Changes in liking for a no added salt soup as a function of exposure

Multiple exposures have been shown to increase preference for novel foods or flavours. This “mere exposure” effect is also well known anecdotally for changes in preference for tastants within foods, for example reducing sugar in tea or coffee. However, to date, this phenomenon has received little scientific attention. The present study addressed this issue in relation to changes in preference for salt within soup. Following an initial assessment of liking, familiarity and saltiness of six soups varying in salt content (0–337 mg NaCl/ml), 37 participants, previously assessed for their preferred salt level in soup, were allocated to either an exposure group that received 20 ml soup samples with no added salt, to a group that received a 280 ml bowl of this soup, or to a control group that received 20 ml soup samples containing salt at 280 mg/100 g (within normal, commercial range). Soups were presented on eight occasions, at approximately daily intervals. The two groups receiving the no added salt soup showed increases in liking starting at the third exposure, and also evident in a repeat assessment following the exposures. Increases in familiarity of the no added salt soup were also evident during exposure. Rated saltiness of all soups increased as a function of exposure, so a change in saltiness perception could not account for changes in liking for just the no added salt soups. These data suggest that simple exposure to the taste of the no added salt soup was sufficient to increase liking to a level equivalent to the initially more preferred salt level.     

The prevalence of keratoconus in northern Poland: A cross-sectional study of patients from a primary healthcare practice

IntroductionKeratoconus is defined as central and/or paracentral corneal thinning and steepening with consequent irregular astigmatism. To date, no prospective study has reported its prevalence in Central Europe. This study aimed to evaluate the prevalence of keratoconus assessed with Scheimpflug imaging in a profile of general medicine practice in Poland.MethodsThis cross-sectional study collected data by inviting all patients aged 10–80 years subscribed to a single general practitioner in the Elbląg area, Poland. Corneal measurements were performed using a rotating Scheimpflug corneal tomography system. Three masked examiners established the diagnosis of keratoconus in the right or left eye. Fleiss’ kappa coefficient (κ) was used to qualitatively analyze the interexaminer agreement.ResultsOf 1,705 patients invited to the study, 771 agreed to participate (45.2%). The mean age of the 728 patients (60.6% female and 39.4% male) with gradable images in at least one eye was 53.6 ± 16.5 years. All of the examiners classified the same four cases as keratoconus (0.549%, 549 per 100,000, 95% confidence interval 150 to 1,400 per 100,000), of which two were bilateral. Fleiss’ kappa showed almost perfect agreement among the three examiners regarding the diagnostic decision (κ = 0.784, 95% confidence interval 0.750 to 0.817, p < 0.001). The keratoconus cases were all women (p = 0.106), aged 48, 69, 70, and 71 years old.ConclusionThe prevalence of keratoconus in this area was higher than that previously demonstrated in many European countries. Underestimation of the prevalence has been postulated but never demonstrated.     

Impact of COVID-19 confinement on eating behaviours across 16 European countries: The COVIDiet cross-national study

We aimed to evaluate the changes in eating behaviours of the adult population across 16 European countries due to the COVID-19 confinement and to evaluate whether these changes were somehow related to the severity of the containment measures applied in each country. An anonymous online self-reported questionnaire on socio-demographic characteristics, validated 14-items Mediterranean diet (MedDiet) Adherence Screener (MEDAS) as a reference of a healthy diet, eating and lifestyle behaviours prior to and during the COVID-19 confinement was used to collect data. The study included an adult population residing in 16 European countries at the time of the survey. Aggregated Stringency Index (SI) score, based on data from the Oxford COVID-19 Government Response Tracker, was calculated for each country at the time the questionnaire was distributed (range: 0–100). A total of 36,185 participants completed the questionnaire (77.6% female, 75.2% with high educational level and 42.7% aged between 21 and 35 years). In comparison to pre-confinement, a significantly higher adherence to the MedDiet during the confinement was observed across all countries (overall MEDAS score prior to- and during confinement: 5.23 ± 2.06 vs. 6.15 ± 2.06; p < 0.001), with the largest increase seen in Greece and North Macedonia. The highest adherence to MedDiet during confinement was found in Spain and Portugal (7.18 ± 1.84 and 7.34 ± 1.95, respectively). Stricter contingency restrictions seemed to lead to a significantly higher increase in the adherence to the MedDiet. The findings from this cross-sectional study could be used to inform current diet-related public health guidelines to ensure optimal nutrition is followed among the population, which in turn would help to alleviate the current public health crisis.     

