Antimicrobial compound incorporated corn starch based self-supporting film and its properties

The issue of environmental pollution arising from disposable synthetic packaging films and the lack of petroleum resources demand development of alternatives from renewable natural biopolymers such as starch. In the present work, the effect of benzoic acid (BA), potassium sorbate (PS), and sodium propionate (SP) as antimicrobials on ultimate tensile strength (TS), elongation at break (%El), water vapour permeability (WVP) and optical properties of films developed from a mixture (100 mL) containing 7.50 g corn starch, 0.875 g polyvinyl alcohol and 0.125 g glutaraldehyde was evaluated. Antimicrobials varied within 0-1.791 g/100 g total polymers modified the properties of film containing no antimicrobial. At 1.791 g/100 g polymer, BA and PS decreased TS of control film by 24.01% and 26.84%, while SP indicated 12.35% increase. Simultaneously, BA decreased El by 82.82%, while PS and SP increased by 12.73% and 167.52%. All the three raised WVP, while SP decreased yellowness index, with minimum deterioration in opacity. SP at this level was, therefore, recommended as the best suitable antimicrobial, and the developed film coupled with high WVP could be useful to extend the storage life of fresh fruits and vegetables