RESUMO
Microbial metabolism drives changes in the physicochemical properties and, consequently, the sensory characteristics of fermented cocoa beans. In this context, information regarding the structure, function, and metabolic potential of microbial communities' present during cocoa pulp-bean mass fermentation is limited, especially concerning the formation of aromatic compounds. To bridge the gap, the metagenome of fermented cocoa pulp-bean mass (Criollo and Forastero) has been investigated using shotgun metagenomics coupled with physicochemical, microbiological, quality, and sensory analyses to explore the impact of microbial communities on the quality of fermented cocoa pulp-bean mass on one farm in one season and in one region under the same environmental conditions. Our findings showed that the metagenomic diversity in cocoa, the fermentation length, and the diversity and function of metagenome-assembled genomes (MAGs) greatly influence the resulting distinctive flavors. From the metabolic perspective, multiple indicators suggest that the heterolactic metabolism was more dominant in Criollo fermentations. KEGG genes were linked with the biosynthesis of acetic acid, ethanol, lactic acid, acetoin, and phenylacetaldehyde during Criollo and Forastero fermentations. MAGs belonging to Lactiplantibacillus plantarum, Limosilactobacillus reuteri, and Acetobacter pasteurianus were the most prevalent. Fermentation time and roasting are the most important determinants of cocoa quality, while the difference between the two varieties are relatively minor. The assessment of microbiological and chemical analysis is urgently needed for developing fermentation protocols according to regions, countries, and cocoa varieties to guarantee safety and desirable flavor development. IMPORTANCE Monitoring the composition, structure, functionalities, and metabolic potential encoded at the level of DNA of fermented cocoa pulp-bean mass metagenome is of great importance for food safety and quality implications.
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Cacau/microbiologia , Microbiota/genética , Adulto , Bactérias/genética , Feminino , Fermentação , Fungos/genética , Humanos , Masculino , Metagenômica , Odorantes , Paladar , Adulto JovemRESUMO
Heat shock activates the transcription of arrays of Satellite III (SatIII) DNA repeats in the pericentromeric heterochromatic domains of specific human chromosomes, the longest of which is on chromosome 9. Long non-coding SatIII RNAs remain associated with transcription sites where they form nuclear stress bodies or nSBs. The biology of SatIII RNAs is still poorly understood. Here, we show that SatIII RNAs and nSBs are detectable up to four days after thermal stress and are linked to defects in chromosome behavior during mitosis. Heat shock perturbs the execution of mitosis. Cells reaching mitosis during the first 3 h of recovery accumulate in pro-metaphase. During the ensuing 48 h, this block is no longer detectable; however, a significant fraction of mitoses shows chromosome segregation defects. Notably, most of lagging chromosomes and chromosomal bridges are bound to nSBs and contain arrays of SatIII DNA. Disappearance of mitotic defects at the end of day 2 coincides with the processing of long non-coding SatIII RNAs into a ladder of small RNAs associated with chromatin and ranging in size from 25 to 75 nt. The production of these molecules does not rely on DICER and Argonaute 2 components of the RNA interference apparatus. Thus, massive transcription of SatIII DNA may contribute to chromosomal instability.
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Cromossomos Humanos/metabolismo , DNA Satélite/metabolismo , Fatores de Transcrição de Choque Térmico/genética , RNA Longo não Codificante/metabolismo , Segregação de Cromossomos , Células HeLa , Humanos , Mitose , Pequeno RNA não Traduzido/metabolismo , Sítio de Iniciação de TranscriçãoRESUMO
BACKGROUND: Cane-cut on-vine withering is a grape dehydration technique used for dry and sweet wine production. The aim of this work was to study the influence of the cane-cut technique applied at harvest to Moscato bianco grapes during the on-vine withering process to produce dehydrated berries with a different chemical composition and a volatile profile. RESULTS: After 24 days of dehydration, an on-vine withering system using the cane-cut technique induced an increase in the total volatile content compared with grapes produced with a normal on-vine withering process. This increase was greater in glycosidically bound volatile compounds than in the free fraction. Bound linalool showed a significant increase of 52% when the cane-cut withering system was applied but the grapes that were normally withered appeared to be less prone to the loss of free linalool. A significant increase in the glycosylated forms of nerol and geraniol was also observed in the two on-vine withering systems on the 24th day compared with the control (fresh grapes at harvest date). CONCLUSION: A cane-cut, on-vine withering system applied at harvest induced changes in the volatile composition of Moscato bianco grapes increasing total volatile content, consisting mainly of bound compounds, by the 24th day of dehydration. The grapes dehydrated on-vine using this new system also showed significantly greater content of most of the free volatile compounds detected. © 2018 Society of Chemical Industry.
