Saltiness Intensity Research Articles

Development of an initial lexicon for and impact of forms (cube, liquid, powder) on chicken stock and comparison to consumer acceptance

AbstractThe objectives of this study were to develop an initial descriptive sensory lexicon of commercial chicken stock products, determine the flavor profile and groupings of various forms of chicken stock, and understand consumer acceptability of chicken broth. Nine trained panelists evaluated 10 samples and consumers evaluated 6 of these 10 samples. The lexicon consisted of 23 sensory attributes, including 5 for appearance, and 18 for flavor. Cube type samples had high saltiness intensity, powder type had moderate saltiness and higher chicken flavor intensity, and liquid type had low saltiness and chicken flavor intensity. As results from overall acceptability and JAR ratings, consumer evaluation was not affected by type of chicken stock, and appropriateness (just about right) of chicken flavor and saltiness intensities were important for consumer acceptability. Chicken flavor and saltiness might be important drivers of consumer liking for chicken stock products.Practical applicationsAlthough chicken stock products are widely used, research on their use as bases in preparing dishes is limited. This study developed a lexicon for chicken stock products and conducted a consumer acceptability evaluation of chicken broth. The findings from this study can help manufacturers develop and improve chicken stock products by modifying flavor attributes to increase consumer acceptance. For consumers, chicken flavor was more important than saltiness for acceptability.

Asians' Facial Responsiveness to Basic Tastes by Automated Facial Expression Analysis System.

Growing evidence shows that consumer choices in real life are mostly driven by unconscious mechanisms rather than conscious. The unconscious process could be measured by behavioral measurements. This study aims to apply automatic facial expression analysis technique for consumers' emotion representation, and explore the relationships between sensory perception and facial responses. Basic taste solutions (sourness, sweetness, bitterness, umami, and saltiness) with 6 levels plus water were used, which could cover most of the tastes found in food and drink. The other contribution of this study is to analyze the characteristics of facial expressions and correlation between facial expressions and perceptive hedonic liking for Asian consumers. Up until now, the facial expression application researches only reported for western consumers, while few related researches investigated the facial responses during food consuming for Asian consumers. Experimental results indicated that facial expressions could identify different stimuli with various concentrations and different hedonic levels. The perceived liking increased at lower concentrations and decreased at higher concentrations, while samples with medium concentrations were perceived as the most pleasant except sweetness and bitterness. High correlations were founded between perceived intensities of bitterness, umami, saltiness, and facial reactions of disgust and fear. Facial expression disgust and anger could characterize emotion "dislike," and happiness could characterize emotion "like," while neutral could represent "neither like nor dislike." The identified facial expressions agree with the perceived sensory emotions elicited by basic taste solutions. The correlation analysis between hedonic levels and facial expression intensities obtained in this study are in accordance with that discussed for western consumers.

The Effect of Breaking Properties and Fragmentation on the Perceived Saltiness of Surimi Gels Prepared with Various Heating Conditions

The strength of taste is thought to be affected not only by content of food, but also by the texture. The previous study on the relationship between the saltiness and texture of heat-induced surimi gels prepared with different setting conditions revealed that the difference of physical properties did not affect the perceived saltiness of surimi gels, notwithstanding the breaking strength was very different according to the setting time. This result was seemed to contradict to the findings obtained with other food material so far. Therefore, this study was aimed to clarify the relationship between the intensity of saltiness and texture of heat-induced surimi-based products focusing on the fragmentation of the gel. To prepare various types of surimi gels having different physical properties from the same material, surimi gels were prepared by 2-steps heating with different level of pre-heating at 60oC (modori). The physical properties of surimi gels were evaluated by puncture test, two-bite texture profile analysis and measurement of expressible water. The particle size of surimi gels after chewing in mouth by every panelist was also evaluated. The physical properties of heat-induced surimi gels became softer and more fragile according to the preheating time at 60oC. Maximum saltiness intensity in the gel was evaluated comparing with different reference solutions. The result of the sensory evaluation suggested that the difference in physical properties derived by heat induced degradation during pre-heating at 60oC affected the perceived saltiness during consumption of surimi gels, and that the fragmentation of the gel will strongly correlate to the perceived saltiness of surimi gels.

