Application of high-temperature gas chromatography-mass spectrometry to the investigation of glycosidically bound components related to cashew apple (Anacardium occidentale L. Var. Nanum) volatiles

Microbial Production of Value-added Products from Cashew Apples- an Economical Boost to Cashew Farmers

Cashew farming-considered as one of the major profit-making agricultural businesses-requires renewed practices in processing its products and by-products for sustained growth. The current review highlights the commercial potential of cashew apples by proposing value-addition strategies through microbial fermentation routes that can help garnering additional profit to the growers. The immense potential of cashew apples and pulp wastes generated after juice-extraction in producing a range of products through the fermentation process such as bioethanol, hydrolytic enzymes, lactic acid, biosurfactants, wine and Feni (an alcoholic beverage) is discussed. Furthermore, a case on the existing Feni-making practices in Goa, India is reviewed, and the need for upgrades in the processing methods for waste mitigation is emphasized. Based on the literature survey and from the gathered knowledge on cashew industries through visits to various cashew farming sites, it is strongly emphasized that a radical improvement in cashew farming is possible only through the adoption of holistic approaches in the cultivation and proper utilization of wastes and its management of cashew apples. Also, Feni production, which is the mainstay of India’s current cashew processing industry, requires major up-gradation in processing methods to improve its quality, marketability, and export potential.

Chemometric analysis of the volatile profile in peduncles of cashew clones and its correlation with sensory attributes

Cashew apple, the hypertrophied peduncle of cashew nut, is a functional food with a high antioxidant activity and with good characteristics for juice industrialization and fresh consumption such as fleshy pulp, soft peel, without seeds, and exotic flavor. However, it is still poorly used or totally wasted. For this reason, the quality of cashew apples has received more attention from the Brazilian breeding program to maximize their uses. In this study, the volatile compound profiles of peduncles of seven cashew clones and their relation to the aroma and flavor differences were investigated. Nine trained panelists evaluated the cashew apples by descriptive analysis. After the standardization of headspace solid-phase microextraction (HS-SPME) extraction and chromatographic conditions, the volatile organic compounds were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 48 compounds were identified with esters being the major chemical class, both in number of compounds and chromatographic peak area. The targeted and untargeted principal component analysis (PCA) analyses showed complementary and corroborative results from the cashew apple volatile composition based on genotype. The partial least squares (PLS) modeling revealed the high correlation of the unpleasant sensory attributes with the PRO805 and CAPI17 clones; sweet taste and sweet odor with the CCP76 clone; and cashew aroma/cashew flavor with the EMBRAPA51, HAC276, PRO555, and SLC12.20 clones. The correlation between the most relevant volatile organic compounds (VOC) for cashew apples and the sensory descriptors showed that the compounds methyl butanoate, methyl 3-methylbutanoate, ethyl 2-methylbutanoate, methyl 2-butenoate, methyl 3-methylpentanoate, 3-carene, methyl (E)-2-methyl-2-butenoate, ethyl 4-methylpentanoate, 2-hexenal, butyl 3-methylbutanoate, butyl pentanoate, and 3-methyl butanoic acid were important to explain differences in the characteristic fruit aroma and flavor of cashew apples among the studied clones. PRACTICAL APPLICATION: Cashew crops have been developed by using improved clones with increased nut productivity and resistance to diseases. The Brazilian genetic improvement program is also seeking to improve the quality of peduncles to maximize their use and prevent their destination as agricultural waste. In this study, the volatile profile of peduncles of seven cashew clones was determined and its correlation with the differences in their aroma and flavor attributes established. The results will provide important information about the potential of the new materials for fresh consumption and for the manufacturing of cashew juices, in addition to be used by breeders interested in improving the aroma of the fruit.

