Improvement of compositional, textural, and rheological characteristics in plant-based cheese analogs fermented by kefir grain

Although plant-based cheese has been developed as a healthful food, it has limitations in terms of texture and flavor. In this study, novel soybean-based cheese analogs were prepared using soy protein isolate and kefir grains for improved properties. The analogs containing 3 % (w/v) soy protein isolate exhibited high water-holding capacity (90.80 %), and the sample prepared with 0.3 % (w/v) CaCl₂ showed the high hardness (0.52 N). Additionally, hydrophobic interactions mainly contributed to structure formation and a significant proportion (> 90 %) of immobilized water was determined using low-field nuclear magnetic resonance analysis. Furthermore, the enhanced thermal stability and secondary structures of the analogs were demonstrated using thermogravimetric analysis, Fourier-transform infrared spectroscopy, and X-ray diffraction. The porous and compact microstructures of the analogs were observed using scanning electron microscopy. Our results provide an innovative approach for the preparation and application of plant-based cheese analogs using kefir grains.