Preference and perception of fat in salty and sweet foods
Bolhuis, Dieuwerke P. ; Costanzo, Andrew ; Keast, Russell S.J. - \ 2018
Food Quality and Preference 64 (2018). - ISSN 0950-3293 - p. 131 - 137.
Fat - Preference - Salt - Saltiness - Sugar - Sweetness - Taste
Introduction Higher liking for fat is a risk factor for obesity. Fat in food is often combined with a sweet or salty taste. This study aims to investigate the role of fat on pleasantness and perception in both a salty and a sweet liquid food product. Methods In a complete factorial design, 47 participants (23 males) tasted creamy tomato soup and custard in four fat concentrations (0, 7.5, 15, 30%), combined with four salt concentrations (0.04, 0.35, 0.7, 1.5%) in soup, and four sugar concentrations (0.56, 4.5, 9, 18%) in custard. Participants rated pleasantness, saltiness intensity, sweetness intensity and fattiness intensity. The preferred fat concentrations were determined by hedonic ranking. Results Fat and salt separately affected pleasantness in soup (P <.01). Fat, sugar and their interaction affected pleasantness in custard (P <.001). Sugar and salt were a stronger influencer of pleasantness than fat. Preference for fat in soup was variable, whereas the highest concentration of 30% fat was preferred in custard (P <.001). Ratings of fattiness intensity were more responsive to fat concentrations in soup than in custard (P-interaction fat × food base <.001). Conclusion Salt and sugar are stronger influencers on food liking than fat. Across foods, there is no consistent effect of fat on perception or on liking, therefore the attractiveness of fat in foods cannot be generalised. The attraction to high fat levels in custard, while hardly perceiving differences in fat concentrations, remains unclear and needs further investigation.
Effects of salt and fat combinations on taste preference and perception
Bolhuis, Dieuwerke P. ; Newman, Lisa P. ; Keast, Russell S.J. - \ 2016
Chemical Senses 41 (2016)3. - ISSN 0379-864X - p. 189 - 195.
Fat - Fat taste sensitivity - Salt - Taste intensity - Taste preferences
Fat and salt are a common and attractive combination in food and overconsumption of either is associated with negative health outcomes. The major aim was to investigate contributions and interactions of salt and fat on taste pleasantness and perception. The minor aim was to investigate individual fat taste sensitivity (detection threshold of oleic acid [C18:1]) on pleasantness for fat. In a complete factorial design, 49 participants (18-54 years, 12 males) tasted tomato soups with 4 different fat concentrations (0-20%) and 5 different salt concentrations (0.04-2.0%). The preferred concentration and the discrimination ability for both fat and salt were determined by ranking tests. Results show that salt and fat affected pleasantness separately (P < 0.01), with salt having the strongest effect. Fat concentrations 0%, 5%, and 10% did not differ in pleasantness, whereas 20% was less pleasant (P < 0.05). There were no interactions for fat and salt on pleasantness or saltiness and fattiness intensity. Fat taste sensitive participants preferred lower fat concentrations than less sensitive participants (P = 0.008). In conclusion, the strong effect of salt on pleasantness in this study suggests that salt, rather than fat, play a major role in the attraction to savory fatty foods.
Salt promotes passive overconsumption of dietary fat in humans
Bolhuis, Dieuwerke P. ; Costanzo, Andrew ; Newman, Lisa P. ; Keast, Russell S.J. - \ 2016
The Journal of Nutrition 146 (2016)4. - ISSN 0022-3166 - p. 838 - 845.
Ad libitum food intake - Fat - Fat taste sensitivity - Salt - Satiation
Background: Excess fat consumption has been linked to the development of obesity. Fat and salt are a common and appetitive combination in food; however, the effect of either on food intake is unclear. Fat taste sensitivity has been negatively associated with dietary fat intake, but how fat taste sensitivity influences the intake of fat within a meal has, to our knowledge, not yet been investigated. Objectives: Our objectives were, first, to investigate the effects of both fat and salt on ad libitum food intake and, second, to investigate the effects of fat taste sensitivity on satiation responses to fat and whether this was affected by salt. Methods: Forty-eight healthy adults [16men and 32women, aged 18-54 y, bodymass index (kg/m2): 17.8-34.4] were recruited and their fat taste sensitivity was measured by determination of the detection threshold of oleic acid (18:1n-6). In a randomized 2 × 2 crossover design, participants attended 4 lunchtime sessions after a standardized breakfast. Meals consisted of elbow macaroni (56%)with sauce (44%); sauces weremanipulated to be 1) low-fat (0.02% fat, wt:wt)/low-salt (0.06% NaCl,wt:wt), 2) low-fat/high-salt (0.5% NaCl, wt:wt), 3) high-fat (34% fat, wt:/wt)/low-salt, or 4) high-fat/high-salt. Ad libitum intake (primary outcome) and eating rate, pleasantness, and subjective ratings of hunger and fullness (secondary outcomes) were measured. Results: Salt increased food and energy intakes by 11%, independent of fat concentration (P = 0.022). There was no effect of fat on food intake (P = 0.6), but high-fat meals increased energy intake by 60% (P < 0.001). A sex × fat interaction was found (P = 0.006), with women consuming 15% less by weight of the high-fat meals than the low-fat meals. Fat taste sensitivity was negatively associated with the intake of high-fat meals but only in the presence of low salt (fat taste × salt interaction on delta intake of high-fat 2 low-fat meals; P = 0.012). Conclusions: The results suggest that salt promotes passive overconsumption of energy in adults and that salt may override fat-mediated satiation in individuals who are sensitive to the taste of fat.
