Hirotoshi Tamura

• Ph.D
• Specially appointed Professor and president of Flavor Science Institute at Kagawa University

Abstract Volatile compounds in foods are a significant factor that affects food intake and preference. However, volatile components in edible oils are poorly understood due to a strong matrix effect. In this study, we developed a method of extracting volatile compounds from extra virgin coconut oil (EVCO) by means of oiling-out assisted liquid-liqu...

3,4,5-Tricaffeoylquinic acid (TCQA) that is not found in intact plant of lettuce leaves was isolated from the cultured cells. The intact plant produced chicoric acid (dicaffeoyl tartaric acid: L-CCA) as well as chlorogenic acid (3-caffeoylquinic acid: 3-CQA) as the major metabolites. After subculturing of the cells for 40 days, the amount of 3,4,5-...

Bourbon beans of vanilla would be the best in aroma quality. The objective is to evaluate the aroma quality of vanillas by odour threshold techniques. The recognition threshold of vanilla extracts against a reference, vanillin was determined to be 12.3 ppm. Model oils, Oilmodel5 and Oil model10, prepared along with the top 5 and 10 chemicals in the...

Rosmarinic acid extract with potent biological activities was successfully isolated by supramolecular technique and solvent extraction from Perilla leaves. By the supramolecular complex which was formed from flavocommelin and Perilla leaf extract as initial materials, the supernatant containing rosmarinic acid was isolated. Rosmarinic acid extract...

Uvedafolin, 1, a new sesquiterpene lactone dimer, isolated from the leaves of Smallanthus sonchifolius with five related compounds, 2-6, and their cytotoxicity was assessed against three tumor cell lines (HeLa, HL-60, B16-F10 melanoma). The stereostructure of 1 was newly elucidated by ESI-TOF-MS, 1D/2D NMR and single-crystal X-ray diffraction. Dime...

Three tsukudani seasoning liquid models of soy sauce and amino acid seasoning liquid mixed with rare sugar syrup (RSS, main rare sugars: D-allulose, D-sorbose, D-tagatose, D-allose), glucose-fructose liquid sugar (GF), and white sugar (WS) were heated in a headspace sampler to create a delicious aroma. The aroma components generated were then analy...

I would like to open my lecture on flavor chemistry that was done in my laboratory in 30 years at 23rd February, 2023. If someone are interested in it, please register by pushing the registration URL site shown below, Registration site (URL): https://kagawa-u-ac-jp.zoom.us/meeting/register/tZIkd-ippzwpH9EIFPxGysiafmq88QMRnHdr Title: “Lessen the GA...

For rare sugars to be used in fermented foods, their effect on microorganisms used in soy sauce brewing must first be determined. Here, when soy sauce-brewing microorganisms were cultured with a mixture of four rare sugars (D-allulose, D-allose, D-tagatose, and D-sorbose) with D-glucose, growth was not inhibited when the percentage of each rare sug...

Awa‐bancha is a traditional Japanese post‐fermented tea made by residents in Tokushima Prefecture in the Shikoku region. Tea was picked, boiled, rubbed, anaerobic fermented, and dried in the process of making Awa‐bancha. Nevertheless, the details of making Awa‐bancha differs depending on the producer, such as how the tea leaves are boiled, the weig...

The antiallergic activity of extracts of Naruto Kintoki sweet potato peel was enhanced after cooking the peel using three conventional methods. Using 400 µg/mL extracts, baking showed the highest suppression of β-hexosaminidase release (36.9 %), followed by microwaving (41.9 %) and boiling (64.2 %). Significant suppression of β-hexosaminidase relea...

Black garlic was produced using germinated garlic to increase the functional ingredient, cycloalliin. Compared to fresh garlic with 430 mg cycloalliin/100 g, black garlic made using germinated garlic heated at 70 °Cfor 14 days had 2.6 times higher cycloalliin content (1100 mg/100 g) and black garlic made from fresh garlic had 1.6 times higher cyclo...

