Development of new active packaging film made from a soluble soybean polysaccharide incorporated Zataria multiflora Boiss and Mentha pulegium essential oils.

An active edible film from soluble soybean polysaccharide (SSPS) incorporated with different concentrations of Zataria multiflora Boiss (ZEO) and Mentha pulegium (MEO) essential oils was developed, and the film's optical, wettability, thermal, total phenol and antioxidant characteristics were investigated, along with their antimicrobial effectiveness against Staphylococcus aureus, Bacillus cereus, Escherichia coli O157:H7, Pseudomonas aeruginosa and Salmonella typhimurium. The film's colour became darker and more yellowish and had a lower gloss as the levels of ZEO or MEO were increased. Antioxidant activity of the films was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric-reducing antioxidant power assays. DPPH was reduced in the range of 19.84-74.12% depending on the essential oil type and concentration. Film incorporated with 3% (v/v) ZEO showed the highest DPPH radical scavenging activity and ferric reducing antioxidant power (IC50=4188.60±21.73mg/l and EC50=8.86±0.09mg/ml, respectively), compared with the control and MEO added film. Films containing ZEO were more effective against the tested bacteria than those containing MEO. S. aureus was found to be the most sensitive bacterium to both ZEO or MEO, followed by B. cereus and E. coli. A highest inhibition zone of 387.05mm(2) was observed for S. aureus around the films incorporated with 3% (v/v) ZEO. The total inhibitory zone of 3% (v/v) MEO formulated films was 21.98 for S. typhimurium and 10.15mm(2) for P. aeruginosa. Differential scanning calorimetry (DSC) analysis revealed a single glass transition temperature (Tg) between 16 and 31°C. The contact angle increased up to 175% and 38% as 3% (v/v) of ZEO or MEO used: it clearly shows that films with ZEO were more hydrophobic than those with MEO. The results showed that these two essential oils could be incorporated into SSPS films for food packaging.

Characterization of soluble soybean polysaccharide film incorporated essential oil intended for food packaging.

This study examines the development of new bio-active polysaccharide-based bioplastics through casting and solvent-evaporation. Soluble soybean polysaccharide (SSPS) films incorporated with Zataria multiflora Boiss (ZEO) or Mentha pulegium (MEO) at various concentrations were prepared and characterized. The presence of ZEO and MEO improved polysaccharide interactions, reducing the films' water solubility and water vapor barrier properties, but did not markedly modify their moisture content or thickness. Differing amounts of ZEO or MEO had no significant effect on mechanical behavior, with the exception of 3% oil concentration, which decreased tensile strength and significantly increased elongation at break. DMTA curves revealed a single Tg, which may indicate the compatibility of essential oil and SSPS. The electron scanning micrograph for the composite film was homogeneous, without signs of phase separation between the components. These results suggest that ZEO and MEO can potentially be directly incorporated into SSPS to prepare active biodegradable films for food-packaging applications.

Soluble soybean polysaccharide: a new carbohydrate to make a biodegradable film for sustainable green packaging.

Biodegradable edible films based on soluble soybean polysaccharide (SSPS), a new film-forming material, and three levels of glycerol (20%, 30% and 40%, w/w) as plasticizer, were developed and evaluated in terms of physical, mechanical, barrier and optical properties as well as their microstructure. SSPS-based films with a concentration of 20% glycerol possessed the lowest water vapor permeability. Increasing the glycerol content increased (P<0.05) values for elongation at break, but decreased (P<0.05) tensile-strength values. It was found that plasticizer concentration significantly affected the films' glass-transition temperature; however, it had no significant effect on their melting point. Color measurement showed that increasing the glycerol concentration caused the b and L values to increase, while ΔE value decreased. These results were explained by the film's microstructure, which was analyzed by atomic force microscopy and scanning electron microscopy. The results indicated that SSPS could be a promising food-packaging material.