Pungent Flavor Research Articles

Antimicrobial Properties of Chili Peppers

Chili peppers are used worldwide in foods for their pungent flavor, aroma, and to prolong food spoilage. With capsaicin contents ranging from zero to millions of Scoville heat units, the different varieties offer a wide range of options for people all over the world. In addition to their use in cuisines, chili peppers have been explored for their antimicrobial and antifungal properties. Consequently, research is underway to determine the potential for the application of chili pepper extracts in the food industry in place of artificial preservatives. As new antibiotic-resistant food borne pathogens emerge, the discovery of natural antimicrobials in chili peppers will be invaluable to food scientists. This review goes over some relevant research that has already been done in this area. In addition it lays the ground for the new research that is emerging testing new varieties of chili peppers for nutrient content, flavor profiles, and for antimicrobial activities against numerous human pathogens.

Effect of high hydrostatic pressure (HHP) treatment on flavor, physicochemical properties and biological functionalities of garlic

The characterization of flavor, physicochemical properties and biological activities of garlic extracts prepared by high hydrostatic pressure (HHP) treatment (500 MPa) was conducted at various HHP reaction times and pH conditions. The evaluation of flavor revealed that HHP treated garlic samples in acidic condition (pH 1.8–3) were most effective to reduce the pungent flavor of garlic among all conditions.After HHP treatment, the hardness and color values of L*(lightness), a*(redness), and b*(yellowness) of garlic samples decreased, while the cohesiveness value of garlic samples was increased (P < 0.05). The antioxidative, antimicrobial and antitumor activities of HHP treated garlic samples were decreased compared with control. A rapid decrease in antimicrobial and antioxidative activities was observed over 3 min HHP reaction time. No antitumor activities were observed after 3 min HHP reaction time. Up to 56 s HHP reaction time, the alliinase activity was not changed significantly but it was dramatically decreased at a longer HHP reaction time compared with control (P < 0.05), showing higher stability in acidic condition than alkaline condition. Based on present observations, this study supports high potentials of HHP treatment to produce new value-added garlic products with modified garlic flavor profile, and minimized physicochemical properties and biological activities.

Influence of particle size on bioprocess induced changes on technological functionality of wheat bran

Wheat bran is nutritionally an important source of dietary fibre, vitamins and minerals, but its negative influence on dough rheology, texture and sensory quality of bread limits its use in bread baking. The current study aimed at improving the technological functionality of bran by bioprocessing Wheat bran of different particle size (750, 400, 160, 50 μm) was fermented 8 h or 24 h with Lactobacillus brevis E95612 and Kazachstania exigua C81116 with or without addition of enzyme mixture with various carbohydrase activities. Kinetics of growth and acidification showed that the growth of the starters was enhanced in the presence of enzymes in bran having particle size of 160 and 50 μm. Fermentation was critical to improve dough stability and volume of bran enriched breads, whereas addition of enzymes had the most significant effect in improving bread shelf-life. Wheat bread containing 160 μm bran fermented 8 h with enzymes had mild flavour, the highest volume and shelf-life. Reduction of particle size increased perceived smoothness of mouthfeel but provided darker colour in bran-containing breads. The short 8 h bioprocessing, with or without enzymes did not increase pungent flavour or bitter aftertaste in comparison with the native bran.

SPME를 이용한 참외와인의 휘발성 향기성분의 모니터링

This study was conducted to investigate changes in the main volatile flavor components of oriental melon during the process of alcohol fermentation via SPME (solid phase micro extraction). The flavor components of oriental melon were shown to have mainly included melon and green flavors. The green flavor was identified to be nonanal, 1-butanol, 1-octen-2-ol and benzene, and its relative concentration was shown to be 16.66%. The nonanal concentration was shown to have been reduced among the green-flavor components, but no significant change in remaining components was observed. Mainly, sweet flavor tended to increase, and the relative concentration of benzene was particularly shown to have increase by 25.58%, accounting for the highest relative concentration. The amount of green-flavor components, except for 1-butanol, was shown to have significantly decrease after alcohol fermentation. Then, no component of green-flavor, which causes an offensive smell, was found during fermentation and aging. Meanwhile, the volatile flavor components, which are consist of acids, were shown to have been produced during alcohol fermentation. In particular, octanoic acid, which causes off-flavor, was shown to be 60.99%, a very high relative concentration during the aging stage. In addition, acetic acid with a pungent sour flavor tended to be produced. A further study on the improvement of flavor in the production of oriental melon wine is required.

