RESUMEN
Dehydration is an effective method for the long-term storage and aroma retention of gonggan (Citrus sinensis Osb. 'Deqing Gonggan'), which is a Chinese variety of citrus, with unique and characteristic floral, fruity, and citrus flavors. However, the aroma profiles of gonggans prepared using oven- and freeze-drying, the most widely-used drying methods, remain unclear. In this study, a total of 911 volatile organic compounds (VOCs) were detected in dried gonggan. These were primarily composed of alcohols (7.69%), aldehydes (7.03%), esters (15.38%), ketones (7.58%), and terpenoids (23.19%). A total of 67 odorants contributed significantly to the overall aroma of dried gonggans, with the major odor qualities being detected as green, citrus, fruity, floral, and sweet. These were mainly attributed to the presence of aldehydes, esters, and terpenoids. Freeze-drying was more effective in maintaining the unique citrus and mandarin-like aromas attributed to compounds such as limonene, citrial, ß-myrcene, ß-pinene, and γ-terpinene. Moreover, (E,E)-2,4-decadienal had the highest relative odor activity value (rOAV) in freeze-dried gonggans, followed by (E)-2-nonenal, furaneol, (E, E)-2, 4-nonadienal, and E-2-undecenal. Oven-drying promoted the accumulation of terpenes such as octatriene, trans-ß-ocimene, cyclohexanone, copaene, and É-irone, imparting a soft aroma of flowers, fruits, and sweet. Increasing the temperature led to an increase in existing VOCs or the generation of new VOCs through phenylpropanoid, terpenoid, and fatty acid metabolism. The findings of this study offer insights into an optimized procedure for producing high-quality dried gonggans. These insights can be valuable for the fruit-drying industry, particularly for enhancing the quality of dried fruits.
Asunto(s)
Liofilización , Odorantes , Terpenos , Compuestos Orgánicos Volátiles , Compuestos Orgánicos Volátiles/análisis , Odorantes/análisis , Terpenos/análisis , Frutas/química , Citrus sinensis/química , Desecación/métodos , Aldehídos/análisis , Cromatografía de Gases y Espectrometría de Masas , Cetonas/análisis , Monoterpenos Bicíclicos/análisis , Ésteres/análisis , Alcadienos/análisis , Ciclohexenos/análisis , Manipulación de Alimentos/métodos , Monoterpenos Acíclicos , Monoterpenos Ciclohexánicos , Alquenos , SesquiterpenosRESUMEN
An electronic biosensor for odors was assembled by immobilizing the silk moth Bombyx mori pheromone binding protein (BmorPBP1) on a reduced graphene oxide surface of a field-effect transistor. At physiological pH, the sensor detects the B. mori pheromones, bombykol and bombykal, with good affinity and specificity. Among the other odorants tested, only eugenol elicited a strong signal, while terpenoids and other odorants (linalool, geraniol, isoamyl acetate, and 2-isobutyl-3-methoxypyrazine) produced only very weak responses. Parallel binding assays were performed with the same protein and the same ligands, using the common fluorescence approach adopted for similar proteins. The results are in good agreement with the sensor's responses: bombykol and bombykal, together with eugenol, proved to be strong ligands, while the other compounds showed only poor affinity. When tested at pH 4, the protein failed to bind bombykol both in solution and when immobilized on the sensor. This result further indicates that the BmorPBP1 retains its full activity when immobilized on a surface, including the conformational change observed in acidic conditions. The good agreement between fluorescence assays and sensor responses suggests that ligand-binding assays in solution can be used to screen mutants of a binding protein when selecting the best form to be immobilized on a biosensor.
Asunto(s)
Técnicas Biosensibles/instrumentación , Proteínas Inmovilizadas/metabolismo , Proteínas de Insectos/química , Proteínas de Insectos/metabolismo , Péptidos y Proteínas de Señalización Intercelular/química , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Odorantes/análisis , Alcadienos/análisis , Técnicas Biosensibles/métodos , Eugenol/análisis , Alcoholes Grasos/análisis , Fluorescencia , Grafito/química , Concentración de Iones de Hidrógeno , Proteínas Inmovilizadas/química , Feromonas/análisis , Feromonas/metabolismo , Soluciones/químicaRESUMEN
The hydrocarbon pattern in the floral scent of Yucca species was found to comprise a group of unbranched, mid-chain alkanes, alkenes, and an alkadiene. In Y. reverchonii, highly dominant (Z)-8-heptadecene is accompanied by (6Z,9Z)-6,9-heptadecadiene and heptadecane as minor components and by traces of other saturated and unsaturated hydrocarbons with similar chain length. Some of these volatiles proved to be perceived by the antennae of Tegeticula cassandra (pollinating seed-eater of Yucca) and Prodoxus decipiens (herbivore on Yucca). The possible biosynthesis of the compounds is discussed.
