Starch-methylcellulose-whey protein film properties

• Published in: International journal of food science & technology 2012-02, Vol.47 (2), p.255-261
• Main Authors: Yoo, SeungRan, Krochta, John M.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Blends; Cellulose; Corn; edible films; Food industries; Foods; Fundamental and applied biological sciences. Psychology; Immiscibility; Milk and cheese industries. Ice creams; Modulus of elasticity; Molecular interactions; Proteins; starch; Starch and starchy product industries; Tensile strength; whey protein
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/j.1365-2621.2011.02833.x

Summary Four % (wt/wt) aqueous solutions were prepared at corn starch:methylcellulose:whey protein isolate (CS:MC:WPI) ratios of 2:2:2, 1:2:3, 2:1:3, 2:2:0, 1:2:0 and 2:1:0. Glycerol (gly) was used as a plasticiser at CS–MC–WPI:gly ratios of 2:1, 2.5:1 and 3:1. CS–MC–WPI blend films were stronger than CS–WPI films and had lower oxygen permeability (OP) than MC–WPI films. The highest tensile strength (TS) of blend films was 8.01 ± 3.41 MPa, at CS:MC:WPI ratio of 2:2:0 and CS–MC–WPI:gly ratio of 3:1. Lowest OP value was 45.05 ± 7.24 cm3 μm m−2 per day kPa−1, at CS:MC:WPI ratio of 2:2:2 and CS–MC–WPI:gly ratio of 3:1. OP values were predictable based on relative amounts of components. However, TS and elastic modulus properties of the CS–MC–WPI blend films did not reflect the relative amounts of the components. All of CS–MC–WPI films were translucent indicating some degree of immiscibility among the CS, MC and WPI. These results indicate the influence of complex molecular interactions among the components.