An Investigation of the Characteristics of Edible Chinese Herbs Recorded in Classic Formulas of China

In order to investigate the characteristics of edible Chinese herbs recorded in classic formulas of China, 86 formulas used for dietetic therapy were selected from Zhong Hua Yi Dian. All the edible Chinese herbs included in these formulas were input into the Access database. The analysis of the nature, flavor, and channel entered for these herbs was followed by using Spss 13.0 software. The results of analysis showed that herbs with neutral nature were the most popular, took up 41.8%, followed by herbs with warm nature, took up 28.1%; Sweet flavor herbs were the most frequently-used, took up 48.7%, next were the pungent flavor herbs, took up 23.0%; Spleen and Stomach channel entered herbs were the most, took up 38.6%, followed were Kidney channel entered herbs, took up 17.3%. These investigation results suggest that sweet flavor Chinese herbs with neutral or warm nature may be used a lot in dietetic therapy. Sweet flavor Chinese herbs enter Spleen channel and Spleen is the foundation of acquired constitution in Traditional Chinese Medicine [1,2]. Pungent flavor correspondences to Yang and pungent flavor herbs can improve the movement of Qi on the basis of the theory of Traditional Chinese Medicine [3]. Therefore, Spleen and Stomach channel entered sweet or pungent flavor Chinese herbs are popular in dietetic therapy. Acknowledgements: Thanks to the support for this research from the project of Beijing University of Chinese Medicine (No.101002604).

The Physico-Chemical Influences of Yellow Mustard Paste - Comparison with the Powder in Mayonnaise

The aim of this study was to investigate the influences of different concentrations of yellow powder and paste mustard on viscosity, stability, rancidity and organoleptic properties of mayonnaise sauce. The concentrations of mustard in 0%, 0.01%, 0.02%, 0.03%, 0.04%, 0.05% and 1%, were used in mayonnaise formulation and the results turned out to signify an increase in viscosity, improvement in the other chemical properties with the increasing of the amounts of powder mustard. The sensory properties evaluation demonstrated undesired changes in color and flavor of mayonnaise (p≤ 0.05).Thus, in the next step a thermal treatment applied on powder mustard during which myrosine enzyme and the effective factor in pungent flavor of mustard were deactivated. The produced material, called paste mustard, and with the concentrations of 0%, 0.75%, 1%, 1.25% and 1.5% were used in the production of mayonnaise samples in fully the same circumstances and the above tests all repeated. The results of physiochemical tests and evaluation of sensory properties in comparison of what was observed showed a remarkable increase in viscosity, stability improvement and reduction of rancidity in samples containing paste mustard. However, the undesired changes in color and flavor of the sauce were removed to some extent and the sensory properties of the samples ameliorated (p≤ 05). The research results concluded that mayonnaise sample containing 1% paste mustard without any synthetic preserver, due to high viscosity, appropriate suspension stability, rancidity reduction rate and concerning the desirability of its organoleptic features recognized as the most appropriate sample.

Desenvolvimento e avaliação físico-química, sensorial e da estabilidade de ácido ascórbico de doce de leite com pimenta

The dulce de leche or milk candy is a food widely consumed in Brazil, which shows typical characteristics of taste, color, flavor and texture. The lady-finger red pepper is regularly present on the Brazilian people table as this product contains a pungent flavor favoring various spices; and it is also rich in ascorbic acid (vitamin C) which is an excellent antioxidant. This study aimed at developing a dulce de leche containing lady-finger red pepper, and to determine the composition of the product. Also, the ascorbic acid contents were quantified in products stored for different periods (0, 30 and 60 days). The product acceptance by consumers on the sensory characteristics was evaluated by means of hedonic scale for color, aroma, flavor and texture attributes. The composition of the product was in accordance with the legislation in force, and the ascorbic acid contents were practically stable during the storage, and the sensory analyses indicated that the red pepper-containing dulce de leche was well accepted.

