Estimation of environment stability for fruit yield and capsaicin content by using two models in Capsicum chinense Jacq. (Ghost Pepper) with multi-year evaluation.

Background: Capsicum chinense Jacq. (Ghost Pepper) is well-known for its high pungency and pleasant aroma. The recent years witnessed a significant decline in popularity of this important crop due to the use of inferior planting material and lack of elite lines. To maintain constant performance across a variety of settings, it is crucial to choose stable lines with high yield and capsaicin content, as these are the most promising traits of Ghost Pepper. Method: In this study, 120 high-capsaicin genotypes were subjected to a 3-year (kharif 2017, 2018 and 2019) stability investigation utilizing two well-known stability methods: Eberhart-Russell (ER) and additive main effects and multiple interaction (AMMI). Three replications were used following Randomized Complete Block Design for 11 traits. The experiment soil was sandy loam with pH 4.9. Minimum and maximum temperature of 18.5 °C, 17.5 °C, 17.4 °C and 32.2 °C, 31.3 °C, 32.7 °C and rainfall of 1,781, 2,099, 1,972 mm respectively was recorded for the study period. Result: The genotype-environment linear interaction (G×E Lin.) was highly significant for days to 50% flowering, capsaicin content, fruit length and girth, fruit yield per plant and number of fruits per plant at p < 0.005. G×E interaction for fruit yield and capsaicin content in AMMI-analysis of variance reported 67.07% and 71.51% contribution by IPCA-1 (interactive principal component axis) and 32.76% and 28.49% by IPCA-2, respectively. Eight genotypes were identified to be stable with high yield and capsaicin content. The identified stable lines can be opted for cultivation to reduce the impact of crop failure when grown in different macro-environments. Moreover, the pharmaceutical and spice sectors will also be benefitted from the lines with high capsaicin content. Further research assessing the lines' performance across various regions of India can provide a solid foundation for the crop's evaluation at national level.

Preparation, pungency and bioactivity transduction of piperine from black pepper (Piper nigrum L.): A comprehensive review.

Piperine, derived from black pepper (Piper nigrum L.), is responsible for the pungent sensation. The diverse bioactivities of piperine underscores its promising potential as a functional food ingredient. This review presents a comprehensive overview of the research progress in extraction, synthesis, pungency transduction mechanism and bioactivities of piperine. Piperine can be extracted through various methods, such as traditional, modern, and innovative extraction techniques. Its synthesis mainly included both chemical and biosynthetic approaches. It exhibits a diverse range of bioactivities, including anticancer, anticonvulsant, antidepressant, anti-inflammatory, antioxidant, immunomodulatory, anti-obesity, neuroprotective, antidiabetic, hepatoprotective, and cardiovascular protective activities. Piperine can bind to TRPV1 receptor to elicit pungent sensation. Overall, the present review can provide a theoretical reference for advancing the potential application of piperine in the field of food science.

Enhancing the perception of saltiness and reducing NaCl levels in snacks through sensory interaction: Immobilizing NaCl nanocrystals in Litsea oleoresin-sunflower seed oleogels.

Excessive dietary salt intake leads to health issues, while reducing NaCl content compromises flavor. Therefore, identifying methods to decrease salt levels without sacrificing flavor is crucial. This study investigated the sensory interaction between the saltiness of NaCl and the pungency of Litsea oleoresin. Glyceryl monostearate (6.6%) and soy lecithin (4.4%) were used as gelling agents to create oleogels, which were then employed to immobilize NaCl nanocrystals, optimizing sensory interactions. NaCl nanocrystals (427.73 ± 61.98 nm) were encapsulated in a Litsea oleoresin-sunflower seed oleogel system with uniform distribution. Sensory evaluation indicated that the NaCl nanocrystal/Litsea oleoresin@oleogel system, with moderate pungency, significantly enhanced perceived saltiness intensity (29.00 ± 1.14, compared to the control, 18.48 ± 1.12) (P < 0.05). When applied to potato chips, this system noticeably increased saltiness perception. This research provides a promising approach for developing low-sodium yet flavorful foods.

