TY - JOUR
T1 - Influence of different proteolytic strains of Streptococcus thermophilus in co-culture with Lactobacillus delbrueckii subsp. bulgaricus on the metabolite profile of set-yoghurt
AU - Settachaimongkon, S.
AU - Nout, M.J.R.
AU - Antunes Fernandes, E.C.
AU - Hettinga, K.A.
AU - Vervoort, J.J.M.
AU - van Hooijdonk, A.C.M.
AU - Zwietering, M.H.
AU - Smid, E.J.
AU - van Valenberg, H.J.F.
PY - 2014
Y1 - 2014
N2 - Proto-cooperation between Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus is one of the
key factors that determine the fermentation process and final quality of yoghurt. In this study, the interaction between
different proteolytic strains of S. thermophilus and L. delbrueckii subsp. bulgaricuswas investigated in terms
of microbial growth, acidification and changes in the biochemical composition of milk during set-yoghurt fermentation.
A complementary metabolomics approach was applied for global characterization of volatile and
non-volatile polar metabolite profiles of yoghurt associated with proteolytic activity of the individual strains in
the starter cultures. The results demonstrated that only non-proteolytic S. thermophilus (Prt-) strain performed
proto-cooperation with L. delbrueckii subsp. bulgaricus. The proto-cooperation resulted in significant higher populations
of the two species, faster milk acidification, significant abundance of aroma volatiles and non-volatile
metabolites desirable for a good organoleptic quality of yoghurt. Headspace SPME-GC/MS and 1H NMR resulted
in the identification of 35 volatiles and 43 non-volatile polar metabolites, respectively. Furthermore, multivariate
statistical analysis allows discriminating set-yoghurts fermented by different types of starter cultures according
to their metabolite profiles. Our finding underlines that selection of suitable strain combinations in yoghurt
starters is important for achieving the best technological performance regarding the quality of product.
AB - Proto-cooperation between Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus is one of the
key factors that determine the fermentation process and final quality of yoghurt. In this study, the interaction between
different proteolytic strains of S. thermophilus and L. delbrueckii subsp. bulgaricuswas investigated in terms
of microbial growth, acidification and changes in the biochemical composition of milk during set-yoghurt fermentation.
A complementary metabolomics approach was applied for global characterization of volatile and
non-volatile polar metabolite profiles of yoghurt associated with proteolytic activity of the individual strains in
the starter cultures. The results demonstrated that only non-proteolytic S. thermophilus (Prt-) strain performed
proto-cooperation with L. delbrueckii subsp. bulgaricus. The proto-cooperation resulted in significant higher populations
of the two species, faster milk acidification, significant abundance of aroma volatiles and non-volatile
metabolites desirable for a good organoleptic quality of yoghurt. Headspace SPME-GC/MS and 1H NMR resulted
in the identification of 35 volatiles and 43 non-volatile polar metabolites, respectively. Furthermore, multivariate
statistical analysis allows discriminating set-yoghurts fermented by different types of starter cultures according
to their metabolite profiles. Our finding underlines that selection of suitable strain combinations in yoghurt
starters is important for achieving the best technological performance regarding the quality of product.
KW - lactic-acid bacteria
KW - nuclear-magnetic-resonance
KW - food fermentations
KW - volatile compounds
KW - functional foods
KW - flavor formation
KW - fermented milks
KW - dairy-cows
KW - shelf-life
KW - metabolomics
U2 - 10.1016/j.ijfoodmicro.2014.02.008
DO - 10.1016/j.ijfoodmicro.2014.02.008
M3 - Article
SN - 0168-1605
VL - 177
SP - 29
EP - 36
JO - International Journal of Food Microbiology
JF - International Journal of Food Microbiology
ER -