30C-10 |
In vitro digestibility and surface activity of salt incorporated protein films |
S. Eswaranandam, N. S. HETTIARACHCHY, and Z. Y. Ju. Dept. of Food Science, Univ. of Arkansas, Fayetteville, AR 72704 Protein films can be used as vehicles to control release of nutraceuticals, drugs, and additives (NDA). Digestibility of protein films can be influenced by salt incorporation. These films can influence release times of NDA. Surface activity of the film determines the water intake rate and influences the diffusion rate of NDA. The objectives of this study were to determine the (a) digestibility of the Soy protein (SP) and whey protein (WP) films, and (b) surface activity of SP and WP films with and without NaCl or CaCl2. Soy protein and WP films with 0 to 200 mM NaCl or 0 to 40 mM CaCl2 were prepared with a thickness of 125 mm and their in-vitro digestibility in simulated gastric fluid (GF) and simulated intestinal fluid (IF) were evaluated. Surface activity of the film was evaluated by the time taken to fall down in polyoxyethylene sorbitan monooleate (PSM), sodium dodesyl sulfate (SDS) and food grade surfactant (FG-10) solutions. Whey protein and SP films dissolved in the GF in 29.4 and 4.8 min, respectively and in IF in 36.0 and 23.8 min, respectively. Incorporation of CaCl2 to SP films decreased digestibility in GF. Incorporation of NaCl (20 - 40 mM) and CaCl2 (5-10 mM) into WP and SP films significantly (P < 0.05) increased digestibility in GF and IF. Surfactant solutions PSM, SDS and FG-10 gave the lowest fall down times in concentrations of 0.5% (21 s), 0.5% (5 s) and 1.0% (5.5 min) respectively for WP films and in 1.0% (41 s), 0.5% (22 s) and 0.5% (9 s) respectively for SP films. There were no significant differences in surface activities of salt modified and unmodified films. Digestibility of SP and WP films can be used to control release of NDA by incorporation of NaCl or CaCl2 without influencing surface activity of the film.
Session 30C, Food Chemistry: Proteins
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