Electronic Tongue Analysis Research Articles

Quality diversity of three calcium-rich Primulina vegetables: A comprehensive analysis of calcium content, metabolite profiles, taste characteristics, and medicinal potential

Primulina plants native to karst regions are exceptionally rich in calcium and have been developed into high‑calcium leafy vegetables. However, limited knowledge of their metabolites, taste characteristics, and potential medicinal value restricts further genetic improvements. This study conducted a comprehensive analysis on three breeding species of Primulina vegetables. Common garden experiment demonstrated significant calcium enrichment capability, with calcium content ranging from 204.45 to 391.52 mg/100 g. Through widely-targeted metabolomics, 1121 metabolites were identified within these Primulina vegetables. Furthermore, comparative analysis identified 976 differentially accumulated metabolites across nine comparison groups, driven mainly by flavonoids, phenolic acids, and lipids. Integration of electronic tongue analysis and metabolomics revealed taste profiles and identified 17 key candidate compounds related to taste. Based on network pharmacology analysis, 32 active ingredients were found in Primulina vegetables, which highlighted potential medicinal value. These findings provide a data-driven foundation for breeding programs aimed at enhancing nutritional and flavor traits.

Enhancement of γ-aminobutyric acid content in Huangjiu through rice bran fermentation and its impact on the volatile organic compounds

Rice bran has high glutamic acid decarboxylase (GAD) activity and can be used to enrich and produce γ-aminobutyric acid (GABA). Glutinous rice was used as raw material to brew Huangjiu by liquefaction fermentation. Rice bran extract was added at different fermentation stages, then the content of GABA and basic physicochemical properties were tested, the changes of flavor substances and volatile organic compounds (VOCs) were observed in Huangjiu. The results showed the addition of concentrated GABA-enriched rice bran extract during the post-fermentation stage significantly increases the GABA content in Huangjiu. When the amount of rice bran used is 50 g, the GABA content in the Huangjiu can reach 592.44 mg/L after fermentation. The total sugar and pH of Huangjiu fermented with rice bran extract were higher than the control group, and the total acid and non-sugar solids were lower than the control group. Electronic tongue analysis showed that the addition of rice bran extract would affect the sourness, umami and saltiness taste of Huangjiu. Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) analysis of Huangjiu made by adding rice bran extract at the post-fermentation stage showed increased isoamyl acetate, 2-heptanol, and other substances in comparison with the control group. The results of the study provide a cost-effective and rapid method for increasing the GABA content in Huangjiu. It also offers a theoretical basis and scientific guidance for the production of health-oriented Huangjiu.

Decoding of the saltiness enhancement taste peptides from Jinhua ham and its molecular mechanism of interaction with ENaC/TMC4 receptors

This study focused on unlocking the potential of Jinhua ham-derived peptides (JHP) for enhancing saltiness. JHP (<3 kDa) was obtained through ultrafiltration and desalting, reducing the salt content by 96 %. Four peptide fractions (JHP-P1/P2/P3/P4) were isolated using Sephadex G-25 gel filtration and anion-exchange chromatography. Sensory evaluation and electronic tongue analysis revealed that JHP-P2 (0.5 mg/mL) exhibited the highest saltiness which could replace four-fold NaCl salinity. Three peptides (DL, FMSALF, and HVRRK) identified by UPLC-QTOF-MS/MS were simulated with salty taste receptors ENaC/TMC4. Results indicated that Ser84 and Phe89 of ENaC and Asn404 and Lys567 of TMC4 are crucial for peptide docking related to salty taste. Molecular dynamics simulations showed that the three peptides bind to the TMC4 and ENaC through van der Waals forces, electrostatic interactions, and hydrogen bonds. These findings establish a robust theoretical foundation for salt reduction strategies and provide novel insights into the potential applications of Jinhua ham.

