Fracture resistance and bonding performance after antioxidants pre-treatment in non-vital and bleached teeth.

This study aimed to evaluate the effect of antioxidant solutions on fracture strength and bonding performance in non-vital and bleached (38% hydrogen peroxide) teeth. One hundred and eighty dentin specimens were obtained, 60 for each test: fracture strength, hybrid layer thickness, and bond strength. The groups (n=10) were randomly composed according to post-bleaching protocol: REST - restoration, without bleaching; BL - bleaching + restoration; SA - bleaching, 10% sodium ascorbate solution, and restoration; AT - bleaching, 10% α-tocopherol solution, and restoration; CRAN - bleaching, 5% cranberry solution, and restoration; CAP - bleaching, 0.0025% capsaicin solution, and restoration. Data were analyzed with ANOVA, Kruskal-Wallis, Dunn, and Qui-Square tests (α=0.05). The highest fracture strength values were observed in REST (1508.96 ±148.15 N), without significant difference for the bleached groups (p>0.05), regardless of the antioxidant use. The hybrid layer thickness in the group that was not subjected to bleaching (REST) was significantly higher than in any other group. The bond strength in the bleached and antioxidants-treated groups (SA, AT, CRAN, CAP) has no differences with the bleached group without antioxidants (BL). Adhesive failures were predominant in the groups that did not receive the antioxidant application. In conclusion, the evaluated antioxidants did not show an effect on the fracture strength, hybrid layer thickness, or bond strength of dentin bleached after endodontic treatment. The application of 10% sodium ascorbate, 10% alpha-tocopherol, 5% cranberry, or 0.0025% capsaicin solutions is not an effective step and should not be considered for the restorative protocols after non-vital bleaching.

Phenolic Compounds and Capsaicinoids in Three Capsicum annuum Varieties: From Analytical Characterization to In Silico Hypotheses on Biological Activity.

The affinity of specific phenolic compounds (PCs) and capsaicinoids (CAPs) present in three Capsicum annuum varieties (Friariello, Cayenne and Dzuljunska Sipka) to the transient receptor potential vanilloid member 1 (TRPV1) was investigated by integrating an analytic approach for the simultaneous extraction and analysis through high-performance liquid chromatography coupled with ion trap mass spectrometry (HPLC/ITMS) and UV detection (HPLC-UV) of PCs and CAPs and structural bioinformatics based on the protein modelling and molecular simulations of protein-ligand docking. Overall, a total of 35 compounds were identified in the different samples and CAPs were quantified. The highest content of total polyphenols was recorded in the pungent Dzuljunska Sipka variety (8.91 ± 0.05 gGAE/Kg DW) while the lowest was found in the non-pungent variety Friariello (3.58 ± 0.02 gGAE/Kg DW). Protein modelling generated for the first time a complete model of the homotetrameric human TRPV1, and it was used for docking simulations with the compounds detected via the analytic approach, as well as with other compounds, as an inhibitor reference. The simulations indicate that different capsaicinoids can interact with the receptor, providing details on the molecular interaction, with similar predicted binding energy values. These results offer new insights into the interaction of capsaicinoids with TRPV1 and their possible actions.

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.

A Little Pepper-Upper? Systematic Review of Randomized Controlled Studies on Capsaicinoids, Capsinoids, and Exercise Performance.

Capsaicinoids and capsinoids are bioactive compounds mostly found in peppers. Although preclinical studies have reported that these compounds can improve exercise performance due to transient receptor potential vanilloid subtype 1 (TRPV1)-mediated thermogenesis, sympathetic modulation, and releasing calcium, it is still unclear how they affect exercise performance in humans as ergogenic supplements. Conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guide 2020, this systematic review examined the ergogenic effect of capsaicinoids and capsinoids on exercise performance in healthy adults. A total of 19 randomized placebo-controlled trials were included in the study. Studies were accessed by searching five databases (PubMed, Scopus, SPORTDiscus, Web of Science, and Cochrane Library). The quality of the studies was evaluated using the Cochrane risk-of-bias assessment tool. According to the study results, 10 studies examining the effect of capsaicinoid and capsinoid supplements on exercise performance reported positive effects. Also, the effect of capsaicinoids and capsinoids on exercise performance is more pronounced in resistance training. This difference, which varies according to the type of exercise, may be due to the correlation between capsaicin transient receptor potential vanilloid subtype 1 and insulin-like growth factor-1.

