Increasing Oil Concentration Affects Consumer Perception and Physical Properties of Mayonnaise‐type Spreads Containing KCl

Reducing sodium intakes remains a global challenge for the food industry. KCl is a potential salt substitute but imparts bitterness when used at high concentrations. Little is known about how oil concentrations (OC) affect consumers’ perception of saltiness and bitterness in emulsion products such as mayonnaise containing KCl. We evaluated consumers’ perception and physical properties of mayonnaise‐type spreads at various oil and tastant (NaCl or KCl) concentrations. Consumers (N = 306) evaluated saltiness, bitterness, overall taste liking (OTL) and purchase intent (PI). Viscosity, pH, water activity, and consistency/texture were also measured. Oil and tastant (NaCl or KCl) concentrations had significant effects on saltiness, viscosity, and pH. As OC increased, saltiness intensity slightly decreased for spreads. Increasing oil concentration increased viscosity. Generally, spreads containing KCl had higher bitterness and pH than spreads containing NaCl. All spreads containing KCl were penalized for being “too bitter.” PI was affected by OTL for all spreads but OC was also a significant factor in the purchase decision of spreads containing NaCl. This study demonstrated that increasing OC affected consumers’ taste perception (saltiness and bitterness) and spreads’ physical properties including pH and viscosity.     

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.     

Effects of colorant concentration and ‘natural colour’ or ‘sodium content’ claim on saltiness perception,consumer liking and emotion,and purchase intent of dipping sauces

Natural colorant (no colorant, NC = 0%; moderate colorant, MC = 1.2%; high colorant, HC = 3.6% w/w) and salt (regular salt, RS = NaCl; reduced sodium, ReS = KCl; no salt, NS) were added in mayonnaise‐based dipping sauces to evaluate effects of colorant concentration and ‘natural colorant’ or ‘sodium content’ claim on saltiness expectation, consumer liking and emotion, and purchase intent (PI) of these products. Regardless of the salt type and content, increasing colorant concentration decreased colour liking scores while saltiness expectation tentatively increased as indicated by higher % of ‘too much’ responses for saltiness on a JAR (Just‐About‐Right) scale. At a given salt type and content, liking scores of salty taste decreased with increasing colorant concentration, both before and after the ‘sodium content’ claim was given to consumers. Emotion scores elicited by consuming dipping sauces were affected by colorant concentration. Positive emotions (good, interested, satisfied) decreased while negative emotions (guilty, unsafe, worried) increased with increasing colorant concentration. Statements of ‘natural colorant’ and ‘sodium content’ claim had minimal effects on elicited emotions and PI.     

Oil‐in‐Water Emulsion Exhibits Bitterness‐Suppressing Effects in a Sensory Threshold Study

Little is known about how emulsion characteristics affect saltiness/bitterness perception. Sensory detection and recognition thresholds of NaCl, caffeine, and KCl in aqueous solution compared with oil‐in‐water emulsion systems were evaluated. For emulsions, NaCl, KCl, or caffeine were dissolved in water + emulsifier and mixed with canola oil (20% by weight). Two emulsions were prepared: emulsion 1 (viscosity = 257 cP) and emulsion 2 (viscosity = 59 cP). The forced‐choice ascending concentration series method of limits (ASTM E‐679‐04) was used to determine detection and/or recognition thresholds at 25 °C. Group best estimate threshold (GBET) geometric means were expressed as g/100 mL. Comparing NaCl with KCl, there were no significant differences in detection GBET values for all systems (0.0197 ‐ 0.0354). For saltiness recognition thresholds, KCl GBET values were higher compared with NaCl GBET (0.0822 ‐ 0.1070 compared with 0.0471 ‐ 0.0501). For NaCl and KCl, emulsion 1 and/or emulsion 2 did not significantly affect the saltiness recognition threshold compared with that of the aqueous solution. However, the bitterness recognition thresholds of caffeine and KCl in solution were significantly lower than in the emulsions (0.0242 ‐ 0.0586 compared with 0.0754 ‐ 0.1025). Gender generally had a marginal effect on threshold values. This study showed that, compared with the aqueous solutions, emulsions did not significantly affect the saltiness recognition threshold of NaCl and KCl, but exhibited bitterness‐suppressing effects on KCl and/or caffeine.     

