Sweet Research Articles

ChemSweet: An AI-driven computational platform for next-gen sweetener discovery

Nowadays, the overconsumption of artificial sweeteners and their related adverse health impacts have proposed an urgent need to develop safe and healthy alternatives. Herein, we introduce ChemSweet, an AI-based platform for the rapid discovery of potential sweet molecules (http://chemsweet.ddai.tech) with the consideration of their physicochemical properties, sweetness profile, and health risks at the same time. Machine learning prediction models of four important physicochemical and four toxicity properties were established and integrated with the platform to evaluate the candidate molecules' biosafety and stability during the processing processes. Then, a new sweet taste prediction system was developed which ensures the sweet evaluation of six specific kinds of sweeteners. To facilitate the practical application of ChemSweet, the SuperNatural database was integrated for the rational screening of promising new sweeteners. We successfully identified 294 potential sweeteners that simultaneously meet the multiple anticipated criteria. We believe that ChemSweet will serve as a useful tool for identifying safe and healthy sweeteners while reducing the timeframe and high experimental costs.

Chronic Use of Artificial Sweeteners: Pros and Cons.

Over the past few decades, the scientific community has been highly concerned about the obesity epidemic. Artificial sweeteners are compounds that mimic the sweet taste of sugar but have no calories or carbohydrates; hence, they are very popular among patients suffering from diabetes or obesity, aiming to achieve glycemic and/or weight control. There are four different types of sweeteners: artificial, natural, rare sugars, and polyols. Artificial and natural sweeteners are characterized as non-nutritional sweeteners (NNSs) since they do not contain calories. The extended use of sweeteners has been reported to have a favorable impact on body weight and glycemic control in patients with type 2 diabetes (T2DM) and on tooth decay prevention. However, there is concern regarding their side effects. Several studies have associated artificial sweeteners' consumption with the development of insulin resistance, nonalcoholic fatty liver disease (NAFLD), gastrointestinal symptoms, and certain types of cancer. The present review focuses on the description of different types of sweeteners and the benefits and possible deleterious effects of the chronic consumption of NNSs on children's health. Additionally, possible underlying mechanisms of the unfavorable effects of NNSs on human health are described.

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.

Determination of objective taste perception among Iranian medical sciences students during COVID‑19 pandemic in Yazd, Eastern Iran: a case-control pilot study

BackgroundTaste disorders in patients suffering from COVID-19 were popular. Some people even after recovery report residual effects of loss of smell and taste. This study aimed to investigate the taste Perception of Iranian Medical Sciences students during the COVID-19 pandemic.MethodsThe case-control study evaluated 50 Medical Sciences students with a history of COVID-19 infection, as confirmed by the Novel Coronavirus (2019-nCOV) CFX96™ Real-Time PCR Detection System. The other participants consisted of 50 volunteer students with COVID-19 negative. The taste perception was measured with 4 different concentrations of the basic tastes. The stimuli were applied to the protruded tongue. Subjects were asked to identify the researcher when they felt the taste. Data are expressed as frequency distribution and analyzed with the Chi-Square test (P < 0.05).ResultsIn this survey, 54% of participants were male and 46% were female, the mean age of participants was 22.96 ± 5 years. The results showed a significant difference in the sweet and bitter taste perception score according to the history of dietary supplement use. The bitter taste perception score declared a considerable difference since COVID-19 infection. There was no significant difference between the taste perception in the two studied groups for all 4 basic tastes according to gender, COVID-19 infection status, history of taste and smell disorders, and the elapsed time since COVID-19 infection.ConclusionOur findings could provide important insights into taste perception. The history of dietary supplementation may influence how sweetness and saltiness are perceived. There was a noticeable difference in bitter taste perception depending on the time that had elapsed since the most recent COVID-19 infection.

