Investigating the Biphasic Effect of Ethanol Concentration on Pepsin Proteolytic Activity

This investigation explores how varying ethanol concentrations (0% to 40% v/v) influence the proteolytic activity of pepsin on an egg albumin substrate under simulated gastric conditions.

Utilizing a colorimetric Biuret assay, the study measures absorbance at 540 nm to quantify undigested protein. The methodology maintains strict control over pH, temperature, and incubation time to ensure reliability.

Findings reveal a biphasic relationship: mild stimulation at 5% ethanol followed by significant enzymatic inhibition at higher concentrations. Statistical significance is rigorously confirmed via One-Way ANOVA and Tukey’s HSD post-hoc testing, supported by a polynomial trendline (R² = 0.966).

The exemplar is distinguished by its sophisticated error analysis, addressing light scattering from protein aggregation and detailed uncertainty propagation.