1- Department of Environmental Agricultural Sciences and Agro-Food Biotechnologies, University of
Sassari, 07100 Sassari, Italy.
Abstract: (5801 Views)
The effect of a selected autochthonous starter culture made up by Streptococcus
thermophilus, Lactobacillus delbrueckii subsp. lactis and Lactobacillus helveticus on the
microbiological and physicochemical properties of Pecorino Romano cheese during
ripening was investigated. The suitability of the experimental starter culture was tested at
industrial scales in cheese-making trials of Pecorino Romano. Pecorino Romano cheese
manufactured by use of scotta-fermento served as control. The lactic microflora increased
significantly in experimental cheeses as compared to the control and this was also
accompanied by a substantial decrease of spoilage microorganisms in experimental
cheeses. Free amino acids (FAAs) were more abundant in experimental cheeses,
arginine+g-aminobutyric acid and leucine in particular. These differences could be likely
due to a different enzymatic activity of the selected starter culture as compared to the
scotta-fermento used in the control trials. Oleic (C18:1), palmitic (C16:0), butyric (C4),
stearic (C18:0) and myristic (C14:0) acids were the most abundant Free Fatty Acids
(FFAs) detected in both brand of cheeses at the end of ripening. Overall, the level of FFAs
in experimental and control cheeses did not show significant differences, even if the
average values in experimental cheeses were always slightly higher than those recorded
for the control. Moreover, the average content of FFAs of Pecorino Romano was found
the lowest when compared with the other Sardinian PDO cheeses; most likely the high
content of sodium chloride and the low aW of Pecorino Romano influenced all the lipase
activities, even those present in the rennet paste. Despite this, the employment of the
selected starter culture revealed useful to improve the physico-chemical features of
Pecorino Romano while preserving its tipicity.
Received: 2011/02/5 | Accepted: 2011/02/5 | Published: 2011/02/5