Encapsulated sodium supplementation of 4 weeks does not alter salt taste preferences in a controlled low sodium and low potassium diet

Preference for saltiness is learned by oral exposure to salt taste; however, some data suggest a role for bodily sodium and potassium levels on salt taste preferences as well. The objective was to investigate whether encapsulated sodium and potassium supplementation lead to altered salt taste responses among adults with high blood pressure on a low sodium and low potassium diet. Twenty-six participants with untreated upper-range prehypertension or stage 1 hypertension were on a fully controlled low sodium and low potassium diet (both targeted at 2 g/day) for 13 weeks. Participants received capsules with sodium (3 g/d), potassium (3 g/d), or placebo, for 4 weeks each, in randomized order in a double blind crossover design. Sensory evaluation was done before and after each supplementation period and involved ratings of pleasantness and intensity in different salt (NaCl) concentrations in food and water, desire-to-eat salty food, and detection threshold for NaCl. Neither sodium supplementation nor potassium supplementation led to alterations in salt taste responses in food and water, and did not affect detection threshold (P = 0.59). There was no clear role for sodium or potassium supplementation on desire-to-eat salty food. In addition, we did not find effects of reduced oral exposure to salt over weeks, through the sodium-reduced diet, on salt taste preferences, in contrast to earlier studies. In conclusion, the results of this study suggest preference for saltiness is independent of changes in bodily sodium or potassium levels.     

Analysis of the spatial distribution and dispersion of Plodia interpunctella (Lepidoptera: Pyralidae) in South Korea

This study proposes a novel method to predict the spatial dispersion of Plodia interpunctella by considering the climatic conditions and location of agricultural storage facilities. To accomplish the study objectives, a rearing experiment was conducted, and the CLIMEX model was used to evaluate the climatic suitability of P. interpunctella based on the model parameters estimated from the direct rearing experimental results, in addition to the previous rearing data. Subsequently, we evaluated the distances between the agricultural storage facilities [represented by rice processing complexes (RPCs) and agricultural product processing centers (APCs)] and main ports of grain entry by calculating the flight distance of P. interpunctella. As a result, the climate of South Korea was found unsuitable for P. interpunctella, but the suitability increased throughout the country when considering the indoor temperatures of storage facilities. The analysis of its dispersion with the consideration of grain entry ports, RPCs, and APCs showed that P. interpunctella could be dispersed to areas near storage facilities within 10 d by flying after its first introduction into the ports, as estimated by the calculated flight distance of 32.5 km. However, its dispersion could be accelerated by grain delivery and reach the farthest point in a day. This study provides a methodology to combine species distribution modeling with geographic information system, besides providing a possible scenario of P. interpunctella dispersion, which could serve as the fundamental data for establishing an adequate control strategy.     

Impact of corneal collagen cross-linking on vision-related quality of life measured with the keratoconus outcomes research questionnaire (KORQ) in patients with keratoconus

