Stabilization of Soybean Oil Bodies Using Protective Pectin Coatings Formed by Electrostatic Deposition

Abstract

Soybeans contain oil bodies that are naturally coated by a layer of phospholipids and proteins. In nature, this coating protects the oil bodies from environmental stresses and could be utilized by food manufacturers for the same purpose. However, natural oil bodies are physically unstable to aggregation because of the relatively weak electrostatic repulsion between them, which limits their application in many foods. In this study, oil bodies were extracted from soybean using an aqueous extraction method and then coated by a pectin layer using electrostatic deposition. The influence of NaCl (0-500 mM), pH (2-8), and freeze-thaw cycling (-20 degrees C, 22 h/40 degrees C, 2 h) on the properties and stability of the oil bodies coated by the pectin layer was analyzed using zeta-potential, particle size, and creaming stability measurements. These results suggest that pectin-coated oil bodies have similar or improved stability compared to uncoated oil bodies and may provide a new way of creating functional soy products for use in the food and other industries.