Sodium tripolyphosphate is a non-toxic and economic alternative to glutaraldehyde for preparation of L-asparaginase CLEAs to reduce acrylamide in potato fries

Abstract

L-Asparaginase CLEAs were prepared utilizing sodium tripolyphosphate (TPP) as a crosslinker (TA-CLEA). Under optimized conditions (pH 3, 0.3% TPP concentration, and a crosslinking time of 1 h), an 85% activity recovery was achieved. TA-CLEAs demonstrated superior pH stability (pH 3-8) compared to GA (glutaraldehyde)-CLEA but lost structural integrity at pH 9. TA-CLEAs were thermally more stable (concerning activity) and structurally less stable than GA-CLEA owing to the presence of weaker ionic bonds. TA-CLEAs reported an increase in apparent K_m (reduced substrate affinity) and apparent V_max values and displayed excellent reusability after 10 cycles of use (> 75%). The increase in β-sheet and random coil structures indicated a trade-off between structure stability and flexibility of the protein. TA-CLEAs reduced the acrylamide content in potato fries by 79% after 40 min of treatment time. Thus, the use of TPP as a non-toxic, economical, and biocompatible alternative to the conventionally used toxic crosslinker glutaraldehyde was demonstrated.