Thresholds and Suprathreshold Intensity Functions for Capsaicin in Oil and Aqueous Based Carriers

Thresholds and responses to capsaicin in oil‐ and water‐based model systems were compared. Thresholds were measured among 23 individuals using an ascending forced choice method of limits. Detection thresholds were 11.75 (± 1.31) mg/L in oil and 0.31 (± 0.03) mg/L in water. A horizontal labeled magnitude scale was used to obtain suprathreshold scaling functions in corn and soybean oils and in water systems using an emulsifier (polysorbate) or alcohol to solvate the capsaicin. In the water‐based systems, capsaicin ranged from weak to very strong ratings over a range of 0.3 to 10 mg/L while the same perceptual range was achieved in oil over a range of 10 to 316 mg/L. Nonconsumers of hot/spicy foods generally had higher thresholds and higher suprathreshold responses in oil systems. Differences between user groups were less pronounced in water‐based stimuli.