Smartphone-based digital image colorimetry for the determination of total capsaicinoid content in chili pepper extracts.

A simple smartphone-based digital image colorimetry was proposed for the determination of total capsaicinoid content and the assessment of chili pepper pungency. The biobased solvent D-limonene was used for the first time to isolate analytes. Capsaicinoids were efficiently separated from chili pepper by solid-liquid extraction with D-limonene followed by partitioning of the analytes into the ammonium hydroxide solution to eliminate the matrix interference effect. For colorimetric detection of total capsaicinoid content, a selective chromogenic reaction was performed using Gibbs reagent (2,6-dichloroquinone-4-chloroimide). Measurements were performed using a smartphone-based setup and included image analysis with the program ImageJ. The limit of detection of the proposed procedure was 0.15 mg g-1. The intra-day repeatability did not exceed 10.0 %. The inter-day repeatability was less than 16.5 %. The comparison of the smartphone-based procedure with high-performance liquid chromatography showed satisfactory results.

Pungency related gene network in Allium sativum L., response to sulfur treatments.

Pungency of garlic (Allium sativum L.) is generated from breakdown of the alk(en)yl cysteine sulphoxide (CSO), alliin and its subsequent breakdown to allicin under the activity of alliinase (All). Based on recent evidence, two other important genes including Sulfite reductase (SiR) and Superoxide dismutase (SOD) are thought to be related to sulfur metabolism. These three gene functions are in sulfate assimilation pathway. However, whether it is involved in stress response in crops is largely unknown. In this research, the order and priority of simultaneous expression of three genes including All, SiR and SOD were measured on some garlic ecotypes of Iran, collected from Zanjan, Hamedan and Gilan, provinces under sulfur concentrations (0, 6, 12, 24 and 60 g/ per experimental unit: pot) using real-time quantitative PCR (RT-qPCR) analysis. For understanding the network interactions between studied genes and other related genes, in silico gene network analysis was constructed to investigate various mechanisms underlying stimulation of A. sativum L. to cope with imposed sulfur. Complicated network including TF-TF, miRNA-TF, and miRNA-TF-gene, was split into sub-networks to have a deeper insight. Analysis of q-RT-PCR data revealed the highest expression in All and SiR genes respectively. To distinguish and select significant pathways in sulfur metabolism, RESNET Plant database of Pathway Studio software v.10 (Elsevier), and other relative data such as chemical reactions, TFs, miRNAs, enzymes, and small molecules were extracted. Complex sub-network exhibited plenty of routes between stress response and sulfate assimilation pathway. Even though Alliinase did not display any connectivity with other stress response genes, it showed binding relation with lectin functional class, as a result of which connected to leucine zipper, exocellulase, peroxidase and ARF functional class indirectly. Integration network of these genes revealed their involvement in various biological processes such as, RNA splicing, stress response, gene silencing by miRNAs, and epigenetic. The findings of this research can be used to extend further research on the garlic metabolic engineering, garlic stress related genes, and also reducing or enhancing the activity of the responsible genes for garlic pungency for health benefits and industry demands.

Rapid determination of geographical authenticity and pungency intensity of the red Sichuan pepper (Zanthoxylum bungeanum) using differential pulse voltammetry and machine learning algorithms.

The development of an analytical method for assessing pungency intensity and determining geographical origins is crucial for evaluating the quality of visually similar Zanthoxylum bungeanum pericarp (PZB). This study analyzed 210 PZB samples from 14 origins across China, focusing on origin adulteration identification and pungency intensity using a combination of differential pulse voltammetry (DPV) and machine learning algorithms. The artificial neural network (ANN) and K-nearest neighbor (KNN) algorithms provided the highest accuracy in origin identification (100 %) and adulteration detection (97.9 %) respectively. Moreover, the ANN excelled in predicting pungency intensity (R2 = 0.918). Assessment via feature importance analysis of DPV features revealed that segments of polyphenols (0.34-0.52 V and 1.0-1.2 V) and alkylamides (1.0-1.2 V) contributed significantly to the PZB pungency intensity. These findings highlight the potential of DPV as a reliable method for assessing the quality of PZB, and offer a promising solution for ensuring the geographical authenticity of this important crop.

