INVESTIGADORES
MOZZI Fernanda Beatriz
congresos y reuniones científicas
Título:
A functional fermented beverage formulated with whey protein concentrate
Autor/es:
M. PESCUMA; E. M. HÉBERT; F. MOZZI; G. FONT DE VALDEZ
Reunión:
Simposio; III Simposio Internacional de Bacterias Lácticas. II Encuentro RED BAL Argentina; 2009
Resumen:
Over the years, numerous efforts have been made to
transform whey, generated as by-product of the cheese industry, into a suitable
product for food use. Whey constitutes about 90% of the milk volume used for
cheese manufacture retaining 55% of milk nutrients. Whey proteins are recovered
by ultrafiltration and spray dried to produce powdered whey protein concentrate
(WPC). The main whey protein, β-lactoglobulin (BLG), is the major cause of milk
allergy in children under three years old. Lactic acid bacteria have been extensively
used in the development of dairy foods and are able to degrade milk proteins. This
work addressed the development of a fermented whey-based drink with reduced BLG
content. Cell viability, lactose consumption, lactic acid production, proteolytic
activity, amino acid release and BLG degradation by the strains Lactobacillus acidophilus CRL 636, Lb. delbrueckii subsp. bulgaricus CRL 656 and Streptococcus thermophilus CRL 804, as
single or mixed (SLaB) starter cultures were evaluated in WPC (10%, w/v) incubated
at 37°C for 12 h. The fermented WPC was then mixed with peach juice and calcium
lactate (2%, w/v) and stored for 28 days at 10°C. During fermentation, single
cultures grew 2-3 log cfu/ml and produced between 12 and 101 mM of lactic acid
as consequence of lactose consumption (4-42 mM). Lb. delbrueckii subsp. bulgaricus
CRL 656 was the most proteolytic strain (576 µg/ml Leu) and released the branched
chain essential amino acids Leu (16 mg/ml), Ile (27 mg/ml) and
Val (43 mg/ml) and S.
thermophilus showed the lowest proteolytic activity (70 mg/ml Leu).
All strains degraded BLG in a range of 8-27%
after 12 h. The starter culture SLaB grew 3 log cfu/ml, showed a marked pH
reduction, produced 84 mM of lactic acid and displayed high proteolytic
activity (484 mg/ml Leu) releasing Leu (13 mg/ml), Ile (18 mg/ml) and Val (35 mg/ml), and hydrolyzed 16% of BLG. The addition of peach
juice improved the organoleptic characteristics of the fermented WPC and
calcium lactate maintained the drink pH stable during the shelf-life, no
contamination being observed after 28 days. During this period, a decrease in cell
viability was observed for all strains being more pronounced for Lb. acidophilus CRL 636 (0.7 log cfu/ml).
No significant changes in amino acid concentration were detected. These results
evidence that WPC fermentation by selected lactic acid bacteria might be used
for developing novel functional beverages with improved properties such as reduced
BLG content and increased branched-chain essential amino acids.