Using a colorimetric Lab-on-a-Chip (LOC) device, the activity of different organic enzyme formulations produced by an efficient fermentation technology are measured. Similar enzyme sensing strategies were chosen to take advantage of synergies in chip design. The methodology consists in a one-step reaction that uses specific substrates to produce a coloured end-product1. The microfluidic chip design compatible with roll-to-roll (R2R) extrusion coating fabrication consists on an inlet for the enzyme sample, a reaction chamber, and a capillary pump. The enzyme substrates were immobilized on the reaction chamber for simplify the handle for final user. Spotting was employed for the integration of the reagents on the chip because it is a compatible technique with R2R process2. COC was chosen for the chip fabrication for its flexibility required in R2R manufacturing and its transparency necessary for colorimetric detection. An adhesive foil is used to cover the structured microfluidic foil. A portable readout device with UV-LED and photodiodes was developed for measuring the enzymatic activity in situ in the manufacturing plant. 1. Posoongnoen, S. & Thummavongsa, T. Purification and characterization of thermostable α-amylase from germinating sword bean (Canavalia gladiata (jacq.) DC.) seeds. Plant Biotechnol. 37, 31–38 (2020). 2. Toren, P. et al. High-throughput roll-to-roll production of polymer biochips for multiplexed DNA detection in point-of-care diagnostics. Lab Chip 20, 4106–4117 (2020).