Advancing sensory metrology: establishing a standardized protocol for measuring the concentration-dependent sweetness...

This study aimed to identify an optimal sensory evaluation protocol for accurately modeling concentration-response (C-R) curves of sweeteners using the generalized Labeled Magnitude Scale (gLMS). Four protocol configurations were compared, focusing on three variables: serving methodology (traditional [T-method] vs. sucrose-sweetener combined [SSC method]), sample presentation order (ascending vs. Williams Latin square), and scaling technique (15-point rating scale [15PRS] vs. gLMS). The gLMS proved highly robust for quantifying sweetness intensity and modeling C-R curves. Protocols employing the gLMS delivered more accurate sweetness potency measurements and exhibited significantly higher resistance to contextual bias compared to the 15PRS. The 15PRS consistently overestimated sweetness potency at low concentrations, especially for high-intensity sweeteners. Although the SSC method has previously mitigated contextual effects in category scales, it offered little significant improvement in accuracy when used with the gLMS. Additionally, serving order did not affect gLMS-derived potency measurements, showing the scale's stability. Overall, the gLMS is inherently less susceptible to contextual effects in sensory evaluation, making it a reliable alternative to traditional category scales for standardized sweetness metrology.