Pungent qualities of sanshool-related compounds evaluated by a sensory test and activation of rat TRPV1

The detection threshold and taste characteristics of sanshools were examined by sensory evaluation, after isolating four sanshools (alpha-, beta-, gamma-, and delta-), and two hydroxy sanshools (alpha- and beta-) from the pericarp of Japanese pepper. The Scoville unit (SU) values of the four sanshools were in the range of 80,000-110,000, while those of hydroxy sanshools were 3-5 fold lower than corresponding sanshools. The pungent qualities of each sanshool were different. Burning and tingling were predominantly perceived and lasted for the longest time with alpha-sanshool. Burning and fresh for gamma-sanshool, and tingling and numbing for hydroxy alpha-sanshool were perceived. Tests on the activation of rat TRPV1 were also performed. All of them were weak agonists. Among them, gamma-sanshool was the most potent agonist, although its EC50 value of 5.3 microM was 230 fold higher than that of capsaicin. These results indicate that it would be difficult to explain the pungent quality of each sanshool simply in terms of TRPV1 activation.     

DESCRIPTIVE ANALYSIS OF ORAL PUNGENCY1

Pungent spices are well-recognized for their aromatic and pungent nature; however, relatively little is known about their pungent or ‘burning’ responses. Therefore, this research was undertaken to characterize oral pungency of the principal irritants or red pepper (capsaicin), black pepper (piperine), cinnamon (cinnamaldehyde), cumin (cuminaldehyde), cloves (eugenol), ginger (ginger oleoresin), and alcohol (ethanol). These compounds were evaluated for four pungent qualities (burning, tingling, numbing, overall), two temporal qualities (lag time, overall duration), and three spatial qualities (longitudinal location, lateral location, localized/diffuse). The pungency of cinnamaldehyde was primarily burning and tingling. It had a quick onset and rapid decay. The pungency of eugenol had a long-lasting, predominantly numbing effect. The pungency piperine, capsaicin and ginger were primarily burning, but had different temporal and spatial responses. The pungency of ethanol was most diffuse in nature, with some burning and tingling sensations. It had the shortest perceived onset and overall duration. The pungency of cuminaldehyde was equally burning, tingling and numbing.     

Isolation of cDNA clones differentially accumulated in the placenta of pungent pepper by suppression subtractive hybridization

Capsaicinoids responsible for pungency of chili pepper are synthesized exclusively in the placenta tissue of the fruit. As an elementary step in the molecular genetics study of capsaicinoid biosynthesis, a cDNA library was constructed from the placenta of a highly pungent pepper, Capsicum chinense cv. Habanero using the suppression subtractive hybridization (SSH). Thirty-nine cDNA clones from about 400 subtracted clones were selected through dot blot analysis and according to their nucleotides sequence. Sequence information of the chosen clones was evaluated by comparing it with DNA and protein databases. Results showed that the cDNA clones could be divided into 4 groups; cDNAs with similarities in genes encoding metabolic enzymes including acyl transferase and fatty acid alcohol oxidase (Group I), putative cell wall proteins (Group II), biotic and abiotic stress-inducible proteins (Group III), and lastly, cDNAs with no similarity (Group IV). Northern blot analysis was performed to confirm that these clones are differentially expressed in pungent pepper. The results revealed that all cDNA clones were differentially expressed in pungent pepper. In addition, the cDNA clones of Groups I and IV were differentially or preferentially expressed in the placenta of pungent pepper.     

Metabolite biodiversity in pepper (Capsicum) fruits of thirty-two diverse accessions: variation in health-related compounds and implications for breeding

A comprehensive study on morphology and biochemical compounds of 32 Capsicum spp. accessions has been performed. Accessions represented four pepper species, Capsicum annuum, Capsicum frutescens, Capsicum chinense and Capsicum baccatum which were selected by their variation in morphological characters such as fruit color, pungency and origin. Major metabolites in fruits of pepper, carotenoids, capsaicinoids (pungency), flavonoid glycosides, and vitamins C and E were analyzed and quantified by high performance liquid chromatography. The results showed that composition and level of metabolites in fruits varied greatly between accessions and was independent of species and geographical location. Fruit color was determined by the accumulation of specific carotenoids leading to salmon, yellow, orange, red and brown colored fruits. Levels of both O- and C-glycosides of quercetin, luteolin and apigenin varied strongly between accessions. All non-pungent accessions were devoid of capsaicins, whereas capsaicinoid levels ranged from 0.07 up to 80 mg/100g fr. wt. in fruit pericarp. In general, pungent accessions accumulated the highest capsaicinoid levels in placenta plus seed tissue compared to pericarp. The non-pungent capsaicinoid analogs, capsiates, could be detected at low levels in some pungent accessions. All accessions accumulated high levels of vitamin C, up to 200 mg/100g fr. wt. The highest vitamin E concentration found was 16 mg/100g fr. wt. Based on these metabolic data, five accessions were selected for further metabolic and molecular analysis, in order to isolate key genes involved in the production of these compounds and to assist future breeding programs aimed at optimizing the levels of health-related compounds in pepper fruit.     

