The Peng-Robinson equation of state is adapted to calculate phase equilibria for industrial sugar juices using the pseudocomponent approach. These juices were characterized by sugar, amino acid, carboxylic acid and ash pseudocomponents in aqueous solution. New correlating equations are developed for calculating the pseudocomponents equation of state constants using the molecular structure. Pseudo-binary interaction parameters of Peng-Robinson equation of state were fitted by means of the maximum likelihood principle and experimental vapor-liquid equilibria data. Experimental data were obtained using an Othmer-type apparatus at atmospheric pressure for 10 synthetic systems: four pseudo-binary systems (sugar-water, amino acid-water, carboxylic acid-water, ash-water), four pseudo-ternary systems (sugar-amino acid-water, sugar-carboxylic acid-water, sugar-ash-water, amino acid-carboxylic acid-water) and two pseudo-quaternary systems (sugar-amino acid-ash-water and sugar-carboxylic acid-ash-water). The adapted Peng-Robinson equation of state obtained was successfully used to estimate the boiling temperatures of industrial beet and cane sugar juices over a wide range of dry substances content.