Asunto(s)
Alcadienos/metabolismo , Alcanos/metabolismo , Alquenos/metabolismo , Flores/metabolismo , Yucca/metabolismo , Alcadienos/análisis , Alcanos/análisis , Alquenos/análisis , Flores/química , Yucca/químicaRESUMEN
A new generation of silver-based polymeric ionic liquid (PIL) sorbent coatings has been developed and applied in solid-phase microextraction (SPME). The new materials are based on ionic liquid monomers formed by cations containing the silver(I) ion coordinated with two 1-vinylimidazole ligands. Up to seven different silver-based PIL sorbent coatings were developed by polymerizing the silver-IL monomer in the presence of either silver bis[(trifluoromethyl)sulfonyl]imide, and/or a dicationic ionic liquid crosslinker. The obtained sorbent coatings were found to possess adequate thermal stability despite the presence of the silver(I) ions. Thermal desorption of the analytes at 175⯰C was effectively used without any significant decrease in extraction efficiency. The developed sorbent coatings were used in two different applications: the determination of alkenes/alkynes via headspace SPME and the determination of unsaturated fatty acids using direct-immersion SPME. In the former approach, the silver-based PILs were particularly selective for the determination of unsaturated compounds with terminal double bonds such as 1,5-hexadiene, 2-methyl-1,5-hexadiene, and 1,8-nonadiene. A study of the extraction mechanism of the analytes to the sorbent coating revealed a competitive partitioning of the analytes. In the second approach, the most selective silver-based PILs were applied for the determination of oleic acid, linoleic acid, and linolenic acid. After proper optimization of the method, the coatings were found to be more or as sensitive as the commercial polydimethylsiloxane fiber. Limits of detection between 2.6 and 8.2⯵gâ¯L-1 in ultrapure water and from 12 to 14⯵gâ¯L-1 in tap water were obtained for the best silver-based PIL, with relative standard deviations lower than 13% in all cases at a spiked level of 160⯵gâ¯L-1. Finally, the fiber was effectively applied for the analysis of rinse water from a dairy farm, with adequate detection of the analytes at concentrations between 52 and 179⯵gâ¯L-1.
Asunto(s)
Alcadienos/análisis , Ácidos Grasos Insaturados/análisis , Líquidos Iónicos/química , Polímeros/química , Plata/química , Microextracción en Fase Sólida/métodos , Calibración , Líquidos Iónicos/síntesis química , Límite de Detección , Polímeros/síntesis química , Microextracción en Fase Sólida/instrumentaciónRESUMEN
To protect themselves, insects cover their bodies with what is called cuticular lipid. The cuticular lipid of an American cockroach has a unique lipid content; the most abundant is a cis-alkadiene, cis, cis-6,9-heptacosadiene, amounting to about 70%, which is followed by a branched alkane 3-methylpentacosane. In order to clarify the structural features of the unique lipid composition below the critical temperature, the cuticular lipid was studied by Fourier transform infrared (FTIR) spectroscopy in combination with an attenuated total reflection (ATR) sampling technique. The infrared spectra measured on an extracted lipid sample at 20 °C suggested that the lipid keeps an appreciable level of conformational and lateral packing regularity, in spite of a high cis-unsaturated lipid content, and also a highly disordered condition around the methyl terminals and cis-olefin groups. The CH2 scissoring and the CH2 rocking regions showed the characteristics of the O⥠subcell. The same characteristics were observed also by in situ measurements on a forewing of the American cockroach. Combining the spectral features of these bands and the physicochemical properties of each component, it can be inferred that saturated lipids form highly ordered domains within the liquid containing the cis, cis-diene as the main component. For comparison, the cuticular lipid of a male cricket, which consisted of many different hydrocarbons, including 15% of unsaturated hydrocarbons, showed a lower regularity both in the conformation and in the lateral packing of hydrocarbon chains. These results imply that not only the degree of cis-unsaturation but also the chemical structure diversity of hydrocarbons are the important factors to determine the physicochemical properties of cuticular lipid.
