Low-volume sprays to treat fresh-sliced apples with anti-browning solution

Abstract

Use of sprays to sanitize and treat apple (Malus xdomestica) slices helps to reduce the potential for cross-contamination that can occur when treatments are done in dip tanks. This research examined several factors that may affect the efficacy of spray treatments: 1) spray volume; 2) efficacy of spray application of anti-browning solution (ABS) compared with dipping; 3) effect of slice density during spraying; and 4) effect of the addition of an antimicrobial compound, vanillin, on microbiologically associated browning. Low-volume sprays (36-50 mL·kg-1 slices) of ABS gave maximal control of browning and this was equivalent to the control afforded by a 2-minute dip in the ABS. Spray application resulted in significant reduction in incidence and severity of microbiologically associated "secondary browning" as compared with dip application. However, if more than one layer of slices were present on the support mesh during the spray treatment, then secondary browning increased. This was attributed to potential cross-contamination between layers of apples in the spray treatment. Addition of vanillin into the ABS resulted in a 50% reduction of the incidence of "secondary browning." Low-volume spray applications of ABS can be managed such that the microbiologically associated "secondary browning" is much lower than possible with dip application.