Effect of fat replacement in high internal phase emulsions constructed by high temperature saccharification of grafted proteins on gel properties and flavor profiles of sausages

In order to mitigate the risk of cardiovascular diseases associated with excessive saturated fatty acid intake, utilizing high internal phase emulsions (HIPEs) as a substitute for animal fat in producing high-quality fat-substituted meat products is an ideal approach. This study involves the preparation of glycosylation products of egg white protein (EWP) through saccharification at high temperatures in the presence of fructooligosaccharides (FO). The resulting glycation products of EWP were employed to create colloidal particles, forming HIPEs, which were further utilized to induce the formation of HIPEs gels (HIPEs-Gs). The study investigated the effects of substituting different ratios (25%, 50%, 75%, and 100%) of animal fat with HIPEs and HIPEs-Gs on the gel properties and flavor characteristics of sausages. Results showed that, compared to the control group, substituting fat with HIPEs significantly improved the gel properties, cooking yield, and G' of sausages, while excessive HIPEs-Gs substitution yielded negative effects. Low-field nuclear magnetic resonance results also demonstrated that adding HIPEs improved water and oil distribution in the sausage batter, enhancing protein's binding capacity with water. Scanning electron microscope revealed that HIPEs substitution led to a denser gel network with smaller pores, effectively "locking in" more water. Analysis of volatile compounds indicated accelerated release of aromatic compounds, alkanes, sulfides, and lipids when fat was substituted with HIPEs and HIPEs-Gs. Electronic tongue analysis suggested that HIPEs-Gs substitution reduced response values for umami and saltiness. In conclusion, compared to HIPEs-Gs, using HIPEs as a fat substitute improves the quality of sausages.

Preparation of umami peptides from chicken breast by ultrasound-assisted gradient dilution feeding substrate and study of their formation mechanism

Gradient dilution feeding substrate (GDFS) is regarded as an effective method for the production of active peptides, as it compensates for substrate limitations and minimizes substrate contamination of the ultrafiltration membrane. This study further investigated the impact of ultrasound-assisted gradient dilution feeding substrate (UA-GDFS) on the peptide yield and the intensity of umami. The chicken breast was used as ingredients. The umami compounds in the hydrolysate were determined using an automatic amino acid analyzer and HPLC. The hydrolysate's umami intensity was determined by electronic tongue in all modes. These findings indicated that UA-GDFS enhanced the umami intensity and peptide yield. Hydrolysate from UA-GDFS with molecular weight below 1 kDa was analyzed by nano-scale liquid chromatography-tandem mass spectrometry (Nano-HPLC-MS/MS). Electronic tongue analysis showed that GPSGPVG and VDGPSGK had umami taste and could enhance the umami taste of monosodium glutamate (MSG) solution. Asn68 and His145 were important sites on T1R3 for umami peptide binding.

Qingqianliutianosides A–E: five new sweet dammarane triterpenoid glycosides derived from the leaves of Cyclocarya paliurus – identification, characterization and interactions with T1R2/T1R3 sweet taste receptors

AbstractBACKGROUNDCyclocarya paliurus, as a new food resource, is utilized extensively in human and animal diets due to its bioactive compounds, health benefits, and its highly prized sweet flavor. This study aimed to investigate the sweet‐taste ingredient of C. paliurus leaves.RESULTSFive new dammarane triterpenoid glycosides were isolated and identified as qingqianliutianosides A–E (1–5) by comprehensive spectroscopic data analysis and a single crystal X‐ray diffraction experiment. Qingqianliutianoside A (1) and qingqianliutianoside C (3), present in relatively high quantities in the plant, were shown to exhibit sweetness by sensory evaluation and electronic tongue analysis. Further monitoring was conducted on the content changes in 3 in leaves at different growth stages, indicating that 3 reached its peak content in April and then showed a decreasing trend. Molecular docking studies revealed that T1R2/T1R3 receptors Ser212, Ser105, Thr239, Asn380, Thr305, and Val381 may play critical roles, demonstrating that hydrogen bonding and hydrophobic interactions were the dominant interaction forces between all of the identified compounds and the active sites in the Venus flytrap module of the T1R2/T1R3 receptors.CONCLUSIONQingqianliutianosides A–E are promising natural source sugar substitutes for use in functional foods and beverages. © 2024 Society of Chemical Industry.