KUALITAS ORGANOLEPTIK SUSU NABATI BIJI CEMPEDAK (Artocarpus Champeden) TERSUSPENSI PROBIOTIK BERDASARKAN SUHU PENYIMPANAN

Background: Cempedak (Artocarpus champeden) is a local fruit of Central Kalimantan that is oval with dark yellow and fibrous flesh and has a fragrant aroma when ripe. So far, cempedak seeds have only become organic waste, not used properly. The nutritional and mineral content of cempedak seeds can be used and processed into a healthy drink, namely vegetable milk. Methods: The method used is an experimental method to produce vegetable milk with cempedak seeds which is then carried out organoleptic tests to determine the quality of the aroma and taste of the vegetable milk made. Results: Based on the research carried out, the results showed that the taste quality of vegetable milk of cempedak seeds (Artocarpus champeden) that was most liked by the respondents/panelists was at the temperature of T1=20o C and T2=30o C, which was with a refreshing sweet and sour taste, while for the sour aroma and distinctive smell of cempedak seeds at the temperature of T3=30o C. Conclusion: Cempedak seeds can be used as probiotic plant-based milk with an optimal storage temperature of 30o C to get the distinctive taste, aroma and smell of cempedak seeds.

Biostimulants Enhance the Nutritional Quality of Soilless Greenhouse Tomatoes.

The application of biostimulants in vegetable cultivation has emerged as a promising approach to enhance the nutritional quality of crops, particularly in controlled environment agriculture and soilless culture systems. In this study, we employed a rigorous methodology, applying various biostimulants amino acids, Plant Growth-Promoting Rhizobacteria (PGPR), fulvic acid, chitosan, and vermicompost along with mineral fertilizers, both foliar and via the roots, to soilless greenhouse tomatoes during spring cultivation. The experiment, conducted in a coir pith medium using the 'Samyeli F1' tomato cultivar, demonstrated that plants treated with biostimulants performed better than control plants. Notable variations in nutritional components were observed across treatments. PGPR had the best effects on the physical properties of the tomato fruit, showing the highest fruit weight, fruit length, equatorial diameter, fruit volume, fruit skin elasticity, and fruit flesh hardness while maintaining high color parameters L, a, and b. PGPR and fulvic acid demonstrated significant enhancements in total phenolics and flavonoids, suggesting potential boosts in antioxidant properties. Amioacid and vermicompost notably elevated total soluble solids, indicating potential fruit sweetness and overall taste improvements. On the other hand, vermicompost stood out for its ability to elevate total phenolics and flavonoids while enhancing vitamin C content, indicating a comprehensive enhancement of nutritional quality. In addition, vermicompost had the most significant impact on plant growth parameters and total yield, achieving a 43% increase over the control with a total yield of 10.39 kg/m2. These findings underline the specific nutritional benefits of different biostimulants, offering valuable insights for optimizing tomato cultivation practices to yield produce with enhanced health-promoting properties.

STUDY OF STEVIA ECAPSULATION FOR USING IN PROBIOTIC DELIVERY SYSTEMS

At the moment, incoming products, beverages, raw materials on the market must comply with the requirements of State standards and safety requirements. The question of nutritional value is growing every day, based on the fact that the constant use of healthy foods develops the body's resistance to various diseases. Such products are called useful or functional products. An equally urgent task for today's specialists is the development of a functional fermented milk product that contains a pleasant sweet taste from natural Stevia plant extract. Stevia rebaudiana Bertoni is a natural sweetener, which has many useful properties. For example, one of the first benefits in low-calorie content does not include fast carbohydrates. So, Stevia has less effect on blood sugar levels and does not increase insulin and is suitable for diabetics. In addition, Stevia extract can be used as prebiotic for co-encapsulation with probiotic microorganisms to enrich functional beverages. Purpose of this study is investigation of formulation parameters for reсeiving саpsules whiсh сreаte а strong bаrrier to penetrаtion of the encapsulated substаnсe to the externаl environment; the саpsules providing more effiсient mаnifestаtion of а сomplex of biologiсаl, phаrmасologiсаl, preventive or mediсinаl properties of bаgged substаnсe. Development of cаpsules of the long term of storаge in whiсh the асtive loaded mаteriаl is proteсted by аn envelope аnd саn preserve activity in vаrious pH environments became the most perspective. Ionic gelation method through extrusion represents a simple encapsulation technique that does not require organic solvents, making it suitable for both hydrophobic or hydrophilic compounds. Stevia extract -loaded Alginate-Chitosan particles with improved physicochemical properties with a process yield of 88-89% were obtained. The release kinetics of active agent was monitored using UV-vis spectroscopy and showed a slow release within 24 hours. Thus, the slow kinetics of the release of the agent demonstrates the effectiveness of the methodology of encapsulation based on the ionic gelation and hardening of shell. Сreаtion of саpsules with the ingredients enсаpsulаted inside, hаving thermostаble properties, resistаnсe to influenсe of асidiс environments аnd enzymes, meсhаniсаl аnd osmotiс resistаnсe to influenсe of externаl physiсаl аnd сhemiсаl fасtors, suсh аs meсhаniсаl effeсt, temperаture inсreаse, сhаnge of pressure, аnd аlso inсreаse in proteсtion of bаgged substаnсes remains as an actual problem at present time. The morphology, average diameters of wet and dry microcapsule were determined by optical microscopy using Olympus Soft Imaging Solutions GmbH, version E_LCmicro_09Okt2009. Twenty microparticles were randomly selected from triplicate batches to determine size distribution. The compositions of microcapsules for analysis on a scanning electron microscope were applied to a highly conductive graphite tape. SEM equipment was used to determine the pore size on the surface of the microparticles. Studies results showed that sizes of microcapsules were 720-830 µm, and color was determined by color of loaded agent. Microencapsulation allows not only protect active agent from aggressive environment, prolong activity, but also can be used for development product with useful properties for human health. Funding: This research is funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP19679879).

