When it comes to eating and drinking, multiple factors from diverse sensory modalities have been shown to influence multisensory flavour perception and liking. These factors have heretofore been strictly divided into either those that are intrinsic to the food itself (e.g., food colour, aroma, texture), or those that are extrinsic to it (e.g., related to the packaging, receptacle or external environment). Given the obvious public health need for sugar reduction, the present review aims to compare the relative influences of product-intrinsic and product-extrinsic factors on the perception of sweetness. Evidence of intrinsic and extrinsic sensory influences on sweetness are reviewed. Thereafter, we take a cognitive neuroscience perspective and evaluate how differences may occur in the way that food-intrinsic and extrinsic information become integrated with sweetness perception. Based on recent neuroscientific evidence, we propose a new framework of multisensory flavour integration focusing not on the food-intrinsic/extrinsic divide, but rather on whether the sensory information is perceived to originate from within or outside the body. This framework leads to a discussion on the combinability of intrinsic and extrinsic influences, where we refer to some existing examples and address potential theoretical limitations. To conclude, we provide recommendations to those in the food industry and propose directions for future research relating to the need for long-term studies and understanding of individual differences.

While virtual reality (VR) has become increasingly popular in food-related research, there has been a lack of clarity, precision, and guidelines regarding what exactly constitutes a virtual reality study, as well as the options available to the researcher for designing and implementing it. This review provides a practical guide for sensory and consumer scientists interested in exploring the emerging opportunities offered by VR. We take a deep dive into the components that make up a VR study, including hardware, software, and response measurement methods, all the while being grounded in immersion and presence theory. We then review how these building blocks are put together to create two major categories of research scenarios: product selection, which can be entirely created in VR, and food evaluation, which involve tasting products in real life. For each category, we review current literature with a focus on experimental design, then highlight future avenues and technical development opportunities within sensory and consumer research. Finally, we evaluate limitations and ethical issues in VR food research, and offer future perspectives which go above and beyond ensuring ecological validity in product testing.

People intuitively match basic tastes to sounds of different pitches, and the matches that they make tend to be consistent across individuals. It is, though, not altogether clear what governs such crossmodal mappings between taste and auditory pitch. Here, we assess whether variations in taste intensity influence the matching of taste to pitch as well as the role of emotion in mediating such crossmodal correspondences. Participants were presented with 5 basic tastants at 3 concentrations. In Experiment 1, the participants rated the tastants in terms of their emotional arousal and valence/pleasantness, and selected a musical note (from 19 possible pitches ranging from C2 to C8) and loudness that best matched each tastant. In Experiment 2, the participants made emotion ratings and note matches in separate blocks of trials, then made emotion ratings for all 19 notes. Overall, the results of the 2 experiments revealed that both taste quality and concentration exerted a significant effect on participants’ loudness selection, taste intensity rating, and valence and arousal ratings. Taste quality, not concentration levels, had a significant effect on participants’ choice of pitch, but a significant positive correlation was observed between individual perceived taste intensity and pitch choice. A significant and strong correlation was also demonstrated between participants’ valence assessments of tastants and their valence assessments of the best-matching musical notes. These results therefore provide evidence that: 1) pitch–taste correspondences are primarily influenced by taste quality, and to a lesser extent, by perceived intensity; and 2) such correspondences may be mediated by valence/pleasantness.

It has recently been demonstrated that the reported tastes/flavours of food/beverages can be modulated by means of external visual and auditory stimuli such as typeface, shapes, and music. The present study was designed to assess the role of the emotional valence of the product-extrinsic stimuli in such crossmodal modulations of taste. Participants evaluated samples of mixed fruit juice whilst simultaneously being presented with auditory or visual stimuli having either positive or negative valence. The soundtracks had either been harmonised with consonant (positive valence) or dissonant (negative valence) musical intervals. The visual stimuli consisted of images of emotional faces from the International Affective Picture System (IAPS) with valence ratings matched to the soundtracks. Each juice sample was rated on two computer-based scales: One anchored with the words sour and sweet, while the other scale required hedonic ratings. Those participants who tasted the juice sample while presented with the positively-valenced stimuli rated the juice as tasting sweeter compared to negatively-valenced stimuli, regardless of whether the stimuli were visual or auditory. These results suggest that the emotional valence of food-extrinsic stimuli can play a role in shaping food flavour evaluation and liking.

Shape can play an important role in our perception of food. In this study, the consequences of crossmodal correspondences between shape and taste on the expected and actual experience of eating chocolate were evaluated. Participants were given two identical dark chocolates differing only in terms of their shape (round or angular) and then rated their expectations of sweetness, bitterness, creaminess and liking. Subsequently, they rated their experience of those attributes on tasting the chocolates. Repeated-measures multivariate analyses (RM-MANOVA) of variance were conducted to assess the role of chocolate shape and cacao content on expected and post-taste chocolate ratings. In addition, we assessed the differences between expected and post-taste ratings for each chocolate shape. The results revealed that the shape of the chocolate significantly influenced expected sweetness, bitterness and creaminess. By contrast, it had no significant effect on post-tasting ratings. The round chocolates were judged to be less sweet, more bitter, less creamy and liked less than expected, whereas the angular chocolates were judged to be slightly more creamy than expected. The theory of assimilation and contrast is outlined as one plausible mechanism behind the differences between expectation and the actual taste experience. Implications for food product design and directions for future research are discussed.