Evaluating the impact of parameter variability on O₂ control and model robustness in modified atmosphere storage for fresh produce

The effects of variation in product respiration, supply chain temperature, gas diffusion, product quantity, and storage volume on gas control in fresh produce storage remain unexplored. This study aimed to evaluate the impact of such parameters on O₂ control, using broccoli as a case study under dynamic temperature profiles ranging from 1°C to 20°C. Sensitivity analysis of each parameter was performed using Monte Carlo simulations and one-factor-at-a-time method and the results were experimentally validated. The blower ON frequency (BOF) needed for O ₂ control exhibited a mean of 47.8 ± 3.7 s, illustrating variability due to model parameter uncertainties. The product weight and respiration rate were the most influential parameters affecting the BOF. These parameters collectively accounted for over 80% of the BOF variability, highlighting the importance of prioritizing and incorporating non-linear relationships and parameter interactions for model robustness. Temperature variations affected BOF and respiration rates while maintaining overall O₂ and CO₂ concentrations stable over a longer period. However, O₂ and CO₂ concentrations exhibited temporary fluctuations because, at higher temperatures, the blower operated for longer durations compared to lower temperatures, leading to more pronounced O₂ fluctuations. The results of the validation experiment, using a 70-litre box containing 16 kg of broccoli, confirmed the stability of the model in effectively handling the parameters variation while maintaining the O ₂ concentration at 3.5 ± 0.5% and CO ₂ at 15.3 ± 1% during storage and transport of the fresh produce.