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.

Estimation of genetic variation in yield, its contributing characters and capsaicin content of Capsicum chinense Jacq. (ghost pepper) germplasm from Northeast India.

Capsicum chinense Jacq. (ghost pepper), a naturally occurring chili species of Northeast India is known throughout the world for its high pungency and a pleasant aroma. The economic importance is due to the high capsaicinoid levels, the main source for pharmaceutical industries. The present study focused on identifying important traits necessary for increasing the yield and pungency of ghost pepper and to determine the parameters for the selection of superior genotypes. A total of 120 genotypes with more than 1.2% capsaicin content (>1,92,000 Scoville Heat Unit, w/w on dry weight basis) collected from different northeast Indian regions were subjected to variability, divergence and correlation studies. Levene's homogeneity test of variance studied for three environments did not show significant deviation and so homogeneity of variance was reasonably met for analysis of variance study. Genotypic and phenotypic coefficient of variation was highest for fruit yield per plant (33.702, 36.200, respectively), followed by number of fruits per plant (29.583, 33.014, respectively) and capsaicin content (25.283, 26.362, respectively). The trait number of fruits per plant had maximum direct contribution to fruit yield per plant and the trait fruit yield per plant towards capsaicin content in the correlation study. High heritability with high genetic advance, which is the most favored selection criteria was observed for fruit yield per plant, number of fruits per plant, capsaicin content, fruit length and fruit girth. The genetic divergence study partitioned the genotypes into 20 clusters, where fruit yield per plant contributed maximum towards total divergence. Principal components analysis (PCA) studied to determine the largest contributor of variation showed 73.48% of the total variability, of which the PC1 and PC2 contributed 34.59% and 16.81% respectively.

Characterization of phenolics and tocopherol profile, capsaicinoid composition and bioactive properties of fruits in interspecies (Capsicum annuum X Capsicum frutescens) recombinant inbred pepper lines (RIL).

In this study, 104 RIL (Recombinant Inbred Pepper Lines: F6) populations which generated by selfing Capsicum annuum (Long pepper) × Capsicum frutescens (PI281420) F6 population were characterized in terms of detailed bioactive properties, major phenolic composition, tocopherol and capsaicinoid profile. Total phenolics, flavonoid and total anthocyanin contents of the red pepper lines were in the range of 7.06-17.15 mg gallic acid equivalent (GAE)/g dw, 1.10-5.46 mg catechin equivalent (CE)/g dw and 7.9-516.6 mg/kg dw extract, respectively. Antiradical activity and antioxidant capacity values also ranged between 18.99 and 49.73% and 6.97-16.47 mg ascorbic acid equivalent (AAE)/kg dw, respectively. Capsaicin and dihydrocapsaicin levels showed a wide variance with the range of 27.9-1405.9 and 12.3-640.4 mg/100 g dw, respectively. Scoville heat unit revealed that the 95% of the peppers were highly pungent. The major tocopherol was alpha tocopherol for the pepper samples with the highest level of 1078.4 µg/g dw. The major phenolics were detected as p-coumaric acid, ferulic acid, myricetin, luteolin and quercetin. Pepper genotypes showed significant differences in terms of the characterized properties and principal component analysis was applied successfully to reveal the similar genotypes.

Biosynthesis of capsaicinoids in pungent peppers under salinity stress.

The synthesis of capsaicinoids occurs in the placenta of the fruits of pungent peppers. However, the mechanism of capsaicinoids' biosynthesis in pungent peppers under salinity stress conditions is unknown. The Habanero and Maras genotypes, the hottest peppers in the world, were chosen as plant material for this study, and they were grown under normal and salinity (5 dS m-1 ) conditions. The results showed that salinity stress harmed plant growth but increased the capsaicin content by 35.11% and 37.00%, as well as the dihydrocapsaicin content by 30.82% and 72.89% in the fruits of the Maras and Habanero genotypes, respectively, at 30 days after planting. The expression analysis of key genes in capsaicinoids biosynthesis revealed that the PAL1, pAMT, KAS, and PUN1 genes were overexpressed in the vegetative and reproductive organs of pungent peppers under normal conditions. However, under salinity stress, overexpression of PAL1, pAMT, and PUN1 genes was identified in the roots of both genotypes, which was accompanied by an increase in capsaicin and dihydrocapsaicin content. The findings showed that salinity stress caused an enhancement in the capsaicin and dihydrocapsaicin contents in the roots, leaves, and fruits of pungent peppers. Nonetheless, it was found that the production of capsaicinoids is generally not restricted to the fruits of pungent peppers.