Expression of alcohol acyltransferase is a potential determinant of fruit volatile ester variations in Capsicum.

KEY MESSAGE: The transcript level of alcohol acyltransferase 1 (AAT1) may be the main factor influencing the variations in volatile esters that characterizing the fruity/exotic aroma of pepper fruit. Volatile esters are key components for characterizing the fruity/exotic aroma of pepper (Capsicum spp.) fruit. In general, the volatile ester content in the fruit is the consequence of a delicate balance between their synthesis by alcohol acyltransferases (AATs) and degradation by carboxylesterases (CXEs). However, the precise role of these families of enzymes with regard to volatile ester content remains unexplored in Capsicum. In this study, we found that the volatile ester content was relatively low in C. annuum and much higher in C. chinense, particularly in pungent varieties. Additionally, fruits collected from multiple non-pungent C. chinense varieties, which harbor loss-of-function mutations in capsaicinoid biosynthetic genes, acyltransferase (Pun1), putative aminotransferase (pAMT), or putative ketoacyl-ACP reductase (CaKR1) were analyzed. The volatile ester contents of non-pungent C. chinense varieties (pamt/pamt) were equivalent to those of pungent varieties, but their levels were significantly lower in non-pungent NMCA30036 (pun12/pun12) and C. chinense (Cakr1/Cakr1) varieties. Multiple AAT-like sequences were identified from the pepper genome sequences, whereas only one CXE-like sequence was identified. Among these, AAT1, AAT2, and CXE1 were isolated from fruits of C. chinense and C. annuum. Gene expression analysis revealed that the AAT1 transcript level is a potential determinant of fruit volatile ester variations in Capsicum. Furthermore, enzymatic assays demonstrated that AAT1 is responsible for the biosynthesis of volatile esters in pepper fruit. Identification of a key gene for aroma biosynthesis in pepper fruit will provide a theoretical basis for the development of molecular tools for flavor improvement.

Identification of novel SNPs in Pun1 locus for pungency in Capsicum species.

BACKGROUND: Capsaicin and its analogues known as capsaicinoids are the principal sources of pungency in Capsicum spp. In this study, characterization of North-West Himalayan chilli germplasm and commercial landraces of different Indian states known for different pungency-color combinations was done based on capsaicin concentration. Moreover, molecular variation in pungency among high, medium and mild/not pungent Capsicum spp., especially those adapted to North-West Himalayas were elucidated. METHODS AND RESULTS: Forty-nine genotypes of chilli comprising breeding lines of Kashmiri origin, commercial landraces of Southern Indian origin and one of the world's hottest chilli Bhut Jolokia from Nagaland state of India were used as an experimental material. Wide variation in capsaicin content was observed among the genotypes, wherein, Bhut Jolokia (Capsicum chinense) expressed the highest capsaicin content (10,500.75 µg/g). Further, molecular analysis of PunI gene was done for discovering SNPs responsible for variations in pungency. In the non-pungent Nishat-1 (Capsicum annuum var. grossum), the 650 bp DNA fragment was not amplified due to 2.5 kb deletion spanning the putative promoter and first exon of AT3. The amplified DNA product for high and medium pungent was sequencing. Sequence alignment among revealed SNPs which were further observed responsible for variations in amino acid sequence and protein structure. CONCLUSION: The observed variation in protein structure might be responsible for high capsaicin production in one genotype as compared to the other and hence the protein conformation determines its interaction with the substrate.

Capsaicin derived from endemic chili landraces combats Shigella pathogen: Insights on intracellular inhibition mechanism.

