45D-3 |
Properties of soybean protein isolate films with cinnamaldehyde |
K. M. KIM1, C. L. Weller1, M. A. Hanna1, and A. Gennadios2. (1) Industrial Agricultural Products Center, Univ. of Nebraska, Lincoln, 233 L.W. Chase Hall, Lincoln, NE 68583-0730, (2) Pharmaceutical Technologies & Services, Cardinal Health Inc., 645 Martinsville Rd., Ste. 200, Basking Ridge, NJ 07920 Protein films are effective lipid, oxygen and gas barriers. However, due to the inherent hydrophilicity of proteins and the substantial amounts of added plasticizers, protein films perform poor moisture barriers. Aldehydes such as formaldehyde and glutaraldehyde promote inter- and intramolecular cross-linking in proteins. Formaldehyde treatment significantly increased tensile strength and reduced water solubility and water vapor permeability. However the inherent toxicity of the aldehydes restricts their use for improving properties. Cinnamaldehyde has an aldehyde group in its structure and is less toxic than formaldehyde. Cinnamaldehyde’s mode of action in the cross-linking of film protein has not previously been investigated. The objective of this study was to investigate the use of cinnamaldehyde as a cross-linking agent in soy protein isolate (SPI) film. SPI-films were prepared by casting method with different level of cinnamaldehyde addition of 0, 0.1, 0.2, 0.3, 0.4 and 0.5 ml per 5 g SPI. The properties which were tested included total color differences (delta E ), tensile strength (TS), elongation at break (E), water vapor permeability (WVP) and total soluble matter (TSM). Cinnamaldehyde-treated SPI films resulted an increase in delta E. TS increased significantly by the addition of cinnamaldehyde. Mean TS of the control film was 3.45 MPa and TS increased up to 5.6MPa. Mean E of the films decreased from 169.0 % down to 69.5%. WVP of cinnamaldehyde-treated SPI films were not significantly different from control films until 0.4 ml of cinnamaldehyde was added. TSM decreased with increasing amounts of cinnamaldehyde. This study showed the potential use of cinnamaldehyde as a cross-linking agent. Significant increases in mechanical strength of SPI films were achieved by incorporation of small amounts of cinnamaldehyde. Cinnamaldehyde was effective in cross-linking protein films. Use of cinnamaldehyde provides non-toxic alternative for modifying the properties of protein films compared to low molecular weight aldehyde compounds.
Session 45D, Food Packaging: General
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