Efficient Capture of Cannabis Terpenes in Olive Oil during Microwave-Assisted Cannabinoid Decarboxylation.

The development of selective extraction protocols for Cannabis-inflorescence constituents is still a significant challenge. The characteristic Cannabis fragrance can be mainly ascribed to monoterpenes, sesquiterpenes and oxygenated terpenoids. This work investigates the entrapment of Cannabis terpenes in olive oil from inflorescences via stripping under mild vacuum during the rapid microwave-assisted decarboxylation of cannabinoids (MW, 120 °C, 30 min) and after subsequent extraction of cannabinoids (60 and 100 °C). The profiles of the volatiles collected in the oil samples before and after the extraction step were evaluated using static headspace solid-phase microextraction (HS-SPME), followed by gas chromatography coupled to mass spectrometry (GC-MS). Between the three fractions obtained, the first shows the highest volatile content (~37,400 mg/kg oil), with α-pinene, ß-pinene, ß-myrcene, limonene and trans-ß-caryophyllene as the main components. The MW-assisted extraction at 60 and 100 °C of inflorescences using the collected oil fractions allowed an increase of 70% and 86% of total terpene content, respectively. Considering the initial terpene amount of 91,324.7 ± 2774.4 mg/kg dry inflorescences, the percentage of recovery after decarboxylation was close to 58% (mainly monoterpenes), while it reached nearly 100% (including sesquiterpenes) after extraction. The selective and efficient extraction of volatile compounds, while avoiding direct contact between the matrix and extraction solvents, paves the way for specific applications in various aromatic plants. In this context, aromatized extracts can be employed to create innovative Cannabis-based products within the hemp processing industry, as well as in perfumery, cosmetics, dietary supplements, food, and the pharmaceutical industry.

Volatile-Based Diagnosis for Pathogenic Wood-Rot Fungus Fulvifomes siamensis by Electronic Nose (E-Nose) and Solid-Phase Microextraction/Gas Chromatography/Mass Spectrometry.

Wood rot fungus Fulvifomes siamensis infects multiple urban tree species commonly planted in Singapore. A commercial e-nose (Cyranose 320) was used to differentiate some plant and fungi volatiles. The e-nose distinctly clustered the volatiles at 0.25 ppm, and this sensitivity was further increased to 0.05 ppm with the use of nitrogen gas to purge the system and set up the baseline. Nitrogen gas baseline resulted in a higher magnitude of sensor responses and a higher number of responsive sensors. The specificity of the e-nose for F. siamensis was demonstrated by distinctive clustering of its pure culture, fruiting bodies collected from different tree species, and in diseased tissues infected by F. siamensis with a 15-min incubation time. This good specificity was supported by the unique volatile profiles revealed by SPME GC-MS analysis, which also identified the signature volatile for F. siamensis-1,2,4,5-tetrachloro-3,6-dimethoxybenzene. In field conditions, the e-nose successfully identified F. siamensis fruiting bodies on different tree species. The findings of concentration-based clustering and host-tree-specific volatile profiles for fruiting bodies provide further insights into the complexity of volatile-based diagnosis that should be taken into consideration for future studies.

Deeper Insight into the Volatile Profile of Rosa willmottiae with Headspace Solid-Phase Microextraction and GC-MS Analysis.

As the distribution center of Rosa in the world, China has abundant wild germplasm resources, which can contribute to the breeding of modern roses. To explore the potential value of wild roses distributed in the Sichuan-Tibet region, solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used to determine the volatile organic compounds (VOCs) in Rosa willmottiae flowers at three flowering stages (bud stage, initial flowering stage, full flowering stage). Meanwhile, we compared the VOCs of R. willmottiae with different phenotypes (double flowers and single flowers). A total of 74 volatile compounds were identified. The results show that the essential substances belong to alcohols and terpenoids. The main volatile organic compounds are 2-phenyl ethanol (20.49%), benzyl alcohol (10.69%), ß-maaliene (8.66%), geranyl acetate (8.47%), and (+)-α-long pinene (6.127%). Different flowering stages had great influence on the volatile profile, from the bud stage to full flowering stage; the content of terpenoids released decreased by 6.17%, whereas alcohols and esters increased by 8.58% and 11.56%, respectively. The chemical diversity and the content of the main components with a different phenotype were not significantly different. Our result will provide a theoretical basis for the development and utilization of Rosa willmottiae in Sichuan and Tibet.

