The hedonic thresholds methodology varying two stimuli: Extending the range of sensory threshold applications

Abstract

In several situations it is desired to simultaneously alter the intensities of two food stimuli without affecting acceptance or causing sensory rejection. However, at present it is only possible to determine sensory thresholds by varying just one stimulus at a time. The objective of this study was to propose a new methodology, the Hedonic Thresholds Methodology Varying Two Stimuli (HTM2s), which allows for determining the compromised acceptance threshold and the hedonic rejection threshold by simultaneously varying the intensities of two stimuli in a food. For this purpose, the central composite rotatable design was used, with response surface graphs, obtaining the equations that allow for calculating the different intensity combinations of the two stimuli that result in the beginning of compromised acceptance (CAT) and the beginning of sensory rejection (HRT) of the product. It was found that by adding 0.96% garlic powder only to reduce the hamburger sodium concentration from 0.827% to 0.2504%, sensory acceptance of the product began to deteriorate; and when adding 0.9907% garlic powder, only for reducing the sodium content from 0.827% to 0.1319%, sensory rejection of the hamburger begins to occur. In addition, a new sensory threshold is proposed, the favored acceptance threshold (FAT), defined as the stimulus intensity at which significant improvement in sensory acceptance of the product begins to occur. It was also found that by adding 0.96% garlic powder it is possible to reduce the sodium content from 0.827% to 0.3707% and improve the sensory acceptance of the product.