Synergistic Effect Mechanism of Binary Sweet Taste Compounds.

In our previous study, phloridzin, sucrose, l-alanine, and dulcitol presented synergistic effects in Camellia nanchuanica black tea (NCBT). This study aims to verify the synergistic effects of the aforementioned sweet taste compounds and the mechanism involved. By conducting σ-τ plot analysis, phloridzin at the recognition threshold concentration (phl) exhibited synergistic effects with different concentrations of sucrose (Lsuc-6suc). Various concentrations of sucrose, phloridzin, and their combinations were selected to investigate the impact on sweet taste receptor cells. The results revealed that sucrose/phloridzin significantly increased the calcium signal compared to phloridzin and sucrose alone, attributed to the greater stability of the sucrose/phloridzin combination when binding to Taste 1 Receptor Member 3 (TAS1R3; one subunit of sweet taste receptor proteins). Ultimately, the sweet taste signal of sucrose/phloridzin was transmitted to the brain, triggering the activation of more brain regions associated with sweet taste perception (right insular, postcentral, and amygdala).

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.

Emerging roles of the renin-angiotensin system in select oral diseases.

The renin-angiotensin system (RAS) plays essential roles in cardiovascular and renal function regulation. Recent studies have shown that the RAS components are widely expressed in oral tissues, but their roles in oral diseases remain underexplored. This review aims to summarize the effects of the RAS in select oral diseases including oral squamous cells carcinoma (OSCC), periodontitis, oral submucous fibrosis (OSF), and ageusia/dysgeusia. Data searches were performed using PubMed, Web of Science and Scopus through July 2024. A narrative overview of current literature was undertaken to synthesize the contexts with elaboration and summary. In OSCC, ACE/Ang II/AT1R promotes OSCC by inducing angiogenesis, cell proliferation and invasiveness. Conversely, ACE/Ang II/AT2R and ACE2/Ang (1-7)/MasR inhibit OSCC progressions. In periodontitis, ACE/Ang II/AT1R upregulates inflammatory cytokines and promotes osteoclast differentiation factor RANKL, whereas ACE2/Ang (1-7)/MasR exerts opposite effects by preventing inflammation and alveolar bone loss. In OSF, Ang (1-7) counters the profibrotic and proinflammatory action of Ang II. In dysgeusia, Ang II suppresses salt taste responses and enhances sweet taste sensitivities, while Ang (1-7) exhibits opposite effects. The RAS cascade plays crucial roles in OSCC, periodontitis, OSF and ageusia/dysgeusia. The imbalanced RAS may aggravate the progression of these diseases.

O mundo do açúcar: como a substância doce transformou nossa política, saúde e meio ambiente ao longo de 2.000 anos

Resenha: BOSMA, Ulbe. The World of Sugar. How the Sweet Stuff Transformed Our Politics, Health, and Environment over 2,000 Years. Cambridge, Mass.: Harvard UP, 2023.

Responsiveness and Reliability of a Sipping Device to Measure Motivation in Normal-Weight Individuals and Bariatric Surgery Patients.

