-The objective of this research was to study the effect of the following modifications to the traditional manufacturing process of Prato cheese: use of milk concentrated by ultrafiltration (UFCM) up to a concentration factor (CF) of 4:1, and partial pre-fermentation of the UFCM and indirect curd cooking on the composition, pH, titratable acidity (TA) and melting capacity (MC) of the cheese as compared with the standard cheese. Three processings of each of the following five treatments were carried out: Treatment 1 (T1), without ultrafiltration; Treatment 2 (T2), ultrafiltration without pre-fermentation of the UFCM; Treatment 3 (T3), pre-fermentation of 100 g·kg -1 of the UFCM; Treatment 4 (T4), pre-fermentation of 200 g·kg -1 of the UFCM; and Treatment 5 (T5), pre-fermentation of 200 g·kg -1 of the UFCM, and the only one with indirect curd heating. There was a significant difference for total solids between cheeses T4 and T5 with respect to T2. T2 presented the lowest fat and fat in dry matter content, although the observed differences were not statistically significant. The UFCM cheeses presented lower values for fat recovery in cheeses with a significant difference between the treatments T2 and T3 with respect to T1, the fat losses in processing being the main factor affecting cheeses' composition. The pre-fermentation of 200 g·kg -1 of the UFCM increased the acidity and reduced the pH of the cheeses. The time did not exert an influence on the pH but it increased cheeses's TA and MC. There was no difference in MC between the treatments but there was a tendency for greater MC values for cheeses with a higher water to total protein ratio and higher pH value.Cheese / ultrafiltration / pre-fermentation / cooking / melting Résumé -Évaluation de la capacité de fusion du fromage « Prato » obtenu par modifications du procédé de fabrication traditionnel. L'objectif de cette recherche était d'étudier l'effet de modifications du procédé de fabrication traditionnel du fromage « Prato » sur la composition, le pH, l'acidité titrable (TA) et la capacité de fusion (MC) du fromage, comparé au standard traditionnel. Les modifications ont été les suivantes : utilisation de lait concentré par ultrafiltration (UFCM) jusqu'à un facteur de concentration (CF) de 4:1 ; pré-fermentation partielle de l'UFCM et