Sk. Park et al., Mechanical properties and water-vapor permeability of soy-protein films affected by calcium salts and glucono-delta-lactone, J AGR FOOD, 49(5), 2001, pp. 2308-2312
Edible films were prepared from solutions of soy protein with calcium salts
and glucono-delta -lactone (GDL). Calcium salts cross-linking interactions
with soy-protein isolate (SPI) could result in the formation of films with
rigid three-dimensional structure. GDL contributed to the formation of a h
omogeneous film structure due to increased protein-solvent attraction. Tens
ile strength (TS! of calcium sulfate treated SPI film (8.6 MPa) was higher
than the TS of calcium chloride treated SPI films (6.4 MPa) and the control
SPI film (5.5 MPa). Puncture strength (PS) of calcium sulfate treated SPI
film (9.8 MPa) was higher than the PS of calcium chloride treated SPI films
(8.5 MPa) and the control SPI film (5.9 MPa). SPI film formulated with GDL
had larger elongation at break (39.4%) than that of SPI control film (18.2
%). Calcium salts and GDL-treated SPI films had lower water-vapor permeabil
ity than the SPI control film.