There is an urgent need to measure the motivation to taste a sweet fluid in order to determine the influence of sweet tastes on the potential choices and consumption of beverages in patients with obesity. Current methods utilize either survey instruments or arbitrary operant tasks. The sipometer enables the participant to utilize an actual ingestive behavioral response to measure motivation during access to beverages on either ad libitum (AL) or progressive time ratio (PR) schedules. We determined the sipometer's responsiveness and reliability as a test of change in motivation for sweet tastes after bariatric surgery. Participants (58 patients and 28 controls, BMI: 18.5-24.9 kg/m2) sham-consumed an aspartame-sweetened (S) and non-sweetened (N) beverage under AL and PR schedules at a pre-surgery/baseline and a 3-month and 24-month visit (patients only). Cumulative pressure (CumPres), a measure of effort, was the sum of the pressures exerted during sipping under each condition. Baseline CumPres for PRS was higher than ALS and ALN in patients (p < 0.03) and higher than PRN in controls (p = 0.009). At 3 months, CumPres did not differ amongst conditions in patients, but CumPres for PRS was higher than all other conditions in controls (p < 0.0005). There were no baseline group differences; however, patients' CumPres for PRS was lower than controls' at 3 months (p = 0.002). Patients' CumPres for PRS decreased non-significantly between the baseline and 3 months but increased at 24 months compared to 3 months (p = 0.025) and was no different from baseline. Controls' CumPres for PRS increased at 3 months (p = 0.0359), but CumPres for all conditions was correlated between visits (p's < 0.038). The sipometer is a reliable and sensitive measure of motivation to consume sweet beverages and may reflect changes in post-operative energy intake.

An ultra-dense linkage map identified quantitative trait loci corresponding to fruit quality- and size-related traits in red goji berry.

Goji berries are a small-fruited shrub with industrial importance whose fruit considered beneficial in both fresh and dried forms. Current germplasms of goji berries include small fruits with a short shelf life, less sweet and bitter taste, and a lack of appropriate genetic information. This study aimed to employ whole genome resequencing to generate an ultra-dense bin linkage map and to elucidate the genetic basis of goji fruit quality and size using quantitative trait loci (QTL) mapping analysis in a cross-pollinated hybrid population. To achieve this goal, human sensory tests were carried out to determine the bitter taste (BT) and sweet taste (ST), and to quantify the soluble solid content (SSC), fruit firmness (FF), and fruit size-related traits of fresh goji fruits over three or four years. The results revealed that the goji bin linkage map based on resequencing spanned a total length of 966.42 cM and an average bin interval of 0.03 cM. Subsequent variant calling and ordering resulted in 3,058 bins containing 35,331 polymorphic markers across 12 chromosomes. A total of 99 QTLs, with individual loci in different environments explaining a phenotypic variance of 1.21-16.95% were identified for the studied traits. Ten major effects, including colocalized QTLs corresponding to different traits, were identified on chromosomes 1, 3, 5, 6, 7, and 8, with a maximum Logarithm of Odds (LOD) of 29.25 and 16.95% of explained phenotypic variance (PVE). In addition, four stable loci, one for FF, one for fruit weight (FW), and two for fruit shape index (FSI), were mainly mapped on chromosomes 5, 6, and 7, elucidating 2.10-16.95% PVE. These findings offer valuable insights into the genetic architecture of goji fruit traits along with identified specific loci and markers to further improve and develop sweeter, less bitter and larger fruited goji berry cultivars with extended shelf life.

Discovery, Expression, and In Silico Safety Evaluation of Honey Truffle Sweetener, a Sweet Protein Derived from Mattirolomyces terfezioides and Produced by Heterologous Expression in Komagataella phaffii.

Honey truffle sweetener (HTS), a 121 amino acid protein is identified as a high-intensity sweetener found naturally occurring in the Hungarian Sweet Truffle Mattirolomyces terfezioides, an edible mushroom used in regional diets. The protein is intensely sweet, but the truffle is difficult to cultivate; therefore, the protein was systematically characterized, and the gene coding for the protein was expressed in a commonly used host yeast Komagataella phaffii. The heterologously expressed protein maintained the structural characteristics and sweet taste of the truffle. Preliminary safety evaluations for use as a food ingredient were performed on the protein including digestibility and in silico approaches for predicting the allergenicity and toxicity of the protein. HTS is predicted to be nonallergenic, nontoxic, and readily digestible. This protein is readily produced by precision fermentation of the host yeast, making it a potential replacement for both added sugars and small molecule high-intensity sweeteners in food.

Differential gene expression in leaves and roots of Hydrangea serrata treated with aluminium chloride.