Assuntos
Desidratação , Frutas/metabolismo , Vitis/metabolismo , Compostos Orgânicos Voláteis/análise , Produção Agrícola/métodos , Frutas/química , Itália , VinhoRESUMO
Changes in the microbial gene content and abundance can be analyzed to detect shifts in the microbiota composition due to the use of a starter culture in the food fermentation process, with the consequent shift of key metabolic pathways directly connected with product acceptance. Meat fermentation is a complex process involving microbes that metabolize the main components in meat. The breakdown of carbohydrates, proteins, and lipids can lead to the formation of volatile organic compounds (VOCs) that can drastically affect the organoleptic characteristics of the final products. The present meta-analysis, performed with the shotgun DNA metagenomic approach, focuses on studying the microbiota and its gene content in an Italian fermented sausage produced by using a commercial starter culture (a mix of Lactobacillus sakei and Staphylococcus xylosus), with the aim to discover the connections between the microbiota, microbiome, and the release of volatile metabolites during ripening. The inoculated fermentation with the starter culture limited the development of Enterobacteriaceae and reduced the microbial diversity compared to that from spontaneous fermentation. KEGG database genes associated with the reduction of acetaldehyde to ethanol (EC 1.1.1.1), acetyl phosphate to acetate (EC 2.7.2.1), and 2,3-butanediol to acetoin (EC 1.1.1.4) were most abundant in inoculated samples (I) compared to those in spontaneous fermentation samples (S). The volatilome profiles were highly consistent with the abundance of the genes; elevated acetic acid (1,173.85 µg/kg), ethyl acetate (251.58 µg/kg), and acetoin (1,100.19 µg/kg) were observed in the presence of the starters at the end of fermentation. Significant differences were found in the liking of samples based on flavor and odor, suggesting a higher preference by consumers for the spontaneous fermentation samples. Inoculated samples exhibited the lowest scores for the liking data, which were clearly associated with the highest concentration of acetic acid.IMPORTANCE We present an advance in the understanding of meat fermentation by coupling DNA sequencing metagenomics and metabolomics approaches to describe the microbial function during this process. Very few studies using this global approach have been dedicated to food, and none have examined sausage fermentation, underlying the originality of the study. The starter culture drastically affected the organoleptic properties of the products. This finding underlines the importance of starter culture selection that takes into consideration the functional characteristics of the microorganism to optimize production efficiency and product quality.
