Evaluation of Probiotic-Beverage Matrix Interaction for Efficient Control of Enterobacter aerogenes and Staphylococcus aureus

Abstract

ABSTRACT Second-generation functional foods based on nonconventional matrices such as fruits, vegetables, and cereals demand high-quality food products with an extended shelf life. The aim of this work was to evaluate the protective efficiency of probiotic strain Lactobacillus rhamnosus GG incorporated into two phenolic-rich fruit matrices, sea buckthorn juice (SBT) and apple juice (APJ) both supplemented with whey protein concentrate (WPC), during refrigerated storage (4°C). The protective potential after a cold chain break (at 10 and 20°C) was also evaluated. The efficiency of L. rhamnosus GG substantially depended on the matrix components. L. rhamnosus GG in SBT+WPC inhibited Enterobacter aerogenes and Staphylococcus aureus by 1 log CFU/mL within 7 days of refrigerated storage compared with less inhibition of E. aerogenes and S. aureus by 0.75 and 0.83 log CFU/mL, respectively, by L. rhamnosus GG in APJ+WPC. Principal component analysis clustered L. rhamnosus GG in SBT+WPC as the most efficient matrix based on its ability to inhibit both E. aerogenes and S. aureus. The rheological parameters of the WPC-supplemented L. rhamnosus GG matrices were also evaluated. The consistency index and flow behavior index were derived from shear experiments. All juice matrices had shear-thinning properties. The pseudoplastic behavior of the juices increased with the addition of WPC and L. rhamnosus GG. HIGHLIGHTS