Evaluation of probiotic-beverage matrix interaction for efficient control of enterobacter aerogenes and staphylococcus aureus

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 (48C). The protective potential after a cold chain break (at 10 and 208C) was also evaluated. The efficiency of L. rhamnosus GG substantially depended on the matrix components. L. rhamnosus GG in SBTþWPC 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 APJþWPC. Principal component analysis clustered L. rhamnosus GG in SBTþWPC 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.