Integrated design of epigallocatechin gallate nanoparticles and tannic acid to reinforce the porous structure of κ-carrageenan/pullulan absorbent pads for extending beef shelf life.

This study aimed to develop sustainable bioactive absorbent pads as a green alternative for meat packaging. Gelatin (Gel) self-assembled nanocarriers were constructed to encapsulate epigallocatechin gallate (EGCG), yielding Gel@EGCG nanoparticles with an encapsulation efficiency of 76.18% and a loading capacity of 10.65%. Subsequently, these nanocomposites were incorporated together with natural crosslinker tannic acid (TA) into a κ-carrageenan/pullulan (Car/Pul) matrix to fabricate biopolymer absorbent pads (CPTGE). The resulting three-dimensional porous structure (stabilized by hydrogen bonding and electrostatic interactions) endowed CPTGE pads oil-water superabsorbent characteristics, while reinforcing compressive resistance. Moreover, CPTGE2 (Car/Pul containing TA and 0.2%wt Gel@EGCG) effectively scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals, with inhibition rates of 86.72% against Escherichia coli and 92.07% against Staphylococcus aureus, conferring active antioxidant and antibacterial activities. Notably, CPTGE2 significantly delayed quality deterioration by suppressing myoglobin oxidation (reducing metmyoglobin content by 50.47%) and lipid peroxidation (lowering thiobarbituric acid reactive substances [TBARS] values by 51.10%), ultimately extending beef shelf life. This provides new insights for designing active packaging that integrates efficient liquid absorption with antimicrobial and antioxidant functions.