Moreover, sequential application of acid treatment before or after chi-tosan application (chitosan solution 1% w/w at pH 3.0) does not provide fruit with adequate protection as for carrageenan and sucrose ester coating (McGuire and Baldwin, 1998). Such treated fruit behaved similarly to control fruit, and this result (data not shown) confirms that acid and chitosan must be mixed to be effective. This optimal performance may be explained by the formation of an acid coat which favours a stable acid-ification of the epicarp during soaking and minimizes the fruit’s buffering capacity.