Ethnic tribals in northeast India have been growing and maintaining local chili landraces for ages. These chilies are known for their characteristic pungency and immense therapeutic properties. Capsaicin, a significant chili metabolite, is recognized as a natural drug for pain relief, diabetic neuropathy, psoriasis, arthritis, etc. In this study, we tried to observe the influence of locality factors on the pungency and bioactive features of Capsicum annuum L. landraces. We also checked the gastro-protective ability of these chilies, especially in the cure of shigellosis. Phytometabolite characterization and estimation were done through spectrophotometric methods. Preparative and analytical HPLC techniques were employed for extracting and purifying capsaicin-enriched fractions. Shigella flexneri growth retardation was determined through the broth dilution method. Gentamicin protection assay and ELISA were done to assess the intracellular invasion and IL-1ß inflammasome production by S.flexneri. The correlation analyses postulated that phenols, flavonoids, chlorophylls, ß-carotene, and capsaicin synthase upregulation strongly influenced capsaicin biosynthesis in chili cultivars. Correspondingly, the inhibitory efficacy of the HPLC-purified Balijuri-derived capsaicin was more effective than the Raja-derived capsaicin in inhibiting intracellular Shigella growth. Reduced levels of pro-inflammatory cytokine (IL1ß) in capsaicin-treated Shigella-infected cells probably reduced inflammation-mediated intestinal damage, limiting bacterial spread. This investigation advocates the unique potential of local chilies in curing deadly 'shigellosis' with mechanistic evidence. Our observation justifies the traditional healing practices of the ethnic people of NE India.

MYB24 Negatively Regulates the Biosynthesis of Lignin and Capsaicin by Affecting the Expression of Key Genes in the Phenylpropanoid Metabolism Pathway in Capsicum chinense.

The wide application of pepper is mostly related to the content of capsaicin, and phenylpropanoid metabolism and its branch pathways may play an important role in the biosynthesis of capsaicin. The expression level of MYB24, a transcription factor screened from the transcriptome data of the pepper fruit development stage, was closely related to the spicy taste. In this experiment, CcMYB24 was cloned from Hainan Huangdenglong pepper, a hot aromatic pepper variety popular in the world for processing, and its function was confirmed by tissue expression characteristics, heterologous transformation in Arabidopsis thaliana, and VIGS technology. The results showed that the relative expression level of CcMYB24 was stable in the early stage of pepper fruit development, and increased significantly from 30 to 50 days after flowering. Heterologous expression led to a significant increase in the expression of CcMYB24 and decrease in lignin content in transgenic Arabidopsis thaliana plants. CcMYB24 silencing led to a significant increase in the expression of phenylpropanoid metabolism pathway genes PAL, 4CL, and pAMT; lignin branch CCR1 and CAD; and capsaicin pathway CS, AT3, and COMT genes in the placenta of pepper, with capsaicin content increased by more than 31.72% and lignin content increased by 20.78%. However, the expression of PAL, pAMT, AT3, COMT, etc., in the corresponding pericarps did not change significantly. Although CS, CCR1, and CAD increased significantly, the relative expression amount was smaller than that in placental tissue, and the lignin content did not change significantly. As indicated above, CcMYB24 may negatively regulate the formation of capsaicin and lignin by regulating the expression of genes from phenylpropanoid metabolism and its branch pathways.

Reliable prediction of sensory irritation threshold values of organic compounds using new models based on linear free energy relationships and GC×GC retention parameters.

The human sensory irritation threshold (SIT) is an important biochemical parameter for the exposure assessment of organic air pollutants. First, we recalibrated the Abraham solvation models (ASMs) for 9 SIT endpoints by curating 720 individual experimental SIT values to find an accurate and parsimonious ASM variant, which exhibited root mean square error (RMSE) = 0.174-0.473 log unit. Second, we report linear free energy relationships - henceforth called partition models (PMs) - which exploit the correlations of 9 SIT endpoints with the linear combinations of partition coefficients for octanol-water and air-water systems showing RMSE = 0.221-0.591 log unit. These PMs can easily be integrated into widely used EPI-Suite™ screening tool. The explanatory and predictive performance of PMs were like parameter-intensive ASMs. Third, we present GC × GC models that are based on the retention times of the nonpolar analytes on the comprehensive two-dimensional gas chromatography (GC × GC), which successfully described the SIT variance (R2=0.959-0.996) and depicted a strong predictive power (RMSE = 0.359-0.660 log unit) for an independent set of nonpolar analytes. Taken together, PMs allow easy SIT screening of organic chemicals compared to ASMs. Unlike ASMs, our GC × GC models can be applied to estimate SIT of complex nonpolar mixtures.