Effects of low-temperature plasma, microwave and 60Co γ-irradiation treatments on the flavor characteristics of lychee whole fruit powder

Powdering whole lychee fruit is one of the most effective methods for improving the comprehensive utilization rate of lychees. In this study, lychee whole fruit powder (LWFP) was prepared and treated with low-temperature plasma, microwave, and 60Co γ-irradiation treatments to enhance its quality. Volatile organic compounds (VOCs) were analyzed using Headspace Solid Phase Micro-extraction Gas Chromatography-mass Spectrometry (HS-SPME-GC-MS), Headspace Gas Chromatography Ion Mobility Spectrometry (HS-GC-IMS), and electronic nose (E-nose) techniques. Electronic tongue (E-tongue) analysis revealed that both sweetness and bitterness were significant taste indicators of LWFP. GC-MS analysis revealed that the predominant volatile compounds in LWFP were terpenoids and alcohols, specifically nerol, geraniol, ɑ-pinene, hexylbenzene, ɑ-caryophyllene, caryophyllene oxide, and isoamylenol. GC-IMS identified small-molecule aldehydes such as 2-methyl propanal, hexanal, propanal, and 2-methylbutanal as significant contributors to the aroma profile. Moreover, key aromatic contributors include dimethyl sulfide, 1-penten-3-one, and acetic acid. Notably, microwave treatment exerted the most significant effect on the aroma profile of lychee. In contrast, low-temperature plasma and irradiation treatments exhibited similar and consistent changes. Specifically, microwave treatment primarily increased the concentration of larger terpenoid molecules such as nerol, 1-phenylhexane, and caryophyllene oxide, whereas low-temperature plasma and irradiation had a greater impact on smaller aldehyde molecules such as hexanal and 2-methylbutanal. All treatments enriched the sweet fruity, brilliant woody, and cabbage scents of LWFP.

Fermentation with Bacillus natto and Bifidobacterium improves the functional, physicochemical properties, and taste qualities of coix seed-natto

Coix seed-natto (CS-natto) is a nutritious food rich in various functional components such as nattokinase (NK), and the strains’ fermentation is crucial for enhancing its quality. This work utilized Bacillus natto GUTU09 (B9) and Bifidobacterium animalis subsp. lactis BLH1 or BLH6 to ferment soybeans that were soaked in a saccharified liquid made from CS, resulting in the preparation of CS-natto, studied the physicochemical and functional characteristics during fermentation, and analyzed the correlation of various indicators. Finally, an electronic tongue analysis was conducted on CS-natto. The results indicated that fermentation significantly increases NK and antioxidant activity in CS-natto, with NK activity in BLH6-B9 natto reaching 425.00 FU/g. Co-fermentation notably enhanced the content and composition of phenolic substances. Furthermore, the study revealed that the organic acid and soy isoflavone content in co-fermentation were significantly higher than in single-strain fermentation. Fermentation could elevate the levels of amino peptide nitrogen and soluble peptides. Additionally, the addition of Bifidobacterium exhibited a synergistic effect on the fermentation of B9 to produce natto. Correlation analysis indicated that Bifidobacterium promoted B9 to produce NK. The BLH1 encouraged the conversion of organic acids. Daidzein and daidzin were positively correlated (P<0.01), suggesting a potential mutual conversion. Finally, electronic tongue analysis indicated that co-fermentation could effectively enhance the taste. The results indicated that CS-natto could serve as an improved dietary supplement offering enhanced quality and more beneficial effects on people’s health.

Exploring Novel Umami Peptides from Bovine Bone Soups Using Nano-HPLC-MS/MS and Molecular Docking.

In this study, umami peptides were screened and characterized from bovine bone soups manufactured via atmospheric and high-pressure boiling. Peptide fractions with molecular weights less than 3 kDa were selected for peptide sequencing using LC-MS/MS, the toxicity prediction of the umami peptides was carried out by using an website, and the peptides were screened according to the binding energy, i.e., three peptides including YDAELS, TDVAHR, and ELELQ were selected. The three umami peptides were further synthesized, and their umami thresholds were determined through sensory evaluation and electronic tongue analysis, ranging from 0.375 to 0.75 mg/mL. All three peptides exhibited a significant synergistic taste enhancement effect when combined with MSG (monosodium glutamate) solution. The molecular docking of the umami peptides with the T1R1/T1R3 receptor revealed the mechanism of umami presentation, and the main interaction forces between the three umami peptides and the receptor were hydrogen bonding, electrostatic interactions, and hydrophobic interactions.

