Effect of High-Pressure Processing on Quality and Microbiological Properties of a Fermented Beverage Manufactured from Sweet Whey Throughout Refrigerated Storage

PEGA, JUAN; DENOYA, G. I.; CASTELLS, M. L.; SARQUIS, S.; ARANIBAR, G. F.; VAUDAGNA, S. R.; NANNI, M.

FOOD AND BIOPROCESS TECHNOLOGY

SPRINGER

Lugar: Berlin; Año: 2018

1935-5130

The production of fermented beverages is a promising way to valorize by-products of dairy manufacturing. However, the shelflifeof these products is often limited by the post-acidification process that occurs during storage. In this work, we manufactured afermented beverage from sweet whey by using the starter lactic acid bacteria (SLAB) Streptococcus thermophilus andLactobacillus delbrueckii subsp. bulgaricus. High-pressure processing (HPP) at 200 MPa for 10 min or 400 MPa for 1 minwere applied after manufacturing. The aim of this study was to evaluate the effect of HPP on the quality of the beverage and onthe behavior of the SLAB. Both high hydrostatic pressure treatments preserved flavor and texture attributes until 45 days post-HPP, without affecting chromatic parameters. Plate counts for both species were lower in HPP-treated beverages (HB) than incontrol beverages (CB), although treatment at 200 MPa maintained optimal amounts of total SLAB (6.6?7.9 log CFU/mL).Conversely, quantitative PCR (qPCR) and reverse transcription-qPCR (RT-qPCR) revealed that bacterial DNA or mRNA levelspersisted after HPP (> 1.4 × 105 genome or cDNA copies/mL), even upon 400-MPa treatments. As a whole, this study indicatedthat HPP preserved the quality of the beverage until 45 days post-HPP, which is longer than the shelf-life of conventionalfermented beverages obtained from milk. Moreover, our results obtained with these SLAB in a fermented dairy beverage uponHPP extend previous findings regarding the limitations of culture-dependent methods to assess microbial viability.