Hydrangea serrata, also knowen as the Japanese tea hortensia, is known for its sweet taste and health properties of bevarages produced from this plant. The H. serrata 3,4-dihydroisocoumarins, hydrangenol and phyllodulcin harbour a variety of biological activities and pharmacological properties. Therefore, a detailed understanding of dihydroisocoumarin biosynthesis in H. serrata is of major interest. Their biosynthesis is assumed to be enhanced by elicitors and mediated by polyketide synthases like in cases of phenylpropanoid derived phytoalexins. A de-novo transcriptome assembly of leaves and roots from the aluminium chloride treatment group versus the control group alongside with annotation was generated. Secondary plant metabolites were analysed by LC-MS. It revealed that a terpene synthase and a triterpenoid synthase gene as well as lignin biosynthesis encoding genes were upregulated in roots. Many genes for transporters, glycosyl, and other transferases as well as glycosylases were found to be differentially expressed in both organs. As no differentially expressed polyketide synthase gene homolog was found, the relative leaf and root 3,4-dihydroisocoumarin content was analysed by LC-MS measurement. Although Hydrangea species are known for their aluminium detoxification using phenylpropanoid-derived compounds, the levels of 3,4- dihydroisocoumarins were not enhanced. In this metabolite analysis, an organ- specific accumulation profile of hydrangenol, phyllodulcin, hydrangeic acid and their mono- and di-glycosides was figured out.

Effect of tea stems on the quality formation of large-leaf yellow tea: Sensomics and flavoromics approaches

In this study, the stems (ST) and leaves (LT) isolated from Large-leaf yellow tea (LYT) were used for sensory evaluation and quantitative analysis of flavor metabolites by sensomics and flavoromics. The results showed that the flavors of ST and LT in LYT were significantly different, and ST had stronger roasty and nutty aroma and sweet taste, which was mainly due to the accumulation of higher theanine and soluble monosaccharides in ST, and provided more substrates for the production of more pyrazine by the Maillard reaction; whereas LT contributed to the mellow and thick taste quality of LYT, and the abundance of catechins and caffeine were the main reason. The metabolic patterns of flavor metabolites indicated that the flavor differences between ST and LT were mainly due to biological metabolism in tea plants. This study provides the selection of raw materials for LYT in the future and product development of tea stems.

Choline chloride and amino acid solutions taste and hydration behavior with experimental thermodynamic properties and COSMO-PC-SAFT calculation

Aqueous amino acid solutions have been introduced as dietary supplements for both animals and humans. This study investigates the physicochemical properties of the solutions containing amino acids (l-glycine, d,l-alanine, l-proline), choline chloride, and water at temperature range of 288.15 to 318.15 K. The results show that increasing concentrations of amino acids and choline chloride lead to higher solution densities. Analysis of apparent molar volume (Vφ) and apparent molar isentropic compressibility (κφ) reveals that Vφ values increase with choline chloride concentration and temperature, indicating enhanced solute–solvent interactions, while κφ values decrease, suggesting increased solution compression. Thermodynamic analysis using the Redlich-Mayer model and COSMO-based modeling provides insights into molecular interactions. However, COSMO-based parameters show high average relative deviation percentage (ARD %) values, indicating poor predictive performance for the density of these systems. In contrast, the ePC-SAFT equation of state effectively predicts the densities, particularly for l-proline-based solutions, which show very low ARD % values, indicating high accuracy. The ePC-SAFT model also performs reasonably well for l-glycine solutions but shows poorer results for d,l-alanine-based solutions. The study also examines the sweetness and saltiness criteria (ASV and ASIC) of these solutions. The ASV values, which serve as a sweetness criterion, are higher than the ideal range of 0.5 < ASV < 0.7, suggesting an overly sweet taste. The ASIC values follow a similar trend, indicating increased saltiness. To achieve an appropriate grade of sweetness and saltiness, dilution to lower concentrations of the solution is recommended. Furthermore, the use of choline chloride is found to increase salt intake and enhance the taste of salt, which can be beneficial in amino acid supplements used in animal food.

Neural processing of sweet taste in reward regions is reduced following bariatric surgery.

