INVESTIGADORES
MOZZI Fernanda Beatriz
congresos y reuniones científicas
Título:
Hydrolysis of beta-lactoglobulin by LAN in an in vitro gastric/pancreatic system. Effect of exopolysaccharides
Autor/es:
M. PESCUMA; E. M. HÉBERT; M. DALGALARRONDO; T. HAERTLE; F. MOZZI; G. FONT DE VALDEZ; J.M. CHOBERT
Reunión:
Simposio; Antimicrobial peptide symposium; 2009
Resumen:
Peptides generated by
hydrolysis of BLG by non-proliferating cells of the strain Lactobacillus
acidophilus CRL 636 were analyzed. Polysaccharides are commonly used in the dairy
industry to improve food texture. They may interact with proteins in the form
of hydrocolloids , affecting their digestibility. The effect of polysaccharides
(pectin, and two EPS synthesized by two Streptococcus thermophilus
strains, EPS1190 and EPS804) on BLG digestibility using an in vitro gastric/pancreatic system was determined.
Non-proliferating cells of Lb. acidophilus CRL 636 were able to hydrolyze
52% of BLG. Twenty-six resulting peptides with molecular masses in the range
544 - 4119 Da were identified by LC-MS/MS. These peptides resulted mostly from
the hydrolysis of the more accessible N-terminal part of BLG. Degradation of
BLG by pepsin was poor (8%). When BLG was previously hydrolyzed by Lb. acidophilus CRL 636, peptic
hydrolysis reached 54.8%. After addition of pectin and EPS1190 hydrolysis
increased till 58.2 and 57.2%, respectively. Peptides crossing 8 kDa dialysis
membranes after trypsin/chymotrypsin hydrolysis were analyzed by HPSEC. The
produced peptides were smaller when BLG was hydrolyzed previously by the Lb. acidophilus strain. Moreover, in the
presence of pectin, the amount of larger peptide (3.5 kDa) observed in the size
exclusion chromatograms was reduced considerably. Our studies showed that
pre-hydrolysis of BLG by Lb. acidophilus
CRL 636 had a positive influence on BLG digestibility and that polysaccharides
may change the peptide profile yielded by tryptic/chymotryptic hydrolysis,
releasing smaller size peptides, which are known to be less immuno-reactive.
Additionally, Lb. acidophilus CRL 636
was able to hydrolyze the main epitopes (41-60, 102-124, 149-162) of BLG,
reducing its allergenic potency.