BITTERNESS AND NITROGEN FRACTIONS OF MOLD RIPENED CHEESE OF CAMEMBERTTYPE - IMPACT OF THE ASSOCIATION OF PENICILLIUM-CAMEMBERTI WITH GEOTRICHUM-CANDIDUM

Sixteen experimental camembert cheeses were prepared with 4 strains of Penicillium camemberti used alone or in mixed culture with 3 strains of Geotrichum candidum. They were tasted by a panel of 18 selected and trained judges. Nitrogen fractions of these cheeses were analysed (to tal nitrogen, soluble nitrogen at pH 4.6, soluble nitrogen in phosphot ungstic acid, ammonia). Proteolytic and aminopeptidasic activities wer e also measured. Bitterness of cheeses is correlated with the concentr ation of soluble nitrogen at pH 4.6 or concentration of peptides. The ammonia taste is also correlated with the free ammonia concentration. Cheeses inoculated with pure Penicillium camemberti were judged to be more bitter. They have also the highest concentrations in soluble nitr ogen at pH 4.6 and in peptides. Geotrichum candidum has a higher amino peptidasic activity than Penicillium camemberti; it may be the pathway by which Geotrichum candidum would decrease bitterness. Total nitroge n concentration and soluble nitrogen concentration in phosphotungstic acid of the 16 cheeses were not significantly different.