Polymer Hydrogels Formulated with Various Cross-Linkers for Food-Surface Application to Control Listeria monocytogenes

• Published in: Han'gug sigpum wi'saeng anjeonseong haghoeji Vol. 32; no. 5; pp. 443 - 446
• Main Authors: Kim, Sejeong, Oh, Hyemin, Lee, Heeyoung, Lee, Soomin, Ha, Jimyeong, Lee, Jeeyeon, Choi, Yukyoung, Yoon, Yohan
• Format: Journal Article
• Language: Korean
• Published: 2017
• Subjects: CarboxyMethylCellulose (CMC); Polymer; Hydrogel; Carrageenan
• ISSN: 1229-1153; 2465-9223

This study investigated the physical properties of polymers and antimicrobial activities of organic acids on Listeria monocytogenes to develop hydrogels. ${\kappa}-carrageenan$ (1, 2, and 3%), carboxymethylcellulose (CMC; 1, 3, and 5%), and agar (1.5 and 3%) were mixed with cross-linkers ($Na^+$, $K^+$, $Ca^{2+}$, and $Al^{3+}$) or each other by stirring or heating to form cross-linkage, and their physical properties (hardness, elasticity, and swelling) were measured. The hydrogels formulated with organic acid (1, 3, and 5%) were analyzed by spot assay against L. monocytogenes. ${\kappa}-carrageenan$ formed hydrogels with high hardness without other cross-linkers, but they had low elasticity. The elasticity was improved by mixing with other cross-linkers such as $K^+$ or other polymer, especially in 3% ${\kappa}-carrageenan$. CMC hydrogel was formed by adding cross-linkers $Al^{3+}$, $Na^+$, or $Ca^{2+}$, especially in 5% CMC. Thus, stickiness and swelling for selected hydrogel formulations (two of ${\kappa}-carrageenan$ hydrogels and three of CMC hydrogels) were measured. Among the selected hydrogels, most of them showed appropriate hardness, but only 3% ${\kappa}-carrageenan-contained$ hydrogels maintained their shapes from swelling. Hence, 3% ${\kappa}-carrageenan+0.2%$ KCl and 3% ${\kappa}-carrageenan+1%$ alginate+0.2% KCl+0.2% $CaCl_2$ were selected to be formulated with lactic acid, and showed antilisterial activity. These results indicate that 3% ${\kappa}-carrageenan$ hydrogels formulated with lactic acid can be used to control L. monocytogenes on food surface.