Acrylamide mitigation in foods using recombinant L-asparaginase: An extremozyme from Himalayan Pseudomonas sp. PCH182

Acrylamide has received worldwide attention due to its existence in commonly consumed foods. L-asparaginase reduces acrylamide formation in foods by hydrolyzing available L-asparagine. Herein, L-asparaginase (Ps-ASNase II) of Pseudomonas sp. PCH182 was expressed in Escherichia coli (E. coli), purified, and evaluated for acrylamide reduction in food samples. The monomeric 37 kDa Ps-ASNase II protein was purified to homogeneity with a 70 % yield. The enzyme was active at a wide pH range (5.0-11.0) and temperature (10-80 °C) with optimum activity at 45 °C in 50 mM Tris-HCl (pH 8.5) after 10 min. The K_m and V_max for L-asparagine were 0.52 ± 0.06 mM and 42.55 ± 4.0 U/mg, respectively. Also, the half-life and K_d value of the enzyme at 37 °C was 458 min and 1.51 × 10^-3/min, suggesting its higher stability. Consistently, the enzyme retained 62 % residual activity after 60 days of storage at 4 °C. The Ps-ASNase II enzyme (5 U/mL) treatment of raw potato chips resulted in 90 % asparagine hydrolysis exhibiting high efficiency. Ps-ASNase II (5 U/mL) treated potato chips significantly reduced acrylamide content by 73 % at 37 °C within 24 min compared to untreated controls. Collectively, these findings verified Ps-ASNase's effectiveness and capability to lower acrylamide formation in fried potato chips without altering the food product's nutritional profile.