Texture and colour characteristics,and optimisation of sodium chloride,potassium chloride and glycine of reduced-sodium frankfurter

The three-components mixture design was applied to optimise a ratio of NaCl (0%–65%), KCl (35%–100%) and glycine (0%–20%) in reduced-sodium frankfurters. Fourteen frankfurters were analysed for texture and colour, and consumer (n = 100) acceptability. Results indicated that NaCl levels affected consumer acceptability of reduced-sodium frankfurters. Increasing NaCl generally increased texture hardness. Optimisation of a salt mixture was performed by superimposing contour plots of predicted acceptability scores (≥5.5 on a 9-points hedonic scale) of all sensory attributes and revealed the optimal salt mixture: 40.03%–63.66% NaCl, 35.00%–55.90% KCl and 0.00%–20.00% glycine. The optimal salt mixture contained 220–340 mg Na/100g frankfurter compared with 540 mg Na/100 g of the control formulation (100% NaCl). The mean overall liking score (5.9 vs. 5.9) of the optimal reduced-sodium frankfurter was not different from the control (100% NaCl). This optimal formulation had >25% sodium reduction and could be claimed as ‘reduced-sodium’ according to US Food and Drugs Administration regulation.     

The influence of sodium on liking and consumption of salty food

Excessive sodium (Na) intake has been linked to development of hypertension and related pathologies. In this study, we assessed if the sodium chloride (NaCl) concentration in a prototypical food influences the liking and intake of that food. In study 1, detection and recognition thresholds for NaCl were assessed, and perceived salt intensity and liking for hash browns of varying sodium concentrations (40 mg, 120 mg, 170 mg, and 220 mg Na/100 g) were compared in a lab setting. In study 2, detection and recognition thresholds for NaCl were assessed in a lab setting, and lunches consisting of hash browns, basic salad, and beverages were consumed freely in a dining setting on 4 separate occasions. Intake and liking ratings for hash browns were recorded after the lunch. In both studies, detection and recognition thresholds for NaCl were not associated with perceived saltiness, liking, or intake of hash browns. Liking and perceived salt taste intensity of hash browns were correlated (r = 0.547 P < 0.01), and in study 1 the 220 mg sodium hash brown was most liked (P < 0.05). In study 2, there was no association between Na concentration and liking or consumption of hash browns. In summary, liking of hash browns were influenced by whether testing was in a lab or dining room environment. In a dining room environment, large decreases (>50%) of sodium content of food were achievable with only minor decrease in liking and no effect on consumption of the food.     

Partial replacement of sodium chloride with potassium chloride in marinated rabbit meat

This study was aimed at evaluating the consequences of sodium chloride reduction by potassium chloride up to 50% on technological, sensorial and microbiological traits of marinated rabbit meat. In total, 226 rabbit loin meat samples were obtained and subjected to vacuum tumbling using solutions with different NaCl/KCl ratios. Replacing of sodium chloride up to 30% by potassium chloride did not change microbiological traits (total aerobic mesophilic and lactic acid bacteria maximum cell loads), sensorial acceptability (perceived saltiness and overall liking) and technological traits (pH, colour, texture, cooking loss and yield). Otherwise, reduction in sodium chloride to 50% significantly decreased perceived saltiness (4.15 vs. 4.73; P < 0.05) and reduced microbial shelf life by 1 day when compared to control, even if there was still no effect on technological traits. In conclusion, it is feasible imparting an added value for processed rabbit meat products by reduction in sodium content that could increase market interest.     

