Flavour Release from Monoglyceride Structured Oil-in-Water Emulsions through Static Headspace Analysis

Abstract

Release behaviour of four flavour compounds from monoglyceride (MG) structured oil-in-water emulsions (structured emulsions) and conventional emulsions (without MG, unstructured emulsions) were studied using static headspace analysis. DSC confirmed that MG formed crystalline phase in the emulsions. The flavours had lower air-emulsion partition coefficients (K A/E ) in MG structured emulsions, and changes in MG content, oil content and oil type resulted in significantly modified K A/E (p < 0.05). In structured emulsions when MG content was ≥1 %, the flavours also had lower initial headspace concentrations (Cinitial) and maximum headspace concentrations (Cmax) compared with those in unstructured emulsions. However, the flavours had higher release rates in structured emulsions. When oil content was reduced from 20 to 10 %, more limonene and hexanal, but less propanol and diacetyl were released. In emulsions with medium-chain triglyceride (MCT), the flavours had significantly lower Cinitial and Cmax than in emulsions with soybean oil (SO) (p < 0.05). Among the flavour compounds tested, lipophilic compounds were more influenced by MG structured emulsions than the hydrophilic compounds (p < 0.05).