Effect of the enzymatic remotion on the rheological properties of coffee mucilage (Coffea arabica - Castillo)

The present study investigates the rheological behavior of native (NM) and enzymatically hydrolyzed (HM) coffee mucilage extracted using the commercial pectinase cocktail NaturalZyme 40XL. Proximate analysis revealed high moisture and carbohydrate contents in both NM and HM, with minor differences attributable to agroclimatic factors and enzymatic action. Rheological characterization, including rotational, amplitude, frequency, temperature sweeps, and thixotropy tests, showed that both NM and HM behave as pseudoplastic fluids with weak gel characteristics. The Herschel–Bulkley model accurately described their flow behavior (R² > 99%), with HM presenting lower yield stress, consistency index, and flow behavior index, indicating a more fluid-like behavior. Amplitude and frequency sweep analyses revealed that enzymatic hydrolysis significantly reduced gel strength and structural integrity, although HM exhibited greater thermal and structural stability. Temperature sweep results confirmed mild thermal dependence in both materials, with more pronounced sensitivity in HM. Thixotropic analysis demonstrated that HM has a higher structural recovery capacity (>99%) compared to NM (≈78%), due to the presence of shorter molecular chain, flexible polygalacturonic acid molecules formed during enzymatic hydrolysis. These findings highlight the potential of enzymatically treated coffee mucilage as a tunable ingredient for food applications requiring flowability and structural resilience.