Assuntos
Produtos da Carne/microbiologia , Microbiota/genética , Microbiota/fisiologia , Compostos Orgânicos Voláteis/análise , Ácido Acético/análise , Ácido Acético/metabolismo , Acetoína/análise , Acetoína/metabolismo , Animais , Contagem de Colônia Microbiana , Enterobacteriaceae/isolamento & purificação , Enterobacteriaceae/metabolismo , Fermentação , Alimentos Fermentados/microbiologia , Microbiologia de Alimentos , Lactobacillus/isolamento & purificação , Lactobacillus/metabolismo , Produtos da Carne/análise , Redes e Vias Metabólicas , Metagenômica/métodos , Odorantes/análise , Staphylococcus/isolamento & purificação , Staphylococcus/metabolismo , Suínos , VolatilizaçãoRESUMO
Forastero hybrid cocoa bean fermentations have been carried out in a box (B) and in a heap (H), with or without the inoculation of Saccharomyces cerevisiae and Torulaspora delbrueckii as starter cultures. The bacteria, yeasts, and microbial metabolites (volatile and nonvolatile organic compounds) were monitored during fermentation to assess the connection between microbiota and the release of metabolites during this process. The presence of starter cultures was detected, by means of culture-dependent analysis, during the first 2 days of both fermentations. However, no statistical difference was observed in any of the physicochemical or microbiological analyses. Plate counts revealed the dominance of yeasts at the beginning of both fermentations, and these were followed by acetic acid bacteria (AAB) and lactic acid bacteria (LAB). Hanseniaspora opuntiae, S. cerevisiae, Pichia pijperi, Acetobacter pasteurianus, and Lactobacillus fermentum were the most abundant operational taxonomic units (OTUs) during both fermentation processes (B and H), although different relative abundances were observed. Only the diversity of the fungal species indicated a higher level of complexity in the B fermentations than in the H fermentations (P < 0.05), as well as a statistically significant difference between the initially inoculated starter cultures (P < 0.01). However, the microbial metabolite analysis indicated different distributions of the volatile and nonvolatile compounds between the two procedures, that is, B and H (P < 0.05), rather than between the inoculated and noninoculated fermentations. The box fermentations showed faster carbohydrate metabolism and greater production of organic acid compounds, which boosted the formation of alcohols and esters, than did the heap fermentations. Overall, the microbial dynamics and associations between the bacteria, yeasts, and metabolites were found to depend on the type of fermentation.IMPORTANCE In spite of the limited effectiveness of the considered inoculated starter strains, this study provides new information on the microbial development of box and heap cocoa fermentations, under inoculated and noninoculated conditions, as we coupled yeast/bacterial amplicon-based sequencing data with microbial metabolite detection. The information so far available suggests that microbial communities have played an important role in the evolution of aroma compounds. Understanding the pathways that microorganisms follow during the formation of aromas could be used to improve the fermentation processes and to enhance chocolate quality.
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Bactérias/isolamento & purificação , Bactérias/metabolismo , Biodiversidade , Cacau/microbiologia , Sementes/microbiologia , Leveduras/isolamento & purificação , Leveduras/metabolismo , Bactérias/classificação , Bactérias/genética , Cacau/química , Metabolismo dos Carboidratos , Fermentação , Microbiologia de Alimentos , Sementes/química , Leveduras/classificação , Leveduras/genéticaRESUMO
Sataw-Dong is a fermented stink bean in brine, made with Parkia speciosa subjected to spontaneous fermentation. This study aimed to investigate the impact of Lactobacillus plantarum KJ03 as a starter culture during Sataw-Dong fermentation and to determine its effect on the volatilome profile. Two fermentations were performed: spontaneous and inoculated with starter. The surface of the beans and the brines were separately analyzed throughout fermentation period for 15 days. Inoculated samples clearly showed a significantly higher acidification of the brine, reaching a pH of 3.98 within 5 days of fermentation. The microbiota was investigated through 16S amplicon based sequencing and revealed the dominance of Lactobacillus plantarum and Lactobacillus sanfranciscensis throughout the fermentation in both brine and bean samples. The starter used clearly influenced volatile organic compounds (VOCs) profiles. Inoculated samples showed the lowest abundance of Brevundimonas, Corynebacterium, Enterobacteriaceae, Methylobacterium and Klebsiella, compared to the spontaneous fermentation. Correlation between OTUs and VOCs revealed that acids, aldehydes, and alcohols exhibited a positive correlation with L. plantarum and L. sanfranciscencis. Overall aldehydes were mostly produced at the beginning, while acids, alcohols, and ketones at the middle until the end of the fermentation. Sataw-Dong produced with the starter significantly perceived a positive response in the overall acceptance. As shown through microbiological changes, acidification, VOCs and sensory analysis, the successful and accelerated Sataw-Dong fermentation was achieved when using a functional starter strain.
