Assessing matrix-specific IgG loss across 50–70 °C using an insulated mug protocol
Abstract
Objective: Quantify IgG stability after 15 minutes in black coffee versus hot water across common drinking temperatures, and determine whether coffee constituents accelerate IgG loss beyond temperature alone. Design: Bench study with duplicate coffee replicates at 50–70 °C and water controls at 50, 60, 70 °C; aliquots sampled at 15 minutes. Findings: Coffee exhibited a strong temperature-dependent decline (slope ≈ -0.00461 %-IgG/°C, R² = 0.97), whereas water was essentially flat (slope ≈ -0.00005 %-IgG/°C, R² = 0.04). At matched temperatures, coffee contained approximately 95%, 81%, and 59% of the IgG measured in water at 50, 60, and 70 °C, respectively, indicating a coffee matrix effect.
Methods
Study arms: Coffee (50, 55, 60, 65, 70 °C; two technical replicates each) and water control (50, 60, 70 °C). Protocol: Beverages were prepared in an insulated double-wall mug; temperature verified immediately prior to sampling; aliquots taken at T = 15 minutes. Analytics: IgG quantified per the study guideline; outcomes summarized as %-IgG (w/w). Comparisons: Coffee replicates averaged (±SD); linear models characterized temperature response; coffee–water differences reported at matched temperatures.
Results
Coffee showed a near-linear decrease in %-IgG with increasing temperature (R² ~ 0.97). Water controls remained stable from 50–70 °C (R² ~ 0.04 over three points). At matched temperatures, coffee minus water (pp) was −0.013 (50 °C), −0.049 (60 °C), and −0.105 (70 °C). Replicate variability (CV%) increased with temperature (≈0% at 50 °C to ≈9% at 70 °C).
Conclusions
Coffee matrix constituents likely accelerate IgG degradation beyond heat alone over 50–70 °C.
Heat-tolerant immune proteins: Independent bench testing shows that when our IgG supplement is stirred into hot coffee, more than 80% of IgG remains after 15 minutes at about 60 °C, and around 60% still remains even at 70 °C. For best results, let your coffee cool slightly before stirring.
Further work: time-course kinetics, broader matrices (tea, milk, decaf), and mechanistic assays (binding activity) to confirm causality.
Acknowledgements
Cawthron Laboratory in Nelson, New Zealand for temperature handling and sampling followed the insulated-mug protocol as per the study guideline (Research Design for IgG Stability in Hot Beverages).