Asunto(s)
Alcadienos/análisis , Exoesqueleto/química , Lípidos/análisis , Alas de Animales/química , Alcadienos/química , Animales , Gryllidae/química , Lípidos/química , Masculino , Periplaneta/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , EstereoisomerismoRESUMEN
Aronia melanocarpa has attracted scientific interest due to its dense contents of different polyphenols. We aimed to analyse effects of Aronia melanocarpa (AME) extract on blood pressure (BP), lipid peroxidation, cytokine level, total NOS activity in the left ventricle (LV), and aorta of L-NAME-induced hypertensive rats. 12-week-old male WKY rats were assigned to the control group and groups treated with AME extract (57.90 mg/kg/day), L-NAME (40 mg/kg/day), or combination of L-NAME (40 mg/kg/day) and AME (57.90 mg/kg/day) in tap water for 3 weeks. NOS activity, eNOS protein expression, and conjugated diene (CD) concentration were determined in the LV and aorta. After 3 weeks of L-NAME treatment, BP was increased by 28% and concomitant treatment with AME reduced it by 21%. NOS activity of the LV and aorta in the L-NAME group was decreased by about 40%, while AME increased it almost on the control level. AME-induced eNOS upregulation may contribute to increase NOS activity. Moreover, AME decreased CD concentration in the LV and aorta and TNF-α and IL-6 production in the plasma were increased by L-NAME treatment. In conclusion, our results showed that active substances of Aronia melanocarpa may have a positive effect on blood pressure, NOS activity, and proinflammatory processes in L-NAME-induced hypertension.
Asunto(s)
Aorta/efectos de los fármacos , Ventrículos Cardíacos/efectos de los fármacos , Photinia/química , Extractos Vegetales/farmacología , Regulación hacia Arriba/efectos de los fármacos , Alcadienos/análisis , Alcadienos/metabolismo , Animales , Aorta/química , Aorta/enzimología , Presión Sanguínea/efectos de los fármacos , Ventrículos Cardíacos/química , Ventrículos Cardíacos/enzimología , Hipertensión/etiología , Hipertensión/prevención & control , Hipertensión/veterinaria , Interleucina-6/sangre , Masculino , NG-Nitroarginina Metil Éster/toxicidad , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico Sintasa de Tipo III/genética , Óxido Nítrico Sintasa de Tipo III/metabolismo , Photinia/metabolismo , Extractos Vegetales/química , Extractos Vegetales/uso terapéutico , Polifenoles/química , Polifenoles/farmacología , Polifenoles/uso terapéutico , Ratas , Ratas Endogámicas WKY , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Chilecomadia valdiviana (Philippi) (Lepidoptera: Cossidae) is an insect native to Chile. The larval stages feed on the wood of economically important fruit tree species such as apple, pear, olive, cherry, and avocado, and also on eucalyptus. This causes weakening and, in case of severe infestation, death of the tree. We report identification of the sex pheromone produced by females of this species. Hexane extracts of the abdominal glands of virgin females were analyzed by gas chromatography (GC) with electroantennographic detection, GC coupled with mass spectrometry, and GC coupled to infrared spectroscopy. The major pheromone component was identified as (7Z,10Z)-7,10-hexadecadienal (Z7,Z10-16:Ald), and minor components present in the extracts were (Z)-7-hexadecenal and (Z)-9-hexadecenal, hexadecanal, and (9Z,12Z)-9,12-octadecadienal. Structural assignments were carried out by comparison of analytical data of the natural products and their dimethyl disulfide adducts with those of authentic reference samples. In field tests, traps baited with Z7,Z10-16:Ald captured significantly more males than control traps.