Relationship between the Physical Properties and Perceived Saltiness of Various Surimi Gels Prepared by Different Setting Conditions

Salt intake is an important concern for health reasons and saltiness is affected not only by content of food, but also by the texture. Surimi-based products, such as kamaboko, are elastic gels with approximately 2% NaCl; despite recent concerns among Japanese consumers regarding high-salt foods, little is known about the relationship between saltiness and texture in these products. This study was aimed to clarify the relationship between saltiness and texture using heat-induced surimi gels as a model of surimi-based product. Various types of heat-induced gels with different physical properties were prepared from surimi and washed surimi by two-step heating with different setting (preheating) times at 30°C. Washed surimi was prepared to remove the additives, because the additives were thought to affect the taste of surimi gel. The physical properties of heat-induced gels were characterized by puncture breaking strength and expressible water. The perceived saltiness of the heat-induced surimi gels was evaluated with fixed number of chewing. Next, to improve the demerit of this method, the perceived saltiness of the washed surimi gels was evaluated by free chewing conditions. The perceived saltiness after fixed number of chewing and the maximum saltiness intensity during free chewing was evaluated using sensory tests by comparisons with salt solutions of known concentrations. The physical properties of heat-induced gels differed considerably depending on the salt content and heating conditions. A longer setting time was associated with a higher breaking force and lower expressible water, regardless of salt content. On the other hand, perceived saltiness depended on the NaCl concentration, but not greatly influenced by the physical properties of the gels prepared from both surimi and washed surimi. The perceived saltiness of all gels tested was less than 1/3 of solution with the same NaCl concentration. The maximum saltiness intensity did not correlate with breaking force, breaking strain and expressible water of heat-induced gels. From these results, it was suggested that the difference in physical properties derived by setting did not affect the relative saltiness intensity of gels to NaCl solution during consumption of surimi gels.

Influence of the Number of Chewing Cycles on the Sweetness and Saltiness Intensity of Agarose Gel

Influence of the Number of Chewing Cycles on the Sweetness and Saltiness Intensity of Agarose Gel

The effect of salt concentration on swelling power, rheological properties and saltiness perception of waxy, normal and high amylose maize starch.

The effect of salt concentration on swelling power, rheological properties and saltiness perception of waxy, normal and high amylose maize starch was investigated. The swelling power decreased with increasing salt concentration from 0% to 2.0% among all starch samples. Waxy starch showed the highest swelling power at different salt levels, while high amylose starch showed the least swelling power. The salt addition increased the gelatinization temperature of waxy starch and normal starch from 71.3 °C to 77.1 °C and from 72.3 °C to 78.2 °C. Their storage modulus (G'), loss modulus (G''), and viscosity values at lower salt concentration were greater than those at higher salt concentration. The increasing tan δ of waxy and normal starch against frequency sweep indicated liquid-like behavior, while high amylose starch exhibited decreasing tan δ indicating solid-like behavior as it was difficult to gelatinize. When sensory evaluation was conducted by trained panelists, it was found that high amylose starch displayed the highest initial saltiness and in-mouth saltiness intensity, accompanied by the greatest thickness, lubrication and stickiness, while waxy starch displayed the lowest values for saltiness perception and mouthfeel.

Taste intensities of ten vegetables commonly consumed in the Netherlands

Bitterness has been suggested to be the main reason for the limited palatability of several vegetables. Vegetable acceptance has been associated with preparation method. However, the taste intensity of a variety of vegetables prepared by different methods has not been studied yet. The objective of this study is to assess the intensity of the five basic tastes and fattiness of ten vegetables commonly consumed in the Netherlands prepared by different methods using the modified Spectrum method. Intensities of sweetness, sourness, bitterness, umami, saltiness and fattiness were assessed for ten vegetables (cauliflower, broccoli, leek, carrot, onion, red bell pepper, French beans, tomato, cucumber and iceberg lettuce) by a panel (n=9) trained in a modified Spectrum method. Each vegetable was assessed prepared by different methods (raw, cooked, mashed and as a cold pressed juice). Spectrum based reference solutions were available with fixed reference points at 13.3mm (R1), 33.3mm (R2) and 66.7mm (R3) for each taste modality on a 100mm line scale. For saltiness, R1 and R3 differed (16.7mm and 56.7mm). Mean intensities of all taste modalities and fattiness for all vegetables were mostly below R1 (13.3mm). Significant differences (p<0.05) within vegetables between preparation methods were found. Sweetness was the most intensive taste, followed by sourness, bitterness, fattiness, umami and saltiness. In conclusion, all ten vegetables prepared by different methods showed low mean intensities of all taste modalities and fattiness. Preparation method affected taste and fattiness intensity and the effect differed by vegetable type.

