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Characterization and Industrial Application of the Enzyme Papain Through the Use of a Biosensor
Guilber Vergara Velez1, Lorena Daniela Domínguez Brito2, Melissa Lisbeth Cerón Erazo3
1Carrera de Agroindustria, Talleres y Laboratorios, Escuela Superior Politécnica Agropecuaria de Manabí, Manuel Feliz López, ESPAM - MFL, Calceta, 130250, Ecuador.
Background/Aims:
Casein influences coagulation, yield, and product quality. This study aimed to develop and validate a papain (EC 3.4.22.2)-based biosensor to quantify casein in whole milk, evaluating its kinetic behavior and comparing it with HPLC.
Methods:
Papain was immobilized on nylon membranes and a cassava starch biopolymer. Enzyme kinetics (KM), stability, sensitivity, precision, and linearity of the system were evaluated. A t-test (α = 0.05) was applied to compare the casein concentration obtained by the biosensor versus HPLC (n = 20). Interference from milk proteins and calcium was also analyzed.
Results:
The biosensor showed high affinity for casein (KM = 0.037 mM), with a linear range of 0.001-0.03 mM (R² = 0.9974) and a response time <5 s. No significant differences were found with HPLC (p = 0.0665). Stability reached 70 days at 4°C and was reusable up to 15 times.
Conclusion:
The developed biosensor proved to be an accurate, fast, and sustainable analytical alternative for the determination of casein in complex milk matrices.