PurposeTo assess the impact of corneal collagen cross-linking on self-reported vision-related quality of life (VR-QoL) in keratoconus patients by means of the Keratoconus Outcomes Research Questionnaire (KORQ), a new disease-specific patient reported outcomes measures (PROMs) tool.MethodsPatients with progressive keratoconus undergoing corneal collagen cross-linking were consecutively enrolled. Patients completed the KORQ before and after the treatment, at 1, 3 and 6 months. Data were collected regarding the visual acuity and the topographic, aberrometric and pachymetric parameters of both eyes. Patients were also asked to quantify their eye rubbing behavior on a Visual Analogue Scale (VAS) from 0 to 10, before and 6 months after treatment.The KORQ scores were associated with the visual acuity, topographic, aberrometric and pachymetric data by means of the Spearman correlation coefficient.ResultsThe Activity Limitation (AL) subscale score was higher after surgery. Preoperatively, negative correlations were observed between the KORQ AL score and Best Corrected Visual Acuity (logMAR), maximum keratometry, flattest keratometry, steepest keratometry, symmetry index front and higher order aberrations (HOA) of the treatment eye. Postoperatively, we observed a shift toward the fellow eye, with stronger correlation of the KORQ scores with the fellow eye parameters. The Symptoms subscale score correlated with the aberrometric parameters of both eyes at various time points. Statistically significant correlations were observed between the change in KORQ scores and the change in aberrometric parameters. A statistically significant reduction in the eye rubbing behavior was detected (p < 0,0001).ConclusionsThese results suggest that the corneal cross-linking treatment is effective both in improving the subjective perception of the disease by the patient and in stabilizing the objective indicators of disease progression. Keratometric, aberrometric and visual acuity values showed a significant impact on self-reported VR-QoL. Corneal cross-linking, by halting the worsening of these parameters, may bear a beneficial effect on VR-QoL.     

Application of central composite face centered design for the optimization of multiple-pass ultrasonication with mechanical homogenization (MPUMH) for carrot puree processing

Multiple-pass ultrasonication with mechanical homogenization was used as a novel method for the processing of carrot puree. The experimental design was based on the face centered composite design using response surface methodology. The carrot puree was assessed for its physical, chemical and nutraceutical properties. Significant difference (p ≤ 0.05) was recorded for bostwick consistency, sedimentation index, phase volume, color, particle size distribution and β-carotene content. Process optimization was based on the selected responses through a desirability function. Ultrasonication for 9 min followed by mechanical homogenization for 1 min, subjected to 3 passes, gave the optimum results with d (0.1), d (0.5) as 142.19 and 327.89 μm; β-carotene (1471.58 μg/g) and “a” value (21.42) with a composite desirability (0.85). The variation between the predicted and experimental values was <12%. This study is the first attempt towards using a combination of ultrasonication and mechanical homogenization for carrot puree processing.     

Modulation of native structural architecture and hydrodynamic properties of apple seed protein isolates

The study aimed to synthesize apple seed protein nanoparticles (APN) using planetary ball milling (PBM). On ball milling, protein nanoparticles displayed uniform size distribution with a hydrodynamic diameter of 490.21 nm. Electron microscopy showed irregular, disordered, and rough surfaces of nano-protein particles. FTIR analysis reveals increased β-turn and random coil in APN, indicating loss of ordered protein structure. Changes in secondary structure and microenvironment of amino-acid residues were also depicted by fluorescence quenching and circular dichroism. Owing to conformational changes, a notable decrease in thermal characteristics (∆H = 5.86 to 2.92 J/g) and % crystallinity (36.93 to 32.21%) was observed in APN. Moreover, PBM was found effective in improving the hydrodynamic properties of protein isolates. CLSM demonstrated that emulsions prepared with APN showed increased stability. These results suggest that mechanochemical reduction via ball-milling can be a powerful approach for fabricating nanoparticles with excellent structural and functional characteristics for use in various food systems.     

(Not to be taken) with a grain of salt: Enhancing perceived saltiness by 3D-printed surface textures

Seeking to promote healthy food options through design, this study investigates whether food saltiness perception can be enhanced through the design of the surface texture of the container from which the product is sampled, using 3D-printing. An experimental study was conducted at a supermarket in which shoppers (N = 270) participated in a taste test. A full-factorial 3 (surface texture: smooth, rough, rough and irregular) × 3 (salt content: low, medium and high salt content) between-subject design was employed. Participants in each condition were asked to try the product and assess saltiness perception, taste intensity, taste liking and willingness to try. Results testify to the feasibility of enhancing saltiness impressions through both rough and irregular 3D-printed surface textures, but only for the medium-salt and high-salt variants. Findings on taste liking and willingness to try likewise testify to the importance of considering the interaction between surface texture and saltiness. These findings qualify previous research on cross-modal correspondences by showing that applications of surface textures may backfire when the gap between expectations triggered by tactile sensations and actual food contents becomes too large. Implications for initiatives aimed at promoting healthy food choices are discussed.     