News and Views

A big challenge for natural ways to reduce sodium in recipes in nearly every culture is taste. Consumers typically describe reduced-sodium foods as lacking in taste and flavor. Findings of a study by researchers from the Institute of Food Technologists (IFT), found that Vietnamese fish sauce added to chicken broth, tomato sauce and coconut curry reduced the amount of sodium chloride by 10-25 per cent while still maintaining the perceived deliciousness, saltiness and overall flavor intensity.

Taste intensity modulates effective connectivity from the insular cortex to the thalamus in humans

Evaluation of taste intensity is one of the most important perceptual abilities in our daily life. In contrast with extensive research findings regarding the spatial representation of taste in the insula and thalamus, little is known about how the thalamus and insula communicate and reciprocally influence their activities for processing taste intensity. To examine this neurophysiological relationship, we investigated the modulatory effect of intensity of saltiness on connections in the network processing taste signals in the human brain. These “effective connectivity” relationships refer to the neurophysiological influence (including direction and strength of influence) of one brain region on another. Healthy adults (N=34), including 17 males and 17 females (mean age=21.3years, SD=2.4; mean body mass index (BMI)=20.2kg/m2, SD=2.1) underwent functional magnetic resonance imaging as they tasted three concentrations of sodium chloride solutions. By effective connectivity analysis with dynamic causal modeling, we show that taste intensity enhances top-down signal transmission from the insular cortex to the thalamus. These results are the first to demonstrate the modulatory effect of taste intensity on the taste network in the human brain.

Saltiness enhancement of oil roasted peanuts induced by foam‐mat salt and soy sauce odour

SummaryOdour‐induced saltiness enhancement (OISE) method can be used to reduce salt in food. This study was performed to examine the effect of OISE on saltiness perception of oil roasted peanuts seasoned with foam‐mat salt. First, 410 consumers rated saltiness intensity elicited by odour names of fifty‐seven food/ingredient items. Soy sauce odour name was among from the top five items with higher saltiness intensities, hence it was selected to further investigate the effect of saltiness enhancement in conjunction with foam‐mat salt. The control (commercial salt, 100%), CS50 (commercial salt:soy sauce odour; 50:50) or FS50 (foam‐mat salt:soy sauce odour; 50:50) was mixed with roasted peanuts, which were subsequently evaluated by a descriptive panel for saltiness intensity and by consumers for sensory acceptance. OISE in conjunction with foam‐mat salt produced FS50 roasted peanuts, having 10 mg of sodium per 100 g sample less than CS50 but being as acceptable as the control.

Physicochemical, microbiological, and sensory characteristics of soy sauce fermented in different regional ceramics

Korean traditional soy sauce was fermented for 120 days in ceramics obtained from five different regions in Korea. The average internal and external temperatures of soy sauce in ceramics were 20.0 and 18.3 °C, respectively. Physicochemical, microbiological, and sensory characteristics were analyzed. Ceramics from different regions generated differences in physicochemical characteristics. Soy sauce fermented in the southwest regional ceramic, which has a low height and wide circumference, had significantly lower salt content, higher reducing sugar content, and protease activity rather than others. In descriptive analysis, soy sauce fermented in the ceramic from Seoul capital region had a lower intensity of saltiness and biting taste, whereas the soy sauce in the southwest ceramic had comparable saltiness and biting taste attributes as those in the southeast and central regions, and Jeju Island ceramics. Five regional ceramics were categorized into three groups by principal component analysis. Based on the physicochemical characteristics, soy sauces from southwest and Seoul capital regions had distinctive characteristics in comparison with the soy sauces from Jeju Island, southeast, and central regions.