A versatile PCR marker for pungency in Capsicum spp.

Pungency in Capsicum spp. is an important quality trait for pepper breeding. The perception of pungency in pepper is due to the presence of a group of compounds named capsaicinoids, only found within the Capsicum genus. How pungency is controlled at genetic and molecular levels has not been completely elucidated. The use of molecular markers to assess pungency trait is required for molecular breeding, despite the difficulty of development of universal markers for this trait. In this work, a DNA sequence possibly related to pungency with a high similarity to Pun1 locus was studied, and sequence analysis of this homolog revealed a 15?bp deletion in non-pungent pepper accessions. An allele-specific pair of primers was designed and specific fragments of 479?bp from non-pungent and 494?bp from pungent accessions were obtained. Polymorphism of this marker, named MAP1, was tested in a wide range of accessions, belonging to several Capsicum species, including pungent and non-pungent accessions of C. annuum L., and pungent accessions of C. chinense, C. baccatum, C. frutescens, C. pubescens, C. galapagoense, C. eximium, C. tovarii, C. cardenasii, and C. chacoense. All these Capsicum accessions were correctly discriminated. The marker suitability to assess pungency in domesticated and wild Capsicum species was demonstrated, and therefore it will be very useful in marker assisted selection (MAS). Moreover, MAP1 was located in a saturated pepper linkage map and its possible relationship with the Pun1 locus has been discussed. Among the available markers for this complex quality trait, the marker developed in this study is the most universal so far.     

Metabolomics and molecular marker analysis to explore pepper (Capsicum sp.) biodiversity

An overview of the metabolic diversity in ripe fruits of a collection of 32 diverse pepper (Capsicum sp.) accessions was obtained by measuring the composition of both semi-polar and volatile metabolites in fruit pericarp, using untargeted LC–MS and headspace GC–MS platforms, respectively. Accessions represented C. annuum, C. chinense, C. frutescens and C. baccatum species, which were selected based on variation in morphological characters, pungency and geographic origin. Genotypic analysis using AFLP markers confirmed the phylogenetic clustering of accessions according to Capsicum species and separated C. baccatum from the C. annuum–C. chinense–C. frutescens complex. Species-specific clustering was also observed when accessions were grouped based on their semi-polar metabolite profiles. In total 88 semi-polar metabolites could be putatively identified. A large proportion of these metabolites represented conjugates of the main pepper flavonoids (quercetin, apigenin and luteolin) decorated with different sugar groups at different positions along the aglycone. In addition, a large group of acyclic diterpenoid glycosides, called capsianosides, was found to be highly abundant in all C. annuum genotypes. In contrast to the variation in semi-polar metabolites, the variation in volatiles corresponded well to the differences in pungency between the accessions. This was particularly true for branched fatty acid esters present in pungent accessions, which may reflect the activity through the acyl branch of the metabolic pathway leading to capsaicinoids. In addition, large genetic variation was observed for many well-established pepper aroma compounds. These profiling data can be used in breeding programs aimed at improving metabolite-based quality traits such as flavour and health-related metabolites in pepper fruits.     

QTL analysis for pseudostem pungency in bunching onion (Allium fistulosum)

Low pungency is one of the most important agronomic traits in bunching onion (Allium fistulosum L.). Although the degree of pungency can be evaluated indirectly using a colorimetric test for pyruvic acid, DNA markers linked to low-pungency quantitative trait loci (QTLs) are still desired. In this study, we evaluated pungency in the bunching onion pseudostem through six trials conducted over 3?years using an F _2:3 population. QTL analysis based on the genetic linkage map revealed that the major pungency QTL was located within a 24.2-cM interval on Chr. 2a. The low-pungency parent-derived allele at AFAT04B03, a simple sequence repeat locus linked to the pungency QTL, was rare among commercial bunching onion cultivars. In addition, individuals homozygous for the low-pungency parent-derived allele at AFAT04B03 were significantly less pungent than those that were homozygous or heterozygous. Thus, these findings suggest that AFAT04B03 is an effective selection marker for low pungency in bunching onion breeding.     

