In previous studies it was observed that milk fatty acid (FA) compositionis mainly affected by diet, and when ruminants graze pasturethe percentages of polyunsaturated FA and conjugatedlinolenic acid (CLA) are higher than in milk from preserved forage.The maintenance in the cheese of the beneficial FA profile ofmilk from grazing ruminants is advisable. Little number of studyexists concerning the effect of milk processing conditions oncheese FA profile, but no study was done with regard to PecorinoSiciliano cheese. The aim of this study was to evaluate the transferof FA from ewes milk to cheese manufactured according to thePecorino Siciliano technology, in order to verify if the cheesemakingprocess could modify the FA profile of cheese, as yet observedby other authors for CLA and C18:1 isomers. Bulk milk fromComisana ewes grazing a spring pasture was processed six timesduring three consecutive weeks. For each cheesemaking, the 48-hbulk milk was divided equally, one part was processed as raw milkand the other one was pasteurized (72°C for 20 s) and inoculatedwith a starter culture. FA transfer from milk to cheese did not seemto be greatly affected by cheesemaking technology also when milkwas treated by pasteurization. However, some significant differenceswere recorded for C11:0 (P=0.0434) and C14:1c9(P=0.0132) that resulted higher in cheese than in milk. Also someisomers of CLA, such as C18:2 t-9, c-11 and CLA C18:2 t-11, t-13,resulted higher in cheese than in milk (P=0.058 and P=0.0058,respectively), but the difference reached the significance onlybetween milk and cheese from raw milk, probably as consequenceof a different activity between natural microflora and added micro -organisms. This trial showed that during the cheesemaking thetotality of milk FA are transferred into the cheese even when themilk is processed after a thermal treatment. Nevertheless, somevariations had been observed with regard to CLA isomers, in linewith other findings on sheep cheese produced in other Italianregions.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2011|