MICROSCOPIC CRYSTALLINE INCLUSIONS IN MAHON CHEESE

The incidence, structure and composition of microscopic crystalline in clusions have been studied in 32 samples of Mahon cheese (non-cooked p ressed cheese manufactured from cow's milk) at different ripening time s. Samples were observed by light microscopy (LM), transmission electr on microscopy (TEM) and scanning electron microscopy (SEM). Circular, oval or kidney-shaped structures approximately 20 mu m in diameter (ra nge 4-65 mu m), were observed in all Mahon cheese samples. The quantit y of crystalline inclusions per unit surface observed in Mahon cheese was heterogeneous, with an average of 30 crystals/m(2). It was possibl e to differentiate two different structures in the crystals: the nucle us with disorganized morphology and the cortex with radial laminar mor phology. The ratio between nucleus and inclusion diameters was 0.2-0.5 . Crystalline inclusions observed in Mahon cheese were studied by X-ra y microanalysis in SEM and TEM. Calcium and phosphorous were found to be the most common elements present in these inclusions.