Identification and screening of umami peptides from skipjack tuna (Katsuwonus pelamis) hydrolysates using EAD/CID based micro-UPLC-QTOF-MS and the molecular interaction with T1R1/T1R3 taste receptor

In this study, the enzymatic hydrolysates of skipjack tuna, Katsuwonus pelamis, were purified by ultrafiltration and further identified through micro-ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (micro-UPLC-QTOF-MS). The potential umami peptides were identified using both conventional collision-induced dissociation (CID) and novel electron-activated dissociation (EAD) fragmentation techniques. Nine novel umami peptides with iUmami-SCM > 588 were screened. Sensory evaluation and electronic tongue analysis were performed to confirm the taste characteristics of the umami peptides, indicating that these umami peptides all exhibited varying degrees of umami taste. Molecular docking and molecular dynamics simulation were utilized to investigate the interaction with T1R1/T1R3 taste receptors. The docking results revealed that Asp234, Ser23, Glu231, and Ile237 appeared most frequently in all docking sites and formed stable complexes through hydrogen bonding and electrostatic interactions. Furthermore, molecular dynamics simulation allowed for a more comprehensive analysis of their interactions within a dynamic environment, providing a deeper understanding of the umami perception mechanism involving umami peptides and receptors.

Change in volatile profiles of wheat flour during maturation

The volatile profiles of wheat flour during maturation were examined through headspace solid-phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC/MS) combined with electronic nose (E-nose) and electronic tongue (E-tongue) analyses. The wheat flour underwent maturation under three distinct conditions for predetermined durations. While GC/MS coupled with E-tongue exhibited discernment capability among wheat flour samples subjected to varying maturation conditions, E-nose analysis solely relying on principal component analysis failed to achieve discrimination. 83 volatile compounds were identified in wheat flour, with the highest abundance observed in samples matured for 50 d at 25 °C. Notably, trans-2-Nonenal, decanal, and nonanal were the main contributors to the characteristic flavor profile of wheat flour. Integration of HS-SPME-GC/MS with E-tongue indicated superior flavor development and practical viability in wheat flour matured for 50 d at 25 °C. This study furnishes a theoretical groundwork for enhancing the flavor profiles of wheat flour and its derivative products.

One of the major challenges of masking the bitter taste in medications: an overview of quantitative methods for bitterness.

The aim of the present study was to carry out a systematic research on bitterness quantification to provide a reference for scholars and pharmaceutical developers to carry out drug taste masking research. Significance: The bitterness of medications poses a significant concern for clinicians and patients. Scientifically measuring the intensity of drug bitterness is pivotal for enhancing drug palatability and broadening their clinical utility. The current study was carried out by conducting a systematic literature review that identified relevant papers from indexed databases. Numerous studies and research are cited and quoted in this article to summarize the features, strengths, and applicability of quantitative bitterness assessment methods. In our research, we systematically outlined the classification and key advancements in quantitative research methods for assessing drug bitterness, including in vivo quantification techniques such as traditional human taste panel methods, as well as in vitro quantification methods such as electronic tongue analysis. It focused on the quantitative methods and difficulties of bitterness of natural drugs with complex system characteristics and their difficulties in quantification, and proposes possible future research directions. The quantitative methods of bitterness were summarized, which laid an important foundation for the construction of a comprehensive bitterness quantification standard system and the formulation of accurate, efficient and rich taste masking strategies.

Discover the secrets of salty taste in Manila clam (Ruditapes philippinarum): MALDI-TOF MS and flavor fingerprint

In this work, the ultrasound-assisted enzymatic (UAE) conditions for salty compounds from Manila clam were optimized using a combination of fractional factorial design (FFD) and Box-Behnken design (BBD). The optimum protein extraction rate (40.13 ± 0.37), DH (25.92 ± 0.78), and salty score (4.01 ± 0.02) of salty extract were achieved with a solid-liquid ratio of 1:4 (w/w), hydrolysis temperature of 49 °C, and ultrasound time of 10 min. Sensory results showed that the UAE hydrolysates exhibited pronounced saltiness (6.25 ± 0.03) and umami (6.62 ± 0.03), with an impressively low detection threshold for salty taste at 69 mmol/L. The electronic tongue analysis revealed that the UAE hydrolysate had a distinct saltiness (3.73 ± 0.05), umami (8.96 ± 0.02) and richness (0.83 ± 0.00). The molecular weights of the peptides in the UAE solution were 84.497 Da, 211.710 Da, 380.530 Da, 568.644 Da and 830.696 Da, respectively. It was rich in alcohols, ketones and furans, and total of 79 volatile compounds (VOCs) were identified. After ultrasonic pretreatment, the content of organic acids was significantly increased, the content of succinic acid was 8.5 ± 0.24, and the content of malic acid was 4.68 ± 0.07. In conclusion, ultrasound-assisted enzymatic is an effective treatment for the extraction of salty compounds.

