Comparative Evaluation of Inulin and High-Ester Pectin for Microencapsulation of Bacillus coagulans TBC-169:...

New types of functional peanut butter containing the probiotic strain Bacillus coagulans TBC-169 and Bacillus coagulans microcapsules with different wall materials were developed. After 24 h of in vitro simulated digestion, the peanut butter with high-ester pectin (group A) and inulin (group B) microcapsules still retained 5.94 ± 0.58 × 10⁸ and 1.79 ± 0.73 × 10⁹ CFU/g of Bacillus coagulans, respectively. Both the high-ester pectin and inulin microcapsules could be well preserved in the peanut butter substrate and stored at 4 °C and 25 °C for 120 days. The biological activities of B. coagulans in the two groups were 2.64 ± 0.58 × 10¹⁰ and 2.31 ± 0.4 × 10¹¹ CFU/g, and 5.20 ± 0.10 × 10⁸ and 2.24 ± 0.11 × 10⁹ CFU/g, respectively. The addition of microcapsules improved the texture, stability, and rheological properties of the peanut butter. Differential scanning calorimetry revealed that the microcapsules showed certain binding interactions with the oil and proteins in the peanut butter. The rheological and texture tests demonstrated an improved ductility and reduced hardness and viscosity after the microcapsule addition. Targeted metabolomics identified inulin as a synergistic substrate for Bacillus coagulans in the probiotic peanut butter, which enhanced the functionality and stability of the microencapsulated probiotics. This study delivered essential information and parameters for the preparation of probiotic microcapsule peanut butter and laid the foundation for future research efforts geared toward the formulation, preparation, and characterization of functional peanut butter.