Garlic has unique aroma and functional components, exhibits anti-platelet aggregation activity, anti-allergic effects of ajoene, and so on, and is indispensable for many tasty dishes. To understand the characteristic metabolites, comprehensive metabolomic analysis of water-soluble components from garlic and black garlic (Kinkyou, Taisou, and Katei...

Volatile compounds in food play a crucial role in affecting food quality and consumer preference, but the volatile compounds in olive oil are not fully understood due to the matrix effect of oil. The oiling-out assisted liquid-liquid extraction (OA-LLE), which we previously reported, is an effective method for isolating volatile compounds from edib...

The objective of this study was to determine which volatile compounds are responsible for the aroma of fresh sweet cream butter, using a liquid–liquid extraction method coupled with a Porapak Q column and limited odour units (Lod) as technical methods. Sixty-four compounds were quantitatively identified. Assessors determined 100 ppm as the critical...

Understanding native aroma of chocolate is important for development of food science and food industry. However, isolation of volatile compounds from chocolate is difficult due to matrix effects of cocoa butter and, so far, done using evaporation, vaporization, and distillation techniques with losing volatile compounds. The aim of this study is to...

Background: Onion has antiallergic activity but lack of evidence for shallot. Objectives: To determine whether shallot owns similar antiallergic activity to onion and its therapeutic effects in allergic rhinitis when added to standard treatment METHODS: In-vitro β-hexosaminidase inhibitory activities of shallot was compared with onion on RBL-2H3...

Most methods for quantification of catechins in guaraná and other food matrices rely on lengthy gradients to resolve all peaks, and the analysis time for one sample is around 45-135 min. The present method is a fast, sensitive and simple HPLC-UV method, with a 16-minute isocratic run that deliver the high throughput needed to process a large number...

Guaraná (Paullinia cupana) seeds are rich in flavan-3-ols (catechins) and reduce oxidative stress in humans. We determined the concentration and in vitro bioaccessibility of catechins in guaraná seeds from two geographical origins, and measured their Caco-2 permeability. The effect of macronutrients on catechins' bioaccessibility and Caco-2 permeab...

Rosmarinic acid (RA), commonly found in Nepetoidae subfamily of Lamiaceae family, possesses various biological activities. To expand its application, RA was modified by esterification with methyl (me), propyl (pro), and hexyl (hex) alcohols and then tested antibacterial, α‐glucosidase inhibitory, and lipid accumulation suppression activities. Conse...

Cytotoxicity on sonchifolinic acid (1) isolated from Samallunthus leaf and synthetic compounds related to compound 1 were comparatively studied for the first time. Derivatives of 1 such as propyl (1a), butyl (1b), pentyl (1c) and 2-methoxy ethyl (1d) sonchifolate were prepared and their cytotoxic activity on HeLa cells were compared with sonchifoli...

Dimer sesquiterpene lactones (SLs), uvedafolin and enhydrofolin, against four monomer SLs isolated from yacon, Smallanthus sonchifolius, leaf were the most cytotoxic substances on HeLa cells (IC50 values 2.96e3.17 mM at 24 hours). However, the cytotoxic mechanism of dimer SL has not been elucidated yet. Therefore, in this study, we clarified the in...

Celiac disease (CD) and gluten-related disorders are significant health and social issues in Western countries, and CD individuals need to exclude gluten from their diets. The adverse health impacts of CD have extended to Asian countries in which CD was not a problem previously. Thai commercial food products that do not contain wheat, rye, barley,...

Objective: The objectives of this study were to investigate the antioxidant activities in peel and seed of six tropical fruits from Indonesia and to evaluate their bioavailability by in vitro digestion model. Methods: Six tropical fruits namely kapundung, matoa, papaya, rambai salak and soursop were used. The study measured antioxidant activities t...

Absorption, metabolism, and excretion of 3,4-DHPEA-EDA, oleuropein, and hydroxytyrosol isolated from olive fruits were newly evaluated after oral and intravenous administration in freely moving rats cannulated in the portal vein, jugular vein, and bile duct. Orally administered 3,4-DHPEA-EDA, an important bioactive compound in olive pomace, was rea...

