Background: Fiore Sardo PDO is one of the oldest Mediterranean hard cheeses, exclusively produced in Sardinia (Italy) from raw whole ewe’s milk. Some manufacturers, improperly, submit raw milk to heat-treatment. Aim of this study was to evaluate the proteomic profile of Fiore Sardo PDO and to investigate possible differences between cheese made from raw milk and from heat-treated milk.
Materials and methods: Starting from the same ovine bulk milk, eight cheese wheels of Fiore Sardo PDO were produced, four from raw milk and four from heat-treated milk. The subsequent production steps were the same for both types of cheese as was sampling at different ripening times. Samples were analyzed by Urea-PAGE electrophoresis. Afterwards, blind analysis of 32 cheese samples, produced by 17 different cheesemakers was performed to evaluate the method’s analytical performance.
Results: Urea-PAGE analysis showed the presence of a protein band only in cheese made from raw milk, regardless of cheese ripening time. Protein identification analysis by liquid chromatography mass spectrometry identified two different proteins in the band, alpha-S1 and alpha-S2 casein. Blind analyses conducted to verify the analytical performance of the method showed that it could be a useful tool for the protection of this typical agri-food product.
Conclusion: We developed a simple, robust, and economic method for discriminating between Fiore Sardo PDO cheese made from raw milk with up to 24 months of maturation and Sardinian sheep milk cheese made from heattreated milk.
Published Date: 2019-10-18; Received Date: 2019-09-27