Modelling respiration in fresh-cut pineapple and prediction of gas permeability needs for optimal modified atmosphere packaging

This study investigated the effects of intrinsic factors (origin, physiological age and seasonality) and extrinsic factors (cut-size, blade-sharpness and dipping treatments) on respiration rate (R-CO2) of fresh-cut pineapple chunks. A mathematical model for respiration rate based on exponential decay was developed that showed a gradual decrease in rate with time. The model parameters (R-i and R-eq, initial respiration rate and equilibrium respiration rate, respectively) were found useful to compare respiration rates for the factors studied. The average values were 8.52 +/- 4.68 and 2.64 +/- 0.68 ml/kg h for R-i and R-eq, respectively. R-i was affected to a greater extent by physiological age and origin than by season. Cut size had a considerable effect on R-i and R-eq, with larger cut pieces having the lowest R-i and R-eq of 5.9 and 2.7 ml/kg h, respectively. In contrast, smallest cut pieces had highest R-i (7 ml/kg h) and R-eq (3.2 ml/kg h). Cutting the fruit with a razor sharp blade versus a blunt blade decreased the Rh while only caused a slight reduction in R-eq. The target O-2 and CO2 transmission rate required for optimal modified atmosphere packaging were 7300-12,500 and 13,900-23,500 ml/m(2) day atm covering variability in respiration rate due to intrinsic and extrinsic factors studied. (c) 2013 Elsevier B.V. All rights reserved.