Unveiling Antimicrobial and Antioxidant Compositional Differences between Dukkah and Za'atar via SPME-GCMS and HPLC-DAD.

Interest in plant-based diets has been on the rise in recent years owing to the potential health benefits of their individual components and the notion that plant-based diets might reduce the incidence of several diseases. Egyptian dukkah and Syrian za'atar are two of the most historic and famous Middle Eastern herbal blends used for their anti-inflammatory, hypolipidemic, and antidiabetic effects. Headspace SPME-GCMS and HPLC-DAD were adopted for characterizing the aroma profile and phenolic compounds of both herbal blends, respectively. Further, vapor-phase minimum inhibitory concentration was employed for assessing each blend's antibacterial potential, while their antioxidant potential was estimated via in vitro antioxidant assays. SPME headspace analysis indicated the abundance of ethers and monoterpene hydrocarbons, while HPLC revealed the presence of several phenolics including rosmarinic acid, ferulic acid, and rutin. Biological investigations affirmed that vapor-phase of the tested blends exhibited antibacterial activities against Gram-positive and Gram-negative pathogens, while the antioxidant potential of the blends was investigated and expressed as Trolox (125.15 ± 5.92 to 337.26 ± 13.84 µM T eq/mg) and EDTA (18.08 ± 1.62 to 51.69 41 ± 5.33 µM EDTA eq/mg) equivalent. The presented study offers the first insight into the chemical profile and biological activities of both dukkah and za'atar.

Evaluation of Vetiver Volatile Compound Production under Aeroponic-Grown Conditions for the Perfume Industry.

Vetiver (Chrysopogon zizanioides (L.) Roberty) is a major tropical perfume crop. Access to its essential oil (EO)-filled roots is nevertheless cumbersome and land-damaging. This study, therefore, evaluated the potential of vetiver cultivation under soilless high-pressure aeroponics (HPA) for volatile organic compound (VOC) production. The VOC accumulation in the roots was investigated by transmission electron microscopy, and the composition of these VOCs was analyzed by gas chromatography coupled with mass spectrometry (GC/MS) after sampling by headspace solid-phase microextraction (HS-SPME). The HPA-grown plants were compared to plants that had been grown in potting soil and under axenic conditions. The HPA-grown plants were stunted, demonstrating less root biomass than the plants that had been grown in potting soil. The roots were slender, thinner, more tapered, and lacked the typical vetiver fragrance. HPA cultivation massively impaired the accumulation of the less-volatile hydrocarbon and oxygenated sesquiterpenes that normally form most of the VOCs. The axenic, tissue-cultured plants followed a similar and more exacerbated trend. Ultrastructural analyses revealed that the HPA conditions altered root ontogeny, whereby the roots contained fewer EO-accumulating cells and hosted fewer and more immature intracellular EO droplets. These preliminary results allowed to conclude that HPA-cultivated vetiver suffers from altered development and root ontology disorders that prevent EO accumulation.

Investigating the Relationship of Genotype and Geographical Location on Volatile Composition and Sensory Profile of Celery (Apium graveolens).

Numerous varieties of celery are grown in multiple countries to maintain supply, demand and availability for all seasons; thus, there is an expectation for a consistent product in terms of taste, flavour, and overall quality. Differences in climate, agronomy and soil composition will all contribute to inconsistencies. This study investigated the volatile and sensory profile of eight celery genotypes grown in the UK (2018) and Spain (2019). Headspace analysis determined the volatile composition of eight genotypes, followed by assessment of the sensory profile using a trained panel. Significant differences in the volatile composition and sensory profile were observed; genotype and geographical location both exerted influences. Two genotypes exhibited similar aroma composition and sensory profile in both locations, making them good candidates to drive breeding programmes aimed at producing varieties that consistently display these distinctive sensory properties. Celery samples harvested in the UK exhibited a higher proportion of sesquiterpenes and phthalides, whereas samples harvested in Spain expressed a higher aldehyde and ketone content. Studying the relationship between growing environment and genotype will provide information to guide growers in how to consistently produce a high-quality crop.