This present study determined antioxidant activity, lipid peroxidation, total phenolic, total flavonoids and phytochemicals in moringa leaves and moringa stem. Analysis used in this study was 1, 1-diphenyl-2-picrylhydrazyl (DPPH) method for antioxidant activity, thiobarbituric acid reactive substances (TBARS) method for lipid peroxidation, Folin-Ci...

Analytical pyrolysis combined with gas chromatography-mass spectrometry (Py-GC-MS) is an effective technique for studying combustion processes such as cigarette smoking. Direct pyrolysis of tobacco leaf results in a very complex mixture of organic compounds containing volatile, semi-volatile and non-volatile compounds. Consequently, detecting and i...

Micro-vial pyrolysis (PyroVial) was used to study the production of compounds important for the aroma of heat-treated natural products such as tobacco. Firstly, a mixture of glucose and proline was pyrolyzed as model, as this sugar and amino acid are also abundant in tobacco leaf (Nicotiana tobacum L.). The pyrolysate was analyzed using headspace-G...

The following compounds with higher antiallergic activities were isolated from Eau de Cologne mint leaves: 5,6,4'-trihydroxy-7,8-dimethoxyflavone (6), 5,6,4'-trihydroxy-7,8,3'-trimethoxyflavone (7), 5,6-dihydroxy-7,3',4'-trimethoxyflavone (8), 5,6-dihydroxy-7,8,3',4'-tetramethoxyflavone (9), and 5,6-dihydroxy-7,8,4'-trimethoxyflavone (10). The IC50...

Methyl, propyl and hexyl esters of rosmarinic, caffeic and p-coumaric acids were tested for antiallergic activity, and rosmarinic acid propyl ester exhibited the greatest β-hexosaminidase release suppression (IC50, 23.7 μM). Quadratic correlations between pIC50 and cLogP (r2 = 0.94, 0.98, and 1.00, respectively) were observed in each acid ester ser...

Forty-six kinds of vegetables and fruits were tested the antiallergic activity by means of suppression rates of a histamine related substance-release from RBL-2H3 cells. Solid Phase Extraction Technique with QuEChERS (STQ) method was applied for quick and efficient extraction of active food ingredients. Consequently we found that sweet potato, lotu...

Bioactive compounds from citrus fruits contribute many benefits to human health. Extracellular signal-regulated kinase (ERK) signaling plays an important role in the regulation of multiple cellular processes. Activation of the ERK-cAMP response element binding protein (CREB) signaling is required for longterm memory formation. In this study, aurapt...

3,4-DHPEA-EA is a kind of secoiridoids first found in three Japanese olive pomaces: Mission, Lucca and Manzanillo. These varieties showed high activity of 3,4-DHPEA-EA as an antiallergic active substance with IC50 at 33.5 ± 0.6 μg/mL. As 3,4-DHPEA-EA was the most abundant among the active substances in the pomaces and the activity of 3,4-DHPEA-EA w...

A new diterpene, identified as (+)-6-(4-hydroxy-4-methyl-2-pentenoyl)-4,6-dimethyl-5-(3-methyl-2-butenyl)-1,3-cyclohexadienecarbaldehyde (1, cubelin), was isolated from a methanol extract of Litsea cubeba fruits by normal phase column chromatography and purified by preparative HPLC. The structure elucidation was conducted by spectroscopic methods (...

An aluminum complex of crude Delaware grape anthocyanins, bearing an ortho-dihydroxyl group on the B ring and/or a p-coumaroyl group as an ester with flavocommelin, was formed and isolated by ethanol precipitation. Using a Discovery DPA-6S short column, selected anthocyanins were isolated to give cyanidin 3-glucoside (Cy3G, 48.2% yield with 95.2% p...

Isolation techniques for anthocyanidin 3,5-diglucosides and their derivatives from three types of supramolecular pigments were newly developed using two SPE (Discovery DPA-6S and DSC-SCX) cartridges. Initially, malonylawobanin from commelinin supramolecular complex yielded 79.5% with 85.7% purity using DPA-6S, while DSC-SCX gave a rather lower yiel...