Sensory Analysis of Protected Geographical Indication Products: An Example with Turnip Greens and Tops

AbstractIn Galicia (northwestern Spain), Brassica rapa L. var. rapa vegetable products (such as turnip greens and turnip tops) are characterized by a particular sulfurous aroma, pungent flavor and bitter taste that differentiate them from other vegetables. This characteristic bitter taste is highly valued by some consumers. The regulation of the protected geographical indication “Grelos de Galicia” was approved, given the nutritional and economic importance of these products. Turnip greens and turnip tops, products covered by this regulation, are defined as the vegetative parts suitable for human consumption of plants of the species B. rapa L. var. rapa (commonly known as turnip), which is an ecotype of A Coruña and Lugo. In this work, the quantitative descriptive analysis for turnip greens and turnip tops of the two main producing regions of Galicia (Lugo and A Coruña) was developed. A significant homogeneity among the samples was found.Practical ApplicationsThis study provides sensory lexicons of turnip greens and turnip tops to support the development of their quality control plans. The study also provides the quantitative descriptive analysis developed to determine the sensory characteristics of turnip greens and turnip tops. This information is required for inclusion in the “Grelos de Galicia” protected geographical indication certification.

Investigation of Glucosinolate Profile and Qualitative Aspects in Sprouts and Roots of Horseradish (Armoracia rusticana) Using LC-ESI–Hybrid Linear Ion Trap with Fourier Transform Ion Cyclotron Resonance Mass Spectrometry and Infrared Multiphoton Dissociation

Within the family of Brassicaceae, an important source of glucosinolates (GLSs) is represented by horseradish ( Armoracia rusticana P. Gaertner, B. Meyer & Scherbius), cultivated for its roots, which are grated fresh or processed into a sauce and used as a condiment. The characteristic pungent flavor of the root depends on the abundance of the bioactive GLS molecules. In crude plant extracts (sprouts and roots) of an accession of horseradish largely diffused in the Basilicata region (southern Italy), which develops many sprouts and produces white, fiery, and sharp-flavored marketable roots, we characterized the GLS profile by LC-ESI-LTQ-FTICR-MS and IRMPD. In sprouts and roots we identified 16 and 11 GLSs, respectively. We confirmed the presence of sinigrin, 4-hydroxyglucobrassicin, glucobrassicin, gluconasturtin, and 4-methoxyglucobrassicin and identified glucoiberin, gluconapin, glucocochlearin, glucoconringianin, glucosativin, glucoibarin, 5-hydroxyglucobrassicin, glucocapparilinearisin or glucobrassicanapin, glucotropaeolin, and glucoarabishirsutain, not previously characterized in horseradish. Of particular note was the presence of the putative 2-methylsulfonyl-oxo-ethyl-GLS.

감마선 조사가 건조-발효소시지의 Trans 지방산, 유리아미노산 및 관능검사 특성에 미치는 영향

본 연구는 감마선 조사가 건조-발효햄의 조직감, 지방산, 유리아미노산 및 관능적 특성에 미치는 영향을 조사하기 위해 실시하였다. 경도(hardness) 및 부착성(adhesiveness) 의 경우 조사 처리구가 유의적으로 낮게 나타났다(p<0.01). 검성(gumminess)의 경우에는 2 및 4 kGy처리구가 대조구 및 1 kGy처리구보다 유의적으로 높은 값을 나타내었다(p<0.01). 지방산의 경우 처리구의 포화지방산(SFA)(C14:0, C16:0, C18:0)은 유의적으로 높았고(p<0.05), 불포화지방산 (UFA)(C16:1, C18:1 및 C18:3), trans 지방산, n-3 및 n-6 지방산 의 함량은 4 kGy처리에서 감소하였다(p<0.05). 감마선 조사처리는 phosposerine, aspartic acid, glutamic acid를 증가 시켰으나, lysine은 감소시켰다(p<0.05). 관능검사의 경우, 황취(sulfur odor) 및 지방산화 맛(fat pungent flavor)은 4 kGy에서 가장 높게 나타났으며(p<0.05), 곰팡이 냄새(moldy odor) 및 곰팡이 맛(moldy flavor)은 낮게 나타났다(p<0.05). 이상의 결과 감마선 조사가 조직감, 지방산조성 및 관능적 특성에 영향을 미쳤다. In this study, the effects of gamma-irradiation (1, 2 and 4 kGy) on texture profiles, fatty acid composition, free amino acids and sensory evaluation of dry-fermented sausage were evaluated. The hardness and adhesiveness of irradiated samples were significantly lower (p<0.01) than that of the control, while the gumminess of samples irradiated with 2 and 4 kGy was higher than the other tested samples (p<0.01). The sample irradiated at 4 kGy had a higher saturated fatty acid (SFA) content (C14:0, C16:0, C18:0) and significantly lower (p<0.05) unsaturated fatty acid content (UFA) (C16:1, C18:1, C18:3), trans, n-3 and n-6 fatty acid than the non-irradiated sample. Gamma-irradiation resulted in an increase (p<0.05) in phosposerine, aspartic acid and glutamic acid and a decrease (p<0.05) in glutamic acid in free amino acids. For the samples irradiated at 4 kGy, the sulfur odor and fat pungent flavor were significantly higher (p<0.05) and the moldy odor and moldy flavor were significantly lower than the control sample. In conclusion, gamma-irradiation had a significant effect on the texture profiles, fatty acid composition and sensory evaluation of dry-fermented sausage.