Minimal inhibitory concentrations of undissociated lactic, acetic, citric and propionic acid for Listeria monocytogenes under conditions relevant to cheese
Wemmenhove, Ellen ; Valenberg, Hein J.F. van; Zwietering, Marcel H. ; Hooijdonk, Toon C.M. van; Wells-Bennik, Marjon H.J. - \ 2016
Food Microbiology 58 (2016). - ISSN 0740-0020 - p. 63 - 67.
Growth inhibition - PH - Salt - Temperature - Undissociated organic acid
Minimal inhibitory concentrations (MICs) of undissociated lactic acid were determined for six different Listeria monocytogenes strains at 30 °C and in a pH range of 4.2-5.8. Small increments in pH and acid concentrations were used to accurately establish the growth/no growth limits of L. monocytogenes for these acids. The MICs of undissociated lactic acid in the pH range of 5.2-5.8 were generally higher than at pH 4.6 for the different L. monocytogenes strains. The average MIC of undissociated lactic acid was 5.0 (SD 1.5) mM in the pH range 5.2-5.6, which is relevant to Gouda cheese. Significant differences in MICs of undissociated lactic acid were found between strains of L. monocytogenes at a given pH, with a maximum observed level of 9.0 mM. Variations in MICs were mostly due to strain variation. In the pH range 5.2-5.6, the MICs of undissociated lactic acid were not significantly different at 12 °C and 30 °C. The average MICs of undissociated acetic acid, citric acid, and propionic acid were 19.0 (SD 6.5) mM, 3.8 (SD 0.9) mM, and 11.0 (SD 6.3) mM, respectively, for the six L. monocytogenes strains tested in the pH range 5.2-5.6. Variations in MICs of these organic acids for L. monocytogenes were also mostly due to strain variation. The generated data contribute to improved predictions of growth/no growth of L. monocytogenes in cheese and other foods containing these organic acids.
Phosphatidic acid, a versatile water-stress signal in roots
McLoughlin, Fionn ; Testerink, Christa - \ 2013
Frontiers in Plant Science 4 (2013). - ISSN 1664-462X
Arabidopsis thaliana - Drought - Phosphatidic acid - Protein kinase - Roots - Salt
Adequate water supply is of utmost importance for growth and reproduction of plants. In order to cope with water deprivation, plants have to adapt their development and metabolism to ensure survival.To maximize water use efficiency, plants use a large array of signaling mediators such as hormones, protein kinases, and phosphatases, Ca2+, reactive oxygen species, and low abundant phospholipids that together form complex signaling cascades. Phosphatidic acid (PA) is a signaling lipid that rapidly accumulates in response to a wide array of abiotic stress stimuli. PA formation provides the cell with spatial and transient information about the external environment by acting as a protein-docking site in cellular membranes. PA reportedly binds to a number of proteins that play a role during water limiting conditions, such as drought and salinity and has been shown to play an important role in maintaining root system architecture. Members of two osmotic stress- activated protein kinase families, sucrose non-fermenting 1-related protein kinase 2 and mitogen activated protein kinases were recently shown bind PA and are also involved in the maintenance of root system architecture and salinity stress tolerance. In addition, PA regulates several proteins involved in abscisic acid-signaling. PA-dependent recruitment of glyceraldehyde-3-phosphate dehydrogenase underwater limiting conditions indicates a role in regulating metabolic processes. Finally, a recent study also shows the PA recruits the clathrin heavy chain and a potassium channel subunit, hinting toward additional roles in cellular trafficking and potassium homeostasis. Taken together, the rapidly increasing number of proteins reported to interact with PA implies a broad role for this versatile signaling phospholipid in mediating salt and water stress responses.