Preparation of an Aroma Fraction from Dried Bonito by Steam Distillation and Its Effect on Modification of Salty and Umami Taste Qualities.

To study the effects of dried bonito aroma on taste perception, dried bonito aroma fraction (DBAF) as a steam distillate in liquid was added to the salt solutions containing 5 different salt concentrations (0.68% to 1.5% [w/v]) before sensory evaluations. Perception of the taste qualities of salt solutions with added DBAF varied depending on the salt concentration. At low salt concentrations (0.68% to 0.83%), after-taste intensity of saltiness and overall taste intensity were significantly enhanced by the addition of DBAF. This suggests that DBAF can be applied to a low-salt seasoning at these salt concentrations. Umami taste intensity was significantly enhanced by the addition of DBAF at all salt concentrations (0.68% to 1.5%). The addition of heat-treated DBAF, which no longer had the dried bonito odor, exerted no significant influences on any taste descriptors. As the result of gas chromatography-mass spectrometry analysis, sulfur-containing compounds, pyrazines, alcohols, and phenols were contained in DBAF and not detected in heat-treated DBAF. Because these compounds contributed to the dried bonito odor, the taste modifications were thought to be induced by these compounds. The effects of the DBAF on Japanese noodle soup (mentsuyu) were also examined. The saltiness intensity of 1.2% salt concentration of mentsuyu containing both DBAF and DBS (dried bonito stock) as a hot water extract of dried bonito was not significantly differ from that of 1.5% salt concentration of mentsuyu not containing any of them. It will thus be possible to develop a reduced salt seasoning by combining DBAF and DBS.

Effect of Protein-Lipid-Salt Interactions on Sodium Availability in the Mouth and Consequent Perception of Saltiness: In Solutions.

The influence of protein-sodium interactions on the availability of sodium in the aqueous phase of liquid samples and consequently on the perception of saltiness was investigated. The aqueous effluents of casein and casein emulsion-salt solutions were monitored for sodium availability from a tongue column system. In the aqueous protein-salt solutions, increasing the protein/salt ratio from 1:1 to 5:1 or 10:1 significantly decreased the initial salt concentration in the effluent and resulted in a higher salt concentration in the effluent over time. Sensory analysis was in agreement. Samples with increased protein were rated as having significantly lower initial saltiness and a higher salty aftertaste. However, when casein was formulated as an emulsion, the initial release of sodium in the effluent was enhanced (compared to nonemulsified protein). Increasing the emulsion interfacial area (more hydrophilic segments of the protein were structured into the aqueous phase) resulted in a higher salt concentration in the aqueous phase and greater perceived saltiness intensity. In summary, protein interactions, specifically ionic, were reported as food interactions that influence salt perception and provide a basis to develop higher flavor quality low-sodium food products.

Oil and tastant concentrations affect saltiness and bitterness perception of oil‐in‐water emulsions

SummarySaltiness of NaCl and KCl and bitterness of KCl and caffeine were evaluated in emulsions prepared with varying oil (20/40/60%) and tastant [NaCl (0.50/0.75/1.00%), KCl (0.50/1.00/1.50%) or caffeine (0.05/0.10/0.15%)] concentrations. A panel (N = 16) evaluated saltiness and bitterness intensities of emulsions using the modified short‐version Spectrum™ descriptive analysis. Viscosity and pH of emulsions were measured. The type of tastant (NaCl/KCl/caffeine) and its concentration had significant effects on saltiness and/or bitterness intensities. At a given tastant concentration, NaCl had higher saltiness intensity compared to KCl in emulsions. Increasing oil concentration increased saltiness of both NaCl and KCl, while it slightly increased bitterness of KCl, but did not significantly affect bitterness of caffeine in emulsions. RSM plots indicated that saltiness enhancement of NaCl and KCl imparted by oil was more pronounced between 20% and 40% oil. Viscosity was the discriminating property among emulsions and possibly contributed to changes in salty and bitter perception.