Influence of post-harvest moisture on roasted almond shelf life and consumer acceptance.

BACKGROUND: The harvest weights of sweet almonds (Prunus dulcis) have significantly increased to meet consumer demand and now exceed processing facility capabilities. Crops are stockpiled for longer periods, increasing the probability of moisture exposure. Wet almonds can be mechanically dried prior to processing; however, it is unclear how this practice influences lipid oxidation, shelf-life, and consumer acceptance. To address this, almonds were exposed to 8% moisture and dried with low heat (ME). Almonds were roasted and stored under accelerated conditions for 12 months and markers of lipid oxidation, headspace volatiles, sensory attributes, and consumer liking were evaluated. RESULTS: At 7 months of storage, light roast ME almonds had higher levels of volatiles related to lipid oxidation than non-moisture exposed almonds (NME) and were significantly higher in oxidized, cardboard and painty / solvent flavors. Although untrained consumers did not show significant preferences between the light roast ME and NME almonds, there were quality losses related to lipid oxidation that trained panelists could detect. Dark roast ME almonds demonstrated significant lipid oxidation by 5 months of storage, indicating they will have a compromised shelf life. Findings also indicate that octanal, nonanal, 2-octenal, and hexanoic acid are good indicators of consumer acceptability. CONCLUSION: The results of this research illustrate that post-harvest moisture exposure with mechanical drying has a significant effect on the storage quality of roasted almonds and is most pronounced in dark roast products. © 2020 Society of Chemical Industry.

Unveiling the Molecular Basis of Mascarpone Cheese Aroma: VOCs analysis by SPME-GC/MS and PTR-ToF-MS.

Mascarpone, a soft-spread cheese, is an unripened dairy product manufactured by the thermal-acidic coagulation of milk cream. Due to the mild flavor and creamy consistency, it is a base ingredient in industrial, culinary, and homemade preparations (e.g., it is a key constituent of a widely appreciated Italian dessert 'Tiramisù'). Probably due to this relevance as an ingredient rather than as directly consumed foodstuff, mascarpone has not been often the subject of detailed studies. To the best of our knowledge, no investigation has been carried out on the volatile compounds contributing to the mascarpone cheese aroma profile. In this study, we analyzed the Volatile Organic Compounds (VOCs) in the headspace of different commercial mascarpone cheeses by two different techniques: Headspace-Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (HS-SPME GC-MS) and Proton-Transfer Reaction-Mass Spectrometry coupled to a Time of Flight mass analyzer (PTR-ToF-MS). We coupled these two approaches due to the complementarity of the analytical potential-efficient separation and identification of the analytes on the one side (HS-SPME GC-MS), and effective, fast quantitative analysis without any sample preparation on the other (PTR-ToF-MS). A total of 27 VOCs belonging to different chemical classes (9 ketones, 5 alcohols, 4 organic acids, 3 hydrocarbons, 2 furans, 1 ester, 1 lactone, 1 aldehyde, and 1 oxime) have been identified by HS-SPME GC-MS, while PTR-ToF-MS allowed a rapid snapshot of volatile diversity confirming the aptitude to rapid noninvasive quality control and the potential in commercial sample differentiation. Ketones (2-heptanone and 2-pentanone, in particular) are the most abundant compounds in mascarpone headspace, followed by 2-propanone, 2-nonanone, 2-butanone, 1-pentanol, 2-ethyl-1-hexanol, furfural and 2-furanmethanol. The study also provides preliminary information on the differentiation of the aroma of different brands and product types.

Foal meat volatile compounds: effect of vacuum ageing on semimembranosus muscle.

BACKGROUND: Cooked meat flavor arises through a combination of thermally generated aroma volatile and nonvolatile compounds in a matrix of muscle fiber, connective tissue, and fat. Ageing could affect meat odor, taste, and flavor by the development of odor compounds in the raw product. The aim of the work is to assess the ageing effect on the volatile compounds profile by solid-phase microextraction and gas chromatography-mass spectrometry analysis of foal meat vacuum packaged for storage at 4 °C for a period of 14 days. RESULTS: Only pentane and 3,7-dimethylnonane were significantly affected by ageing time (P < 0.01). Octanal and nonanal presented an increasing trend with higher values at 14 ageing days compared with six ageing days (P < 0.01). CONCLUSIONS: Ageing poorly affects the volatile compounds production of foal meat. Probably, 14 days is considered to be a short maturation time in vacuum packaging for foal meat. © 2018 Society of Chemical Industry.