Seven aroma chemicals identified in Citrus limon oils were selected as potent character-impact compounds on the basis of their limited odor unit values (Lod). Those seven compounds selected have high aroma intensities. The recognition threshold of a target lemon oil against a reference lime oil was 32.9 ppm. A model oil (Oilmodel7) prepared by mixi...

Anticancer activity in vitro of Litsea cubeba fruit extracts was investigated, focusing on the fruit residue from essential oil extraction. The methanol extract was fractionated by an Amberlite® XAD-7 column. Cell viability, cell proliferation and cell death were determined using conversion of WST-8, BrdU incorporation and measurement of released L...

Coriander aroma from Coriandrum sativum L. leaves, having a strong oriental scent was characterized by using limited odor unit (Lod) and sensory perception in preference. Forty-two volatile compounds from the coriander extracts collected by modified solvent extracts were identified by GC/MS and retention indices. (E)-2-Tetradecenal was a major comp...

Coriander aroma from Coriandrum sativum L. leaves, having a strong oriental scent was characterized by using limited odor unit (Lod) and sensory perception in preference. Forty-two volatile compounds from the coriander extracts collected by modified solvent extracts were identified by GC/MS and retention indices. (E)-2-Tetradecenal was a major comp...

(E)-2-alkenals (C10-C16), isolated from coriander (Coriandrum sativum L.) leaves, were found to be a chemopreventive agent for deformation of Raji cells carrying the genome of Epstein-Barr virus (EBV) early antigen, induced by 12-O-teradecanoylphorbol 13-acetate (TPA). Intensities of chemopreventive activity of (E)-2-alkenals (C6-C14) were positive...

Bilberry anthocyanin bearing an ortho-dihydroxyl group on the B ring was selectively isolated by complex formation with flavocommelin and aluminum ions (Al(3+)). The interaction between the anthocyanins, flavocommelin, and Al(3+) might have happened in a manner similar to rigid supramolecules, such as commelinin, protocyanin, and other complex pigm...

Some of common flavonoids, phytochemicals that may be rich in various vegetables and fruits showed a great suppression of degranulation of RBL 2H3 cells. The activity is determined by the hexsosaminidase release rate that is coupled with the release of histamine, one of chemical mediators from the RBL 2H3 cells. The activities of flavonoids were co...

This study investigates the presence of undeclared allergens – namely milk, egg, wheat and peanut – in commercial processed food products in Thailand. Out of 142 commercial products, 55 positive cases were found (by quantitative ELISA method) to contain an undeclared allergen greater than 10 ppm. Among all positive products, undeclared milk appeare...

The present study investigated the cytotoxicity of enhydrin (1), uvedalin (2) and sonchifolin (3) in cervical cancer cells. We have found that SLs 1-3 in doses in range of 0.22-10 μM inhibited cell proliferation and induced apoptosis in both a dose- and time-dependent fashion. A significant cell death induction was supported by morphological studie...

Yacon is a medicinal plant used as a traditional medicine by the natives in South America. In Japan, it becomes popular as a health food. Sesquiterpene Lactones (SLs) from yacon leaves were investigated and the active SLs such as enhydrin, uvedalin and sonchifolin, bearing alpha-methylene-gamma-lactone and epoxides as the active functional groups,...

This study was designed to develop a novel sandwich enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of coconut milk proteins in processed foods. The developed sandwich ELISA was able to detect coconut milk proteins from various coconut milk products and did not show any cross-reactivity with 41 of 42 kinds of popularl...

The link between nutrition, food and health is well established and the global interest in these areas generates new information every day. This book pulls together the latest research on flavour chemistry and nutritional and functional properties of food. Topics covered in flavour chemistry begin with an overview of the analysis, occurrence and fo...

Grape skins and seeds are sources of phenolic compounds that contribute to the sensory characteristics and beneficial bioactivity of wines and other processed foods. Hence, the study was aimed to evaluate and characterize the phenolic composition and antioxidant activities of five wild grapes native to Japan and two hybrids derived from the wild on...

Four components (geranylacetone, 2-pentylfiiran, 2-ethyl-1-hexanol and n-valeraldehyde) were selected as representative model chemicals for evaluation of perceived odor intensities. Initially, odor intensity adjustment of these four components was performed at the 'moderate' level on a labeled magnitude scale. The contribution of individual compone...

