induction time at 130°C. The raw protein artichoke extract produced similar effects. Finally, an oil/artichoke paste (1:1, w/w), similar to a paté, was prepared; already after 30 minutes from the paste preparation, o-diphenols of the oil were lost fully and the oxidative stability decreased by the 54,2 and 31,8% in respect to the fresh oil and the same oil chemically dephenolized, respectively.
Degradazione enzimatica dei polifenoli e stabilità ossidativa dell’olio extra vergine di oliva
DE LEONARDIS, Antonella
Primo
;MACCIOLA, VincenzoUltimo
2013-01-01
Abstract
Extra virgin olive oil is frequently used in the preparation of vegetable canning and sauces. Several vegetables contain phenol oxidative enzymes, responsible of enzymatic browning. The activity of laccase from Trametes versicolor and that of a raw protein artichoke extract on the polyphenols of two extra virgin olive oils were investigated. In presence of laccase, already after an incubation of 1 hour at 60°C, total phenols and o-diphenols respectively decreased by 74 and 89% in respect to those of the fresh oil; loss of polyphenol caused a 62% reduction of oil rancimat induction time at 130°C. The raw protein artichoke extract produced similar effects. Finally, an oil/artichoke paste (1:1, w/w), similar to a paté, was prepared; already after 30 minutes from the paste preparation, o-diphenols of the oil were lost fully and the oxidative stability decreased by the 54,2 and 31,8% in respect to the fresh oil and the same oil chemically dephenolized, respectively.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