Insights into “Yin Rhyme”: Analysis of nonvolatile components in Tieguanyin oolong tea during the manufacturing process

Tieguanyin (TGY) is renowned for its distinctive “Yin Rhyme” flavor. To elucidate the underlying formation mechanism, we conducted sensory evaluations, electronic tongue analysis, and widely-targeted metabolomics. Our sensory evaluations and electronic tongue results indicated that TGY exhibits a thick and mellow taste profile, contributing to the “Yin Rhyme” flavor. Metabolomics analysis of tea products revealed that TGY shows significantly higher concentrations of umami substances (L-glutamate, L-theanine) and bitter substances (valine, catechins) compared to Jinguanyin (JGY). Additionally, metabolomic analysis during different oolong tea processing stages revealed significant differences in 21 substances, including L-glutamate, L-theanine, valine, and catechins, between fresh leaves of both varieties. These substances exhibited distinct fluctuation patterns during processing, indicating that the cultivar plays a crucial role in developing the “Yin Rhyme” flavor, which was enhanced throughout processing. This study provides a theoretical foundation for understanding the formation of the unique “Yin Rhyme” flavor of TGY.

Sensory Evaluation of Enzymatically Hydrolyzed Plant-Based Food Ingredients (Oilseed Meals, Grains, and Mushrooms): Electronic-Nose and Electronic-Tongue Analyses

Sensory Evaluation of Enzymatically Hydrolyzed Plant-Based Food Ingredients (Oilseed Meals, Grains, and Mushrooms): Electronic-Nose and Electronic-Tongue Analyses

A fused convolutional transformer for voltammetric electronic tongue analysis tasks

Electronic tongue and artificial intelligence have been evaluated as new rapid analysis technologies in complex solution research. The use of nanomaterials to modify the screen-printed carbon electrode (SPCE) increased the specific surface area and electrocatalytic active sites of the electrode. The voltammetric electronic tongue utilizes multiple cross sensitive sensors to describe the overall characteristics of complex samples, and the complementary information between sensors provides rich and comprehensive descriptions for analyzing various components. The use of electronic tongue for rapid analysis of water quality has gradually become a trend, but the overlapping phenomenon of peaks formed by the similar redox potential of each component in water and the interference of the substrate makes it difficult to obtain effective information of each component in water quality. Here, we propose a Fused Convolutional Transformer model (FCvT) that removes the limitation of overlapping peaks by fusing local features and global complementary features to quantify components in complex solutions. The performance of FCvT was evaluated by testing synthetic water samples consisting of four standardized substance solutions and compared with partial least squares (PLS), support vector regression (SVR), artificial neural networks (ANN), and convolutional neural networks (CNN). The results show that the FCvT obtains the lowest mean absolute percentage error in the set of independent tests.The average quantization error of FCvT is reduced by 34.4 % relative to other methods.

Chemosensoric approaches for taste and odor characteristics each broccoli floret by different storage conditions analyzed using electronic sensors.

This study was to identify taste and volatile characteristics in broccoli florets under various storage conditions (room and cold temperatures). Electronic tongue (E-tongue) analysis revealed that the differences were not represented obviously according to the storage temperatures. The sourness sensor (SRS) was the highest in the 2nd week, and the saltiness sensor (STS) was the highest in the 1st week. The umami (UMS) and bitterness sensors (BRS) were the highest in the 3rd week, and the sweetness sensor (SWS) was the highest in the initial sample. Clusters were discriminated according to storage periods, regardless of storage temperature. Electronic nose (E-nose) analysis detected a total of 41 and 35 volatiles during the room and cold temperature storages, respectively. Clusters were discriminated according to storage types. These findings provide valuable data for broccoli flavor quality by different storage types.

