Search

How we perceive the world is not solely determined by our experiences at a given moment in time, but also by what we have experienced in our immediate past. Here, we investigated whether such sequential effects influence the affective appraisal of food images. Participants from 16 different countries (N = 1278) watched a randomly presented sequence of 60 different food images and reported their affective appraisal of each image in terms of valence and arousal. For both measures, we conducted an inter-trial analysis, based on whether the rating on the preceding trial(s) was low or high. The analyses showed that valence and arousal ratings for a given food image are both assimilated towards the ratings on the previous trial (i.e., a positive serial dependence). For a given trial, the arousal rating depends on the arousal ratings up to three trials back. For valence, we observed a positive dependence for the immediately preceding trial only, while a negative (repulsive) dependence was present up to four trials back. These inter-trial effects were larger for males than for females, but independent of the participants’ BMI, age, and cultural background. The results of this exploratory study may be relevant for the design of websites of food delivery services and restaurant menus.

Food experiences can be summarized along two main dimensions: valence and arousal, which can be measured explicitly with subjective ratings or implicitly with physiological and behavioural measures. Food experiences are not only driven by the food’s intrinsic properties, such as its taste, texture, and aroma, but also by extrinsic properties such as brand information and the consumers’ previous experiences with the foods. In this study, valence and arousal to intrinsic and extrinsic properties of soy sauce were measured in consumers that varied in their previous experience with soy sauce, using a combination of explicit (scores and emojis), implicit (heart rate frequency and skin conductance), and behavioural measures (facial expressions). Forty participants, high- and low-frequency users, were presented with samples of rice and three commercial soy sauces without and with brand information that either matched or non-matched the taste of the soy sauce. In general, skin conductance and facial expressions showed relatively low arousal during exposure to the brand name, increased arousal in anticipation of the taste, and again lowest arousal during tasting. Heart rate frequency was lowest during exposure to the brand name, increased during anticipation, and increased further during tasting (probably resulting from the motor activity during chewing). Furthermore, the results showed that explicit liking and arousal scores were primarily affected by the taste of the specific soy sauce and by the participants’ previous experience with soy sauces. These scores were not affected by branding information. In contrast, facial expressions, physiological skin conductance (level and response), and heart rate frequency were primarily affected by 1) the participants’ level of experience with soy sauce, 2) whether or not branding information was provided, and 3) whether or not the branding information matched with the taste. In conclusion, this study suggests that liking scores may be most sensitive to the food’s intrinsic taste properties, whereas implicit measures may be most sensitive to extrinsic properties such as brand information. Both explicit and implicit measures were affected by the consumers’ previous food experiences.

With the increasing globalization, new unfamiliar flavors gradually find their way into local Western cuisines. The mechanisms behind the successful integration of novel flavors into local cuisines are largely unknown. This study investigates the effects of frequency of soy sauce use, levels of food neophobia, and brand specificity on liking of a relatively unknown flavor in the Netherlands, soy sauce. A total of eighty-nine (26 men and 63 women; mean age 47.5 ± 17.7 years) high- and low-frequency users of soy sauce rated liking of five soy sauces separately presented with and without branding information. Liking of four soy sauces with the typical salty and savory flavor increased with increasing frequency of use, and with decreasing levels of food neophobia. Another soy sauce with additives resulting in a distinctive taste was liked irrespective of the frequency of use. Soy sauces, which were recognized correctly or incorrectly as the participants’ own familiar brand, received 50% higher or lower liking ratings than other soy sauces, respectively. Furthermore, users of one of the brands preferred the taste of their own brand over that of other brands, whereas users of the other brands did not show such specificity, indicating clear differences in specificity of liking soy sauce among the various user groups. This study provides insights into consumer liking and preference of semi-familiar foods, revealing the contribution of consumer traits and brand familiarity that may influence the spread of unfamiliar foods.

Because of the globalization of world food markets there is a growing need for valid and language independent self-assessment tools to measure food-related emotions. We recently introduced the EmojiGrid as a language-independent, graphical affective self-report tool. The EmojiGrid is a Cartesian grid that is labeled with facial icons (emoji) expressing different degrees of valence and arousal. Users can report their subjective ratings of valence and arousal by marking the location on the area of the grid that corresponds to the emoji that best represent their affective state when perceiving a given food or beverage. In a previous study we found that the EmojiGrid is robust, self-explaining and intuitive: valence and arousal ratings were independent of framing and verbal instructions. This suggests that the EmojiGrid may be a valuable tool for cross-cultural studies. To test this hypothesis, we performed an online experiment in which respondents from Germany (GE), Japan (JP), the Netherlands (NL) and the United Kingdom (UK) rated valence and arousal for 60 different food images (covering a large part of the affective space) using the EmojiGrid. The results show that the nomothetic relation between valence and arousal has the well-known U-shape for all groups. The European groups (GE, NL and UK) closely agree in their overall rating behavior. Compared to the European groups, the Japanese group systematically gave lower mean arousal ratings to low valenced images and lower mean valence ratings to high valenced images. These results agree with known cultural response characteristics. We conclude that the EmojiGrid is potentially a valid and language-independent affective self-report tool for cross-cultural research on food-related emotions. It reliably reproduces the familiar nomothetic U-shaped relation between valence and arousal across cultures, with shape variations reflecting established cultural characteristics.

