Bioavailability of Soy Protein and Corn Zein Films

Laura B. Matthews, M. Elizabeth Kunkel, James C. Acton, Amod A. Ogale, Paul L. Dawson

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DOI: 10.4236/fns.2011.210148                

Abstract

The in vivo bioavailability of soy protein isolates and corn zein film material before and after film formation by heat/ pressure was determined. The In vitro digestibility of corn zein before and after film formation was also measured. Films were produced from anhydrous protein with 30% glycerol added using a heat-press method with no use of casting solvents or cross-linking agents. Corn zein raw and film material were ground under liquid nitrogen then digested in two enzyme-acid cocktails with free amino acid analysis before and after digestion. The protein efficiency ratio and net protein ratio were determined for both zein and soy protein using a weanling Sprague-Dawley descended rat feeding study. The In vitro digestibility study indicated that the non-heat pressed corn zein was more digestible than the heat pressed zein. However, the in vivo results indicated that corn and soy protein were equally bioavailable whether they were derived from film mixture prior to or after film formation. Both corn zein and soy protein material had lower protein efficiency ratio than the control diet. Furthermore, soy protein films materials had a higher protein efficiency ratio than corn zein.

Keywords

Bioavailability, Bio-Based Films, Edible Films, Protein Digestibility, Packaging

Conflicts of Interest

The authors declare no conflicts of interest.

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