Asunto(s)
Mariposas Nocturnas/química , Atractivos Sexuales/análisis , Aldehídos/análisis , Aldehídos/metabolismo , Alcadienos/análisis , Alcadienos/metabolismo , Animales , Cromatografía de Gases , Femenino , Cromatografía de Gases y Espectrometría de Masas , Masculino , Mariposas Nocturnas/metabolismo , Atractivos Sexuales/metabolismo , Espectrofotometría Infrarroja , Árboles/parasitologíaRESUMEN
Recent work has suggested that hawk moths share pheromone components but are sexually separated by qualitative and quantitative differences in their pheromone blends. During field assays on the sex pheromones of other species, a diurnal hawk moth, Neogurelca himachala sangaica (Lepidoptera: Sphingidae), was frequently captured, but the composition of the sex pheromone of this species was not known. Analysis of hexane extracts of the pheromone glands of calling female by gas chromatography (GC) using an electroantennographic detector (EAD) revealed two components that elicited EAD responses from male moth antennae. These components were identified by their mass spectra and retention indices on two GC columns as (10E,12Z)-10,12-hexadecadienal (E10,Z12-16:Ald) and a trace of its (10E,12E)-isomer (E10,E12-16:Ald) in 98:2 ratio. In field experiments, E10,Z12-16:Ald alone attracted male moths, and addition of E10,E12-16:Ald significantly reduced the attractiveness, even at the naturally-occurring ratio. Analysis of the data using a generalized linear mixed model showed that E10,Z12-16:Ald positively contributed to attractiveness, whereas E10,E12-16:Ald did so negatively, and it was concluded that the sex pheromone of N. himachala sangaica consists solely of E10,Z12-16:Ald, bombykal. The negative effect of E10,E12-16:Ald on attractiveness could promote the species-specificity of this single-component pheromone system.
Asunto(s)
Alcadienos/análisis , Alcadienos/farmacología , Mariposas Nocturnas/efectos de los fármacos , Atractivos Sexuales/análisis , Atractivos Sexuales/farmacología , Animales , Bioensayo , Femenino , Masculino , Conducta Sexual Animal/efectos de los fármacosRESUMEN
Sex pheromones of nocturnal hawk moths have been identified previously, but not those of diurnal hawk moths. Here, we report laboratory analyses and field testing of the sex pheromone of the diurnal hawk moth, Hemaris affinis (Bremer 1861) (Lepidoptera: Sphingidae). Sex pheromone glands were removed and extracted in hexane during peak calling activity of virgin female moths. Analysis of gland extracts by gas chromatography (GC) with electroantennographic detection revealed three components that elicited responses from male moth antennae. These components were identified, based on their mass spectra and retention indices on two GC columns, as (Z)-11-hexadecenal and (10E, 12Z)- and (10E,12E)-10,12-hexadecadienals with a ratio of 45:20:35. In a field experiment, traps baited with the three-component synthetic blend, but none of the single- or two-component blends, caught male moths. All three pheromone components have been identified previously in pheromones of other Lepidoptera, including Sphingid moths, and thus the ternary blend is probably responsible for the species specificity of the pheromone of this moth.
Asunto(s)
Mariposas Nocturnas/química , Atractivos Sexuales/química , Atractivos Sexuales/farmacología , Aldehídos/análisis , Aldehídos/química , Alcadienos/análisis , Alcadienos/química , Animales , Cromatografía de Gases/métodos , Femenino , Cromatografía de Gases y Espectrometría de Masas , Masculino , Mariposas Nocturnas/fisiología , Atractivos Sexuales/análisisRESUMEN
While 11 species in the family Saturniidae are found in Japan, no sex pheromones of the native species had been investigated previously. We collected larvae of Rhodinia fugax in Nagano and Tottori Prefecture, and of Loepa sakaei in Okinawa Prefecture, and extracted sex pheromones of these two species from virgin female moths. In gas chromatography-electroantennogram detection (GC-EAD) analyses, male antennae of each species responded to one component in the respective pheromone extracts of conspecific females. Chemical analyses of the extracts by GC/mass spectrometry revealed that the EAD-active compounds of R. fugax and L. sakaei were a hexadecadienal and a tetradecadienyl acetate, respectively. The two species belong to the subfamily Saturniinae, and the mass spectra of both were similar to that of the 6,11-hexadecadienyl acetate identified from Antheraea polyphemus, classified in the same subfamily, suggesting the same 6,11-dienyl structure for the C16 aldehyde and a 4,9-dienyl structure for the C14 acetate. Based on this assumption, four geometrical isomers of each dienyl compound were stereoselectively synthesized via acetylene intermediates, compared to the natural products, and tested in the field. Male catches confirmed the pheromone structures of the two Japanese saturniid species as (6E,11Z)-6,11-hexadecadienal for R. fugax and (4E,9Z)-4,9-tetradecadienyl acetate for L. sakaei. The compounds have a characteristic 1,6-dienyl motif common to the pheromones of Saturniinae species.