Fluorimetric chemodosimeter for the detection of capsaicinoids in food matrices.

Capsaicin is a major pungent capsaicinoids in chili pepper and it causes duodenal, liver, stomach and gastric cancer in human. Hence, the detection of capsaicinoids becomes important on health issues concern. Here we are reporting, the first organic molecule based fluorimetric sensor for capsaicin detection using simple fluorophore 4-3-(pyren-2-yl-acryloyl) phenyboronic acid (PAPA), which was synthesized via greener microwave method. The probe has detected the capsaicin selectively in presence of other biomolecules in human biofluids through the intramolecular charge transfer mechanism and supported with DFT studies. The sensor has shown an excellent response towards capsaicin from 2 to 40 µM and the limit of detection of 12.84 nM. Real time analysis was done in various food matrices having capsaicinoids and the results have clearly shown good agreement with our optimized data and it also evinced that the developed sensor can be applied to detect the level of pungency of capsaicinoids.

Multi-dimensional pungency and sensory profiles of powder and oil of seven chili peppers based on descriptive analysis and Scoville heat units.

The pungency and flavor experience of peppers determines their economic benefits and consumption; thus, a systematic sensory evaluation of peppers is essential to monitor their production. Here the Scoville heat units (SHUs) of powders and oils of seven commercial peppers in China (i.e., Indian, Erjintiao, Shizhuhong, Zidantou, Xinyidai, Mantianxing and Denglong) were derived based on concentrations of capsaicin and dihydrocapsaicin. Then, the pungency and sensory profiles of pepper products were investigated by 11 trained panelists. The potential indicators for predicting perceived pungency in peppers were found based on correlation analysis. The Indian pepper stood out for its highest SHU (85909), bright redness, peppery, and bitterness, but lacked herb/woody flavor. But other species had more varied flavor profiles and gentler mouth-feelings. SHU and capsaicin were more recommended in predicting the perceived pungency in pepper powder and pepper oil. This study offers a framework for evaluating the sensory characteristics of pepper products.

The effect of ripening on the capsaicinoids composition of Jeromin pepper (Capsicum annuum L.) at two different stages of plant maturity.

The changes of capsaicinoids in the pericarp and placenta of Jeromin pepper fruits, collected at two different stages of plant's maturity (young and adult), has been studied throughout the ripening process. This variety is used in the production of "Pimentón de La Vera" and recognized under a Protected Designation of Origin, so it is of great importance to determine their optimum harvesting time to get the most of its beneficial health effects. Capsaicinoids reached the maximum concentration on the 30th days post-anthesis (dpa) for the young plant, while in the adult plant it was later, specifically on 40th and 60th dpa for the placenta and pericarp, respectively. From this moment on, a sharp decrease in their content is observed. In addition, higher amounts of total capsaicinoids have been found in the second stage of plant maturity with respect to the first one, both in the placenta and in the pericarp.

Separation of Nonivamide and Capsaicin by Ultrahigh-Performance Liquid Chromatography for Routine Analysis of Capsaicinoids in Capsicum Products.

BACKGROUND: Baseline separation of nonivamide (NON) and capsaicin (CAP) has not been achieved by using the existing liquid chromatography (LC) methods for the capsaicinoid analysis. This could lead to large errors in the determination of capsaicinoids for capsicum products. OBJECTIVE: The development of an ultrahigh-performance liquid chromatography (UHPLC) method that simultaneously separates NON and CAP as well as other capsaicinoids for the routine analysis of capsaicinoids in capsicum products. METHOD: Capsaicinoids were separated on a Waters CORTECSTM T3 Column (2.1 mm i.d. × 150 mm, 1.6 µm particle size) that was maintained at 45°C on a UHPLC system with a 3-step gradient elution using a binary mobile phase system consisting of water and acetonitrile. Florescence detection was set at 280 nm excitation wavelength and 325 nm emission wavelength. RESULTS: The UHPLC method was able to simultaneously separate NON and CAP, with a minimum resolution of 1.5, as well as other seven capsaicinoids with a total run time of 27 min. Method selectivity, robustness, accuracy, and precision were evaluated, and excellent performance was achieved. CONCLUSIONS: The UHPLC method for NON and CAP and other seven capsaicinoids has been successfully developed and found suitable for the routine analysis of capsaicinoids. HIGHLIGHTS: For the first time, NON and CAP are well separated (Rs >1.5) in a 27 min LC separation. This UHPLC method offers a suitable solution for the determination of nine capsaicinoids in QC labs.