EVALUATION OF SENSORY PROFILE AND P‐VINYLGUAIACOL (PVG) CONTENT IN ORANGE JUICES DURING STORAGE AT DIFFERENT TEMPERATURE

ABSTRACTThe objective of the present study was to determine the influence of storage conditions on the sensory quality and content of P‐vinylguaiacol (PVG) of pure pasteurized orange juices marketed domestically under two popular brands. No PVG was detected in fresh juices. After 12 months of storage of the orange juices at 18, 28 and 38C, the PVG contents were 284, 1,292 and 2,515 µg/L, respectively. Using principal component analysis differentiation of the sensory quality of fresh and stored juices was possible. The quality of the fresh orange juices was differentiated most considerably by intensity of the sweet, sour and refreshing odors, and by intensity of the sweet, sour and pungent flavor. The sensory quality of the juices stored at 18C for 12 months corresponded to the quality of these stored 2 months at 28C. At 38C, the juices were completely changed after 2 months and were unfit for drinking.PRACTICAL APPLICATIONSThe descriptive analysis (quantitative descriptive analysis) is a very useful tool for performing a detailed sensory comparative analysis of fresh and stored orange juices, allowing to draw precise conclusions as to the sensory quality of juices. The descriptive analysis could also serve as a reference to instrumental methods used for quality control of storage juices.

Extraction of allyl isothiocyanate from wasabi (Wasabia japonica Matsum) using supercritical carbon dioxide

The pungent flavor unique in wasabi is due to isothiocyanates including allyl isothiocyanate (AIT) which has outstanding antimicrobial activity. AIT is converted from sinigrin by enzymatic reaction in the presence of water. The optimum moisture content of wasabi root for supercritical CO2 extraction (SCE) at 20 MPa and 35°C was found to be 125% dry basis. In the ranges of pressure (15–25 MPa) and temperature (35–55°C), yield of AIT by SCE increased as pressure increased and/or temperature decreased. The highest yield was 408 mg/100 g solid at 25 MPa and 35°C. SCE of AIT from the freeze-dried wasabi root, stem, and leaf at 20 MPa and 35°C resulted in the yields of 368, 39, and 11 mg/100 g solid, respectively. The moisture content of wasabi along with the pressure and temperature were the important parameters in SCE of AIT.

Changes in volatile compounds of pickled mustard tuber (Brassica junceavar. tsatsai) during the pickling process

SummaryThis study was carried out to determine the changes of volatile compounds composition during pickled mustard tuber production. The samples were collected at different pickling stages from the traditional industry production way in Chongqing, China. Gas chromatography–mass spectrometry were performed after simultaneous distillation and extraction. The results showed that ITC (isothiocyanates) possessed the highest relative percentage area (RPA) 78.87%, followed by sulphide compounds with RPA of 14.48%. Main volatile compounds that determined were allyl ITC, dimethyl trisulphide, (2‐isothiocyanatoethyl)‐benzene, n‐Hexadecanoic acid and linolenic acid ethyl ester, which were responsible for the hot and pungent flavour of pickled mustard tuber. The sulphides, acids, aldehydes, alcohols, phenols, esters, nitriles and heterocyclic compounds increase with pickling time but ITC increase at the first and second pickling stage, then start to decrease in the last pickling stage. It was also demonstrated that more than 60‐day pickling time was necessary for the formation of the typical aroma notes.

