Enzymatic vegetable extract with bio-active components:: Influence of fertiliser on the colour and anthocyanins of red grapes

BACKGROUND: The obtention and physicochemical characterization of an enzymatic vegetable extract (EVE) from agroindustrial wastes by a proteolytic extraction is described. The main components of EVE are nitrogen (peptides and free amino acids) and phytohormones (auxins, gibberellins, cytokinins), as functional components. The effect of EVE as fertilizer/biostimulant on several parameters of red grapes, such as colour and anthocyanins, was also evaluated. RESULTS: Its application induced high anthocyanin content with the specific induction of petunidin. Tristimulus colorimetry was applied in order to study the colour of musts. Grape juice with significant and perceptible differences in colour characteristics was obtained using EVE. The colour points were located around redder hues (h(ab)) on the (a*b*)-plane and lightness (L*) was lower. CONCLUSION: The fertilization with biostimulant shows a promising future in the functional plant nutrition linked with an increase in the organoleptic and quality food parameters. (C) 2007 Society of Chemical Industry.