Large quantities of natural casings are used in sausage production, affecting quality and cost aspects. The influence of different casing treatments with surfactant solutions on the stuffing yield of Calabrese sausage was studied in this work. The effect of process variables (soy lecithin and soy oil concentrations, temperature and treatment time) on casing properties was evaluated with the aid of an experimental design. Elongation, tensile strength, porosity and water vapor permeability of treated casings, as well as color, sensory attributes and physical-chemical parameters were determined. Higher stuffing yields were obtained using soy lecithin solutions in concentration up to 1:25 w/w for 30-60 min. The surfactant solutions increased the elongation capacity of the treated casings. On the other hand, no significant difference was observed regarding the water vapor permeability of treated casings compared with control. Consequently, the yield of natural hog casings can be improved by the proposed treatment, while the quality characteristics are preserved. (c) 2008 Elsevier Ltd. All rights reserved.