A respiration-transpiration model was developed by applying simultaneous heat and mass transfer principles along with known physiological behavior for the design of MA-P systems containing fresh produce. The model equations were solved numerically using Adams-Moulton method to predict gas compositions, RH, and temperature in model packages. The applicability of the model to packages containing blueberry at 15 and 25degreesC was successfully verified using different types of packaging films. The difference between the experimental and predicted headspace gas composition was less than 1%. The predicted and experimental values were in agreement for RH (within 2%) and temperature (within 0.5degreesC). (C) 2002 Elsevier Science Ltd. All rights reserved.