Deployment of an attractive toxic sugar bait system (ATSB) with insecticide,for adult Tribolium castaneum (Coleoptera: Tenebrionidae)

Tribolium castaneum is a critical stored-grain pest of nuts and cereals. Insecticides have traditionally been used to control it; however, their overuse can result in the development of insecticide resistance. Effective bait pesticides could be useful tools for slowing down the rate of insecticide-resistance development and improving the management of stored grain pests. Attractive toxic sugar bait (ATSB) systems are used with mosquitoes and flies; they lure pests with liquid foods that contain sugars but also an oral toxin. It is unknown whether the ATSB system is applicable to T. castaneum adults who prefer dry food products with reduced water content. The objective of this study is to develop an optimal ATSB system for T. castaneum control. Thus far, it found that T. castaneum consumed a gypsum block. The dietary intake of T. castaneum adult beetles was facilitated with added mannitol into gypsum block. Combining insecticides that are oral toxins of the pests with these facilitating sugars results in the death of the pest. Spirotetramat causes a significant reduction in fatty acid biosynthesis by inhibiting acetyl-CoA carboxylase. In this investigation, we have demonstrated that spirotetramat, at low concentrations, was lethal to T. castaneum adults, when used with the ATSB system, combined with mannitol. The lethality of chlorfenapyr, an inhibitor of mitochondrial ATP synthesis, to adult T. castaneum did not increase when used in the ATSB system with mannitol. These results show that the active ingredient used in the ATSB system is integral for beetle control. Increasing the oral delivery rate of insecticides using carbohydrates leads to increased lethality rates of stored-grain pests.     

Effects of interaction between rice glutelin and starch on starch gelatinization in a simulated storage system

Starch and protein are the two major components of rice and interaction between them will occur during storage. However, whether the interaction between starch and protein impacts rice starch gelatinization is still unclear. In this study, the effects of starch-protein interaction on starch gelatinization (japonica rice) were investigated using a glutelin–starch simulation system under high temperature and humidity storage conditions. A glutelin–starch ratio of 1:4 was used in the simulation system and stored in an artificial climate chamber (40 °C, 60% humidity) for 60 d. The interaction had a significant effect on starch gelatinization. Starch granule particles were broken down, and the bonds of starch granules weakened during interaction with glutelin. The secondary structure of glutelin loosened, as the starch disintegrated the α-helix structure. Correlation analyses revealed that peak viscosity (PV), trough viscosity (TV), and final viscosity (FV) had a significant negative correlation with carbonyl content, and disulfide bonds (P < 0.01), as well as a significant positive correlation with the active thiol content (P < 0.01). Moreover, setback (SB) had a significant positive correlation with the α-helix and a negative correlation with the β-turn content (P < 0.05). PV, TV, breakdown (BD), and FV were significantly related to β-sheet in glutelin (P < 0.05). These results suggest that glutelin and starch can interact and affect starch gelatinization.     

