Barrier properties of starch -based antimicrobial films using antimicrobial nano-particle system

Abstract

Intercalation of antimicrobial agent into layered double hydroxides depended upon the type of antimicrobial agent, concentration of antimicrobial agents, and modification condition. Benzoate and Natamycin anion were loaded successfully into layered double hydroxide matrices and its loading was controlled by reaction condition. However, the molar concentration and the reaction time carried out for modification of benzoate did not seem to be effective for loading propionate anions. Starch films were prepared using modified LDH with Benzoate, and Natamycin (LDHBz and LDH-Nat). Barrier properties in terms of water vapor, oxygen transfer and carbon dioxide were found to be improved in films made with either antimicrobials or 2% modified LDH by antimicrobials compared to the control film. However, there is no significant difference of WVTR and OTR between films with antimicrobials or modified LDH by antimicrobials. Lightness of color (L), red/green color (a) and yellow/blue color (b) of films were tested. No significant difference was found among control films, films with unmodified LDH, and films with benzoate, natamycin, and LDH-Bz. Films with LDH- Nat. were found more yellow with low "L" value, which might not be eye appealing for the use in all types of food packaging.