An investigation on the acrylamide mitigation potential of L-asparaginase from Aspergillus terreus BV-C strain

The presence of acrylamide, in the processed food items when cooked at a temperature above 120 degrees C is a fact that has been well-researched for the past 15 years. Food samples rich in asparagine and reducing sugars processed at higher temperatures, leads to the characteristic crispy brown appearance attributed to the formation of acrylamide and other intermediates, which in the last two decades has been linked to be a potent carcinogen in humans. A contemporary approach for the reduction of acrylamide content in food items is the use of fungal L-asparaginase which can hydrolyze the asparagine into aspartic acid, thereby hindering the Mailard reaction. The present report describes an economically viable approach for the production of extracellular L-asparaginase from Aspergillus terreus sp. using agricultural wastes as substrates. Optimization of factors, such as nature of solid substrate, initial moisture content (%), temperature (degrees C), and incubation time (h), showed the highest enzyme activity (84.3 U) in the medium supplemented with flaxseed oil cake as the substrate for the production of purified enzyme with 6.39-fold purity. The negligible activity of the purified enzyme towards L-glutamine (residual activity > 10%) indicated the absence of dual activity in L-asparaginase. With a combination of physical techniques followed by enzyme treatment of the raw material, a decline of nearly 93% in the acrylamide content was estimated using High Performance Liquid Chromatography (HPLC). Therefore, L-asparaginase from A. terreus purified using affordable means can be used for the mitigation of acrylamide content in the food items.