Protective effects of Capsicum fruits and their constituents on damage in TNF-α-stimulated human dermal fibroblasts.

BACKGROUND: Antioxidant and anti-inflammatory effects of natural products on skin cells have been proved to be effective in improving skin damage. Capsicum species contain capsaicinoids that have antioxidant and anti-inflammatory properties, and various subspecies are cultivated. In this study, the effects of four Capsicum fruits and major constituents on oxidative stress and inflammatory reactions were measured using human dermal fibroblasts (HDFs) to verify their effects on skin damage. RESULTS: The inhibitory effects of nitric oxide (NO), reactive oxygen species (ROS), and prostaglandin E2 (PGE2 ) by cucumber hot pepper, red pepper (RDP), Shishito pepper (SSP), and Cheongyang pepper were determined in HDFs. RDP and SSP inhibited the production of NO, ROS, and PGE2 in tumor necrosis factor-alpha-stimulated HDFs. Additionally, SSP seeds restored tumor necrosis factor-alpha-induced increase in matrix metalloproteinase-1 and decreased procollagen I α1 (COLIA1). In high-performance liquid chromatography analysis of the capsaicinoids capsaicin (CAP) and dihydrocapsaicin (DHC), CAP was detected at a higher level than DHC in the peel and seeds of all four types of Capsicum fruits, and the total amount of capsaicinoids was the highest in SSP. CAP and DHC, which are major constituents of Capsicum fruits, also inhibited NO, ROS, and PGE2 and restored matrix metalloproteinase-1 and procollagen I α1. CONCLUSION: RDP and SSP were shown to have a significant protective effect on skin damage, including oxidative stress, inflammatory reactions, and reduction of collagens. Capsaicinoids CAP and DHC were proved as active constituents. This research may provide basic data for developing Capsicum fruits as ingredients to improve skin damage, such as inflammation and skin aging. © 2022 Society of Chemical Industry.

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.

Supplementation with artificial sweetener and capsaicin alters metabolic flexibility and performance in heat-stressed and feed-restricted pigs.

Substantial economic losses in animal agriculture result from animals experiencing heat stress (HS). Pigs are especially susceptible to HS, resulting in reductions in growth, altered body composition, and compromised substrate metabolism. In this study, an artificial high-intensity sweetener and capsaicin (CAPS-SUC; Pancosma, Switzerland) were supplemented in combination to mitigate the adverse effects of HS on pig performance. Forty cross-bred barrows (16.2 ± 6 kg) were assigned to one of five treatments: thermal neutral controls (TN) (22 ± 1.2 °C; 38%-73% relative humidity) with ad libitum feed, HS conditions with ad libitum feed with (HS+) or without (HS-) supplementation, and pair-fed to HS with (PF+) or without supplementation (PF-). Pigs in heat-stressed treatments were exposed to a cyclical environmental temperature of 12 h at 35 ± 1.2 °C with 27%-45% relative humidity and 12 h at 30 ± 1.1 °C with 24%-35% relative humidity for 21 d. Supplementation (0.1 g/kg feed) began 7 d before and persisted through the duration of environmental or dietary treatments (HS/PF), which lasted for 21 d. Rectal temperatures and respiration rates (RR; breaths/minute) were recorded thrice daily, and feed intake (FI) was recorded daily. Before the start and at the termination of environmental treatments (HS/PF), a muscle biopsy of the longissimus dorsi was taken for metabolic analyses. Blood samples were collected weekly, and animals were weighed every 3 d during treatment. Core temperature (TN 39.2 ± 0.02 °C, HS- 39.6 ± 0.02 °C, and HS+ 39.6 ± 0.02 °C, P < 0.001) and RR (P < 0.001) were increased in both HS- and HS+ groups, but no difference was detected between HS- and HS+. PF- pigs exhibited reduced core temperature (39.1 ± 0.02 °C, P < 0.001), which was restored in PF+ pigs (39.3 ± 0.02 °C) to match TN. Weight gain and feed efficiency were reduced in PF- pigs (P < 0.05) but not in the PF+ or the HS- or HS+ groups. Metabolic flexibility was decreased in the HS- group (-48.4%, P < 0.05) but maintained in the HS+ group. CAPS-SUC did not influence core temperature or weight gain in HS pigs but did restore core temperature, weight gain, and feed efficiency in supplemented PF pigs. In addition, supplementation restored metabolic flexibility during HS and improved weight gain and feed efficiency during PF, highlighting CAPS-SUC's therapeutic metabolic effects.

