We are concerned with a system of equations in R d (d ≥ 2) governing the evolution of isothermal, viscous and compressible fluids of Korteweg type, that can be used as a phase transition model. In the case of zero sound speed P ′ (ρ * ) = 0, it is found that the linearized system admits the purely parabolic structure, which enables us to establish the global-in-time existence and Gevrey analyticity of strong solutions in hybrid Besov spaces of L p -type. Precisely, if the full viscosity coefficient and capillary coefficient satisfy ν2 ≥ 4κ, then the acoustic waves are not available in compressible fluids. Consequently, the prior L 2 bounds on the low frequencies of density and velocity could be improved to the general L p version with 1 ≤ p ≤ d if d ≥ 2. The proof mainly relies on new nonlinear Besov (-Gevrey) estimates for product and composition of functions.