Dynamic Zanthoxylum pungency characteristics and their correlation with sanshool composition and chemical structure.

Huajiao (Zanthoxylum) from different regions varies in pungency features. The objective of this study was to explore the reasons for the differences. Temporal check-all-that-apply (TCATA) and time-intensity (TI)) were used to determine time-related pungency features of huajiao and sanshools. The compositions of sanshools in huajiao were measured by high-performance liquid chromatograph (HPLC). TI results revealed that hydroxy-γ-sanshool tingling and numbing duration (1332.00 ± 50.91 and 1020.00 ± 61.19 s, respectively) were about twice that of hydroxy-α-sanshool (720.00 ± 25.92 and 584.00 ± 22.63 s, respectively). Tingling and numbing were not perceived by hydroxy-ß-sanshool and hydroxy-γ-isosanshool. HPLC results showed that HαSS was the main component of huajiao sanshools, representing 71.06 % to 92.90 %. TCATA results revealed the pungency sensations appearance sequence: tingling, salivating, cooling, and burning appeared first, followed by vibrating, and numbing was perceived last. These findings revealed the relationship between the compositions of sanshool and the pungency features of huajiao.

Co-milling of sound olives with fresh chili peppers improves the volatile compound, capsaicinoid and sensory profiles of flavoured olive oil with respect to the typical infusion.

In the context of the olive oil flavoured with chili peppers, the aim of this study was to compare co-milling of sound olives and fresh chili peppers at mill scale to infusion of dried chili peppers in oil, using the same batch of olives for all oils. Capsaicinoids by HPLC-DAD, volatile profile by HS-SPME-GC-MS and HS-GC-IMS and sensory profile were characterized. Capsaicinoids were statistically higher in oils prepared with green (52.0-68.0 mg/kg) than red (48.0-60.2 mg/kg) chili peppers. Oils flavoured by infusion showed higher contents of volatile compounds linked to defects such as acetic acid, with winey/vinegary sensory defect (median, 1.72-2.02) and no fresh pepper flavour. Oils prepared by co-milling resulted rich in the typical esters of chili pepper (6.175 and 4.156 mg/kg with green and red chili peppers, respectively), with pleasant hotness sensation and fresh pepper flavour. Overall, the co-milling approach allowed obtaining flavoured samples with improved sensory quality.

Genetic analysis of pungency deficiency in Japanese chili pepper 'Shishito' (Capsicum annuum) revealed its unique heredity and brought the discovery of two genetic loci involved with the reduction of pungency.

The sensation of pungency generated by capsaicinoids is a characteristic trait of chili peppers (Capsicum spp.), and the presence or absence of pungency is central in determining its usage as a spice or a vegetable. In the present study, we aimed to clarify the heredity and genetic factors involved in the deficiency of pungency (quite low pungency) that is uniquely observed in the Japanese chili pepper 'Shishito' (Capsicum annuum). First, the F2 population ('Shishito' × pungent variety 'Takanotsume') was used for segregation analysis, and pungency level was investigated using capsaicinoid quantification with high-performance liquid chromatography. Also, restriction site associated DNA sequencing of the F2 population was performed, and genetic map construction and quantitative trait locus (QTL) mapping were implemented. The results indicated that the F2 population showed varying capsaicinoid content and two major QTLs were detected, Shql3 and Shql7, which explained 39.8 and 19.7% of the genetic variance, respectively. According to these results, the quite low pungency of 'Shishito' was a quantitative trait that involved at least the two loci. Further, this trait was completely separate from general non-pungent traits controlled by individual recessive genes, as described in previous studies. The present study is the first report to investigate the genetic mechanism of pungency deficiency in Japanese chili peppers, and our results provide new insights into the genetic regulation of pungency in chili pepper.