Is dietary intake associated with salt taste function and perception in adults? A systematic review

Salt is commonly used in food processing and as a flavour enhancer. Dietary salt intake often exceeds the recommended levels and high intake is associated with several health concerns such as hypertension, cardiovascular disease and certain types of cancer. A systematic review of the literature was conducted to examine if individuals’ salt taste function and perception is associated with dietary intake. Interventional studies were excluded in order to investigate the taste-diet relationships of free-living individuals. The systematic literature search was conducted in five electronic databases and twenty articles that reported on salt taste function and perception, as well as dietary intake, were identified and included. Of these, eleven studies measured salt taste sensitivity as detection and/or recognition thresholds, seven measured salt taste intensity, and twelve assessed hedonic ratings (preference or liking). Based on the studies included in this review, salt taste sensitivity and intensity ratings were poorly associated with dietary intake. Hedonic ratings, on the other hand, were relatively more predictive of dietary intake. Considerable variations in the methods used in salt taste and dietary intake assessment were noted, which may explain the lack of taste-diet associations or inconsistent findings between studies. Although definitive conclusions cannot be drawn, this review suggests that a simple tool that assesses salt taste hedonic ratings may be a useful strategy to identify individuals who consume high levels of salt in a clinical setting and subsequently inform the selection of strategies to improve dietary salt intake in these individuals. Future studies investigating taste-diet relationship should emphasise high quality methodology and adequate statistical power for robust outcomes.     

Field effectiveness of improved hermetic storage technologies on maize grain quality in Central Mexico

Maize is the main crop cultivated by small scale farmers (SSF) in Mexico, and its production represents an important goal for local food security. However, SSF very often face severe post-harvest losses in maize, mainly because of insect pests and the lack of suitable storage technology. This study was conducted to compare the field effectiveness in terms of maize quality under on-field conditions of SSF of two improved hermetic storage technologies with the traditional storage. The field experiment was performed on-farm in the highlands of Central Mexico. Maize grains were stored in three storage devices: hermetic plastic bag (sBag), hermetic plastic silo (Bioxilo), or traditional polypropylene sacks. The study considered the quantitative evaluation of storage, physical, nutritional, and industrial qualities of maize after 4, 8 and 12 months of storage. Environmental conditions of storage such as oxygen levels, temperature and humidity were monitored. After 1 year of field storage, compared with traditional sacks, sBag and Bioxilo showed a significant lower losses in storage due to insects. When controlled infested maize by artificial insect infestation methods was used, the improved technologies were also effective in reducing grain losses. Furthermore, both sBag and Bioxilo prevented grain quality detriment in terms of physical, nutritional and industrial (for tortilla and seed) properties (p < 0.01). Additionally, compared with traditional storage, sBag and Bioxilo showed efficient control of the hermetic conditions in terms of oxygen, temperature and humidity, but no significant differences were detected between the two improved technologies. In summary, under on-farm conditions, the successful preservation of maize grain quality was achieved by the improved sBag and Bioxilo in the highlands of Mexico. In the future, positive effects of this storage system will need to be validated under tropical conditions.     

Two lysozymes are involved in the larva-to-pupa transition and the antibacterial immunity of Lasioderma serricorne (coleoptera: Anobiidae)

Lysozymes play important roles in the innate immune response against pathogen infections of insects. In this study, i-type and c-type lysozymes (LsLysI and LsLysC) were identified from the cigarette beetle, Lasioderma serricorne. Both genes were highly expressed in late larvae and pupae, especially in the fat body and integument. The expression of LsLysI and LsLysC was induced by 20-hydroxyecdysone. The expression levels of both LsLys genes were significantly upregulated after peptidoglycan (PGN) exposure and gram-positive bacterium Staphylococcus aureus infections. RNA interference (RNAi)-mediated knockdown of LsLysI or/and LsLysC in 5th instar larvae reduced lysozyme levels and disrupted the larva-to-pupa molt. Knockdown of LsLysI or LsLysC alone, and co-suppression of both genes, increased larval mortality by 13.3%, 21.1%, and 43.3% after S. aureus infection. The results demonstrated that LsLysI and LsLysC play key roles in a successful larva-to-pupa transition and in the innate immune response of L. serricorne.     