Retronasal odor enhancement by salty and umami tastes

It has been shown that congruent food odors are enhanced by sweet taste, but not by sour or bitter taste. This raises questions regarding the underlying conditions of retronasal odor enhancement by taste. We speculate that a taste quality that signals the presence of “nutritive” or “beneficial” substances (e.g., sweet carbohydrate), as opposed to potentially harmful substances (e.g., toxins, spoilage), can enhance a congruent odor. This study aimed to investigate this possibility by testing two other taste qualities, saltiness and umami, which signal the presence of minerals and protein. The study also examined the possible occurrence of saltiness and umami enhancement by odors and factors that may affect both taste and odor enhancement. Over five sessions, subjects rated (1) intensities of saltiness, bitterness, umami, and specific odor of tastants (NaCl, MSG, MPG, caffeine), odorants (chicken, soy sauce odor), and all possible binary mixtures, (2) degree of liking/disliking of the odorants in the absence and presence of the tastants, (3) degree of congruency of odorants alone and with tastants, and (4) degree of perceptual similarity between tastants and odorants. Results showed that saltiness and umami enhanced chicken and soy sauce odor intensities, but the odors did not enhance saltiness and umami intensities. Importantly, the degree of odor enhancement was highly correlated with the degree of taste–odor congruency, but less so with the degree of perceptual similarity between taste and odor. These findings confirm our hypotheses that the quality of taste dictates the ability to enhance food odors and that the degree of taste–odor congruency can modulate the degree of odor enhancement.

Psychophysical Effects of Increasing Oil Concentrations on Saltiness and Bitterness Perception of Oil-in-Water Emulsions.

Limited research has been done to investigate saltiness and bitterness perceptions of NaCl, KCl, and caffeine in emulsion systems. Saltiness and bitterness intensities of emulsions prepared with different concentrations of oil [0% (that is, solution), 20%, 40%, canola oil] and different concentrations of 3 tastants (NaCl [0.5% to 1.0%], KCl [0.5% to 1.5%], and caffeine [0.05 to 0.15%]) were measured using the Spectrum™ descriptive method (N = 16) and the Electronic-tongue (E-tongue). Linear regression and the Stevens' power law were used to model the taste intensities against the tastant concentrations. From the descriptive data, saltiness intensities in emulsions were higher than solutions, demonstrating a saltiness-enhancing effect imparted by oil. Bitterness intensities in emulsions were lower compared to those of solutions for caffeine, but they were similar for KCl. This demonstrated that oil suppressed bitterness for caffeine. E-tongue saltiness measurements were corresponding to those of the descriptive data; however, E-tongue bitterness intensities of KCl showed an opposite pattern.

Salt taste perception in hydrocolloid systems is affected by sodium ion release and mechanosensory–gustatory cross-modal interactions

The perceived salt taste intensity of viscous solutions and gels of agar–agar and starches varying in their amylose/amylopectin ratio, as well as cellulose suspensions with fine, compact particles up to coarse, fibrous particles was systematically investigated. Saltiness intensity was correlated with instrumental-analytical data on viscosity, gel firmness, and sodium ion availability upon chewing. Salt taste perception was demonstrated to be dependent on the type and concentration of the polysaccharide. It was directly affected by viscosity, gel firmness, the mechanosensory perception of solid particles, and the rate of sodium release. On the one hand, sodium ion availability seemed to be a limiting factor determining salt taste perception in highly viscous and firm gel systems. On the other hand, texture-induced cross-modal interactions between taste and mechanosensory cues seem to play the key role impairing perceived taste impact at lower polysaccharide concentrations and, in particular, in the presence of solid particles. Intriguingly, solid particles that only minimally increased the viscosity drastically reduced perceived taste intensity, not only for saltiness, but also for sour, umami, and sweet tastes, with the exception of bitterness. These findings provide new knowledge on the impact of mechanosensation on taste perception.