Seven aroma chemicals identified in Citrus limon oils were selected as potent character-impact compounds on the basis of their limited odor unit values (Lod). Those seven compounds selected have high aroma intensities. The recognition threshold of a target lemon oil against a reference lime oil was 32.9 ppm. A model oil (Oilmodel7) prepared by mixi...

Twenty-three odor chemicals from 3 Citrus essential oils (lemon, Valencia orange, and Citrus sudachi) were selected as the potent character-impact compounds on the basis of their limited odor unit values, and then every chemical was cross-matched by sensory test to the 3 oils to attribute each aroma character to 1 of the 3 Citrus oils. The matching...

Japanese and European strawberry (Fragaria x ananassa Duch.) cultivars were analyzed for their differences in their concentration and composition of anthocyanins. Within a fruit, the concentration of total anthocyanins is higher in epidermal tissues than in inner cortex or pith for all cultivars, but among cultivars, differences in the concentratio...

Authenticity assessment of γ-decalactone (1) and δ-decalactone (2) from peach (Prunus persica var. persica), apricot (Prunus armeniaca), and nectarine (Prunus persica var. nectarina) was performed using gas chromatography-isotope ratio mass spectrometry (GC-IRMS) in the combustion (C) and pyrolysis (P) mode. In addition, commercially available synt...

A major anthocyanin was isolated from the acidified methanolic extract of Beluga black lentils by XAD7 column chromatography and preparative high-performance liquid chromatography. By means of electrospray ionization mass spectrometry and one- and two-dimensional nuclear magnetic resonance spectroscopy, its structure was determined to be delphinidi...

An extraction method using a high vacuum distillation extraction apparatus coupled to a canister was newly developed for the analysis and sensory test of tobacco leaf volatiles. We extended the application of the canister that is used in environmental analysis, to the extraction of the aroma components in tobacco leaves. The volatile components wit...

The contribution of cecal fermentation of polysaccharides to the restoration of zinc bioavailability suppressed by phytic acid was assessed through the simultaneous evaluation of changes in zinc and magnesium absorption. Three weeks old rats were fed Fiber-free, 1% Chitosan, 2% Chitosan, 7% RS (raw potato starch), 14% RS, 2.5% Alginic acid or 5% Al...

Sixty-five grams of sudachi (Citrus sudachi Hort. ex Shirai) essential oil from 18 kg of peel was isolated by a modified solvent extraction (MSE) in a semi-preparative scale with a hand-screw pressing instrument and a solution of pentane and dichloromethane. Twenty-four compounds were newly identified. The essential oil retained its original aroma...

A solution of carnosic acid quinone, which is a radical chain-termination product having no antioxidant activity in the antioxidant reaction of carnosic acid, recovers potent antioxidant activity upon standing. The HPLC analysis of an aged solution of carnosic acid quinone revealed that several antioxidants are produced in the solution. From the ti...

HPLC enantioseparation of chiral monoterpenes was studied using amylose (AD-H), cellulose (OD-H) and β-cyclodextrin (CD-Ph), phenyl carbamate derivatives as chiral stationary phases (CSPs). The contributions of various functional groups of the chiral monoterpenes in capacity factor (k), separation factor (α) and resolution factor (Rs) were investig...

Changes in concentration and composition of anthocyanins during color development in fruit of strawberry (Fragaria X ananassa Duch.) were determined, using a pelargonidin 3-malonylglucoside (PMG)-producing cultivar 'Nyoho'. Color parameters of fruit appearance (L*: lightness, H°: hue angle and C*: chroma) reached their minimum (L* and H°) or maximu...

Odor detection thresholds of optically active compounds and other volatile compounds found in the oil of yellow Keaw mangoes were determined. Odor intensity of individual components was evaluated by Lod (limited odor unit) based on data of the odor detection threshold and the concentration of individual components at the recognition threshold level...