Bariatric surgery reduces sweet-liking, but mechanisms remain unclear. We examined related brain responses. A total of 24 nondiabetic bariatric surgery and 21 control participants with normal weight to overweight were recruited for an observational controlled cohort study. They underwent sucrose taste testing outside the scanner followed by stimulation with 0.40M and 0.10M sucrose compared with water during functional magnetic resonance imaging. A total of 21 bariatric participants repeated these procedures after surgery. Perceived sweet intensity was not different among the control, presurgery, or postsurgery groups. Bariatric participants' preferred sweet concentration decreased after surgery (0.52M to 0.29M; p = 0.008). Brain reward system (ventral tegmental area, ventral striatum, and orbitofrontal cortex) region of interest analysis showed that 0.40M sucrose activation (but not 0.10M) decreased after surgery. Sensory region (primary somatosensory and primary taste cortex) 0.40M sucrose activation was unchanged by surgery and did not differ between control and bariatric participants. Primary taste cortex activation to 0.10M sucrose solution was greater in postsurgical bariatric participants compared with control participants. Bariatric surgery reduces the reward system response to sweet taste in women with obesity without affecting activity in sensory regions, which is consistent with reduced drive to consume sweet foods.

Comparative Analysis of Taste Perception Among Airline Pilots, Construction Workers, and Office Employees.

Objective Occupational exposures may influence gustatory sensations through mechanisms such as fatigue, acute or chronic stress, circadian rhythm disruptions, and exposure to various chemicals. In this cross-sectional study, we sought to compare taste perception across three professional groups, namely airline pilots, construction workers, and office employees, by assessing taste identification times for sweet, salty, sour, and bitter flavors, alongside salivary pH levels. Methods The study cohort consisted of 90 healthy male participants, with 30 individuals in each occupational group, matched for age and professional experience. Salivary pH was measured using pH meter paper, whereas taste identification times were assessed using aqueous solutions applied to dissolvable strips for each taste. Results There were no significant differences in salivary pH among the study groups. However, airline pilots exhibited a significantly longer identification time for sweet taste (9.8 ± 3.9 seconds) compared to construction workers (7.0 ± 3.1 seconds, P < 0.05) and office employees (7.1 ± 3.3 seconds, P < 0.05). Conversely, construction workers demonstrated a significantly prolonged identification time for sour taste (6.1 ± 2.9 seconds) compared to pilots (4.2 ± 2.6 seconds, P < 0.05) and office employees (4.6 ± 2.5 seconds, P < 0.05). No significant differences were observed in the identification times for salty and bitter tastes across the groups. Conclusion We found significant differences in taste perception among airline pilots, construction workers, and office employees, particularly concerning sweet and sour tastes. These findings suggest that occupational factors may influence gustatory function in a complex manner. Further research is warranted to explore the underlying mechanisms and potential implications for dietary habits and health within specific occupational groups.

Identification and characterization of a key LcTPS in the biosynthesis of volatile monoterpenes and sesquiterpenes in Litchi fruit.

Litchi (Litchi chinensis Sonn.) has a desirable sweet taste and exotic aroma, making it popular in the markets. However, the biosynthesis of aroma volatiles in litchi fruit has rarely been investigated. In this study, the content and composition of volatile compounds were determined during litchi fruit ripening. In the mature green and mature red stages of litchi, 49 and 45 volatile compounds were detected, respectively. Monoterpenes were found to be the most abundant volatile compounds in mature red fruit, and their contents significantly increased compared to green fruit, mainly including citronellol, geraniol, myrcene, and D-limonene, which contributed to the aroma in litchi fruit. By comparing the expression profiles of the genes involved in the terpene synthesis pathway during fruit development, a terpene synthesis gene (LcTPS1-2) was identified and characterized as a major player in the synthesis of monoterpenes and sesquiterpenes. A subcellular localization analysis found LcTPS1-2 to be present in the plastid and cytoplasm. The recombinant LcTPS1-2 enzyme was able to catalyze the formation of three monoterpenes, myrcene, geraniol and citral, from geranyl pyrophosphate (GPP) and to convert farnesyl diphosphate (FPP) to a sesquiterpene, caryophyllene in vitro. Transgenic Arabidopsis thaliana plants overexpressing LcTPS1-2 exclusively released one monoterpene D-limonene, and three sesquiterpenes cis-thujopsene, (E)-β-famesene and trans-β-ionone. These results indicate that LcTPS1-2 plays an important role in the production of major volatile terpenes in litchi fruit and provides a basis for future investigations of terpenoid biosynthesis in litchi and other horticultural crops.