Impact of controlled atmosphere storage on physiological quality of soybean seed

Soybean seed tends to lose its quality property if kept in inappropriate storage conditions. The aim of this work was to evaluate the effect of different oxygen (O₂) and carbon dioxide (CO₂) partial pressures, combined with different temperatures on the soybean seed physiological potential maintenance. In 2017, seed of the cultivars 8473 RSF and TECIRGA 6070RR were stored for 7 months under: [1] ambient air; controlled atmosphere (CA) with [2] 1 kPa O₂ + 0.04 kPa CO₂; [3] 2 kPa O₂ + 0.04 kPa CO₂; [4] 2 kPa O₂ + 30 kPa CO₂; and [5] 2 kPa O₂ + 80 kPa CO₂. In 2018, seed of NA 5909 RG and FEPAGRO 37RR were stored for 7 months under the following conditions: [1] ambient air; and CA with [2] 1 kPa O₂ + 0.04 kPa CO₂; [3] 1 kPa O₂ + 15 kPa CO₂; [4] 1 kPa O₂ + 30 kPa CO₂; [5] 2 kPa O₂ + 0.04 kPa CO_2. In both years the storage conditions were conducted at three temperatures (20, 25 and 30 °C). The seed were stored with moisture content between 11 and 11.5. The reduction of the O₂ until 1.0 kPa maintained higher germination, however, storage above 25 °C is not recommended. High CO₂ partial pressure did not have additional effects on physiological quality conservation compared to solely low O₂. Seed of 8473 RSF stored at 25 and 30 °C resulted in low germination, regardless of the CA condition. NA 5909 RG reached 80% of germination, when CA was used, regardless of temperature. The ambient air did not maintain the seed physiological quality when stored at 25 and 30 °C and CA may efficiently maintain the physiological quality of soybean seed after 7 months, even in the higher temperature for NA5909 RG, but not for the other cultivars.     

Mitochondrial response of the lesser grain borer Rhyzopertha dominica (F.) to modified atmospheres

Rhyzopertha dominica is an insect pest that feeds on a wide variety of grains and stored cereals, producing economical losses. Bioenergetics studies on insects are necessary to eventually plan strategies to reduce pest infestation on stored grains with methods other than insecticides. Modified atmosphere treatments, where insects are exposed to either low O₂ or high CO₂ concentrations, or both, can be used as alternatives. In this research, R. dominica was subjected to a modified atmosphere environment (MA) consisting of 5% O₂ and 10% CO₂ for 24 h and was compared with normoxia insects (21% O₂ and 0.02% CO₂). Mitochondria from the whole insect were isolated and their protein content was analyzed by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) using OFFGEL Fractionator equipment and 12% polyacrylamide gels electrophoresis (SDS-PAGE). Lactate concentration, cytochrome c oxidase (COX) and ATPase activities were measured. Lactate concentration was 29% higher in R. dominica exposed to MA versus normoxia. 2-D PAGE and LC MS/MS revealed the presence of a heat shock protein (hsp60), an actin fragment, and ATP synthase α and β catalytic subunits. Activity levels of COX and ATPase were reduced by 58 and 59%, respectively, in MA versus normoxia. Therefore, R. dominica may have shifted into a hypo-metabolic state because oxygen intake was insufficient to maintain enzymatic activity. This scenario would ultimately result in a decrease in substrate concentration (oxygen) and a reduction in electron transport chain complex activity. Thus, eventually, this knowledge can be use to develop novel environmentally friendly alternatives to eradicate or reduce pests in stored grains.     

Development of resistance in stored grain pest,Trogoderma granarium (Everts) against deltamethrin and its effective control by synergistic toxicity of bifenthrin and chlorpyrifos