Antifungal Potential of Capsaicinoids and Capsinoids from the Capsicum Genus for the Safeguarding of Agrifood Production: Advantages and Limitations for Environmental Health.

Opportunistic pathogenic fungi arise in agricultural crops as well as in surrounding human daily life. The recent increase in antifungal-resistant strains has created the need for new effective antifungals, particularly those based on plant secondary metabolites, such as capsaicinoids and capsinoids produced by Capsicum species. The use of such natural compounds is well-aligned with the One Health approach, which tries to find an equilibrium among people, animals, and the environment. Considering this, the main objective of the present work is to review the antifungal potential of capsaicinoids and capsinoids, and to evaluate the environmental and health impacts of biofungicides based on these compounds. Overall, capsaicinoids and their analogues can be used to control pathogenic fungi growth in plant crops, as eco-friendly alternatives to pest management, and assist in the conservation and long-term storage of agrifood products. Their application in different stages of the agricultural and food production chains improves food safety, nutritional value, and overcomes antimicrobial resistance, with a lower associated risk to humans, animals, and the environment than that of synthetic fungicides and pesticides. Nevertheless, research on the effect of these compounds on bee-like beneficial insects and the development of new preservatives and packaging materials is still necessary.

Agonistic/antagonistic properties of lactones in food flavors on the sensory ion channels TRPV1 and TRPA1.

Flavor compounds provide aroma and sensations in the oral cavity. They are not present alone in the oral cavity, but rather in combination with several other food ingredients. This study aimed to clarify the relationship between the mixing of pungent flavor compounds and the response of pungent receptors, TRPV1 and TRPA1 channels. We focused on lactones that activate TRPV1 despite their presence in bland foods, such as dairy products and fruits, and analyzed their interaction with receptors using TRPV1- and TRPA1-expressing HEK293 cells. We found that γ-octalactone, γ-nonalactone, and δ-nonalactone activated TRPA1. When mixed with pungent components, some γ- and δ-lactones inhibited capsaicin-mediated TRPV1 responses, and δ-dodecalactone inhibited allyl isothiocyanate-mediated TRPA1 responses. Furthermore, the dose-response relationship of capsaicin and γ-nonalactone to TRPV1 suggests that γ-nonalactone acts as an agonist or antagonist of TRPV1, depending on its concentration. Conversely, γ-nonalactone and δ-dodecalactone were found to act only as agonists and antagonists, respectively, against TRPA1. These results suggest that lactones in foods may not only endow food with aroma, but also play a role in modulating food pungency by acting on TRPV1 and TRPA1. The dose-response relationships of a mixture of flavor compounds with TRPV1 and TRPA1 provide insights into the molecular physiological basis of pungency that may be the cornerstone for developing new spice mix recipes.

Preparation, pungency and bioactivity of gingerols from ginger (Zingiber officinale Roscoe): a review.

Ginger has been widely used for different purposes, such as condiment, functional food, drugs, and cosmetics. Gingerols, the main pungent component in ginger, possess a variety of bioactivities. To fully understand the significance of gingerols in the food and pharmaceutical industry, this paper first recaps the composition and physiochemical properties of gingerols, and the major extraction and synthesis methods. Furthermore, the pungency and bioactivity of gingerols are reviewed. In addition, the food application of gingerols and future perspectives are discussed. Gingerols, characterized by a 3-methoxy-4-hydroxyphenyl moiety, are divided into gingerols, shogaols, paradols, zingerone, gingerdiones and gingerdiols. At present, gingerols are extracted by conventional, innovative, and integrated extraction methods, and synthesized by chemical, biological and in vitro cell synthesis methods. Gingerols can activate transient receptor potential vanilloid type 1 (TRPV1) and induce signal transduction, thereby exhibiting its pungent properties and bioactivity. By targeted mediation of various cell signaling pathways, gingerols display potential anticancer, antibacterial, blood glucose regulatory, hepato- and renal-protective, gastrointestinal regulatory, nerve regulatory, and cardiovascular protective effects. This review contributes to the application of gingerols as functional ingredients in the food and pharmaceutical industry.