Influences of a natural colourant on colour and salty taste perception,liking, emotion and purchase intent: a case of mayonnaise‐based dipping sauces

Effects of colourant and a ‘natural source’ statement on sensory liking, emotion, saltiness expectation and purchase intent (PI) of three dipping sauces containing shrimp head colourant [no‐colourant (NC); moderate‐colourant (MC, 1.2% colourant); high‐colourant (HC, 3.6% colourant)] were evaluated. Consumers disliked colour of HC compared to MC (4.65 vs. 6.24). Despite the same NaCl level, saltiness liking decreased with increasing colourant [6.38 (NC), 5.43 (MC), 3.97 (HC)]. Correspondence analysis biplot revealed that sauces with or without natural colourant were associated more with positive emotions. Positive emotion (good, interested, satisfied) scores decreased while negative emotion worried increased with increasing colourant concentration. The ‘natural source’ statement decreased guilty and unsafe scores but minimally affected PI of NC and MC. Saltiness expectation was not different between NC (off‐white colour) vs. MC (lighter orange) and between NC vs. HC (darker orange); however, consumers expected HC to be saltier than MC.     

Personality traits and bitterness perception influence the liking and intake of pale ale style beers

Bitterness is classically considered undesirable in foods and beverages. Yet, widespread commercial success of beers (like Bitters in the UK or IPAs in the US) indicate bitterness is desirable for some consumers. Here, we tested whether personality traits influence beer liking and intake. Under laboratory conditions, beer consumers (n = 109) rated liking and intensity of 2 pale ales and a lager, and intensity of two bitter solutions (quinine, Tetralone®). Participants also completed intake and personality questionnaires (Sensation Seeking, Sensitivity to Punishment and Reward, and Food Involvement). A liking ratio for each beer was calculated from each participant’s liking for that specific beer and their total liking for all beers. Participants were classified as weekly, monthly, or yearly pale ale consumers using intake data. Using intensity ratings, personality measures, and other parameters, hierarchical linear regression was used to predict liking ratios, and logistic regression was used to predict beer intake frequency. A significant interaction between Sensation Seeking and quinine bitterness (p = 0.03) was found for the liking ratio of a pale ale. The interaction revealed liking of the pale ale increased with Sensation Seeking but only if quinine bitterness was also high. Intake models showed increased odds of frequent pale ale intake with greater quinine bitterness and lower liking for lager beer. These data suggest liking and intake of pale ales is positively related to Sensation Seeking and bitter taste perception. Contrary to findings in other bitter foods and beverages, the high bitterness found in pale ales may be desirable for some consumers.     

Modification of perceived beer bitterness intensity,character and temporal profile by hop aroma extract

The effect of hop aroma on perceived bitterness intensity, character and temporal profile of beer was investigated. A hop aroma extract was added at 3 levels (0, 245, 490 mg/L) to beers at low, medium and high bitterness. Beers were evaluated for perceived bitterness intensity, harshness, roundedness and linger by a trained panel using a rank-rating technique at each bitterness level, with and without nose clips. The use of nose clips enabled the olfactory aspect to be decoupled from taste and mouthfeel aspects of bitterness perception. Results showed significant modification of perceived bitterness in beer by hop aroma depending on the inherent level of bitterness. These modifications were mainly driven by olfaction – in an example of taste-aroma interactions, as well as certain tactile sensations elicited by the hop aroma extract in the oral cavity. At low bitterness, beers with hop aroma added were perceived as more bitter, and of ‘rounded’ bitterness character relative to those without hop aroma. When judges used nose clips, this effect was completely eliminated but the sample was perceived to have a ‘harsh’ bitterness character. Conversely, at high bitterness, even when nose clips were used, judges still perceived beers containing hop aroma to be more bitter. These increases in bitterness perception with nose clips indicates the stimulating of other receptors, e.g. trigeminal receptors by hop aroma extract, which in tandem with the high bitterness, cause perceptual interactions enhancing bitterness intensity and also affecting bitterness character. Bitterness character attributes such as ‘round’ and ‘harsh’ were found to significantly depend on bitterness and aroma levels, with the second level of aroma addition (245 mg/L) giving a ‘rounded’ bitterness in low bitterness beers but ‘harsh’ bitterness in high bitterness beers. The impact of aroma on temporal bitterness was also confirmed with time-intensity measurements, and found to be mostly significant at the highest level of hop aroma addition (490 mg/L) in low bitterness beers. These findings represent a significant step forward in terms of understanding bitterness flavour perception and the wider impact of hop compounds on sensory perception.     