The essential oil in the peel and pulp of a popular green Thai mango, Khieo Sawoei cultivar (Mangifera indica L.) has been characterized by means of the odor thresholds. γ-Terpinene, (E)-β-ocimene, (E)-2-hexenal, hexanal, and (Z)-3-hexen-1-ol were the major components. These major components differed from those of African mangoes, Florida mangoes,...

The composition of essential oil from yellow Thai mangoes, Keaw cultivars and other yellow Thai mango cultivars (Ok-rong, Nam Dorkmai and Choak Anand) was analyzed by GC and GC-MS. Yellow Keaw mangoes contained terpinolene as the main volatile, and (Z)-3-hexen-1-ol, 2,5-dimethyl-4-methoxy-3-(2H)-furanone and (E)-2-hexenal as the major oxygenated co...

Pelargonidin glucoside is a predominant pigment in strawberry fruit and usually followed by cyanidin glucoside (CG). But a considerable amount (5-30% of total anthocyanins) of pelargonidin malonylglucoside (PMG) occurred in the half of Japanese cultivars, such as 'Fukuba', 'Hokowase', 'Nyoho' or 'Tchiotome', and its amount often exceeded CG. On the...

Seasonal change of volatile components in Citrus sudachi was monitored by headspace gas-chromatographic analyses. The limonene content increased sharply from 50.87% (unripe sudachi) to 87.23% (over-ripe sudachi) in accordance with maturation of the fruit, while α-thujene, sabinene, α-phellandrene, β-ocimene and γ-terpinene decreased. Linalool decre...

Two types of hydroxy acids, (10E, 12Z)-9-hydroxy-10,12-octadecadienoic acid [1] and (9Z, 11E)-13-hydroxy-9,11-octadecadienoic acid [2], were obtained as cytotoxic compounds from a water extract of rice bran. The cytotoxicity of acid 1 was stronger than that of acid 2 in vitro, against P388 mouse leukemia cells. Acid 1 slightly inhibited the growth...

Since the malvidin type of anthocyanins was found to be the strongest antioxidants among 6 representative types of anthocyanins which activity was evaluated by TBA test, the utilization of the malvidin type of anthocyanins as food additives was investigated with great interest. However, anthocyanins are apt to change their chemical structure to for...

The enantioselective analysis of the volatile components in Citrus sudachi peel oils was achieved using an enantioselective capillary gas chromatography (enantio-cGC) with α- and β-cyclodextrin columns. The two isomers of linalool and α-pinene showed highly significant differences in both odor detection thresholds and odor qualities. The other inve...

Limited odor unit method was newly developed and applied to the evaluation of aroma quality of citrus fruits.

Limited odor unit (Lo) can be used to characterize aroma quality and can be expressed by an odor unit like equation. The Lo value is an index of the significance of each aroma component at the concentration of volatile oils (ppm) diluted below the threshold level. The aroma intensity (Lo) of each aroma component is expressed by dividing the concent...

The volatile concentrates of bamboo shoots were prepared by the adsorption method of head space vapor (HSV) using Tenax® TA trap and by solvent extraction. The volatile concentrates prepared by adsorption of HSV had a light and fresh aroma. On the contrary volatiles prepared by extraction method had a heavy and rich aroma. Each of the concentrates...

A new mycotoxin, sambutoxin (1), has been isolated from wheat culture of Fusarium sambucinum which was obtained from rotted potato tuber. Its chemical structure was elucidated as 3-{5-methyl-6-[(E)-1,3,5-trimethylhept-1-enyl]tetrahydropyranyl}-5-(p-hydroxyphenyl)-1-met -4-hydroxy-2(1H)-pyridone mainly by NMR analyses of 1.

Malonylated anthocyanin was isolated from the receptacle of 3 Japanese strawberries. The chemical structure was identified to be pelargonidin 3-O-(6-O-malonyl-β-D-glucoside) (1) mainly by 1HNMR and FABMS. The anthocyanin content was about 30, 25, and 12% of total anthocyanins in Fragaria x ananassa Ouch. cv. Nyoho, F. ananassa Ouch. cv. Himesodachi...

