Combining experiments and mechanistic modeling to compare ventilated packaging types for strawberries from farm to retailer

Soft fruits like strawberries are highly perishable and susceptible to postharvest decay caused by fungal infes-tation. Mold growth is favored by elevated temperatures in the cold chain or when water vapor condenses in the packaging induced by temperature fluctuations at high relative humidity. Optimal packaging for these products is required to improve homogenous fruit cooling and ventilation inside the package along the entire supply chain. This study analyzed three packaging types (top sealed paperboard, open and closed plastic clamshell) through laboratory storage experiments and simulations. We tested the different packages in a climate chamber, with conditions representing an actual supply chain from farm to retailer. We evaluated the performance of these packages by quality measurements. We measured the fruit mass loss, total soluble solids and acidity content, firmness, color change, and incidence of decay. We also developed physics-based models for the strawberries and packaging to gain complementary information that is difficult to quantify experimentally. These models rely on mechanistic simulations and sensor data to capture fruit's hygrothermal and physiological evolution. To this end, we used monitored sensor data from the lab experiments as input for these physics-based digital fruit twins. We quantified in-silico the time of wetness due to condensation, respiration-driven overall fruit quality, and remaining shelf life along the simulated supply chain. Altogether, our simulation findings revealed that the top sealed paperboard packaging had the best performance in terms of respiration-dependent quality, mass loss and time of wetness. Furthermore, this package showed the least heterogeneities of fruit quality attributes inside the packaging, most likely due to the presence and position of ventilation holes. No clear differences were observed during laboratory experiments in rot incidence and traditional measured quality metrics (i.e., total soluble solids, acidity, color). Combining experiments with mechanistic modeling provides a deeper understanding of how fruit evolves in a supply chain. Also, it can capture packaging evaluating metrics, including moisture loss, time of wetness, or risk for microbial decay in a spatiotemporal manner.

Automated summary

Soft fruits like strawberries are prone to postharvest decay due to fungal infestation, which can be exacerbated by elevated temperatures and condensation in packaging. Optimal packaging, such as top sealed paperboard, is essential for homogenous fruit cooling and ventilation. Through laboratory experiments, simulations, and physics-based models, the study found that top sealed paperboard packaging performed best in terms of respiration-dependent quality, mass loss, and time of wetness, with minimal heterogeneities in fruit quality attributes. Experimenting in combination with mechanistic modeling provides a deeper understanding of fruit evolution in a supply chain.