Apple juice submitted to high hydrostatic pressure was supplemented with chitosan (0.6 and 0.8 g L-1, added in powder and solution) and ascorbate in powder (0.06% and 0.08%) or solution (1%), to optimize its amounts and forms of application, as well as the implications on juice quality during a storage period of 35 days. Thru these experiments it was found that dissociation of hydrogen ions, protonation and ascorbate oxidation was significantly affected. Accordingly, significant variations were found in the pH, total soluble solids, titrable acidity, Hue, turbidity and phenols, exogenous added ascorbate and sugars contents. It is concluded that addition of 0.8% chitosan as powder has the most effective action to counterbalance total phenols drift, which correlate with the inhibition of enzymatic browning and green/yellow Hue.
Key words: Apple juice, Chitosan, High Hydrostatic Pressure, Quality, Shelf life