Free fatty acid profile of Parmigiano-Reggiano cheese throughout ripening: comparison between the inner and outer regions of the wheel.

From each of twenty wheels of Parmigiano–Reggiano cheese of different ages (1-24 months), samples representative of the inner part (I, 10 cm from the round side and 7 cm from the flat side) and of the outer part (O, the rest of the cheese after removing the rind) were collected. For each sample, free fatty acids (FFAs, expressed as mg / kg cheese fat) were determined by quantitative capillary gas chromatography. In 18- and 24-month-old cheese, total levels of FFAs (as sum of individual FFAs) were significantly (P≤0.05) higher in O than I, whereas no differences between regions were observed in 1-, 6- and 12- month-old cheeses. In terms of short (C4–C8) and medium (C10–C14) chain FFAs, levels in the outer regions were higher (P≤0.05) than inner regions for cheeses from 6- to 24-month-old. The content of long-chain FFAs (C16–C18:2) was higher in O than I in 18- and 24-month-old cheeses.