Design of a lactic starter culture for the formulation of a functional fermented whey-based beverage with reduced lactose and beta-lactoglobulin content

M. PESCUMA; E. M. HÉBERT; M. DALGALARRONDO; T. HAERTLE; F. MOZZI; J.M. CHOBERT; G. FONT DE VALDEZ

Copenague, Denmark

Simposio; Food Micro 2010 22nd International ICFMH Symposium; 2010

International Committee on Food Microbiology and Hygiene

  n the past, whey has been considered as a waste by cheese-makers. Transformation of whey into valuable dairy raw material has been facilitated by the advance of scientific knowledge and progress of technology transforming whey into an interesting substrate for formulating functional dairy foods. Whey proteins are rich sources of essential amino acids; however, their main protein component, â-lactoglobulin (BLG) is highly allergenic. Lactic acid bacteria (LAB) 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 LAB and whey protein concentrate (WPC) to obtain a fermented product with low lactose concentration and BLG content. Cell viability (CFU/ml), lactose consumption (HPLC), proteolytic activity (OPA), amino acid release (HPLC) and BLG degradation (HPLC) were evaluated using a starter culture named SLaB composed of 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 degrade BLG) of the 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 well (3 log cfu/ml), consumed 33% of the initial lactose and displayed high proteolytic activity (484 µg/ml Leu) releasing essential amino acids (Leu, 13 µg/ml; Ile, 18 µg/ml and Val, 35 µg/ml) and hydrolyzing 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 pH of the beverage stable and no contamination was detected after the storage period. The lactobacilli strains from SLaB were able to hydrolyze the main epitopes of BLG. This starter is an interesting candidate for the production of functional fermented whey-based beverages (with high essential amino acids concentration, and low BLG and lactose content) using WPC as substrate.