DRIED SAUSAGES FERMENTED WITH STAPHYLOCOCCUS-XYLOSUS AT DIFFERENT TEMPERATURES AND WITH DIFFERENT INGREDIENT LEVELS .4. AMINO-ACID PROFILE

Sausages with added Staphylococcus xylosus were fermented at different temperatures and with different added levels of salt, glucose, nitrit e, nitrate and Pediococcus pentosaceus in accordance with a six-factor fractional design. The amounts of individual amino acids were measure d and the effects of temperature and different ingredients on the amin o acid profile were tested wing multiple linear regression and analysi s of variance. Also, the amino acid profile was correlated to the leve l of volatile compounds by partial least squares analysis. The study s howed that the level of free amino acids was significantly affected by the different factors. High fermentation temperature and nitrite cont ent increased the amount, while high contents of salt, nitrate, glucos e and P. pentosaceus lowered the amount of free amino acids. In genera l, temperature and nitrate had the greatest influence. It was shown th at the amounts of the volatile compounds, 2-methyl propanal, 2- and 3- methyl butanal, were inversely correlated with the amounts of valine, isoleucine and leucine, respectively, indicating that those volatiles were degradation products of the latter. (C) 1997 Elsevier Science Ltd .