Volume 43, Number 421-422, 1963
|22 - 30
Étude d'une méthode de référence pour la détermination de la matière sèche dans les fromages : comparaison avec les méthodes actuellement en usageMme MARTELLI
Ingénieur au Laboratoire Municipal de Paris
Abstract - On examining results we have obtained with these tests, it appears that the following conclusions can be drawn:
1) In the case of cheese, in a fresh condition or well preserved, the method proposed by the International Convention of Rome as well as the method developed by K. FISCHER and adapted to the determination of solids in cheese give very similar results. In a few cases, we have obtained with mouldy soft cheeses significant deviations, especially with a Bleu d'Auvergne, in which the solids determined by the method of the International Convention of Rome were lower than the solids determined by our method, namely about 1 per cent. In fact, volatile fatty acids which are quite plentiful in this sort of cheese are likely, to be partially eliminated under the influence of heating in the oven at 100° C (212° F), procedure provided for in the method of the International Convention of Rome.
2) On the other hand, it appears that the method of drying in the oven at 70° C (158° F) under reduced pressure give most often too high results, chiefly with cooked or pressed cheeses. It is exactly what we have observed with Gruyère I, Hollande, Bonbel, Port-Salut and Edam I. Moreover, it occurs very frequently that dessication takes a long time. The fact that water can be readily retained by proteins is not surprising with these rather hard cheeses. However, in the case of more or less damaged cheeses, this method give results which are higher than those obtained by the method of the International Convention of Rome, and very similar to the data obtained with the method developed by K. FISCHER