Asunto(s)
Mariposas Nocturnas/química , Atractivos Sexuales/química , Atractivos Sexuales/farmacología , Acetatos/análisis , Acetatos/química , Alcadienos/análisis , Alcadienos/química , Animales , Femenino , Cromatografía de Gases y Espectrometría de Masas , Japón , Masculino , Estructura Molecular , Mariposas Nocturnas/efectos de los fármacos , Feromonas/análisis , Feromonas/química , Atractivos Sexuales/análisis , Atractivos Sexuales/síntesis químicaRESUMEN
Development of cell-based odorant sensor elements combined not only high degree of sensitivity and selectivity but also long-term stability is crucial for their practical applications. Here we report the development of a novel cell-based odorant sensor element that sensitively and selectively detects odorants and displays increased fluorescent intensities over a long period of time. Our odorant sensor elements, based on Sf21 cell lines expressing insect odorant receptors, are sensitive to the level of several tens of parts per billion in solution, can selectively distinguish between different types of odorants based on the odorant selectivity intrinsic to the expressed receptors, and have response times of approximately 13s. Specifically, with the use of Sf21 cells and insect odorant receptors, we demonstrated that the established cell lines stably expressing insect odorant receptors are able to detect odorants with consistent responsiveness for at least 2 months, thus exceeding the short life-span normally associated with cell-based sensors. We also demonstrated the development of a compact odorant sensor chip by integrating the established insect cell lines into a microfluidic chip. The methodology we established in this study, in conjunction with the large repertoire of insect odorant receptors, will aid in the development of practical cell-based odorant sensors for various applications, including food administration and health management.
Asunto(s)
Alcadienos/análisis , Técnicas Biosensibles/métodos , Alcoholes Grasos/análisis , Proteínas de Insectos/metabolismo , Insectos/citología , Odorantes/análisis , Receptores Odorantes/metabolismo , Animales , Técnicas Biosensibles/instrumentación , Calcio/análisis , Línea Celular , Diseño de Equipo , Expresión Génica , Humanos , Proteínas de Insectos/genética , Insectos/genética , Insectos/metabolismo , Dispositivos Laboratorio en un Chip , Receptores Odorantes/genéticaRESUMEN
As unsaturated lipids oxidize, they form hydroperoxides, which are susceptible to further oxidation or decomposition to secondary reaction products including aldehydes, ketones, acids, and alcohols. While oxidation reactions of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are responsible for fishy off-flavors in marine oils, gas chromatography-olfactometry (GC-O) and other types of analytical studies have failed to reveal which specific oxidation products are involved. Previous research (Marsili, R.T.; Laskonis, C. The importance of odourant synergy effects in understanding malodour problems in DHA and EPA products. Lipid Technol. 2014, 26 (2), 31-34) has indicated that fishy malodor may be caused by the presence of two lipid oxidation products, heptanal and (E,Z)-3,5-octadien-2-one. The aims of the present study are to provide experimental method details and offer further evidence that these two oxidation products are indeed the cause of fishy malodors. Initial GC-MS-O studies of marine oils with fishy malodors revealed numerous oxidation products, but none were characterized as fishy. However, when all sample volatiles were captured together and then desorbed simultaneously in GC-O experiments, the fishy malodor was evident, indicating odorant synergy effects were responsible. A simple, novel method was developed using an olfactometry detector as a fraction collector to trap various peaks in marine oil chromatograms. The nose cone of the olfactometry detector was replaced with a PDMS foam absorption tube at various times during GC analysis. Combinations of GC peaks were trapped on PDMS tubes, desorbed in a Gerstel thermal extractor (off-line), and sniffed. The combination of two analytes was found to cause fishy malodors: heptanal and (E,Z)-3,5-octadien-2-one. Purge-and-trap, solid phase microextraction (SPME), and headspace stir bar sorptive extraction (HSSE) sample preparation methods prior to GC-MS were investigated. All methods confirmed the combination of heptanal and (E,Z)-3,5-octadien-2-one as the cause of fishy odor.