천연 염미증강제 개발을 위한 완도산 다시마의 열수 추출 조건 최적화 및 염미증강 효능 평가

완도산 다시마를 천연 염미증강제로 개발하기 위하여 다시마로부터 정미성분이 최적으로 추출되는 열수 추출 조건을 평가하였으며, 다시마 추출분말을 이용하여 염미증강 효능과 나트륨 저감화율을 분석하였다. 정미성분 추출에 가장 적합한 완도산 다시마의 수확시기를 선정하기 위하여 5월, 6월, 7월에 수확한 다시마의 일반성분과 유리아미노산을 분석한 결과 정미성분 아미노산(glutamic acid와 aspartic acid)의 함량이 가장 높은 6월 수확 다시마를 추출 원료로 선정하였다. 다시마 열수 추출 온도와 시간 조건을 평가하기 위하여 60°C, 80°C, 100°C에서 1시간, 2시간, 3시간을 각각 추출하여 추출액의 품질 특성을 분석한 결과 100°C 추출 조건에서 가용성 고형분과 조단백의 함량이 35.47~36.93%와 3.75~4.00%로 가장 높게 나타났으며, 점도는 1.96~2.19 cP로 낮게 나타나 추출 온도는 100°C를 선정하였다. 추출 시간 선정을 위하여 100°C에서 추출 시간에 따른 추출액의 정미성분 아미노산 함량과 관능적 특성을 평가한 결과 추출 2시간에서 정미성분 아미노산인 glutamic acid와 aspartic acid의 함량이 각각 275.33 mg%와 121.18 mg%로 가장 높게 나타났으며, 관능적 기호도도 유의적으로 높게 평가되어 다시마로부터 정미성분 추출을 위해 적합한 추출온도와 시간은 100°C, 2시간 조건으로 확인되었다. 정미성분이 최적으로 추출된 다시마의 추출분말을 제조하여 NaCl 용액에 첨가한 후 염미증강 효능을 평가한 결과 짠맛 강도 1, 5, 9의 NaCl 용액이 다시마 추출분말 1% 첨가 후 짠맛 강도 4.25, 10.08, 16.58로 상승하였다. 동일한 짠맛 강도에서 NaCl 용액과 다시마 추출분말이 첨가된 시험용액의 나트륨 함량을 측정하여 나트륨 저감화율을 분석한 결과 12.24~24.33%의 저감화율을 나타내었다. 본 연구를 통하여 감칠맛과 정미성분이 풍부한 다시마 추출물은 조미소재뿐만 아니라 식품에서 나트륨 함량을 줄이기 위한 천연 염미증강제로서 산업적 활용을 기대할 수 있다.

Binding of Na+ ions to proteins: Effect on taste perception

This study investigated the relationship between the ionic binding of sodium and salty perception in protein matrices. Protein type (i.e. gelatin, milk protein and soy protein), protein concentration and pH were varied to obtain matrices with distinct compositions and rheological properties. 23Na NMR spectroscopy was used to determine the ratio of sodium ions bound to proteins and the mobility of sodium ions. The results showed that protein type, concentration and pH affected the rheological properties of the protein matrices, the ionic binding of sodium ions and taste intensity. As the protein concentration increased, the mobility of sodium ions decreased and the ratio of bound sodium ions increased. Gelatin matrices displayed the greatest mobility of total sodium ions and the smallest amount of bound sodium. Soy protein had a larger amount of bound sodium than milk protein. Lowering the pH of milk protein matrices tended to decrease the ratio of bound sodium and increase sodium mobility. We suggest that sodium ionic binding is related to the presence of negatively charged groups in proteins. Although changes in matrix composition modified sodium ionic interactions, taste perception was mainly affected by the rheological properties of the protein matrices. As the values of fracture stress or viscosity increased, firmness intensity increased and saltiness intensity decreased. The observed effects of texture on taste could be explained by cross-modal texture-taste interactions and by differences in the oral breakdown behavior of protein matrices.

Effect of spray-drying process on physical properties of sodium chloride/maltodextrin complexes

The mixture of sodium chloride and maltodextrin was processed by spray-drying with various inlet temperatures (130, 140, 150, 160 and 170°C) or atomization pressure (60, 100, 140, 180 and 220kPa). Physical properties of spray-dried maltodextrin/NaCl powder were characterized such as surface area or morphological images and sensory evaluation was carried out to observe saltiness of maltodextrin/NaCl complexes. At the high atomization pressure produced smallest particle of maltodextrin/NaCl complexes and it was effective to be melted faster and then saltiness was also rapidly recognized compared with bigger complexes. In this study, although inlet temperature was not effective like atomization pressure processing, relatively lower inlet temperature influenced on maltodextrin/NaCl complexes during spray-drying. It was suggested that decrease of salt particle size could improve melting speed and it could be helpful to enhance intensity of saltiness with small amount of salt.