Protein glutaminase-driven structural and functional enhancement of low-cost plant-based meat analogs from soybean meal-soybean powder blends

• PG enhances fibrous structure and texture of PBMA. • PG reduces off-flavors and improves umami in soy-based analogs. • PG increases in vitro protein digestibility by 20.6 %. • PG enables superior quality in low-cost SM-SP formulations. Plant-based meat analogues (PBMA) formulated from soybean meal (SM) and soybean powder (SP) offer a cost-effective alternative to traditional meat, yet their texture and flavor often fall short of consumer expectations. To address these limitations, we introduced protein glutaminase (PG) (0-0.5%) into the SM-SP blend and fabricated PBMA using twin-screw extrusion. Here, we report that PG acts as a key modifier to address these limitations. By incorporating PG (0-0.5%) into a 7:3 SM‑SP blend, we observed marked improvements in structural and sensory properties. At 0.3% PG, PBMA exhibited a fibrous network with the highest fiber degree (1.675), increased springiness (0.987) and cohesiveness (0.713), and enhanced water retention (WHC = 3.34 g/g). Deamidation by PG also reduced undesirable bitterness and astringency, strengthened umami perception, and increased in vitro protein digestibility by 20.6%. Analyses of protein interactions, rheology, and thermal behavior revealed that moderate PG levels promote disulfide and hydrogen bonding while mitigating excessive hydrophobic aggregation. We further developed predictive models (R 2 ˃ 0.74) to accurately tailor PBMA attributes via PG dosage. These findings position PG as a practical tool for producing low‑cost, high‑quality PBMA with meat‑like properties.