Heat stress reduces pig performance due to metabolic responses to heat. During heat stress, pigs lose the ability to metabolize fatty acids for energy and rely on carbohydrates to fuel growth. Evidence has shown that capsaicin, the active ingredient in chili peppers, interacts with heat-sensing receptors to protect against heat stress by preventing changes to metabolism. Artificial sweeteners can also preserve fat metabolism by inducing the secretion of metabolic regulatory hormones from the gut. This study examined a combination of capsaicin and artificial sweetener to restore growth and maintain metabolism during 3 wk of heat stress. As pigs often reduce their feed intake during heat stress, a group of pigs was feed restricted to match the reduced feeding observed in the heat-stressed pigs. Pigs given the feed supplement during heat stress maintained their metabolic flexibility, a measure of metabolic health. In agreement with previous short-term studies, the capsaicin and artificial sweetener supplement improved feed efficiency and weight gain in feed-restricted pigs. This study demonstrated that supplementation with capsaicin and artificial sweetener may prevent metabolic dysfunction during heat stress. This study also confirmed that supplementation with capsaicin and artificial sweetener does improve feed-restricted pigs' growth and feed efficiency.

A monoclonal antibody for identifying capsaicin congeners in illegal cooking oil and its applications.

In this work, we studied the preparation of a high-affinity antibody and its immunochromatographic applications to simultaneously identify capsaicin(LJJ), dihydrocapsaicin(HLJ), nordihydrocapsaicin, homodihydrocapsaicin, and other congeners in illegal cooking oil. We used dihydrocapsaicin hapten-conjugated carrier protein BSA as the immunogen according to the formaldehyde method, and conjugated capsaicin and OVA as the coated detection antigen according to the formaldehyde method. We subsequently screened and cloned a hybridoma cell line 2B3 with the highest affinity, which could stably secrete monoclonal antibodies against compounds in the capsaicin family. We then established a capsaicin indirect ELISA standard curve, which was fitted using the linear regression equation R = 0.9987, curve y = -2.3x + 0.2, and IC50 = 0.2 ng/mL. The cross-reaction rate for capsaicin was 100%, 116% for dihydrocapsaicin, 88% for homodihydrocapsaicin, and 94% for nordihydrocapsaicin. In the second application, we established a simple and accurate sample pretreatment method and a quantum dot-labeled test strip to quickly and quantitatively detect capsaicin family compounds in illegal cooking oil in 8 min. The average recovery rates for each spiked concentration were between 75% and 107.8%, and the coefficient of variation values for each spiked concentration were less than 15%. The high-affinity antibody we identified could simultaneously identify capsaicin, dihydrocapsaicin, nordihydrocapsaicin, homodihydrocapsaicin, and other congeners in illegal cooking oil, and the antibody could be quickly and accurately applied for the qualitative and quantitative detection of capsaicin family residues in illegal cooking oil.

The role of capsaicin stimulation on the physicochemical properties of saliva and aroma release in model aqueous and oil systems.

Capsaicin increases saliva production, but the impact of this additional saliva on the food matrix is unknown. This study aimed to explain the impact of capsaicin on saliva properties and in-vivo release of 14 aroma compounds in aqueous [aqu] and oil systems [oil]. To investigate the physicochemical effect from diverse properties of aroma compounds, one healthy subject participated in all the sessions to minimise large variations between individuals. Capsaicin enhanced saliva flow rate (by 172% [aqu] and 85% [oil]) and salivary protein concentration (by 142% [aqu] and 149% [oil]). Furthermore, capsaicin-in-oil stimulated saliva formed a more stable emulsion in the mouth (17% higher zeta-potential and 15% smaller particle size). In-nose release concentrations measured by APCI-MS for certain esters were reduced by capsaicin (e.g., isoamyl acetate was reduced by 65% [aqu] and 76% [oil]), which suggests that capsaicin may induce stronger oral interactions between specific aroma compounds and salivary proteins.

