Author(s):
Tavaria, F. K. 
; Dahl, S. ; Carballo, F. J. ; Malcata, F. X.
Date: 2002
Persistent ID: http://hdl.handle.net/10400.14/6831
Origin: Veritati - Repositório Institucional da Universidade Católica Portuguesa
Subject(s): Flavor; Catabolism; Starter Cultures; Cheese
Description
Twelve isolates of lactic acid bacteria, belonging to
the Lactobacillus, Lactococcus, Leuconostoc, and Enterococcus
genera, were previously isolated from 180-
d-old Serra da Estrela cheese, a traditional Portuguese
cheese manufactured from raw milk and coagulated
with a plant rennet. These isolates were subsequently
tested for their ability to catabolize free amino acids,
when incubated independently with each amino acid
in free form or with a mixture thereof. Attempts were
made in both situations to correlate the rates of free
amino acid uptake with the numbers of viable cells.
When incubated individually, leucine, valine, glycine,
aspartic acid, serine, threonine, lysine, glutamic acid,
and alanine were degraded by all strains considered;
arginine tended to build up, probably because of transamination
of other amino acids. When incubated together,
the degradation of free amino acids by each
strain was dependent on pH (with an optimum pH
around 6.0). The volatiles detected in ripened Serra da
Estrela cheese originated mainly from leucine, phenylalanine,
alanine, and valine, whereas in vitro they originated
mainly from valine, phenylalanine, serine, leucine,
alanine, and threonine. The wild strains tested
offer a great potential for flavor generation, which
might justify their inclusion in a tentative starter/nonstarter
culture for that and similar cheeses.
(Key words: flavor, catabolism, starter cultures,
cheese)
