title: Effect of molecular weight, type of chitosan, and chitosan solution pH on the shelf-life and quality of coated eggs.
abstract: Effects of the molecular weight and type of chitosans and pH of chitosan solution on antibacterial activity against Salmonella enterica Enteritidis and on internal quality of chitosan-coated eggs were evaluated during 4 wk of storage at 25 degrees C. Two types of chitosans were studied: alpha-chitosans with 4 different molecular weights (Mw = 282, 440, 746, and 1110 kDa) and beta-chitosan (Mw = 577 kDa). The alpha-chitosan with 282 kDa exhibited stronger bactericidal effects than did other alpha- and beta-chitosans. The weight loss, Haugh unit, and yolk index values suggested that coating of eggs with alpha-chitosan with 282 kDa increased the shelf-life of eggs by almost 3 wk at 25 degrees C compared with noncoated eggs. The pH (4.5, 5.0, and 5.5) of the alpha-chitosan (282 kDa) solution did not affect the internal quality of chitosan-coated eggs. Therefore, coating of eggs with 282 kDa alpha-chitosan without pH adjustment (initial pH of 4.5) may offer a protective barrier against contamination of S. Enteritidis while simultaneously preserving the internal quality of eggs.
authors.affiliation: Dept. of Food Science and Technology, Catholic Univ. of Daegu, Hayang 712-702, South Korea.
authors.forename: Su Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Hong Kyoon
authors.initials: HK
authors.lastname: No
authors.forename: Witoon
authors.initials: W
authors.lastname: Prinyawiwatkul
mesh_terms: D048271:Chitosan / Q000737:chemistry / Q000494:pharmacology*; D003257:Consumer Product Safety; D004531:Eggs / Q000382:microbiology* / Q000592:standards*; D005506:Food Contamination / Q000517:prevention & control; D005519:Food Preservation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D012477:Salmonella enteritidis / Q000187:drug effects* / Q000254:growth & development; D013696:Temperature; D013997:Time Factors
chemical_list: D048271:Chitosan