Asunto(s)
Aldehídos/análisis , Alcadienos/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Microalgas/química , Odorantes/análisis , Aceites/análisis , Adulto , Organismos Acuáticos , Sinergismo Farmacológico , Diseño de Equipo , Femenino , Cromatografía de Gases y Espectrometría de Masas/instrumentación , Humanos , Masculino , Aceites/química , Olfatometría/instrumentación , Olfatometría/métodosRESUMEN
BACKGROUND: To increase rice production in Africa, considerable research has focused on creating interspecific hybrids between African (Oryza glaberrima Steud.) and Asian (O. sativa L.) rice in an attempt to obtain the positive attributes of each in new cultivars. Since flavor is a key criterion in consumer acceptance of rice, as an initial inquiry we characterized and compared the aroma chemistry of selected cultivars of African O. sativa ssp. japonica, O. sativa ssp. indica, O. glaberrima, and their interspecific hybrids grown in West Africa, using gas chromatography-mass spectrometry, gas chromatography-olfactometry and descriptive sensory analysis. RESULTS: Of 41 volatiles identified across seven representative rice cultivars grown in West Africa, 3,5,5-trimethyl-2-cyclopenten-1-one, styrene, eucalyptol, linalool, myrtenal and L-α-terpineol had not been previously reported in rice. Thirty-three odor-active compounds were characterized. 4-Ethylphenol and (E,E)-2,4-heptadienal were unique to O. glaberrima, and pyridine, eucalyptol and myrtenal were described only in an interspecific hybrid. Descriptive sensory analysis indicated 'cooked grain', 'barny' and 'earthy' attributes were statistically different among the cultivars. CONCLUSION: The aroma chemistry data suggest that it should be possible to separate African cultivars into distinct flavor types thereby facilitating selection of new cultivars with superior flavor in African rice breeding programs.
Asunto(s)
Productos Agrícolas/química , Cruzamientos Genéticos , Odorantes , Oryza/química , Poaceae/química , Semillas/química , Compuestos Orgánicos Volátiles/análisis , Aldehídos/análisis , Aldehídos/metabolismo , Alcadienos/análisis , Alcadienos/metabolismo , Monoterpenos Bicíclicos , Culinaria , Productos Agrícolas/genética , Productos Agrícolas/crecimiento & desarrollo , Productos Agrícolas/metabolismo , Ciclohexanoles/análisis , Ciclohexanoles/metabolismo , Eucaliptol , Preferencias Alimentarias/etnología , Gambia , Humanos , Monoterpenos/análisis , Monoterpenos/metabolismo , Oryza/genética , Oryza/crecimiento & desarrollo , Oryza/metabolismo , Fenoles/análisis , Fenoles/metabolismo , Pigmentos Biológicos/biosíntesis , Poaceae/genética , Poaceae/crecimiento & desarrollo , Poaceae/metabolismo , Análisis de Componente Principal , Piridinas/análisis , Piridinas/metabolismo , Semillas/genética , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Sensación , Sierra Leona , Terpenos/análisis , Terpenos/metabolismo , Compuestos Orgánicos Volátiles/metabolismoRESUMEN
The purpose of the present study is to investigate the production of trans-1,3-pentadiene in a sorbic acid-containing food which was the subject of a complaint that it was off-flavor. Penicillium sp. was isolated from the off-flavor food. The isolated Penicillium sp. was identified as Penicillium chrysogenum by DNA sequencing of the internal transcribed spacer region and the D1/D2 region of the 28S subunit. When P. chrysogenum was cultured in the presence of potassium sorbate, trans-1,3-pentadiene was produced and detected by GC-MS after solid-phase micro extraction. The production of trans-1,3-pentadiene by P. chrysogenum in the culture solution was pH-dependent. These results suggest that the production of trans-1,3-pentadiene in the off-flavor food was mainly due to the decomposition of sorbic acid by P. chrysogenum.
