Superabsorbent whey protein isolates/chitosan-based antibacterial aerogels: Preparation, characterization and...

Traditional absorbent pads are composed of hard-to-degrade polyethylene film and non-woven bottom layer, which have the characteristic of low absorption rate, without antibacterial effect. The objective of this study is to fabricate a novel superabsorbent and antibacterial aerogel, which consists of whey protein isolate (WPI) and chitosan (CS). The citric acid (CA) and ε-polylysine hydrochloride (ε-PLH) are incorporated into WPI/CS-based aerogel as cross-linking and antibacterial agent, respectively. The application in meat preservation as an absorbent pad is investigated. Results of water absorption, water vapor absorption and stress-strain show that aerogel comprised of 6 % WPI, 1.2 % CS, 2.0 % CA, and 2.0 % ε-PLH have the best water absorption capacity and stress. The density of WPI/CS/CA/ε-PLH aerogel is 82.7 ± 6.4 mg/cm³, and has a uniform and polyporous microstructure, resulting in superabsorbent capacity. Antibacterial rate of WPI/CS/CA/ε-PLH aerogel against Staphylococcus aureus, Escherichia coli, Salmonella and Listeria monocytogenes reach around 80 %. The WPI/CS/CA/ε-PLH aerogel significantly reduces increased velocity of b^⁎, pH, total volatile base nitrogen, and total viable counts and decreased velocity of L^⁎ and b^⁎ of chicken meat (P < 0.05). Results indicate WPI/CS/CA/ε-PLH aerogel effectively extends shelf-life of chicken meat to 7 days, and could be used as an absorbent pad in meat preservation.