Candida Species (Volatile) Metabotyping through Advanced Comprehensive Two-Dimensional Gas Chromatography

Microbial metabolomics is a challenge strategy that allows a comprehensive analysis of metabolites within a microorganism and may support a new approach in microbial research, including the microbial diagnosis. Thus, the aim of this research was to in-depth explore a metabolomics strategy based on the use of an advanced multidimensional gas chromatography for the comprehensive mapping of cellular metabolites of C. albicans and non-C. albicans (C. glabrata and C. tropicalis) and therefore contributing for the development of a comprehensive platform for fungal detection management and for species distinction in early growth times (6 h). The volatile fraction comprises 126 putatively identified metabolites distributed over several chemical families: acids, alcohols, aldehydes, hydrocarbons, esters, ketones, monoterpenic and sesquiterpenic compounds, norisoprenoids, phenols and sulphur compounds. These metabolites may be related with different metabolic pathways, such as amino acid metabolism and biosynthesis, fatty acids metabolism, aromatic compounds degradation, mono and sesquiterpenoid synthesis and carotenoid cleavage. These results represent an enlargement of ca. 70% of metabolites not previously reported for C. albicans, 91% for C. glabrata and 90% for C. tropicalis. This study represents the most detailed study about Candida species exometabolome, allowing a metabolomic signature of each species, which signifies an improvement towards the construction of a Candida metabolomics platform whose application in clinical diagnostics can be crucial to guide therapeutic interventions.

Glycosidically bound aroma precursors in fruits: A comprehensive review

Fruit aroma is mainly contributed by free and glycosidically bound aroma compounds, in which glycosidically bound form can be converted into free form during storage and processing, thereby enhancing the overall aroma property. In recent years, the bound aroma precursors have been widely used as flavor additives in the food industry to enhance, balance and recover the flavor of products. This review summarizes the fruit-derived aroma glycosides in different aspects including chemical structures, enzymatic hydrolysis, biosynthesis and occurrence. Aroma glycosides structurally involve an aroma compound (aglycone) and a sugar moiety (glycone). They can be hydrolyzed to release free volatiles by endo- and/or exo-glucosidase, while their biosynthesis refers to glycosylation process using glycosyltransferases (GTs). So far, aroma glycosides have been found and studied in multiple fruits such as grapes, mangoes, lychees and so on. Additionally, their importance in flavor perception, their utilization in food flavor enhancement and other industrial applications are also discussed. Aroma glycosides can enhance flavor perception via hydrolyzation by β-glucosidase in human saliva. Moreover, they are able to impart product flavor by controlling the liberation of active volatiles in industrial applications. This review provides fundamental information for the future investigation on the fruit-derived aroma glycosides.

Comparison of techniques for the isolation of volatiles from cashew apple juice

BACKGROUND

The aim of this study was to compare the performance of the following techniques on the isolation of volatiles of importance for the aroma/flavor of fresh cashew apple juice: dynamic headspace analysis using PorapakQ(®) as trap, solvent extraction with and without further concentration of the isolate, and solid-phase microextraction (fiber DVB/CAR/PDMS).

RESULTS

A total of 181 compounds were identified, from which 44 were esters, 20 terpenes, 19 alcohols, 17 hydrocarbons, 15 ketones, 14 aldehydes, among others. Sensory evaluation of the gas chromatography effluents revealed esters (n = 24) and terpenes (n = 10) as the most important aroma compounds.

CONCLUSION

The four techniques were efficient in isolating esters, a chemical class of high impact in the cashew aroma/flavor. However, the dynamic headspace methodology produced an isolate in which the analytes were in greater concentration, which facilitates their identification (gas chromatography-mass spectrometry) and sensory evaluation in the chromatographic effluents. Solvent extraction (dichloromethane) without further concentration of the isolate was the most efficient methodology for the isolation of terpenes. Because these two techniques also isolated in greater concentration the volatiles from other chemical classes important to the cashew aroma, such as aldehydes and alcohols, they were considered the most advantageous for the study of cashew aroma/flavor.

