Viability of Lactobacillus plantarum entrapped in double emulsion during Oaxaca cheese manufacture, melting and simulated intestinal conditions

Oaxaca cheese is a Mexican pasta filata-type cheese, and can be considered as a potential vehicle for delivering probiotic cells. Their processing conditions are harsher than for most other cheeses. Thus, the challenge is to provide an adequate protection to the probiotic cells in order that they reach in sufficient numbers the sites for exerting their functionality. Lactobacillus plantarum cells were entrapped in double emulsions (DE) (aguamiel, Ag, or sweet whey, SW, as inner aqueous phase) and incorporated during cheese manufacture to obtain cheese treatments CTAg and CTSW. A control cheese (CTControl) was made with non-encapsulated free cells. Log CFU g−1 was of 6.81 ± 0.08, 8.15 ± 0.17 and 8.22 ± 0.09 for CTControl, CTSW and CTAg, respectively, immediately after CT's manufacture. After melting, Log CFU g−1 dropped down by 2.18 ± 0.17, 1.42 ± 0.15 and 1.94 ± 0.12 for CTControl, CTSW and CTAg, respectively. The exposure of CTAg and CTSW to simulated gastrointestinal conditions (pH of 2.3 and bile salts) did not affect significantly cells viability (6.32 ± 0.13 and 6.02 ± 0.1 Log CFU g−1, respectively), but CTControl exhibited a significant decrease (p<0.05) to 3.36 ± 0.01 Log CFU g−1. The inclusion of cells in DE is an effective method for protecting their viability against harsh processing and usage conditions.