Predicting relative humidity in modified atmosphere packaging system containing blueberry and moisture absorbent

A modified respiration-transpiration model was developed to predict the relative humidity in modified atmosphere packaging system containing fresh produce and moisture absorbent. The model is based on heat and mass balances accounting for the respiratory and transpiratory behavior of the fresh produce, the transport phenomena across the package, and the moisture sorption behavior of the absorbent. A set of experiments was conducted to obtain the parameter values that were necessary for generating model predictions. Another set of experiments was conducted using model packages containing blueberries and moisture absorbents Sanwet and xylitol to obtain experimental data under various conditions, including different weights of blueberries, types of absorbers, weights of absorbers, and temperatures. In general, the model predictions agree well with the experimental data, except the model sometimes exaggerates the effects of the absorbent in the initial period (<10 h).