FACTORS AFFECTING PUNGENCY OF MALT DISTILLATES AND ETHANOL-WATER MIXTURES

paungency is a physical sensation usually perceived as a component of flavor. Foods and beverages which are described as pungent often impart unpalatable sensations to those uninitiated in the experience. Variations in pungency were examined in whiskies, ethanol-water mixtures, and whisky model systems. Effects on sensory pungency of changes in composition showed that pungency in whisky is not only dependent on the concentration of ethanol in the headspace, but also on a complex of other effects.     

Non-pungent Capsicum contains a deletion in the capsaicinoid synthetase gene, which allows early detection of pungency with SCAR markers

The capsaicinoid synthetase (CS) gene cosegregated perfectly with the C locus, which controls the presence of pungency, in 121 F2 individuals from a cross between 'ECW123R' and 'CM334', both of Capsicum annuum. We concluded that CS and C are tightly linked. Sequence analysis of the genes of four pungent and four non-pungent pepper lines showed that the non-pungent peppers had a 2,529 bp-deletion in the 5' upstream region of CS. We have developed molecular markers of the C locus to detect pungency at the seedling stage. Based on the deleted sequence, we developed five SCAR markers, two of them being codominant. These SCAR markers will be useful for easy, accurate, and early detection of non-pungent individuals in breeding programs.     

Application of N-(9-Acridinyl)maleimide as a Fluorescent Detection Reagent of Cysteine and Related Thiols and Disulfide Compounds on Thin-layer Chromatogram

Fluctuations of pungent principles of hot pepper fruits (capsaicinoid), chlorophylls, carotenoid, and fresh fruit weight in Capsicum annuum var. annuum cv. Karayatsubusa at different growth stages after flowering were examined. Capsaicinoid was first detected 20 days after flowering, and reached maximal level around 40 days after flowering, then later decreased gradually. The capsaicinoid composition did not show any appreciable change throughout the stages after flowering. CAP and DC were the major components in all of the stages examined. By using radioisotopic technique, it was found that the main formation and accumulation sites of capsaicinoid are in the placenta of the fruits.     

Genetic and molecular regulation of fruit and plant domestication traits in tomato and pepper

Tomato and pepper are two Solanaceous fruit crops that display an enormous diversity in fruit morphology. In this review, we will present an overview of the history of tomato and pepper and discuss key plant traits that were specifically selected during domestication of the two species. The traits discussed are fruit weight, shape, colour, ripening, pungency and plant architecture. We will review these characteristics as well as the genetic loci or genes that control these features, questioning whether mutations at orthologous loci occurred independently in these two species or whether unique plant and fruit features resulted in selection at different genes.     

Mioganal, a novel pungent principle in myoga (Zingiber mioga Roscoe) and a quantitative evaluation of its pungency

We isolated a novel pungent principle from the flower buds of myoga. Based on an interpretation of the HR-MS, EI-MS, IR, UV, and NMR data, this compound was (8betaH)-14,17-cyclolabda-12,14(17)-diene-15,16-dial (mioganal, 1). We determined the threshold value of mioganal to be 5.6x10(-5) g/ml, which is about eight times greater than that of 8beta(17)-epoxy-12(E)labdene-15,16-dial (miogadial), the main pungent principle in the flower buds of myoga. In addition, we examined the content of mioganal in different parts of different varieties. Mioganal is mainly distributed in the leaves of both natsumyoga and akimyoga varieties at 1.60 mg/100 g fresh weight on average, its amount being three times higher than that in the flower buds.     