Sensory quality of turnip greens and turnip tops grown in northwestern Spain

In Galicia (northwestern Spain), Brassica rapa var. rapa L. includes turnip greens and turnip tops as vegetable products that are characterized by a particular sulfurous aroma, pungent flavor, and a bitter taste. In this work, 12 local varieties grown as turnip greens and turnip tops were evaluated to define the sensory attributes, to relate them with secondary metabolites, and to select those sensorial traits that better describe these crops. Results showed differences in the sensory profiles of B. rapa varieties. Turnip greens were significantly different regarding aroma intensity, leaf color, and salty taste, while turnip tops were for color and firmness of leaves, moistness and fibrosity in mouth, sharpness, and bitter taste. Secondary metabolites as glucosinolates in turnip greens and phenolic compounds in turnip tops were highly correlated with texture and flavor. Glucosinolates, especially progoitrin (in turnip greens) and gluconapin (in turnip tops), showed correlation with bitter taste and aftertaste persistence. Correlation between sensory traits showed highest values between leaf firmness and stalk firmness (R = 0.94**), leaf firmness and fibrosity (R = 0.92**), aftertaste persistence and bitterness (R = 0.91**), and between bitterness and moistness (R = −0.89**).

Comparative analysis of essential oils from eight herbal medicines with pungent flavor and cool nature by GC–MS and chemometric resolution methods

Systematic comparative research was conducted on essential oils from eight traditional Chinese medicines (TCM) of pungent flavor and cool nature because the essential oils are the main active ingredients of herbs of this kind. The work was based on their component analysis by gas chromatography-mass spectrometry (GC-MS), on their retention indices, as well as on chemometric resolution methods. A total of 144 compounds were tentatively identified, accounting for 69.0% to 91.8% of the total essential oils. It is worth noting that there are 67 compounds in at least three of these eight essential oils. Moreover, many biologically active compounds, such as hexanal, alpha-pinene, camphene, beta-pinene, p-cymene, limonene, eucalyptol, (Z)-ocimene, gamma-terpinene, camphor, p-menthone, 4-terpineol, alpha-terpineol, carvone, eugenol, caryophyllene, beta-farnesene, alpha-curcumene, beta-selinene, delta-cadinene, caryophyllene oxide, cedrol, n-hexadecanoic acid, benzaldehyde, benzeneacetaldehyde, phthalic acid diisobutyl ester, linoleic acid, tetradecanoic acid, (Z,Z,Z)-9,12,15-octadecatrienoic acid, eucalyptol, pentadecanoic acid, hexadecanoic acid methyl ester, linoleic acid methyl ester, exist in at least four of the eight essential oils. These results might help us to understand why the eight herbs are all of pungent flavor and cool nature according to the theory of TCM, and may provide a useful chemical basis for future research on herbs of this kind.

Anti‐influenza virus activity of extract of Japanese wasabi leaves discarded in summer

AbstractBACKGROUND: Japanese wasabi (Wasabia japonica) is now habitually used as a spice in some kinds of Japanese foods, and its pungent taste and flavor are preferred. Generally, rhizomes and winter leaves are used as a spice and for processed foods such as pickled wasabi. Since the leaf area of summer leaves is far greater than that of winter leaves, they are not used for food, and are discarded. Thus, we need to develop an effective use for summer leaves. We investigated anti‐influenza virus activity in these summer leaves as a new function.RESULTS: Seventy percent ethanol extracts of leaves harvested in July exhibited a high replication inhibition rate (98% or higher) in the type A strain (AH1N1, A/shimane/48/2002), its subtype (AH3N2, A/shimane/122/2002), and type B strain (B/shimane/2/2002). The extracts of summer leaves exhibited the same anti‐influenza virus activity as winter leaves, and showed a stronger activity than stems, roots, and rhizomes.CONCLUSION: A potent anti‐influenza virus activity was discovered in summer leaves of Japanese wasabi. The ethanol extracts inhibited influenza virus replication regardless of the hemagglutinin antigen type. Therefore, such extracts are expected to be a promising source of a novel anti‐influenza virus agent. Copyright © 2008 Society of Chemical Industry

Thymol and related alkyl phenols activate the hTRPA1 channel

Thymol, a major component of thyme and oregano, has medical uses in oral care products as an astringent and antibiotic. Its distinctive sharp odour and pungent flavour are considered aversive properties. The molecular basis of these aversive properties is not well understood. The ability of thymol to activate human transient receptor potential channel A1 (hTRPA1) expressed in stably transfected human embryonic kidney 293 (HEK293) cells was measured by membrane potential and calcium-sensitive dyes in a fluorescence-imaging plate reader (FLIPR) assay. Direct activation of hTRPA1 currents was measured by whole-cell voltage clamp recording. Intracellular calcium changes were measured using fura-2 dye. The FLIPR assay was also used to measure membrane potential changes elicited by thymol after pretreatment with camphor, a known TRPA1 inhibitor. The ability of related alkyl phenols to activate hTRPA1 was also determined. Thymol potently activated a membrane potential response and intracellular calcium increase in hTRPA1-expressing HEK293 cells in a concentration-dependent manner. Activation by thymol desensitized hTRPA1 to further exposure to thymol or the known ligand allyl isothiocyanate (AITC). The related phenols 2-tert-butyl-5-methylphenol, 2,6-diisopropylphenol (propofol) and carvacrol also activated hTRPA1. Phenols with less bulky carbon substitutions and lower logP values were less potent in general. The response to thymol was blocked by camphor. These results suggest a role for hTRPA1 activation in the reported pungent and aversive properties of some of these pharmaceutically important phenols.