Fermentation-Guided Natural Products Isolation of a Grape Berry Triacylglyceride that Enhances Ethyl Ester Production.

A full understanding of the origin, formation and degradation of volatile compounds that contribute to wine aroma is required before wine style can be effectively managed. Fractionation of grapes represents a convenient and robust method to simplify the grape matrix to enhance our understanding of the grape contribution to volatile compound production during yeast fermentation. In this study, acetone extracts of both Riesling and Cabernet Sauvignon grape berries were fractionated and model wines produced by spiking aliquots of these grape fractions into model grape juice must and fermented. Non-targeted SPME-GCMS analyses of the wines showed that several medium chain fatty acid ethyl esters were more abundant in wines made by fermenting model musts spiked with certain fractions. Further fractionation of the non-polar fractions and fermentation of model must after addition of these fractions led to the identification of a mixture of polyunsaturated triacylglycerides that, when added to fermenting model must, increase the concentration of medium chain fatty acid ethyl esters in wines. Dosage-response fermentation studies with commercially-available trilinolein revealed that the concentration of medium chain fatty acid ethyl esters can be increased by the addition of this triacylglyceride to model musts. This work suggests that grape triacylglycerides can enhance the production of fermentation-derived ethyl esters and show that this fractionation method is effective in segregating precursors or factors involved in altering the concentration of fermentation volatiles.

Dynamic measurement of newly formed carbonyl compounds in vapors from electronic cigarettes.

Recently, the formation of carbonyl compound within e-cigarettes usage has been reported. The aim of this study was to develop a new analytical method for the direct analysis of carbonyl compounds in vaporized liquids. Two different types of e-cigarettes and different puff's duration have been evaluated, using a modified smoking machine for vapor generation. An isotopic dilution approach, based on deuterated internal standard addition to the e-liquid before filling the e-cigarette tank, has been developed. Carbonyl compounds have been sampled in vapors using a direct, simple, solid-phase microextraction technique with on-fiber derivatization. Related oximes have been analyzed by gas chromatography/mass spectrometry technique. Results confirmed that new carbonyl compounds are formed during the vaping process, and that formation depends both from the heating device and from puffing topography.

Muscle fibre type composition influences the formation of odour-active volatiles in beef.

Flavour is a key driver of consumer liking, and odour-active volatiles formed in cooking are important contributors to the flavour of cooked beef. We hypothesised that the formation of odour-active volatiles in beef are influenced by the contents of type I oxidative and type II glycolytic muscle fibres. To test our hypothesis, we combined ground masseter (type I) and cutaneous trunci (type II) into beef patties, cooked them, then their volatile profiles were analysed using gas chromatography-mass spectrometry. Antioxidant capacity, pH, total heme protein, free iron, and fatty acid composition of these patties were also measured to investigate their relationship to volatile formation. Our study showed that beef composed of more type I fibres had higher 3-methylbutanal and 3-hydroxy-2-butanone, but less lipid-derived volatiles, and this could be partially attributed to the higher antioxidant capacity, pH, and total heme protein content in type I fibres. The results of our study indicate that fibre-type composition plays an important role in volatile formation and hence flavour of beef.

Linking Colorimetric Variation with Non-Volatile and Volatile Components of Carob Flour.

