Sodium Formate as an Alternative for the Replacement of Streptococci in the Elaboration of Quartirolo Cheese

Abstract

Influence of sodium formate (SF) on the specific proteolytic activity (SPA) of L. delbrueckii subsp. bulgaricus (LBB, LBP and LBR) and its application in the elaboration of Quartirolo cheese was studied. A comparison between Quartirolo-type cheese, prepared with selected mixed starters of lactobacilli and streptococci (LBB+CP2 and LBP+CP2) with respect to pure lactobacilli starters (LBB and LBP), developed with and without sodium formate was also performed as regards organoleptic and microbiological properties. Different elaborations were performed with each starter and two cheese loaves of each one were analyzed at 10 and 20 days of ripening. For each sample were analyzed: pH, bacterial counts, proteolytic activity, meltability, moisture content, texture and sensorial properties. Statistical analysis was applied to experimental data. Bacterial suspensions obtained from cultures with strain LBB grown with sodium formate (SF) showed higher proteolytic activity than those cultures grown without SF. Texture properties, meltability and proteolytic activity in cheese prepared with lactobacilli LBB+streptococci CP2 were similar to found in cheese prepared with LBB+SF. These results suggest that formate could replace the streptococci on cheese elaboration. The assay of sensorial acceptability indicated that the formate could be supplemented to a pure starter and be employed instead of the streptococci since organoleptic properties were similar on both kinds of cheese.