Asunto(s)
Alcadienos/análisis , Alcadienos/metabolismo , Análisis de los Alimentos/métodos , Contaminación de Alimentos/análisis , Microbiología de Alimentos/métodos , Penicillium chrysogenum/aislamiento & purificación , Penicillium chrysogenum/metabolismo , Pentanos/análisis , Pentanos/metabolismo , ADN de Hongos/genética , Aditivos Alimentarios/metabolismo , Cromatografía de Gases y Espectrometría de Masas/métodos , Concentración de Iones de Hidrógeno , Penicillium chrysogenum/genética , Análisis de Secuencia de ADN , Microextracción en Fase Sólida , Ácido Sórbico/metabolismoRESUMEN
Homologs of bombykal, (10E,12Z)-10,12-hexadecadienal, have been reported to be sex pheromones or sexual attractants of several species of sphingid moths. In this study, we identified novel bombykal analogs as sex pheromone components from a Japanese sphingid moth, Dolbina tancrei. Staudinger (Sphingidae: Lepidoptera). Sex pheromone gland extracts from calling female moths were subjected to gas chromatography/electroantennograhic detection (GC/EAD), gas chromatography/mass spectrometry (GC/MS), and gas chromatography (GC) analyses. GC/EAD analyses showed two active components in the crude pheromone extracts. GC/MS analysis determined these two components to be pentadecadienals. GC/MS of their MTAD derivatives showed conjugated double bonds at the 9- and 11-positions, indicating 9,11-pentadecadienals. The isomeric configurations of these candidates were determined by comparison of their Kováts retention indices with those of synthetic compounds. Field bioassays with the four isomers of 9,11-pentadecadienal and their mixtures confirmed that the two sex pheromone components of D. tancrei are (9E,11Z)-9,11-pentadecadienal and (9Z,11Z)-9,11-pentadecadienal, with the highest male catches observed for a 90:10 blend. This is the first report of 9,11-pentadecadienals as sex pheromone components in lepidopteran species.
Asunto(s)
Alcadienos/análisis , Mariposas Nocturnas/fisiología , Atractivos Sexuales/química , Animales , Femenino , Masculino , Atractivos Sexuales/fisiología , Conducta Sexual AnimalRESUMEN
UNLABELLED: In this study, the important odor impact volatiles generated in the meat of grilled beef loin muscle were characterized. Animals were finished in 4 different diet systems: T1, pasture (a mixture of Medicago sativa, Trifolium repens, and Festuca arundinacea); T2, pasture supplemented with cracked corn grain (offered at 0.6% live weight, LW); T3, pasture supplemented with cracked corn grain (offered at 1.2% LW); and T4, concentrate (pellets with 85% corn and 12.8% sunflower, on a dry-matter basis) plus alfalfa hay (both ad libitum). Aroma compounds were assessed by dynamic headspace-solid phase extraction (DHS-SPE) and gas chromatographic-olfactometric (GC-O) analysis. Most odorants were carbonyl compounds, some of them reaching high GC-O scores, especially 1-octen-3-one, (E)-2-octenal, methional, and hexanal. A specific quantitative analysis of ketones and aldehydes was conducted through their derivatization with o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride directly on the headspace trap and analyzed by GC-MS, with the purpose of studying the effect of finishing diet systems. From the 23 carbonyl compounds quantified, 2 were especially affected by the diet system; methional was higher in the treatment based on concentrates, whereas (E,E)-2,4-heptadienal was higher in the treatment based only in pastures. The results are discussed considering previous published productive and quality traits. PRACTICAL APPLICATION: The knowledge of how production factors, such as animal feeding, can affect the flavor of meat is of significant interest toward in achieving a high-quality and differentiated product. The development of more specific and efficient methodologies is necessary to analyze meat aroma compounds, which would be used as routine analysis, that is for product authentication. In the future, the use of this analysis would allow producing and designing specific foods according to different markets.
