73D-37 |
Improving moisture barrier properties of mesquite gum-candelilla wax edible emulsion coatings |
E. BOSQUEZ-MOLINA1, L. Hernandez-Silva, E. J. Vernon-Carter, and I. Guerrero-Legarreta. (1) Departments of Biotechnology and Chemical Engineering, Universidad Autonoma Metropolitana-Iztapalapa, Michoacan y la Purisima s/n, Mexico City, 09340, Mexico There is an increasing interest in the utilization of natural products that grow in the Mexican arid zones, in order to help stop the continuing desertification, and help to improve the regional economies. Such is the case of mesquite gum Prosopis juliflora and of candelilla wax Euphorbia antisiphylítica. The former is a natural exudate from mesquite tree that has potential use as an emulsifying agent for oil-water emulsions, while the latter is a natural wax obtained from the candelilla reed, having been used as lipid phase in edible films. Both are original from arid zones from Mexico and South-Western United States. The objectives of this study were: 1) to develop composite coatings formulated with candelilla wax, beeswax, white mineral oil and oleic acid blends (all at 2:1 ratios) as the lipid phase, and mesquite gum as the structural material; 2) to evaluate the water vapor permeability (WVP) of the coatings, in comparison with a mesquite gum-candelilla wax formulation. Water vapor transmission rate (WVTR) of coatings was determined gravimetrically at 21±1°C using ASTM standard method E96-80 and the WVP values were calculated using WVP correction method. Results indicate that addition of the lipids to mesquite gum coatings formulations improved the WVP (p <0.05). The WVP from lowest to highest were: candelilla wax-mineral oil (6.19 x 10-10 g.s-1.m-1.Pa-1)< candelilla wax-oleic acid (9.34 x 10-10 g.s-1.m-1.Pa-1)< candelilla wax (1.14 x 10-9 g.s-1.m-1.Pa-1)< candelilla wax-beeswax (1.99 x 10-9 g.s-1.m-1.Pa-1). WVP of the mesquite gum-candelilla wax edible coating can be improved by blending the candelilla-wax with selected lipid materials, allowing for the development of “tailor” made films for specific applications.
Session 73D, Food Packaging
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