Modelling Cooling of Packaged Fruit Using 3D Shape Models

Abstract

This study presents a novel methodology to model the cooling processes of horticultural produce using realistic product shapes rather than commonly-used simplified 3D shapes, such as spheres. Variable 3D apple and pear models were created by means of a validated geometric model generator based on X-ray computed tomography images. The fruit were randomly stacked into a geometrical model of a corrugated fibreboard box using the Discrete Element Method. A forced-air cooling process was simulated for three such apple filling patterns using CFD and the results were compared to those obtained with fruit represented by equivalent spheres. No significant difference in average aerodynamic resistance between the real apple shape and its spherical representation was found. The main contributor to the overall pressure drop was the package design rather than product shape. However, large differences in local air velocity and convective heat transfer coefficients were found between the two representations. The degree of cooling uniformity between individual fruit was overestimated when using simplified product shapes: real apple fruit shapes cooled less uniform. This difference between real and simplified product shapes was even larger for a box filled with pear fruit that are more different from a spherical shape. These results

Digital twins probe into food cooling and biochemical quality changes for reducing losses in refrigerated supply chains

“…In this study, the fruit was evaluated as a single entity. However, when packed in larger bulks, the shape of the fruit will also affect the airflow patterns, thus cooling behavior of the entire shipment (Gruyters et al, 2018). As such, the thermal capacity of the surrounding fruit can induce an additional time lag (Thijs Defraeye et al, 2015b;.…”

“…Firstly, the temperature history has been linked to overall fruit storage life , but not to single quality attributes, such as firmness or vitamin content, which are driven by temperature-dependent biochemical reactions. Secondly, the impact of the complex shape of mango fruit and its internal features (seed) on the thermal and biochemical processes has not yet been identified (Gruyters et al, 2018). Typically, mangos are represented as ellipsoids (without seed), for example, when analyzing hot water treatment (Marcelo et al, 2018;Mendoza Orbegoso et al, 2017).…”

Numerical Study of the Impact on Cooling Behaviour of Vent-Holes Design of Fruit Packaging Boxes

“…The maintenance of adequate temperature slows down the biochemical processes responsible for senescence [8]. Fruit remains physiologically active after harvest resulting in the reduction of quality [9,10]. Adequate cooling is of critical importance when dealing with post-harvest perishable fruits as the mentioned physiological phenomena generates heat that can lead to premature and excessive ripening [11] and the development of colony forming units of microorganisms.…”

“…Therefore, packaging should be designed to prevent heterogeneity by adjusting vent size and position to the necessities of the food products [6,17]. However, perfect cooling uniformity is impossible to operational and environmental conditions as well as biological variance of perishable food products [9,10]. Virtual cold chain simulation clearly demonstrates the negative effects of cooling heterogeneity in the quality of food products [14].…”

“…Fortunately, packaging is one of the easiest parameters to change in post-harvest cold chain as it is not particularly expensive or overburdened with regulations [7]. Also, significantly less expensive is the use of CFD simulations per opposition to experimental tests and computational capabilities becomes less expensive, simulation become more attractive as it can provide accurate spatial and temporal predictions with a resolution and consistency that would be extremely difficult to achieve through experimentation [2,6,7,9,10,26,28,29].…”