Asunto(s)
Aldehídos/análisis , Crianza de Animales Domésticos/métodos , Bovinos/crecimiento & desarrollo , Culinaria , Cetonas/análisis , Carne/análisis , Compuestos Orgánicos Volátiles/análisis , Aldehídos/química , Aldehídos/metabolismo , Alcadienos/análisis , Alcadienos/química , Alcadienos/metabolismo , Métodos Analíticos de la Preparación de la Muestra , Alimentación Animal/análisis , Animales , Cromatografía de Gases , Productos Agrícolas/química , Cromatografía de Gases y Espectrometría de Masas , Humanos , Cetonas/química , Cetonas/metabolismo , Masculino , Odorantes , Extracción en Fase Sólida , Uruguay , Compuestos Orgánicos Volátiles/química , Compuestos Orgánicos Volátiles/metabolismoRESUMEN
This study was designed to assess whether different grazing managements affect the appearance of organic volatile compounds (VOC) in lamb fat. Forty-two lambs were divided into four groups: 9 lambs were restricted in stall and fed concentrate (S group); 12 lambs grazed from 9 am to 5 pm (8h group); 10 lambs grazed from 9 am to 1 pm (4 hAM group) and 11 lambs grazed from 1 pm to 5 pm (4 hPM group). After 72 days on feed the animals were slaughtered and the perirenal fat subjected to SPME-GC/MS analysis of VOC; the data were analyzed by stepwise discriminant analysis. The 6-methyl-2-heptanone and furanone, 2,5-dimethyl, 4-hydroxy-3(2H) allowed discrimination between the 4 hAM and the 4 hPM animals. These are the first results indicating that the time of the day in which the animals are allowed to graze affects the appearance of VOC in lamb fat.
Asunto(s)
Dieta/veterinaria , Grasas/análisis , Carne/análisis , Compuestos Orgánicos Volátiles/análisis , Mataderos , Aldehídos/análisis , Alcadienos/análisis , Alimentación Animal , Animales , Composición Corporal , Análisis Multivariante , OvinosRESUMEN
A simple and practical procedure for the synthesis of aza- and oxacycles, which possess an array of stereogenic functionalities, is described. This protocol relies on tandem Cu-catalyzed coupling of suitably functionalized terminal alkyne with diazoester followed by isomerization and subsequent aza or oxa-Michael reaction, thus generating the required scaffold with high diastereoselectivity.
Asunto(s)
Alcadienos/síntesis química , Alquinos/síntesis química , Compuestos Aza/síntesis química , Química Farmacéutica/métodos , Alcadienos/análisis , Alquinos/análisis , Compuestos Aza/análisis , Catálisis , Cobre/química , Ciclización , Ésteres/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , EstereoisomerismoRESUMEN
Insect cuticular hydrocarbons (CHCs) are not only essential for desiccation resistance, they also play an important role as chemical signals and cues in social as well as solitary insects. The identification of CHCs is, therefore, crucial to an understanding of the chemical communication within and between insect species. We describe a method for rapid, simple, and unambiguous identification of CHCs using gas chromatography-ion-trap mass spectrometry. External ionization configuration in combination with a low ion-trap temperature resulted in dramatically increased intensities of molecular ions for alkanes, alkenes and alkadienes, and in high-mass fragmentation patterns with intense ions characteristic for methyl-branched hydrocarbons comparable to those obtained with quadrupole instruments. Additionally, we present an external chemical ionization-tandem mass-spectrometric method that allows for the determination of double-bond positions in alkenes and alkadienes without the need for derivatization prior to analysis.
Asunto(s)
Drosophila melanogaster/química , Cromatografía de Gases y Espectrometría de Masas/métodos , Hidrocarburos , Avispas/química , Alcadienos/análisis , Alcanos/análisis , Alquenos/análisis , Animales , Drosophila melanogaster/anatomía & histología , Femenino , Hidrocarburos/análisis , Hidrocarburos/química , Avispas/anatomía & histologíaRESUMEN
BACKGROUND: The volatile composition of alcaparras stoned table olives produced from five of the most representative olive cultivars (cv. Cobrançosa, Madural, Negrinha de Freixo, Santulhana and Verdeal Transmontana) from the Trás-os-Montes region (north-east of Portugal) was analytically characterised using headspace-solid phase microextraction/gas chromatography-ion trap-mass spectrometry. RESULTS: Overall, 42 volatile compounds were identified, belonging to distinct chemical classes: 15 aldehydes, seven esters, five alcohols, five sesquiterpenes, four norisoprenoids derivates, three monoterpenes, o ne ketone and two alkenes. Aldehydes were the major chemical class identified in all olive cultivars studied (more than 74% of all the volatile compounds identified). Hexanal, phenylacetaldehyde and (E,E)-2,4-heptadienal were the major volatile compounds identified. CONCLUSIONS: It was possible to discriminate the results obtained from the volatile profile of the five olive cultivars by using principal component analysis. Both qualitative and quantitative fractions of alcaparras table olives were influenced by olive cultivar, which confers a single aroma. This fact certainly influences consumer preference and acceptability towards a specific olive cultivar.