The essential oils of Ulva pertusa were prepared by steam distillation under the reduced pressure, and separated into 6 fractions through a silica-gal column (solvent: pentane/ether). Each fraction was analyzed by a capillary gas chromatograph-mass spectrometer (GC/MS). Sixty compounds were identified by the similarity of GC/MS fragment pattern and...

Malonylated anthocyanin was isolated from the receptacle of 3 Japanese strawberries. The chemical structure was identified to be pelargonidin 3-O-(6-O-malonyl-β-D-glucoside) (1) mainly by 1H-NMR and FABMS. The anthocyanin content was about 30, 25, and 12% of total anthocyanins in Fragaria x ananassa Duch. cv. Nyoho, F. ananassa Duch. cv. Himesodach...

The stereochemical structure of acylated anthocyanins in the Japanese grape, Muscat Bailey A, was determined by homonuclear Hartmann-Hahn (HOHAHA) spectroscopy and liquid chromatography-mass spectrometry. The structures found were peonidin 3-O-(6-O-(trans-p-coumaroyl)-beta-D-glucopyranoside), delphinidin 3-O-(6-O-(trans-p-coumaroyl)-beta-D-glucopyr...

Reconstruction, not decomposition, was used to determine the composition of the pigment from the blue petals of cornflowers, protocyanin. Comparison of optical and mass spectra of natural and reconstructed protocyanin revealed it to be a complex of an anthocyanin and a malonylflavone with iron(iii) and magnesium ions.

Nicht durch Dekonstruktion sondern durch Rekonstitution konnte die Zusammensetzung des Kornblumen-Pigments Protocyanin geklärt werden. Es ist ein Komplex aus einem Anthocyanin und einem Malonylflavon sowie Eisen(III)- und Magnesium-Ionen, wie aus dem Vergleich der optischen und massenspektrometrischen Befunde von natürlichem und rekonstituiertem Pr...

The antioxidative activity of four anthocyanins isolated from the Muscat Bailey A grape, which has a malvidin nucleus, was evaluated according to the amount of malonaldehyde formed by the autoxidation of linoleic acid in Trizma buffer (pH 7.4). Thiobarbituric acid derivatives of malonaldehyde were quantitatively analyzed by a spectrophotometer (at...

Mixtures of two compounds and volatiles in the Citrus peels were analyzed by six semiconductor gas sensors. From the result of mixed compounds, responses of semiconductor gas sensors were affected by vapor pressures of individual compounds. It was found that sensor responses as well as vapor pressures changed by the solubility and the ratio of the...

The aroma quality of six acid citrus fruits was characterized by instrumental and objective methods such as the GC-sniff test with flavor wheel and logarithmic values of odor units. With the GC-sniff test, carvone, carveol, perillaldeyde, linalool and citronellal were found to constitute the characteristic aroma of sudachi oil. Logarithmic odor uni...

8種類の半導体ガスセンサーを用いて,36種類の試料化合物のヘッドスペースガスの測定を行った.測定結果と化合物との関連性を検討するため,測定値をクラスター分析によって分類した.各センサーは特定の化合物や化合物群に特異的応答は示さないものの,相対感度と有機性値,無機性値との相関が高いものがあった.複数のガスセンサーを使用して有機性,無機性との相関関係を検討することにより,化合物の物理化学的性質や香気特性を分類できる可能性が示唆された. 終わりに臨み,本研究にご協力を頂いたフィガロ技研(株),香田弘史氏に深謝いたします.なお,本研究費の一部は文部省科学研究費によったもので,付記して謝意を表します.

Thymus is a perennial herb of the Labiatae family (Fig. 1A) and can grow to a height of some 30 cm. There are more than 100 varieties of Thymus distributed throughout Europe. It has dark green leaves and light mauve-pink flowers in early summer. Thyme is a good rock-garden plant, as it spreads easily. It originates on the coast of the Mediterranean...

Flower colours, from red through purple to blue, are mostly from anthocyanins, a type of flavonoid1-5. Although there are many colours, only a few anthocyanidins, chromophores of the pigments, have been found. The colour of the pigments is stable in plants for a few days to one month but the extracted anthocyanins are, nevertheless, unstable and qu...