Barrier properties of spray-dried emulsions containing flavorings or unsaturated triglycerides

Oxygen diffusion through spray dried particles is the crucial factor in primary determination of product shelf-life. This work investigates the main factors influencing the oxygen barrier properties of maltodextrin-based spray-dried emulsions with different surface-active components (SAC). Low amounts (1.2-4.8 g/100 g emulsion) of SAC (whey protein isolate, gelatin or Capsul (R)) were used to encapsulate an unsaturated triglyceride (fish oil) or a volatile (orange essential oil) at 6 g/100 g emulsion (1:4 oil:wall material). Differences were observed in the oxygen uptake. As the encapsulation efficiency and the bulk matrix were not necessarily related to the oxidation, the interfacial membrane surrounding the oil droplets is suggested to be determinant in the oxidative stability. The protein matrices showed antioxidant capacity that also can contribute to high protection. This work provided insights about the understanding of how barrier properties of powders affect oxidation. (AU)