Identification and quantitation of glycosidically bound aroma compounds in three tobacco types by gas chromatography-mass spectrometry

Glycosidically bound aroma compounds in three different types of tobacco were investigated. After isolation of extracts obtained by Amberlite XAD-2 adsorption and ethyl acetate elution, glycosides were analyzed after enzymatic hydrolysis by gas chromatography-mass spectrometry (GC-MS) or directly after trifluoroacetylated (TFA) derivatization by GC-MS in electron ionization (EI) and negative chemical ionization (NCI) mode. In total 21 bound aglycones were identified by β-glucosidase hydrolysis. These aglycones mainly consisted of C13-norisoprenoids, aromatic components and sesquiterpenoids. Additionally, with the aid of enzymatic hydrolysis, 15 β-d-glucopyranosides and 1 β-d-rutinoside were tentatively identified by TFA derivatization. TFA method was validated by repeatability and successfully employed to analyze different types of tobacco. Principal component analysis (PCA) was carried out on identified glycoside variables to visualize the difference between the tobacco types and the relationship between the glycoside variables and the tobacco types was established.

Chemical composition and antibacterial and cytotoxic activities of Allium hirtifolium Boiss

Allium hirtifolium Boiss. known as Persian shallot, is a spice used as a traditional medicine in Iran and, Mediterranean region. In this study, the chemical composition of the hydromethanolic extract of this plant was analyzed using GC/MS. The result showed that 9-hexadecenoic acid, 11,14-eicosadienoic acid, and n-hexadecanoic acid are the main constituents. The antibacterial activity of the shallot extract was also examined by disk diffusion and microdilution broth assays. It was demonstrated that Persian shallot hydromethanolic extract was effective against 10 different species of pathogenic bacteria including methicillin resistant Staphylococcus aureus (MRSA), methicillin sensitive Staphylococcus aureus (MSSA), Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Escherichia coli, Escherichia coli O157:H7, Salmonella typhimurium, Proteus mirabilis, and Klebsiella pneumoniae. Specifically, the minimum concentration of the extract which inhibited bacterial growth (MIC values) was 1.88 mg/mL for most of the gram-positive bacteria. This concentration was not much different from the concentration that was safe for mammalian cells (1.50 mg/mL) suggesting that the hydromethanolic extract of Persian shallot may be a safe and strong antibacterial agent.

Distribution and organoleptic impact of ethyl 2-hydroxy-4-methylpentanoate enantiomers in wine

The enantiomers of ethyl 2-hydroxy-4-methylpentanoate (ethyl dl-leucate) were assayed in several wines using chiral gas chromatography (γ-cyclodextrin). Analyses of 55 commercial wines from various vintages and origins revealed different distributions. Generally, white wines presented only the R form, whereas red wines contained both enantiomers, in various ratios according to aging. The highest levels of the S form were found in the oldest samples. The R/S average enantiomeric ratio of this compound in red wine was approximately 95:5 with an average total concentration of ∼400 μg/L. The olfactory threshold of R-ethyl 2-hydroxy-4-methylpentanoate (126 μg/L) in hydroalcoholic solution was almost twice that of the S form (55 μg/L). The olfactory threshold of a mixture of R- and S-ethyl 2-hydroxy-4-ethylpentanoate (95:5, m/m) in hydroalcoholic solution was 51 μg/L, suggesting that both enantiomeric forms contribute to perception of this compound in wine, resulting in a synergistic effect. Both enantiomers have quite similar aromatic nuances. Sensory analysis was employed to demonstrate a synergistic effect of this ethyl ester on the perception of fruity aromas in wine: in hydroalcoholic solution supplemented with R- or S-ethyl 2-hydroxy-4-methylpentanoate or a mixture of the R and S forms (95:5, m/m) at their average concentrations in red wines, fruity character was perceived at concentrations 2.2, 4.5, and 2.5 times lower, respectively, than in hydroalcoholic solution alone. Sensory profiles of aromatic reconstitutions, using HPLC fruity fractions, highlighted the contribution of this compound to blackberry fruit and fresh fruit descriptors.

