EXTRATOS VEGETAIS NA QUALIDADE PÓS-COLHEITA DE UVAS CULTIVARES BORDÔ E NIAGARA BRANCA

Abstract

The grape is susceptible to post harvest losses due to physiological changes and fungal infections, causing quantitative and qualitative losses. Studies indicate potential derived from plants to maintain quality. The objective was to evaluate the efficacy of different plant extracts in the postharvest quality maintenance in organic grape cultivars Bordeaux and Niagara Branca (Vitis labrusca). For the preparation of the extracts were used the dried leaves of gervão (Stachytarphetta cayenensis) and Lemongrass (Cymbopogon citratus); fresh leaves of pau d‟alho (Gallesia integrifolia) and wine residue (powder), each of the extracts were applied at a concentration of 12% directly to the clusters 10 days before harvest, in two municipalities of the state of Paraná. A portion of curls received beyond the field application a new application in postharvest and another was aimed at preparing pulp. Were evaluated color, pH, titratable acidity, decay incidence, anthocyanins, phenolic compounds and sensory analysis. Grapes cv. Niagara Branca it was observed that all the extracts applied preharvest were effective to reduce the incidence of decay, preharvest and postharvest vinification residue extract was effective to maintain the titratable and solid acidity higher soluble compared the application only in the pre-harvest; all extracts influenced the color, the treated clusters showed a closer color to yellowish-green. The best sensory acceptance was given to berries treated with gervão extract and all extracts maintained other attributes within recommended range to cultivate. For grape cv. Bordeaux found that the extracts were effective to maintain the soluble titratable solid acidity and sensory analysis with appropriate values pre- and postharvest capim-limão extract application was effective for pH, chroma, anthocyanins and more intense colouration. The capim-limão extract and gervão applied pre and postharvest kept a higher content of phenolic compounds. Thus, the pre application and capim-limão extract postharvest is effective to maintain the quality in storage in grapes. For pulp cv. Bordeaux who received only preharvest treatment all plant extracts were effective to keep the soluble solids in appropriate values in bunches and pulp; It observed that the application of gervão extract maintained the proper pH and the capim-limão extracts and wine residue kept the maturation index as indicated to cultivate; application of gervão extract had better sensory acceptance. Thus, it is indicated that plant extracts applied in the preharvest may be a viable alternative to maintain the quality of grapes.