Application of Asparaginase Enzyme in Reducing Acrylamide Formation in Roasted Coffee Beans

Acrylamide is formed through the Maillard reaction between L-asparagine and reducing sugars during thermal processing. The enzyme L-asparaginase can effectively mitigate acrylamide formation by hydrolyzing asparagine into aspartic acid without affecting product quality. This study investigated the effect of asparaginase application methods, enzyme concentrations, and incubation temperatures on acrylamide reduction and pyrazine preservation in roasted Arabica coffee beans. Two enzyme application methods—soaking and spraying—were compared using 4000 U/g asparaginase. Soaking treatment achieved a greater acrylamide reduction (92.8%) compared to spraying (86.8%), and was therefore selected for optimization. Subsequently, enzyme concentrations (2000, 3000, and 5000 U/g) and incubation temperatures (40, 50, and 60 °C) were tested. The optimal condition was found at 3000 U/g enzyme concentration and 50 °C incubation for 30 minutes, resulting in 96.5% acrylamide reduction and significant conversion of asparagine to aspartic acid, without altering pyrazine concentrations responsible for coffee aroma. The pH of treated beans remained stable (5.38–5.92), indicating no negative impact on sensory attributes. Overall, asparaginase application effectively reduced acrylamide formation in roasted coffee while maintaining desirable flavor compounds, demonstrating its potential as a practical enzymatic strategy for improving the safety and quality of thermally processed coffee products.