Aroma volatiles recovered in the water phase of cashew apple (Anacardium occidentale L.) juice during concentration

BACKGROUND

There is a considerable loss of volatile compounds during the thermal concentration of cashew apple juice, damaging product quality, and as yet there is little research on the subject. Thus the purpose of this research was to identify the aroma volatiles evaporated off from cashew apple juice and recovered in the water phase during concentration of this beverage in an industrial plant. Water phase volatiles were extracted using dichloromethane, concentrated under a nitrogen flow, separated by gas chromatography (GC) and identified by GC-mass spectrometry. In order to determine the contribution of each volatile to the cashew aroma, five trained judges evaluated the GC effluents using the Osme GC-olfactometry technique.

RESULTS

71 volatiles were identified; of these, 47 were odour active. Alcohols were preferentially recovered in the cashew water phase, notably heptanol, trans-3-hexen-1-ol and 3-methyl-1-butanol, representing 42% of the total chromatogram area and imparting green grass and fruity aroma notes to the water phase. Esters represented 21% of the total chromatogram area, especially ethyl 2-hydroxyhexanoate, ethyl trans-2-butenoate and ethyl 2-methylbutanoate, and were responsible for the fruity/cashew-like aroma of the water phase. On the other hand, 3-methylbutanoic and 2-methylbutanoic acids were the volatiles that presented the greatest odour impact in the GC effluents of the water phase.

CONCLUSION

Overall, the results of the present study strongly indicated that further concentration of the esters recovered in the water phase, either by partial distillation or by alternative technologies such as pervaporation, could generate a higher-quality natural cashew apple essence.

Characterization of aroma compounds in Chinese rice wine Qu by solvent-assisted flavor evaporation and headspace solid-phase microextraction

The aroma of Chinese rice wine Qu is one of the most important factors that influences the flavor of Chinese rice wine. To better understand the aroma of Qu, aroma compounds in four wheat Qus and two xiao Qus were identified by chromatography-olfactometry (GC-O) after solvent extraction followed by solvent-assisted flavor evaporation (SAFE). A total of 39 aroma compounds were characterized by GC-O. On the basis of aroma intensity, 1-hexanal, ethyl hexanoate, 1-octen-3-ol, and phenylacetaldehyde were found to be the most important aroma compounds in all six Qus. In addition, 3-methylbutanol and 2-phenylethanol also played an important role in the aroma of two xiao Qus. Headspace solid-phase microextraction (HS-SPME) was used for quantifying aroma compounds identified in the Qus. The method enabled limits of detection and quantification of <40.8 and <136.0 microg/L, respectively. Linearity and recovery were satisfied in all cases. Quantitative analysis revealed that volatiles of six Qus had a wide range of concentration. Principal component analysis applied to the data differentiated the six Qus well.

Brazilian plants with possible action on the central nervous system: a study of historical sources from the 16th to 19th century

Brazil is a country rich in biodiversity, endemism, and cultural diversity, inhabited by different types of population. European expeditions and the migratory processes that began in the 16th century greatly contributed both to cultural diversity and to Brazilian popular therapeutics, and produced the first records on medicinal plants in Brazil. This study comprises a bibliographical survey of historic books found in Sao Paulo libraries (16th through 19th centuries) on medicinal plants exerting effects on the central nervous system (CNS). Thirty-four plants native to Brazil were selected from the reading of the books. Of these 34 plants, 13 were also recorded in ethnopharmacological studies among modern Brazilian communities and 16 have been studied phytochemically. Only eight have been the object of pharmacological studies, six of these, recently, with a request for a patent. Results showed that most of the species recorded in this study have been reported as medicinal for centuries, but have never been the object of pharmacological investigation down to the present time. Such results provide ideas for a selection of these species as potentially bioactive to be included in future pharmacological studies.