Towards engineered yeast as production platform for capsaicinoids.

Capsaicinoids are bioactive alkaloids produced by the chili pepper fruit and are known to be the most potent agonists of the human pain receptor TRPV1 (Transient Receptor Potential Cation Channel Subfamily V Member 1). They are currently produced by extraction from chili pepper fruit or by chemical synthesis. Transfer of the biosynthetic route to a microbial host could enable more efficient capsaicinoid production by fermentation and may also enable the use of synthetic biology to create a diversity of new compounds with potentially improved properties. This review summarises the current state of the art on the biosynthesis of capsaicinoid precursors in baker's yeast, Saccharomyces cerevisiae, and discusses bioengineering strategies for achieving total synthesis from sugar.

Separation of nordihydrocapsiate from capsiate and major capsaicinoid analogues using ultra high performance liquid chromatography.

Accurate, rapid quantitation of the capsaicinoid and capsinoid compounds produced by peppers (Capsicum spp.) is essential to assess quality. Here, we developed a rapid ultra-high performance liquid chromatography method for the simultaneous separation of five major capsaicinoids and three major capsinoids from peppers. Optimal chromatographic separation was achieved using a phenyl-hexyl stationary phase with a mobile phase of acidified water and methanol with a flow rate of 0.5 ml/min at a column temperature of 55 °C over 5 min. The method was validated by testing linearity, precision, robustness, and limits of detection and quantification. The developed method was successfully employed to profile capsaicinoids and capsinoids from different pepper cultivars. Out of the 10 pepper cultivars analysed, all three major capsinoids were detected in two cultivars. To the best of our knowledge, this is the first report of successful separation of nordihydrocapsiate from capsiate and quantification of nordihydrocapsiate.

Smoke of Capsicum baccatum L. var. baccatum (Solanaceae) repels nymphs of triatoma infestans (Klug) (Hemiptera: Reduviidae) / Humo de capsicum baccatum L. var. baccatum (Solanaceae) repele las ninfas de Triatoma infestans (Klug) (Hemiptera: Reduviidae)

Control of the Chagas disease vector, Triatoma infestans (Klug) (Hemiptera: Reduviidae) with synthetic pesticides in Bolivia has become increasingly inefficient due to the development of resistance in the insects. In the Chaco region of Bolivia, guaraní populations have approached the problem by fumigating their houses with the smoke of native plants. Through interviews and field work with local guides, the main plant used by the guaraníes was collected and later identified as Capsicum baccatumL. var. baccatum (Solanaceae). In choice bioassays, filter papers exposed to the smoke of the plant repelled nymphs of T. infestans. Activity remained significant after storing the exposed filter papers for 9 days. Chemical analysis of smoke and literature data suggested that capsaicinoids present in the smoke were responsible for the repellent effect. The data presented provide a rationale for the use of C. baccatumvar. baccatumto control the Chagas vector bythe guaraní populations.

El control del vector de la enfermedad de Chagas, Triatoma infestans (Klug) (Hemiptera: Reduviidae) con plaguicidas sintéticos en Bolivia se ha vuelto cada vez más ineficiente debido al desarrollo de resistencias en los insectos. En la región del Chaco de Bolivia, las poblaciones guaraníes han abordado el problema fumigando sus casas con el humo de las plantas nativas. A través de entrevistas y trabajo de campo con guías locales, se recogió la principal planta utilizada por los guaraníes y posteriormente se identificó como Capsicum baccatumL. var. baccatum (Solanaceae). En bioensayos selectos, los papeles de filtro expuestos al humo de la planta repelieron a las ninfas de T. infestans. La actividad siguió siendo significativa después de almacenar los papeles de filtro expuestos durante 9 días. El análisis químico del humo y los datos de la literatura sugieren que los capsaicinoides presentes en el humo eran responsables del efecto repelente. Los datos presentados proporcionan una justificación para el uso de C. baccatum var. baccatum para el control del vector Chagas por las poblaciones guaraníes.