99C-21

Gelatin is used in a variety of food applications particularly gummi confectionery products.  However, due to growing concerns of Bovine Spongiform Encephalopathy (BSE) and Foot and Mouth Disease along with an increasing demand for Kosher/Halal and vegetarian products there is a demand for alternatives to gelatin.  Carrageenan and pectin are logical potential alternatives to gelatin.  Their rheological characteristics, particularly viscoelasticity, are of interest in comparison to gelatin in a high-solids sugar:corn syrup matrix that represents real food systems.

The objective of this research was to compare the small deformation viscoelastic behavior of carrageenan and pectin high-solids products to a commercial gelatin-based gummi product as a function of frequency and temperature.

Carrageenan (~1.5%) and high-methoxyl pectin (~2.5%) products were prepared according to specifications provided by the suppliers for gummi type products.  Commercially available gummi bears were obtained locally.  The final total solids content of the samples was 80%, which is standard for this type of product.  The shear storage modulus (G’), shear loss modulus (G”) and dynamic viscosity (h’) were determined as functions of frequency (0.006 to 125.6 rad/s) and temperature (30, 50 and 70°C) at 1% strain.  Tan d (G”/G’) was also determined.

Carrageenan and pectin-based products showed similar patterns in the viscoelastic functions for all testing conditions, but were significantly different than for the gelatin-based product.  For the commercial product, G’>G” at the lowest frequencies, but G” actually crossed over G’ at higher frequencies.  The crossover frequency decreased as the temperature increased.  The carrageenan and pectin products were more gel-like (G’>G”) for all test conditions, consistent with their more jelly-like texture.

The results highlight the unusual frequency dependence of the viscoelastic functions for the commercial gummi product relative to carrageenan and pectin-based products.  They also provide a quantitative reference for gummi-type viscoelastic behavior to aid gelatin replacement efforts.