Determination of the flavonoid components of cashew apple (Anacardium occidentale) by LC-DAD-ESI/MS

Liquid chromatography, with diode array detection and electrospray ionization mass spectrometry (LC-DAD-ESI/MS), was used to identify and quantify flavonoids in cashew apple. One anthocyanin and thirteen glycosylated flavonols were detected in a methanol-water extract. Among them, the 3-O-galactoside, 3-O-glucoside, 3-O-rhamnoside, 3-O-xylopyranoside, 3-O-arabinopyranoside and 3-O-arabinofuranoside of quercetin and myricetin, as well as kaempferol 3-O-glucoside were identified by direct comparison with standards or positively identified flavonoids in cranberry. The anthocyanin was the 3-O-hexoside of methyl-cyanidin. Trace amounts of delphinidin and rhamnetin were detected in the hydrolyzed extract, suggesting their glycosides were present, but undetectable, in the original extract. The concentrations of the 14 flavonoids in the tested sample were determined. This is the first report of these flavonoids in cashew apple.

Gas chromatographic-olfactometric characterization of aroma compounds in two types of cashew apple nectar

Cashew apple nectar is a secondary product from the production of cashew nuts and possesses an exotic tropical aroma. Aroma volatiles in pasteurized and reconstituted (from concentrate) Brazilian cashew apple nectars were determined using GC-MS and split, time-intensity GC-olfactometry (GC-O)/GC-FID. Methional, (Z)-1,5-octadien-3-one, (Z)-2-nonenal, (E,Z)-2,4-decadienal, (E,E)-2,4-decadienal, beta-damascenone, and delta-decalactone were identified for the first time in cashew apple products. These compounds plus butyric acid, ethyl 3-methylbutyrate, 2-methylbutyric acid, acetic acid, benzaldehyde, homofuraneol, (E)-2-nonenal, gamma-dodecalactone, and an unknown were the most intense aroma volatiles. Thirty-six aroma volatiles were detected in the reconstituted sample and 41 in the pasteurized sample. Thirty-four aroma active components were common to both samples. Ethyl 3-methylbutyrate and 2-methylbutyric acid were character impact compounds of cashew apple (warm, fruity, tropical, sweaty). Using GC-pFPD, 2-methyl-3-furanthiol and bis(2-methyl-3-furyl) disulfide were identified for the first time in cashew apple. Both were aroma active (meaty).

Analysis of free and bound volatiles by gas chromatography and gas chromatography-mass spectrometry in uncased and cased tobaccos

The free and bound volatiles of tobaccos were analyzed by capillary GC and GC-MS. Bound volatiles were isolated by dichloromethane extraction followed by stream distillation continuous extraction (SDE) at pH 2.5 acid hydrolysis. The bound aromatic compounds were hydrolyzed by acid at pH 2.5, and the bound volatiles were liberated and extracted into dichloromethane by SDE simultaneously. In total, 23 volatiles were identified, with neophytadiene, 2-ethyl hexanol, damascenone, benzene ethanol, palmitic acid, stearic acid, linoleic acid, farnesyl acetone, 3-oxo-ionol, and megastigmatrienone being the major components. They consisted mainly of compounds exhibiting aromatic characteristics. The quality and quantity of free and bound volatiles exhibited different distributions in uncased or cased tobaccos. The volatiles existed in higher amounts in bound form than in free form. Compared with uncased tobaccos, free form volatiles showed a decrease after the casing process, while bound volatiles showed an increase.

Rapid screening of polar compounds in Brazilian propolis by high-temperature high-resolution gas chromatography-mass spectrometry

Methanol extracts of propolis from six different places, five in Rio de Janeiro state and one in São Paulo state, both in the Southeast of Brazil, were investigated using high-temperature high-resolution gas chromatography (HT-HRGC) and HT-HRGC-mass spectometry. The main purpose of the study was to establish the applicability of HT-HRGC as an analytical method for systematic studies of polar propolis fractions. Several compounds, including carbohydrates, phenolic acid derivatives, and high molecular weight compounds (e.g., wax esters of long chain fatty alcohols) could be readily characterized in the crude extracts by HT-HRGC-MS. HT-HRGC and HT-HRGC-MS were shown to be quick and informative tools for rapid analysis of crude polar extracts without cleanup.

Current awareness

In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (6 Weeks journals - Search completed at 7th. June 2000)