Fabrication and characterization of novel porous hydrogels for fragile fruits: A case study

Mechanical damage during transportation impairs fruit quality. Protecting fragile fruits through packaging is essential. Herein, this paper presents a case study of fresh strawberries embeded in porous hydrogels (PHs) to maintain quality and avoid damage during shelf-life period. The hydrogels were biologically fabricated using alginate networks and soy protein isolates to yield a porous structure. With three times of foaming rate, the PH could dissipate 70%-78% deformation energy in the first loading cycles. It also maintained an energy dissipation rate of 51.52% after 200 loading cycles. The strawberries stored in these PHs exhibited a remarkably better quality than those in other package materials after transportation simulation and free-fall tests, their damage indices were inhibited under 14% (above 36% in control). Additionally, during a two-day shelf-life period, rotten rate of strawberries after transportation simulation and that after free-fall tests were detected as 2.49 +/- 1.86% (48.33 +/- 5.67% in control) and 13.34 +/- 3.76% (94.96 +/- 3.76% in control), respectively. Moreover, PHs possessed a high specific heat capacity of 3956 +/- 49 J kg-1 K-1 and a low friction coefficient of 0.081 +/- 0.003, maintaining a low temperature around the fruit and avoiding fruit abrasion. The PHs were also biodegradable. Therefore, the PHs was considered as promising packaging for maintaining fresh and fragile produce.

Automated summary

This study presents a method of using porous hydrogel packaging to maintain the quality of fresh strawberries. The hydrogels have excellent energy dissipation and insulation properties, which can effectively reduce the damage to strawberries during transportation and storage, and improve their quality.