Reducing sodium intake from meat products

Sodium intake exceeds the nutritional recommendations in many industrialized countries. Excessive intake of sodium has been linked to hypertension and consequently to increased risk of stroke and premature death from cardiovascular diseases. The main source of sodium in the diet is sodium chloride. It has been established that the consumption of more than 6g NaCl/day/person is associated with an age-increase in blood pressure. Therefore, it has been recommended that the total amount of dietary salt should be maintained at about 5-6g/day. Genetically salt susceptible individuals and hypertensives would particularly benefit from low-sodium diets, the salt content of which should range between 1 and 3g/day. In industrialized countries, meat products and meat meals at home and in catering comprise one of the major sources of sodium, in the form of sodium chloride. Sodium chloride affects the flavour, texture and shelf life of meat products. The salt intake derived from meat dishes can be lowered by, whenever possible, adding the salt, not during preparation, but at the table. In most cases, salt contents of over 2% can be markedly lowered without substantial sensory deterioration or technological problems causing economical losses. Salt contents down to 1.4% NaCl in cooked sausages and 1.75% in lean meat products are enough to produce a heat stable gel with acceptable perceived saltiness as well as firmness, water-binding and fat retention. A particular problem with low-salt meat products is, however, that not only the perceived saltiness, but also the intensity of the characteristic flavour decreases. Increased meat protein content (i.e. lean meat content) in meat products reduces perceived saltiness. The required salt content for acceptable gel strength depends on the formulation of the product. When phosphates are added or the fat content is high, lower salt additions provide a more stable gel than in non-phosphate and in low-fat products. Small differences in salt content at the 2% level do not have marked effects on shelf life of the products. By using salt mixtures, usually NaCl/KCl, the intake of sodium (NaCl) can be further reduced.     

Aroma–taste interactions between a model cheese aroma and five basic tastes in solution

The flavour perception of cheese results from complex sensory interactions between tastes and aromas. Using a model cheese solution, this study investigated perceived interactions between each of five basic tastes and a cheese aroma mixture containing ten volatile compounds commonly found in cheese. The five tastes – sucrose (sweetness), sodium chloride (NaCl) (saltiness), monosodium glutamate (MSG) (umami), lactic acid (sourness), and caffeine (bitterness) – were individually mixed with cheese aroma in water using a 5 taste level (0.2 log series) by 3 aroma level (0.5 log series) design. Aroma controls with no added taste were also included. This resulted in 18 samples for each single taste–aroma combination. An additional 18 samples were produced using a mixture of all 5 tastes with the 3 aroma levels. A panel of trained assessors (n = 10) evaluated cheese flavour intensity and taste intensity using 100 point line scales. Evaluation was carried out in duplicate, with samples grouped by taste type; 1 evaluation session per taste per replicate. Within type, order of presentation was balanced, and taste type order was randomised between replicates. Cheese flavour intensity was enhanced by sucrose and NaCl, while being suppressed by lactic acid. NaCl enhanced cheese flavour intensity the most at high aroma level, while lactic acid suppressed the most at low aroma level. When MSG level was increased, cheese flavour intensity was enhanced at both low and medium aroma levels, but was suppressed at the high aroma level. The greatest enhancement of cheese flavour intensity was found with the mixture of 5 tastes. Aroma significantly enhanced umami and bitterness, but did not enhance sweetness, saltiness, or sourness. This study showed that the perceived interaction between taste and cheese aroma depended on taste type and on the concentration levels of both taste type and aroma. The mixture of tastes was more effective at enhancing cheese flavour intensity than single tastes. This study provides knowledge that will underpin further study of taste–aroma interactions in a model cheese that aims to optimise cheese flavour intensity and character.     

