High pressure processing of sweet corn milk yogurt: A plant-based probiotic carrier with enhanced stability

Sweet corn milk yogurt represents a promising plant-based matrix for probiotic delivery, but maintaining microbial viability and product quality remains a challenge. High-pressure processing (HPP) offers a non-thermal approach to improve stability. This study examined the effects of HPP at 100–300 MPa for 10 min on probiotic survival, physicochemical quality, and storage stability of sweet corn milk yogurt fortified with Lacticaseibacillus casei 01, Streptococcus thermophilus, and Lactobacillus delbrueckii subsp. bulgaricus. Probiotic counts were monitored during simulated gastrointestinal (GI) digestion and 6 weeks of refrigerated storage (4 °C). All strains declined significantly at ≥200 MPa, with the greatest reduction at 300 MPa (p ≤ 0.05). Among the tested microbes, L. casei 01 exhibited higher tolerance to GI conditions, although survival decreased with increasing pressure. Yogurt processed at 100 MPa maintained viable probiotic levels above 7 log CFU/g, with only slight changes in pH, titratable acidity, sugar content, and browning index. Moderate syneresis and viscosity reduction were also observed. In contrast, higher pressures negatively affected microbial viability and texture. Overall, HPP at 100 MPa was most effective in preserving probiotic viability and yogurt quality, supporting its application as a viable method to extend shelf life and enhance functionality of plant-based probiotic products.