Colour and texture of apples high pressure processed in pineapple juice

Cubes of Granny Smith and Pink Lady apples were vacuum packed in barrier bags with 0% to 50% (v/v) pineapple juice (PJ) at 20 degrees Bx and subjected to high pressure processing (HPP) at 600 MPa for 1-5 min (22 degrees C). The in-pack total colour change (Delta E) was observed over 4 weeks at 4 degrees C. Within <1 week of storage at 4 degrees C, texture, polyphenoloxidase, pectinmethylesterase activities, changes in M and visual browning after opening the bags during air exposure (22 degrees C; 21% O2) for 5 h were also monitored. During the 4 weeks storage in bag visible colour changes were not observed. Texture and Delta E after 5 h air exposure were significantly affected by the apple variety, HPP time and % PJ used. The combined treatment significantly reduced residual PPO activity while PME activity was not affected in both varieties. Pineapple juice in combination with HPP could be used as a natural preservation system for minimally processed apples. industrial relevance: Browning upon opening the packs and during air exposure can adversely affect the quality of fresh-cut fruits. Combined treatment of high pressure processing (HPP) and use of pineapple juice has the potential to prevent browning for several hours giving sufficient time for presentation and use in domestic and foodservice environment where high quality fresh-like fruit is required. (C) 2009 Elsevier Ltd. All rights reserved.