THE SINGLE INTERVAL ADJUSTMENT MATRIX (SIAM) YES-NO TASK APPLIED TO THE MEASUREMENT OF SUCROSE THRESHOLDS

ABSTRACT A technique previously unreported in the food sciences literature, the Single‐Interval Adjustment Matrix (SIAM) Yes‐No task, works by controlling the taster's response criterion, with the goal of producing a bias‐free estimate of the absolute threshold. Absolute thresholds were estimated for sucrose in aqueous solution using the SIAM Yes‐No task. Obtained estimates were similar to those reported in the literature. These estimated threshold concentrations were then used with the same tasters in a two‐alternative forced‐choice task. The performance of the tasters was consistent with a 75% definition of threshold for this task. In terms of speed, the SIAM Yes‐No task performed well. These results suggest that the SIAM Yes‐No task is a useful choice in the measurement of absolute thresholds for gustatory stimuli. PRACTICAL APPLICATIONS Recipe changes or ingredient substitutions introduce challenges for food and beverage manufacturers. Having made changes, it is crucial that sensory and affective tests be undertaken to ensure the product remains in favor with consumers. In regards to sensory testing a common measure employed by food scientists is the absolute threshold. However, given the difficulties inherent in sensory testing there is a need for sensory methods that minimize stimulus presentations while maintaining measurement validity. The SIAM Yes‐No task, a technique hitherto unreported in the sensory sciences literature, presents itself as a reliable procedure for estimating absolute thresholds that has the added benefit of increased efficiency.