Derivation of Thermodynamic Sorption Equation of Flavors with Packaging Films. 2

A further approach to derive the thermodynamic sorption equation for aqueous phase was performed by estimating the molar heat of sorption (ΔH_s) accurately. On the basis of the findings that the sorption of a volatile compound depends on both its molar heat of mixing into film and its enthalpy change toward film, the following equation could be successfully derived: S = S₀ exp γ, [V_v[(δ_w-δ_v)² —, δ_c²]/RT]. The plots of In S into LDPE film vs the term of the equation gave more adequate improvement in the correlation (r = 0.968). Taking into account the volatility (α) of a volatile compound from solution, further improvement of the equation was made: S = α, S₀ exp γ, [V_v[(δ_w-δ_v)² —, δ_c²]/RT]. The plots of In S/α, vs the term of the equation for both sugar-ester and SDS solutions gave a sufficient correlation (r = 0.959). Furthermore, the equation could be sufficiently applied to various polymers (PP, r = 0.931, EVA, r = 0.963, EVOH, r = 0.932).