Chromatic variation was examined for its association with flour composition and quality. Carob samples from variable altitudes and genetic backgrounds were milled and assessed for colorimetric parameter L* (lightness) and analyzed for phenols, tannins, antioxidant capacity, soluble carbohydrates (HPLC-RID), organic acids and protein (IC-CD), and volatile organic compounds (VOCs; HS-SPME/GC-MS). Higher altitudes and grafted genotypes yielded lighter-colored flours of higher antioxidant potential, phenols, tannins, sucrose, and malic acid concentrations. VOCs were mainly acids, esters, aldehydes, ketones, and alcohols. Acids were the most abundant and correlated negatively with L*, though correlation for many individual acids was non-significant, including 2-methyl-propanoic acid, widely considered the carob signature aroma (cheesy acidic buttery). The compositional and quality indexing potential of L* is more robust for grafted than non-grafted material, owing putatively to a narrower genetic basis. Antioxidant capacity and concentrations of phenolics, tannins and sucrose correlated positively with L*, indicating increased levels in carob flours sourced from grafted trees at higher altitudes. These flours also have a lower content of reducing sugars, the implication of which in the darkening of carob flour warrants further investigation. Overall, L* constitutes a reliable index for ranking carob flours for key compositional attributes and may be further reinforced by multiple-year data.

Physicochemical Attributes, Aroma Profile, and Sensory Quality of Organic Crimson Crisp Apples after Storage.

The objective of this study was to determine the effect of various storage conditions (i.e., storage under regular air with temperature control, controlled atmosphere storage and storage after the application of the ethylene blocker (1-MCP)) on the flavor characteristics of Crimson Crisp apples (Malus domestica Borkh.), a scab-resistant cultivar suitable for organic agriculture. Highly ripe organically-grown apples (starch degradation 9.7) were stored under different conditions and evaluated for physicochemical attributes such as fruit weight, firmness, juiciness, total soluble solids, titratable acidity, pH value and aroma profile. The analysis of primary and secondary aroma compounds was conducted utilizing HS-SPME-GCMS and the results were integrated with sensory evaluation. Crimson Crisp apples stored under controlled atmosphere with (MCP) or without (CA) application of 1-MCP, had a higher overall quality than those stored in air (RA) after a storage period of six months. The results from sensory analysis indicated that storage with temperature control alone was not suitable for preserving the distinct properties such as crispness or juiciness of Crimson Crisp apples. However, a significant increase particularly in secondary aroma compounds in RA-stored apples was found accompanied by structural disorders of the apple tissue. While a significant decline in the volatile fraction of CA and MCP-stored apples was observed, PCA showed close correlation between the CA stored and the fresh apple samples. Furthermore, these results demonstrate that the applied measures which are taken to prolong the storage time of Crimson Crisp apples, significantly impact the biochemical reactions in the fruits which are responsible for formation of flavor. These findings underscore the significance of comprehensive aroma analysis for new agricultural products and emphasize the potential for improved the quality of organic apples through carefully considered harvest and storage regimes.

Comparing the Volatile and Soluble Profiles of Fermented and Integrated Chinese Bayberry Wine with HS-SPME GC-MS and UHPLC Q-TOF.

To evaluate the flavor characteristics of Chinese bayberry alcoholic beverages, fermented bayberry wine (FBW) and integrated bayberry wine (IBW) were investigated for their volatile and soluble profiles using HS-SPME GC-MS and UHPLC Q-TOF and were analyzed with multidimensional statistical analysis, including PCA and OPLS-DA. The volatile compounds 1-pentanol, ß-caryophyllene and isopentanol were only detected in IBW. ß-caryophyllene, the key flavor component of bayberry, was found to be the most abundant volatile compound in IBW (25.89%) and was 3.73 times more abundant in IBW than in FBW. The levels of ethyl octanoate, ethyl nonanoate, and ethyl decanoate were also several times higher in IBW than in FBW. These compounds contributed to the strong bayberry aroma and better fruity flavor of IBW. On the other hand, high levels of ethyl acetate and octanoic acid in FBW, representing pineapple/overripe or sweat odor, were key contributors to the fermented flavor of FBW. Soluble sugars, such as sucrose, D-glucose, and D-tagatose, as well as amino acids, such as L-glutamate and L-aspartate, had much higher levels in IBW. The anthocyanin pigment cyanidin 3-glucoside, which generates red color, was also higher in IBW. On the other hand, most of the differentially expressed alcohols, acids, amino acids, purines/pyrimidines and esters were present in higher concentrations in FBW compared to IBW. This demonstrated that IBW has a much sweeter and more savory taste as well as a better color generated by more anthocyanins, while FBW presents a more acidic and drier taste as well as a complex formation of alcohols and esters. The study also prompts the need for further research on the flavor profiles of IBW and its potential application and market value.

