Sensory evaluation pepper heat

Two areas of research, psychophysics and sensory evaluation, have made recent contributions to the understanding of oral sensations of heat derived from peppers. Psychophysical studies have characterized observer s responses to heat from spice-derived compounds, focussing on such aspects as time-intensity functions, areas of oral stimulation, correlation with evoked salivary flow, interactions with basic tastes, and effects of sequential stimulation. Sensory evaluation of the heat level of ground red pepper has recently been advanced by the validation of a new method which solves many of the problems inherent in the previous Scoville procedure. The new method is based on anchored graphic rating by panels Who are trained with physical reference standards. The procedure has shown excellent reliability, fine discriminations among samples, and high correlations with instrumental determinations of capsaicinoid content of pepper samples. 

However, since the act of sensation is an interaction of an observer with a stimulus, the two approaches often end up using similar methods (e.g., scaling) to provide similar information (e.g., observer response as a function of stimulus concentration). Because of this parallel orientation in methods, and because of the concurrent advances recently made in both areas, we have integrated results from the two fields in this paper. The first section will focus on psychophysical characterization of oral chemical irritants. The final section will discuss the development of a new sensory method for evaluation of ground red pepper heat. 

This method is currently being used for routine laboratory analysis of red pepper heat. Results have been consistent and continue to correlate well with HPLC data. A similar procedure has also been used for sensory evaluation of black pepper heat. The American Society for Testing and Materials (ASTM, Committee E-18) has conducted a collaborative study testing the new method in comparison to the Scoville Method. ASTM E-18 is currently preparing to document it as a standardized test method. Also, a modification of the method is being prepared for oleoresin capsicum and for low-heat capsicums. 

Sensations of oral chemical heat, as induced by pepper-derived compounds are amenable to psychophysical investigation and sensory evaluation by supra-threshold scaling techniques such as magnitude estimation and anchored graphic rating scales. 

A new rating method for evaluation of the sensory heat of ground red pepper samples shows important advantages over the traditional Scoville method, especially in the areas of accuracy, reliability and ease of administration. 

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