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

Abstract 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 CO 2 ) 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 R i , while only caused a slight reduction in R eq . The target O 2 and CO 2 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.