Pepper variome reveals the history and key loci associated with fruit domestication and diversification.

Pepper (Capsicum spp.) is an important vegetable crop that provides a unique pungent sensation when eaten. Through construction of a pepper variome map, we examined the main groups that emerged during domestication and breeding of C. annuum, their relationships and temporal succession, and the molecular events underlying the main transitions. The results showed that the initial differentiation in fruit shape and pungency, increase in fruit weight, and transition from erect to pendent fruits, as well as the recent appearance of large, blocky, sweet fruits (bell peppers), were accompanied by strong selection/fixation of key alleles and introgressions in two large genomic regions. Furthermore, we identified Up, which encodes a BIG GRAIN protein involved in auxin transport, as a key domestication gene that controls erect vs pendent fruit orientation. The up mutation gained increased expression especially in the fruit pedicel through a 579-bp sequence deletion in its 5' upstream region, resulting in the phenotype of pendent fruit. The function of Up was confirmed by virus-induced gene silencing. Taken together, these findings constitute a cornerstone for understanding the domestication and differentiation of a key horticultural crop.

Increases in the pungency of allyl isothiocyanate and piperine by CaSR agonists, glutathione and γ-glutamyl-valyl-glycine.

γ-Glutamyl peptides, including glutathione (γ-Glu-Cys-Gly, GSH) and γ-glutamyl-valyl-glycine (γ-Glu-Val-Gly), have been shown to increase the intensity of basic tastes, such as salty, sweet, and umami, and flavor, including mouthfulness, but had no taste themselves at the concentrations tested. Although the mechanisms of action of γ-glutamyl peptides currently remain unclear, the involvement of the calcium sensing receptor (CaSR) has been suggested. Since GSH and γ-Glu-Val-Gly increase the pungency of some spices, the present study investigated their effects on the pungency of allyl isothiocyanate (AITC) using a sensory evaluation. GSH and γ-Glu-Val-Gly both significantly increased the pungency of AITC, while anserine, a peptide without CaSR activity, did not. GSH-induced increases in pungency were suppressed by NPS-2143, a CaSR inhibitor. Further, γ-Glu-Val-Gly significantly increased the pungency of piperine. The present results suggest that GSH and γ-Glu-Val-Gly increased the pungency by activating CaSR.

The Phytochemical and Nutritional Composition of Shallot Species (Allium × cornutum, Allium × proliferum and A. cepa Aggregatum) Is Genetically and Environmentally Dependent.

Shallots are a perennial plant from the Alliaceae family, classified with the common onion under the name of the Allium cepa Aggregatum group. The term shallot is also used for diploid and triploid viviparous onions, known as Allium × proliferum (Moench) Schrad and Allium × cornutum Clementi ex Vis., respectively. In this study, we compared the dry matter, pyruvic acid content, sugar content, flavonoid content, antioxidant capacity and mineral composition of 34 shallot accessions falling into three shallot species (Allium × cornutum, Allium × proliferum and A. cepa Aggregatum). Shallot accessions belonging to the A.× cornutum and A. × proliferum groups are characterized by high dry matter content (around 25%), of which a little less than 50% is formed of inulin-type sugars, polysaccharides, considered an excellent prebiotic with beneficial effects on human health. On the other hand, accessions belonging to the A. cepa Aggregatum group have lower dry matter content and, as a result, lower pungency (measured as pyruvic acid content), making them more suitable for fresh consumption by a broader range of consumers, but, at the same time, abundant in phenolic compounds, especially quercetin and isorhamnetin glycosides. We also observed a greater biodiversity among accessions within the A. cepa Aggregatum group in all the analyzed physico-chemical parameters compared to the other shallot groups. The investigated shallot accessions have an excellent in vitro antioxidant capacity, as well as excellent nutritional properties.