Persimmon (Diospyros kaki) is a very popular fruit in East Asian countries, but its peels are not consumed despite the fact that they contain many antioxidants such as carotenoids and polyphenols. We prepared a fat-soluble extract from persimmon peel (PP) and fed type 2 diabetic Goto-Kakizaki (GK) rats an AIN-93G rodent diet supplemented with persimmon peel extract (PP diet) for 12 weeks. Compared with the control AIN-93G diet, the PP diet significantly reduced plasma glutamic-pyruvate transaminase activity, with accumulation of β-cryptoxanthin in the liver. DNA microarray analysis revealed that the PP diet altered hepatic gene expression profiles. In particular, expression of insulin signaling pathway-related genes was significantly enriched in differentially expressed gene sets. Moreover, Western blotting analysis showed an increase in insulin receptor beta tyrosine phosphorylation in rats fed the PP diet. These data suggest that the PP diet improves insulin resistance in GK rats.

The effects of the administration of molecular hydrogen-saturated drinking water (hydrogen water) on hepatic gene expression were investigated in rats. Using DNA microarrays, 548 upregulated and 695 downregulated genes were detected in the liver after 4 weeks of administration of hydrogen water. Gene Ontology analysis revealed that genes for oxidoreduction-related proteins, including hydroxymethylglutaryl CoA reductase, were significantly enriched in the upregulated genes.

Considering that animals maintain energy homeostasis in response to nutrient levels, experiments were done to elucidate the temporal effects of refeeding after fasting on gene expression profiles in the rat liver. Using DNA microarray technology, we first compared gene expression profiles in the livers of rats allowed to feed for 6 h after fasting for 18 h and those in 24-h fasting rats, and found that the expression levels of energy metabolism-related genes in the two groups were different. In addition, refeeding induced upregulation of the genes encoding immunoproteasome components. Finally, immunoblot analysis confirmed changes in protein levels, suggesting that refeeding after fasting enhanced immune function.

To elucidate the effect of the polyphenols contained in alcoholic beverages on the metabolic stress induced by ethanol consumption, four groups of mice were fed for five weeks on Lieber's diet with or without ethanol, with ethanol plus ellagic acid, and with ethanol plus trans-resveratrol. Alcoholic fatty liver was observed in the group fed the ethanol diet but not in those fed the ethanol plus polyphenol diets. Liver transcriptome analysis revealed that the addition of the polyphenols suppressed the expression of the genes related to cell stress that were up-regulated by ethanol alone. Conversely, the polyphenols up-regulated the genes involved in bile acid synthesis, unsaturated fatty acid elongation, and tetrahydrofolate synthesis that were down-regulated by ethanol alone. Because parts of these genes were known to be regulated by the constitutive androstane receptor (CAR), we performed the same experiment in the CAR-deficient mice. As a result, fatty liver was observed not only in the ethanol group but also with the ethanol plus polyphenol groups. In addition, there was no segregation of the gene expression profiles among these groups. These results provide a molecular basis for the prevention of alcohol-induced stress by the polyphenols in alcoholic beverages.

Taste signals and nutrient stimuli sensed by the gastrointestinal tract are transmitted to the brain to regulate feeding behavior and energy homeostasis. This system is referred to as the gut-brain axis. Here we show that both brush cells and type II taste cells are eliminated in the gastrointestinal tract of transcription factor Skn-1 knockout (KO) mice. Despite unaltered food intake, Skn-1 KO mice have reduced body weight with lower body fat due to increased energy expenditure. In this model, 24-h urinary excretion of catecholamines was significantly elevated, accompanied by increased fatty acid β-oxidation and fuel dissipation in skeletal muscle and impaired insulin secretion driven by glucose. These results suggest the existence of brain-mediated energy homeostatic pathways originating from brush cells and type II taste cells in the gastrointestinal tract and ending in peripheral tissues, including the adrenal glands. The discovery of food-derived factors that regulate these cells may open new avenues the treatment of obesity and diabetes. Research Context Taste signals and nutrient stimuli sensed by the gastrointestinal tract are transmitted to the brain to regulate feeding behavior and energy homeostasis along the gut-brain axis. We propose the concept that taste-receiving cells in the oral cavity and/or food-borne chemicals-receiving brush cells in the gut are involved in regulation of the body weight and adiposity via the brain. The discovery of food-derived factors that regulate these cells may open new avenues for the treatment of obesity and diabetes., Highlights • Skn-1a is a crucial transcription factor for generating brush cells and type II taste cells in the gastrointestinal tract. • Despite unaltered food intake, Skn-1 KO mice have reduced body weight with lower body fat due to elevated energy expenditure. • Urinary excretion of catecholamines was elevated in Skn-1 KO mice, suggesting brain-mediated energy homeostatic pathways.