Conventional and innovative extraction technologies to produce food-grade hop extracts: Influence on bitter acids content and volatile organic compounds profile.

Hop extracts represent a natural alternative to synthetic food additives because of their high content of bitter acids and volatile organic compounds (VOCs) with bittering, flavoring, and antimicrobial properties. However, broader uses of hop extracts as natural techno-functional ingredients rely on the identification of sustainable and affordable extraction technologies allowing to diversify the processes and produce extracts characterized by different compositions and, consequently, qualitative properties. Thus, this study is aimed to evaluate and compare the effect of innovative and conventional extraction methods on the bitter acids content and VOCs pattern of food-grade ethanolic hop extracts for food applications. Innovative extractions were carried out by using two ultrasound systems (a laboratory bath [US] and a high-power ultrasound bath [HPUS]), and a high-pressure industrial process (high hydrostatic pressure [HHP]). Conventional extractions (CONV) were performed under dynamic maceration at 25 and 60°C; for ultrasound and conventional methods, the effect of the extraction time was also investigated. Among the extracts, the highest and lowest content of bitter acids was found in CONV 60°C extracts, and HHP and CONV 25°C extracts, respectively. Of the 34 VOCs identified in dry hops, ∼24 compounds were found in US, HPUS and CONV extracts, while only 18 were found in HHP. CONV extractions showed higher selectivity for sesquiterpenes, while US and HPUS showed higher selectivity for esters and monoterpenes. Hierarchical cluster analysis (HCA) and partial least squares-discriminant analysis (PLS-DA) allowed classifying hop extracts based on the extraction methods and also allowed highlighting the technological conditions to produce hop extracts with specific techno-functional and flavoring properties. PRACTICAL APPLICATION: The study showed that different extraction methods can lead to hop products with varying sensory and functional properties. By selecting the right extraction method, companies can produce hop extracts with specific compositions that meet their needs for clean label and sustainable food products, as well as new edible packaging or coatings.

Adsorption and controlled release performances of flavor compounds by rice bran insoluble dietary fiber improved through steam explosion method.

In this study, steam explosion was employed as a modification process for rice bran insoluble dietary fiber (RBIDF) to improve the flavor adsorption and controlled release capacities of RBIDF. Results showed that the flavor adsorption ability of RBIDF was effectively improved due to the unfolding structure, increased specific surface area and pore volume and exposure of more functional groups after steam explosion treatment. The mechanism of the flavor adsorption behavior of modified RBIDF was preliminarily explored using adsorption kinetics and isotherms combined with SEM and DSC analysis. Results showed that the Langmuir isotherm model and pseudo-second-order kinetic model yielded the best fit to the adsorption data, indicating monolayer adsorption of flavor onto the modified RBIDF, and the adsorption was mainly driven by chemisorption process. The flavor release profile of modified RBIDF was investigated by HS-SPME/GC-MS and E-nose. After long-time storage, the flavor compounds were retained at a higher concentration in the modified RBIDF compared with the untreated RBIDF, indicating that the steam explosion treatment prolonged the retention time and enhanced the retention and controlled release capacities of RBIDF for flavor compounds. This study provides indications for potential applications of steam explosion-modified RBIDF as a novel flavor delivery system and functional ingredient.

Multivariate analysis of chemical and genetic diversity of wild Humulus lupulus L. (hop) collected in situ in northern France.

