Selected starter culture for the formulation of a functional fermented whey drink

MICAELA PESCUMA; ELVIRA MARÍA HÉBERT; MICHELE DALGALLARONDO; JEAN-CHARLES GAUDIN; TOMAS HAERTLE; FERNANDA MOZZI; JEAN MARC CHOBERT; GRACIELA FONT DE VALDEZ

Copenhague

Congreso; FOODMICRO.Food Safety and Food Biotechnology: diversity and global impact; 2010

Historically, whey has been considered a waste stream by cheese-makers. Transformation of whey into a valuable dairy raw material has been facilitated mainly by scientific knowledge and technology advances that recognize the high nutritional value of whey and developed different strategies to optimize its industrial use, transforming whey into an interesting substrate for formulating functional dairy foods. Whey proteins have a high biological value and are a rich source of essential amino acids; however its main protein, β-lactoglobulin (BLG) is highly allergenic. Lactic acid bacteria are extensively used in the dairy industry as starter cultures and are able to hydrolyze milk proteins. The aim of this study was to formulate a functional fermented whey beverage using lactic acid bacteria and WPC to obtain a fermented product with low lactose and BLG contents. Cell viability (CFU/ml), lactose consumption (HPLC), proteolytic activity (OPA), amino acid release (HPLC) and BLG degradation (HPLC) was evaluated for a starter culture named SLaB (Lactobacillus acidophilus CRL 636, L. delbrueckii subsp. bulgaricus CRL 656 and Streptococcus thermophilus CRL 804; 3:1:1, v/v/v). The ability of the lactobacilli strains (known to be able to degrade BLG) from starter SLaB to hydrolyze the main epitopes (41-60, 102-124, 149-162) of BLG was also evaluated by using a non-proliferating cell system using pure BLG and analyzed by LC-MS/MS. SLaB grew 3 log cfu/ml, consumed 33% of the initial lactose, displayed high proteolytic activity (484 ug/ml Leu) releasing essential amino acids (Leu, 13 ug/ml; Ile, 18 ug/ml and Val, 35 ug/ml) and hydrolyzed 92% of BLG. After fermentation, WPC was mixed with peach juice and calcium lactate (2%, w/v) and stored at 10 °C for 28 days.  The addition of calcium lactate maintained the drink pH stable; no contamination was detected after the storage period. The lactobacilli strains from SLaB hydrolyze BLG epitopes probably reducing its allergenic content. This starter is an interesting candidate for the production of functional fermented beverages (high essential amino acids concentration, and low BLG and lactose content) using WPC as substrate.