Effect of Interface in Model Food Emulsions on the Volatility of Aroma Compounds

Abstract

Volatility of two aroma compounds ethyl butanoate and ethyl hexanoate was investigated in monophasic and biphasic systems. Monophasic systems were either water, an aqueous solution of sodium caseinate or sucrose stearate, or triolein. Biphasic systems, emulsified or not, consisted of triolein and one of those aqueous phases. Volatility measurements were carried out by headspace analysis and exponential dilution. In homogeneous systems, aroma retention was affected by the nature of the nonvolatile compounds: it was nearly 100% in triolein for both ethyl butanoate and ethyl hexanoate; in 5 g/L aqueous solution of sodium caseinate or sucrose stearate, retention values were 20% and 35% for ethyl butanoate and ethyl hexanoate, respectively. In biphasic systems, the vapor−liquid partition coefficient of ethyl hexanoate was not changed whether or not the system was emulsified and regardless of the nature of the surface active compound, i.e., sodium caseinate or sucrose stearate. Keywords: Volatility; aroma compounds; emulsions; interface