The hop plant (Humulus lupulus L.) has been exploited for a long time for both its brewing and medicinal uses, due in particular to its specific chemical composition. These last years, hop cultivation that was in decline has been experiencing a renewal for several reasons, such as a craze for strongly hopped aromatic beers. In this context, the present work aims at investigating the genetic and chemical diversity of fifty wild hops collected from different locations in Northern France. These wild hops were compared to ten commercial varieties and three heirloom varieties cultivated in the same sampled geographical area. Genetic analysis relying on genome fingerprinting using 11 microsatellite markers showed a high level of diversity. A total of 56 alleles were determined with an average of 10.9 alleles per locus and assessed a significant population structure (mean pairwise FST = 0.29). Phytochemical characterization of hops was based on volatile compound analysis by HS-SPME GC-MS, quantification of the main prenylated phenolic compounds by UHPLC-UV as well as untargeted metabolomics by UHPLC-HRMS and revealed a high level of chemical diversity among the assessed wild accessions. In particular, analysis of volatile compounds revealed the presence of some minor but original compounds, such as aromadendrene, allo-aromadendrene, isoledene, ß-guaiene, α-ylangene and ß-pinene in some wild accessions; while analysis of phenolic compounds showed high content of ß-acids in these wild accessions, up to 2.37% of colupulone. Genetic diversity of wild hops previously observed was hence supported by their chemical diversity. Sample soil analysis was also performed to get a pedological classification of these different collection sites. Results of the multivariate statistical analysis suggest that wild hops constitute a huge pool of chemical and genetic diversity of this species.

Effects of "nine steaming nine sun-drying" on proximate composition, protein structure and volatile compounds of black soybeans.

Nine steaming nine sun-drying is a traditional processing technology for food or medicinal materials. The dynamic changes of the proximate composition, protein structure and volatile compounds during nine-time steaming and sun-drying of black soybeans (BS) were studied. The proximate composition results showed that the content of protein, carbohydrate and fat of BS decreased after processing, whereas the relative content of amino acids remained basically unchanged. Protein structure was evaluated using Fourier transform infrared spectroscopy (FT-IR), Ultraviolet absorption spectroscopy (UV) and Fluorescence spectroscopy. FT-IR result revealed that the relative contents of ß-sheet and ß-turn of the secondary structure of black soybean protein isolate (BSPI) decreased but the relative contents of α-helix and random coil increased after steaming and sun-drying. The results of UV and fluorescence spectroscopy confirmed changes in the protein conformation. In addition, SPME-GCMS analysis demonstrated that hydrocarbons, alcohols and aldehydes were the main volatile compounds. The relative contents of 1-octen-3-ol and hexanal, which are the main sources of beany flavor decreased significantly compared with raw BS. Principal component analysis (PCA) results showed that the volatile compounds of nine steamed and nine sun-dried BS could be well distinguished during the process. These findings may therefore provide a scientific basis for the application of nine-time steamed and sun-dried BS in food industry and contribute to the understanding of process-induced chemical transformations in this ancient processing technique.

Abiotic and Biotic Damage of Microalgae Generate Different Volatile Organic Compounds (VOCs) for Early Diagnosis of Algal Cultures for Biofuel Production.

Open microalgal ponds used in industrial biomass production are susceptible to a number of biotic and abiotic environmental stressors (e.g., grazers, pathogens, pH, temperature, etc.) resulting in pond crashes with high economic costs. Identification of signature chemicals to aid in rapid, non-invasive, and accurate identification of the stressors would facilitate targeted and effective treatment to save the algal crop from a catastrophic crash. Specifically, we were interested in identifying volatile organic compounds (VOCs) that can be used to as an early diagnostic for algal crop damage. Cultures of Microchloropsis gaditana were subjected to two forms of algal crop damage: (1) active grazing by the marine rotifer, Brachionus plicatilis, or (2) repeated freeze-thaw cycles. VOCs emitted above the headspace of these algal cultures were collected using fieldable solid phase microextraction (SPME) fibers. An untargeted analysis and identification of VOCs was conducted using gas chromatography-mass spectrometry (GC-MS). Diagnostic VOCs unique to each algal crop damage mechanism were identified. Active rotifer grazing of M. gaditana was characterized by the appearance of carotenoid degradation products, including ß-cyclocitral and various alkenes. Freeze-thaw algae produced a different set of VOCs, including palmitoleic acid. Both rotifer grazing and freeze-thawed algae produced ß-ionone as a VOC, possibly suggesting a common stress-induced cellular mechanism. Importantly, these identified VOCs were all absent from healthy algal cultures of M. gaditana. Early detection of biotic or abiotic environmental stressors will facilitate early diagnosis and application of targeted treatments to prevent algal pond crashes. Thus, our work further supports the use of VOCs for monitoring the health of algal ponds to ultimately enhance algal crop yields for production of biofuel.