Reducing the sodium content in meat products: The effect of the formulation in low-sodium ground meat patties

This study investigated the effect of formulation on quality characteristics of low-sodium ground meat patties. The variation in sodium content was achieved by varying the NaCl content. The formulation variables studied were sodium and fat content and the use of phosphate. The patties were made using 50% or 60% meat in the formulations. Formulation affected the perceived saltiness of ground meat patties. Fat and lean meat content affected perceived saltiness, but their effects were opposite. When the fat content was increased the perceived saltiness increased, but when the meat content increased the perceived saltiness decreased. However, the effect of fat content on perceived saltiness was less than the effect of meat content. The use of phosphate effectively decreased cooking loss, particularly of high-fat-low-sodium patties. The same firmness could be reached with lower sodium content when phosphate was used.     

Using taste-induced saltiness enhancement for reducing sodium in Cheddar cheese: Effect on physico-chemical and sensorial attributes

Reduced sodium Cheddar cheese (RSCC) was prepared by substituting 75% of sodium chloride (NaCl) with potassium chloride (KCl). To mask the inherent bitterness of KCl and to improve the flavour profile of RSCC, hydrolysed vegetable protein (HVP) as flavour enhancer (FE) and adenosine-5′-monophosphate (AMP) as bitter blocker (BB) were used. The study evaluated physico-chemical and sensory attributes of RSCC and changes in these attributes during ripening. Flavour, colour and appearance, saltiness and bitterness scores of both the samples were at par (p < 0.05) throughout the period of ripening, but body and texture scores of RSCC was significantly (p < 0.05) lower. This was probably due to increased casein hydration caused by substitution of sodium by potassium. Water activity (a_w) of RSCC was found to be significantly higher. The study suggested successful use of FE and BB for increasing the flavour profile of RSCC.     

Individual differences in responsiveness to oral sensations and odours with chemesthetic activity: Relationships between sensory modalities and impact on the hedonic response

Independent sensory modalities are related and showed covariations in prior literature. However, little is known on the relationship between oral sensations and nasal chemesthesis. This large-scale study aims (I.) to test the hypothesis that response to oral stimuli is related to responsiveness to odours with chemesthetic activity; and (II.) to explore the implications of these relationships on liking.Oral and olfactory responsiveness of 2205 Italians (18–65 years, men = 41%) were evaluated. Intensities of tastes, astringency and pungency were collected in water solutions and in four foods modulated for target sensations. Responses to bitterness of 6-n-propylthiouracil (PROP) was measured. Odour intensity and irritation were assessed for three pure odorants (L-Menthol, trans-anethole, (+)-α-Terpineol) stimulating nasal chemesthesis (respectively: TRPM8, TRPA1, TRPA1). Liking for odours and foods was measured. Specific intensity indices were developed for each sensation.Three clusters were identified based on taste intensity responses (Cl1, Cl2, Cl3). Cl1 (38%) was the most responsive to tastes, astringency, pungency, PROP and odours’ intensity and irritation. This hyper-responsive cluster showed the highest hedonic variation (the span of liking ratings for stimuli with varied tastant concentrations). Cl2 (24%) was intermediate for oral responsiveness (apart for sourness) and Cl3 (38%) was the least responsive. Cl2 and Cl3 did not differ in odours’ responsiveness (neither for perceived intensity nor for irritation). All sensory modalities were correlated but cross-correlations were higher when stimulating the same peripherical areas (oral vs oral more correlated than oral vs nasal). Results corroborate the idea of an overall high ‘sensory responsiveness’ covering different sensory modalities. Practical implications of the study are that less responsive subjects might require greater modifications in products formulations to modify their liking.