Relationship between sensory attributes and volatile compounds qualifying dry-cured hams

This work studies the relationship between 45 volatile compounds and 17 sensory attributes (13 flavour perceptions) of dry-cured hams. Volatile compounds were quantified by SPME-GC while the sensory assessment was carried out by 13 panellists. GC-sniffing was used to determine the odour impact zones of the chromatogram. The odour thresholds of the volatile compounds and their sensory characterisation were determined by dilution analysis. Six sensory attributes (acorn odour and flavour, rancid odour, rancid taste, fat rancid and fat pungent flavours) were explained by regression equations (adjusted –R2⩾0.70) based on ten compounds: benzaldehyde, 2-heptanone, hexanal, hexanol, limonene, 3-methylbutanal, 3-methylbutanol, 2-nonanone, octanol, pentanol. Acorn flavour attribute was successfully emulated by mixing the volatile compounds selected by the equation. Its odour was evaluated by assessors that gave a sensory description that matches with the target. All the procedures performed for the elucidation of volatile-attribute relations showed a basic agreement in their results.

Identification of selenohomolanthionine in selenium-enriched Japanese pungent radish

Sulfur (S) and selenium (Se) are same-group elements that share, in part, a common metabolic pathway. Because a radish variant having pungent flavor (Raphanus sativus L. cv. ‘Yukibijin’) has a unique S metabolic pathway, we expected that it would also produce unique Se compounds through that metabolic pathway. Se metabolites in the radish were assigned by speciation techniques, i.e., HPLC-inductively coupled plasma mass spectrometry (ICP-MS) and HPLC-electrospray ionization tandem mass spectrometry (ESI-MS-MS). 68.5% of total Se in the selenized Japanese pungent radish was water-extractable, and the water extract contained selenate (around 45% of total Se), Se-methylselenocysteine (around 11%), an unknown Se compound tentatively named KD-1 (around 5%), and others (around 1.2%). KD-1 was assigned by ESI-MS-MS as 4,4′-selenobis[2-aminobutanoic acid] or Se-(3-amino-3-carboxypropyl)-homocysteine, commonly known as selenohomolanthionine (SeHLan). This Se compound was first identified in nature. The metabolic pathway of SeHLan was suggested to involve the phosphorylation of homoserine to produce O-phosphohomoserine, and the subsequent reaction of O-phosphohomoserine with selenohomocysteine (SeHCys).

Thymol and related phenols are potent activators of the transient receptor potential channel, TRPA1

Thymol is a major component of the spice thyme. It has a distinctive pungent flavor mediated by receptor mechanisms in the nose and tongue in addition to having aversive properties. Using a voltage-sensitive fluorescent dye, we show that thymol specifically activates the human transient receptor potential channel A1 (TRPA1), EC50 12 μM, but not other taste sensory TRP channels (TRPV1 and TRPM5). Electrophysiology measurements further demonstrated that thymol activation was concentration-dependent, reversible, and rapidly desensitized TRPA1. A number of related phenols including 3-tert-butyl-4-hydroxyanisol (BHA), a food preservative, and propofol, an intravenous anesthetic, also selectively activated TRPA1 (EC50 3 and 13 μM, respectively). Phenols with less bulky carbon substitutions adjacent to the phenolic group, such as 2, 6-dimethlyphenol and 2-methlyphenol (o-cresol), were less potent. TRPA1-specific siRNA inhibited thymol activation, confirming the specificity of the response. In addition, thymol activation was blocked by camphor (IC50 200–500 μM) whereas other camphor analogs, e.g. camphorquinone, camphoric acid and limonene were TRPA1 agonists (EC50 0.3, 2, 3 mM, respectively). Our results suggest a role of TRPA1 activation in the reported pungent and aversive properties of some of the pharmaceutically important phenols.