Characterization of taste and aroma profile in pomegranate (Punica granatum L.) seed oil using electronic sensors, GC-MS/olfactometry

In this study, electronic sensors, gas chromatography–mass spectrometry (GC-MS), and GC-olfactometry (GC-O) were used to analyze the flavor of pomegranate seed oil (PSO) extracted from roasted pomegranate seeds. A preliminary study was conducted to determine the extent to which roasting treatment positively affects the physicochemical and sensory properties of pomegranate seeds, and a total of four conditions including raw were selected (raw, 160 °C for 15 min, 160 °C for 20 min, 180 °C for 10 min). This study aimed to determine if the beneficial effects of roasting seeds are retained when the oil is extracted from the seeds, and to explore their potential use in the food industry as a fat-soluble material. Electronic tongue (E-tongue) analysis revealed that roasting enhanced umami and sweetness while reducing bitterness. A total of 46 and 50 volatile compounds were detected using the electronic nose (E-nose) and GC-MS, respectively. The major volatile compounds were Maillard reaction products, which were not detected in the raw samples, and the terpene content decreased after roasting. A total of 13 odor-active compounds analyzed by GC-O were identified, with the majority having odor-active value (OAV) above 1. This study provides an aroma profile of PSO that can be used as a primary database for controlling the aroma and selecting optimal roasting conditions for application in food processing.

Exploring the Relationship between Small Peptides and the T1R1/T1R3 Umami Taste Receptor for Umami Peptide Prediction: A Combined Approach.

Umami peptides are known for enhancing the taste experience by binding to oral umami T1R1 and T1R3 receptors. Among them, small peptides (composed of 2-4 amino acids) constitute nearly 40% of reported umami peptides. Given the diversity in amino acids and peptide sequences, umami small peptides possess tremendous untapped potential. By investigating 168,400 small peptides, we screened candidates binding to T1R1/T1R3 through molecular docking and molecular dynamics simulations, explored bonding types, amino acid characteristics, preferred binding sites, etc. Utilizing three-dimensional molecular descriptors, bonding information, and a back-propagation neural network, we developed a predictive model with 90.3% accuracy, identifying 24,539 potential umami peptides. Clustering revealed three classes with distinct logP (-2.66 ± 1.02, -3.52 ± 0.93, -2.44 ± 1.23) and asphericity (0.28 ± 0.12, 0.26 ± 0.11, 0.25 ± 0.11), indicating significant differences in shape and hydrophobicity (P < 0.05) among potential umami peptides binding to T1R1/T1R3. Following clustering, nine representative peptides (CQ, DP, NN, CSQ, DMC, TGS, DATE, HANR, and STAN) were synthesized and confirmed to possess umami taste through sensory evaluations and electronic tongue analyses. In summary, this study provides insights into exploring small peptide interactions with umami receptors, advancing umami peptide prediction models.

Salt reduction in myofibrillar protein gel via inhomogeneous distribution of sodium-containing encapsulated fish oil coacervate: Mucopenetration ability of sodium carboxymethyl cellulose

The potential application of fish oil microcapsules as salt reduction strategies in low-salt myofibrillar protein (MP) gel was investigated by employing soy protein isolates/carboxymethyl cellulose sodium (SPI-CMC) coacervates enriched with 25 mM sodium chloride and exploring their rheological characteristics, taste perception, and microstructure. The results revealed that the SPI-CMC coacervate phase exhibited the highest sodium content under 25 mM sodium level, albeit with uneven distribution. Notably, the hydrophilic and adhesive properties of CMC to sodium facilitated the in vitro release of sodium during oral digestion, as evidenced by the excellent wettability and mucopenetration ability of CMC. Remarkably, the fish oil microcapsules incorporating SPI-CMC as the wall material, prepared at pH 3.5 with a core-to-wall ratio of 1:1, demonstrated the highest encapsulation efficiency, which was supported by the strong hydrogen bonding. Interestingly, the presence of SPI-CMC coacervates and fish oil microcapsules enhanced the interaction between MPs and strengthened the low-salt MP gel network. Coupled with electronic tongue analysis, the incorporation of fish oil microcapsules slightly exacerbated the non-uniformity of sodium distribution. This ultimately contributed to an enhanced perception of saltiness, richness, and aftertaste in low-salt protein gels. Overall, the incorporation of fish oil microcapsules emerged as an effective salt reduction strategy in low-salt MP gel.