Why are not all chilies hot? A trade-off limits pungency

Evolutionary biologists increasingly recognize that evolution can be constrained by trade-offs, yet our understanding of how and when such constraints are manifested and whether they restrict adaptive divergence in populations remains limited. Here, we show that spatial heterogeneity in moisture maintains a polymorphism for pungency (heat) among natural populations of wild chilies (Capsicum chacoense) because traits influencing water-use efficiency are functionally integrated with traits controlling pungency (the production of capsaicinoids). Pungent and non-pungent chilies occur along a cline in moisture that spans their native range in Bolivia, and the proportion of pungent plants in populations increases with greater moisture availability. In high moisture environments, pungency is beneficial because capsaicinoids protect the fruit from pathogenic fungi, and is not costly because pungent and non-pungent chilies grown in well-watered conditions produce equal numbers of seeds. In low moisture environments, pungency is less beneficial as the risk of fungal infection is lower, and carries a significant cost because, under drought stress, seed production in pungent chilies is reduced by 50 per cent relative to non-pungent plants grown in identical conditions. This large difference in seed production under water-stressed (WS) conditions explains the existence of populations dominated by non-pungent plants, and appears to result from a genetic correlation between pungency and stomatal density: non-pungent plants, segregating from intra-population crosses, exhibit significantly lower stomatal density (p = 0.003), thereby reducing gas exchange under WS conditions. These results demonstrate the importance of trait integration in constraining adaptive divergence among populations.     

Artepillin C,a Major Ingredient of Brazilian Propolis,Induces a Pungent Taste by Activating TRPA1 Channels

Brazilian green propolis is a popular health supplement because of its various biological properties. The ethanol extract of Brazilian green propolis (EEBP) is characteristic for its herb-like smell and unique pungent taste. However, the ingredients responsible for its pungency have not yet been identified. This study provides the first evidence that artepillin C is the main pungent ingredient in EEBP and that it potently activates human transient receptor potential ankyrin 1 (TRPA1) channels. EEBP was fractionated using column chromatography with a step gradient elution of an ethanol-water solution, and the fractions having the pungent taste were determined by sensory tests. HPLC analysis revealed that the pungent fraction was composed primarily of artepillin C, a prenylated derivative of cinnamic acid. Artepillin C was also identified as the pungent compound of EEBP by organoleptic examiners. Furthermore, the effects of artepillin C and other cinnamic acids found in EEBP on TRPA1 channels were examined by calcium imaging and plate reader-based assays in human TRPA1-expressing cells to investigate the molecular mechanisms underlying their pungent tastes. Artepillin C and baccharin activated the TRPA1 channel strongly, whereas drupanin caused a slight activation and p-coumaric acid showed no activation. Because the EC₅₀ values of artepillin C, baccharin, and allyl isothiocyanate were 1.8 µM, 15.5 µM, and 6.2 µM, respectively, artepillin C was more potent than the typical TRPA1 agonist allyl isothiocyanate. These findings strongly indicate that artepillin C is the main pungent ingredient in EEBP and stimulates a pungent taste by activating TRPA1 channels.     

蚜虫对设施辣椒产量和品质的影响

[目的]探讨不同蚜害等级危害对设施辣椒产量和品质的影响,为设施蔬菜的科学防控、按质定价及制定蚜虫经济阈值提供参考.[方法]通过田间蚜虫量调查,进行蚜害分级,并测定不同蚜害等级下辣椒叶片和果实的SPAD值,采收后记录单株果数,称重,计算座果率及单株果重等产量指标;同时测定不同蚜害等级下辣椒果实可溶性蛋白、可溶性糖、维生素...     

Characterization of newly developed pepper cultivars (Capsicum chinense) ‘Dieta0011-0301’, ‘Dieta0011-0602’, ‘Dieta0041-0401’, and ‘Dieta0041-0601’ containing high capsinoid concentrations and a strong fruity aroma

ABSTRACT

Capsaicinoids are responsible for the pungent flavor of peppers (Capsicum sp.). The cultivar CH-19 Sweet is a non-pungent pepper mutant that biosynthesizes the low-pungent capsaicinoid analogs, capsinoids. Capsinoids possess important pharmaceutical properties. However, capsinoid concentrations are very low in CH-19 Sweet, and Capsicum cultivars with high content capsinoids are desirable for industrial applications of capsinoids.

Habanero, Bhut Jolokia, and Infinity are species of Capsicum chinense, and have strong pungency and intense fruity flavors. In the present study, we report new cultivars with high concentrations of capsinoids (more than ten-fold higher than in CH-19 Sweet), and showed that these cultivars (Dieta0011-0301 and Dieta0011-0602 from Bhut Jolokia, Dieta0041-0401 and Dieta0041-0601 from Infinity) are of nutritional and medicinal value and have fruity aromas. We also obtained a vanilla bean flavor, vanillyl alcohol, and vanillyl ethyl ether from capsinoids in the fruit of these cultivars following the addition of ethanol at room temperature.