BackgroundThere are five common, independent measures used to characterize taste function in humans: detection and recognition thresholds (DT and RT), suprathreshold intensity ratings of prototypical tastants, propylthiouracil (PROP) bitterness intensity, and fungiform papillae (FP) number.MethodsWe employed all five methods to assess taste function of 65 women (21.5 ± 4 years, BMI 22.3 ± 2.8 kg/m2). Pearson correlation coefficients were calculated between the different measures.ResultsThe DT and RT were positively correlated for sweet, bitter, sour, and umami (p < 0.05), but not for salt. The DT or RT did not correlate with suprathreshold intensity ratings, except for umami (suprathreshold intensity and RT: r = −0.32, p = 0.009). FP number did not correlate with any measurement of taste function. PROP bitterness intensity ratings did not correlate with any measurement of taste function, except for suprathreshold ratings for saltiness (r = 0.26, p = 0.033).ConclusionAs most of the individual measures of taste function did not correlate with each other, with exception of the two threshold measures, we conclude that there are multiple perceptual phases of taste, with no single measure able to represent the sense of taste globally.

BackgroundPrevious research has shown that oral processing characteristics like bite size and oral residence duration are related to the satiating efficiency of foods. Oral processing characteristics are influenced by food texture. Very little research has been done on the effect of food texture within solid foods on energy intake.ObjectivesThe first objective was to investigate the effect of hardness of food on energy intake at lunch, and to link this effect to differences in food oral processing characteristics. The second objective was to investigate whether the reduction in energy intake at lunch will be compensated for in the subsequent dinner.DesignFifty subjects (11 male, BMI: 21±2 kg/m2, age: 24±2 y) participated in a cross-over study in which they consumed ad libitum from a lunch with soft foods or hard foods on two separate days. Oral processing characteristics at lunch were assessed by coding video records. Later on the same days, subjects consumed dinner ad libitum.ResultsHard foods led to a ∼13% lower energy intake at lunch compared to soft foods (P<0.001). Hard foods were consumed with smaller bites, longer oral duration per gram food, and more chewing per gram food compared to the soft foods (P<0.05). Energy intake at dinner did not differ after both lunches (P = 0.16).ConclusionsHard foods led to reduced energy intake compared to soft foods, and this reduction in energy intake was sustained over the next meal. We argue that the differences in oral processing characteristics produced by the hardness of the foods explain the effect on intake. The sustained reduction in energy intake suggests that changes in food texture can be a helpful tool in reducing the overall daily energy intake.

Orosensory exposure to sweetness has been shown to be important in satiation, whereas the effect of exposure to a salty taste on satiation is not known. The primary objective was to investigate the effect of orosensory exposure time to and intensity of saltiness in soup on ad libitum intake. The secondary objective was to investigate the effect of intensity on bite size. Fifty-five healthy men consumed ad libitum from both a low-salt (LS) and a high-salt (HS) creamy tomato soup in 2 exposure time conditions ("long" and "short") and a free condition ("free"). Bites were administered and controlled via a pump. In the long condition, bites of 5 g were administered in 2 s at intervals of 5 s (exposure time: 24 s/min). In the short condition, bites of 15 g were administered in 3 s at intervals of 15 s (exposure time: 12 s/min). The eating rate was equal in the long and short conditions (60 g/min). In the free condition, participants adjusted their bite sizes at intervals of 15 s. The short condition resulted in ~34% higher ad libitum intake compared to the long condition (P < 0.001); there was no interaction with intensity. Ad libitum intake of HS soup was ~9% lower than LS soup (P < 0.001). The free condition showed that HS soup was consumed with smaller bite sizes during the first half of the intake period (P < 0.05). Longer orosensory exposure and higher saltiness intensity both decreased food intake, although orosensory exposure had more impact than intensity. Prolonging the orosensory exposure per food unit may be helpful to reduce food intake.

Bread is a major contributor to sodium intake in many countries. Reducing the salt (NaCl) content in bread might be an effective way to reduce overall sodium intake. The objectives of this study were to examine the effects of gradually lowering the salt content in brown bread, with and without flavor compensation (KCl and yeast extract), on bread consumption and sodium intake compensation by choice of sandwich fillings. A total of 116 participants (age: 21 ± 3 y; BMI: 22 ± 2 kg/m²) consumed a buffet-style breakfast on weekdays for 4 wk. Participants received either regular bread (control group: n = 39), bread whose salt content was gradually lowered each week by 0, 31, 52, and 67% (reduced group: n = 38), or bread whose salt content was also gradually lowered each week but which was also flavor compensated (compensated group: n = 39). A reduction of up to 52% of salt in bread did not lead to lower consumption of bread compared to the control (P = 0.57), whereas less bread was consumed when salt was reduced by 67% (P = 0.006). When bread was flavor compensated, however, a reduction of 67% did not lead to lower consumption (P = 0.69). Salt reduction in bread (with and without flavor compensation) did not induce sodium intake compensation (P = 0.31). In conclusion, a salt reduction of up to 52% in bread or even up to 67% in flavor-compensated bread neither affected bread consumption nor choice of sandwich fillings.

ObjectiveIndividuals with obesity may be less sensitive to the taste of fat, and it is hypothesized that this is due to excess dietary fat intake. This study assessed the effect of a 6‐week low‐fat (LF) or portion control (PC) diet matched for weight loss on fat taste thresholds, fat perception, and preference in people with overweight/obesity.MethodsParticipants (n = 53) completed a randomized dietary intervention and consumed either a LF diet (25% fat) or PC diet (33% fat) for 6 weeks. Fat taste thresholds (lowest detectable fat concentration), fat perception (discrimination ability), preference, and anthropometry were assessed at baseline and week 6.ResultsConsumption of a LF diet (n = 26) and PC diet (n = 27) reduced participants' weight (P < 0.001), with no significant differences between groups (LF, −2.9%, PC, −2.7%). Both diets resulted in a decrease in fat taste thresholds (P = 0.014), and the effect tended to be stronger in the LF diet vs. the PC diet (P = 0.060). The ability to perceive different fat concentrations in foods was increased after the LF diet only (P = 0.017); however, food preference did not change on either diet.ConclusionsA PC and LF diet both increase fat taste sensitivity in people with overweight/obesity, with the strongest effect after the LF diet.