The current investigation was conducted to estimate the resistance level against deltamethrin in fourth and sixth instar larvae of Trogoderma granarium collected from wheat storage warehouses of Dera Ghazi Khan (DGK), Okara (OKR) and Gujranwala (GUW). Results showed that the fourth and sixth instar larvae of collected strains warehouses moderately resistant to deltamethrin compared with the same developmental stages of insecticide susceptible laboratory strain (LAB-S). Efficacies of bifenthrin, chlorpyrifos and their various combinations were analyzed against fourth and sixth instar larvae of different strains of pest populations to minimize the development of resistance against deltamethrin. LC_50s of bifenthrin against fourth and sixth instar larvae of all the four populations were recorded at low concentrations compared to deltamethrin. The LC₅₀ values of bifenthrin against fourth instar larvae of LAB-S, DGK, OKR and GUW populations were 359.32, 416.58, 524.01 and 598.91 ppm, respectively, while these values were 204.30, 262.98, 301.89 and 355.22 ppm against sixth instar larvae of those populations, respectively. Chlorpyrifos was found to be the most effective insecticide compared to bifenthrin and deltamethrin. The LC₅₀ values of chlorpyrifos were 189.33, 305.37, 376.30 and 459.15 ppm against fourth instar larvae of LAB-S, DGK, OKR and GUW populations, respectively, whereas for sixth instar larvae those values were 98.24, 129.61, 163.43 and 230.74 ppm, respectively. Various combinations of bifenthrin and chlorpyrifos viz., 1:1, 2:1, 3:1, 1:2 and 1:3 were also tested. Based on the values of LC₅₀ and relative toxic unit, 1:3 combination was observed as the most effective among all combinations. The LC₅₀ values of fourth instar larvae of all the four populations against each insecticide and their combinations were recorded at high concentration compared to that of sixth instar larvae. Results of current investigation need to be considered in present stored grain insect pest control program of warehouses in Punjab¹.     

Taste perception and purchase intent of oil‐in‐water spreads: effects of oil types and salt (NaCl or KCl) concentrations

Associations of sodium intake with heart‐related problems are creating awareness towards reducing sodium. Potassium chloride (KCl), a substitute for sodium chloride (NaCl), has the disadvantage of imparting bitterness at high concentrations. We evaluated physical characteristics, taste perception and purchase intent of KCl and NaCl in oil‐in‐water spreads/emulsions composed by olive, rice bran and soya bean oils. Consumers (N = 300) evaluated saltiness/bitterness of emulsions prepared with 65% oil, and NaCl (0.5% and 1.0%) or KCl (0.75% and 1.5%). Olive oil spreads (104.07–107.43 Pa s) had higher viscosity compared to other spreads (59.16–74.96 Pa s). Type of oil had significant effects on bitterness, overall taste liking and viscosity. Taste liking decreased due to bitterness of olive oil spreads (mean drop=1.72–2.43). Purchase intent was positively associated with saltiness and pH and increased with oil claims (increase = 1.3%–22.1%) compared to sodium claims (increase = 0.0%–12.9%). These findings are useful for understanding taste perception of emulsions.     

Preference for salt in a food may be alterable without a low sodium diet

In response to current efforts to reduce population-wide dietary salt intake, the objective of this study was to determine whether liking for reduced sodium and low sodium tomato juice could increase following repeated exposure over an extended period. Eighty-three adult subjects participated in a three-part study: an initial taste test, a 16-week longitudinal study, and a final taste test. Subjects gave liking ratings of four tomato juice samples ranging in sodium from 640 mg (a concentration comparable to a commercially available product) to 136 mg per 237 ml serving (a low sodium concentration) at both taste tests. For the longitudinal study, subjects were divided into two balanced groups based on PROP sensitivity, hedonic sensitivity to salt, and motivation to reduce dietary salt intake; the abrupt group received tomato juice reduced in sodium to reach a low sodium target at week four, and the gradual group received juice reduced in sodium via difference thresholds to reach the same target at week 14. Though liking for the juice with the highest salt content was unchanged between taste tests, liking for all reduced salt juices increased at the final taste test relative to the initial taste test among subjects in both salt reduction groups. In addition, subjects in both groups experienced a downward shift in preference for salt in tomato juice, indicating that repeated exposure may be sufficient to alter preference for salt in a food in the absence of a low sodium diet. That salt preference may be altered by exposure alone within the context of a high salt diet is promising for both the food industry and individual consumers.