Methacryloxyethyl sulfobetaine (SBMA) based hydrogel with functional enhancement by acrylamide, glycerol, and thymol for strawberry preservation

A robust hydrogel rapidly fabricated via one-pot method within 2 min. • Integrated functional enhancement by acrylamide, glycerol, and thymol. • PSA/Glyc@THY shows >500 kPa compressive strength and 200-cycle stability. • Hydrogel shows 16.74% weight loss rate in air and 125% swelling ratio in water. • PSA/Glyc@THY inhibits the growth of bacteria and fungi without damaging strawberries. Postharvest fruit preservation faces dual challenges of microbial infection and physical impact, necessitating flexible packaging with integrated antimicrobial and mechanical functions. Leveraging acrylamide's (AM) high polymerization activity, efficient redox initiator, methacryloxyethyl sulfobetaine's (SBMA) physical crosslinking synergy, and glycerol's (Glyc) dual function in reducing viscosity and promoting hydrogen bonding, this study achieved rapid gelation within two min to construct PSA/Glyc@THY hydrogel. The material exhibited exceptional mechanical strength (compressive strength of 518.01 kPa, stable over 200 cycles) and remarkable environmental stability (water loss <20% in open air, swelling ratio 125.36%). The 1% thymol-loaded hydrogel showed broad-spectrum antimicrobial activity ( Escherichia coli : 78.9% OD 600 reduction; Staphylococcus aureus : 80.7%; Botrytis cinerea : 24.30 mm inhibition zone), completely suppressing mold on strawberries without surface damage, with confirmed biocompatibility. This study offers a promising solution for flexible fruit packaging that integrates antimicrobial and mechanical functions to reduce postharvest losses during transportation and storage. Download: Download high-res image (246KB) Download: Download full-size image