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Fabaceae/microbiologia , Fermentação , Lactobacillus plantarum/metabolismo , Microbiota/genética , Compostos Orgânicos Voláteis/análise , Ácidos , Alimentos Fermentados/microbiologia , Microbiologia de Alimentos , Concentração de Íons de Hidrogênio , Lactobacillus plantarum/isolamento & purificação , Probióticos , Sais , Compostos Orgânicos Voláteis/químicaRESUMO
Lactococcus lactis, is extensively used as starter culture in dairy products. Nevertheless, it has recently been detected in cheese, as metabolically active cells, in advanced ripening stages. In this study, we assessed the viability of L. lactis subsp. lactis in model cheeses up to 180 days of ripening by both culture-dependent and -independent methods. In addition, we studied the expression of metC and als genes involved in the production of aroma compounds detected by Gas Chromatography-Mass Spectrometry (GC-MS). Three L. lactis subsp. lactis commercial starters were inoculated in pasteurized milk and model cheeses were manufactured and ripened for six months. Samples were analysed at manufacturing and ripening steps, in terms of viability of L. lactis by both traditional plating and direct analysis of RNA by reverse transcription quantitative PCR (RT-qPCR), and in terms of aroma profile by GC-MS. Relatively to RT-qPCR analysis, L. lactis was found viable throughout the whole process of cheesemaking and aging, with final average loads of 3-4 Log CFU/g at 180 days. On the contrary, the microorganism was not detected, in ripened samples, by traditional plating on M17 medium, suggesting its entering in a viable but not cultivable (VBNC) state. The aroma profiles of the cheeses highlighted the presence of volatile compounds related to cheese flavor as acetoin, diacetyl, 2,3-butanediol and dimethyl disulfide, whose presence was partially correlated to metC and als genes expression. These results add new insights on the capability of L. lactis to persist during late cheese ripening and suggest a potential contribution of the microorganism to cheese flavor formation.
Assuntos
Queijo/análise , Queijo/microbiologia , Alimentos Fermentados/análise , Alimentos Fermentados/microbiologia , Cromatografia Gasosa-Espectrometria de Massas/métodos , Lactococcus lactis/crescimento & desenvolvimento , Lactococcus lactis/metabolismo , Acetoína/metabolismo , Animais , Carga Bacteriana , Ácidos Carboxílicos/análise , Contagem de Colônia Microbiana , DNA Bacteriano/análise , Dissulfetos/metabolismo , Fermentação , Microbiologia de Alimentos , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos/genética , Lactococcus lactis/genética , Viabilidade Microbiana , Leite/microbiologia , Odorantes/análise , Reação em Cadeia da Polimerase em Tempo Real , Açúcares/análise , Compostos Orgânicos Voláteis/metabolismoRESUMO
BACKGROUND: Hazelnut skin is the perisperm of the hazelnut kernel. It is separated from the kernel during the roasting process and is normally discarded. Recent studies have reported that hazelnut skin is a rich source of dietary fibre as well as of natural antioxidants owing to the presence of phenolic compounds. The aim of this study was to assess the use of hazelnut skins obtained from different cultivars for enhancing the nutritional value of fresh egg pasta. RESULTS: Skins obtained from roasted hazelnuts of four different varieties were used at three concentrations as a flour replacement in fresh egg pasta. Hazelnut skin concentration significantly influenced all evaluated physicochemical parameters as well as consumers' appreciation for the pasta, but significant differences were also observed between the four varieties. Although pasta produced with 10 and 15% hazelnut skin displayed the highest content of polyphenolic compounds and antioxidant activity in vitro, pasta containing 5% Tombul hazelnut skin showed maximum consumer preference. CONCLUSION: The results obtained in the present study highlighted that it is possible to use hazelnut skin in fresh pasta production to obtain a fortified food with high fibre content and antioxidant activity. The characteristics of the resulting pasta were strictly correlated with the hazelnut variety used for skin production and, of course, with the percentage of skin that was added.
Assuntos
Corylus , Farinha/análise , Manipulação de Alimentos/métodos , Valor Nutritivo , Nozes/química , Polifenóis/análise , Antioxidantes/administração & dosagem , Antioxidantes/análise , Fibras na Dieta , Ovos , Qualidade dos Alimentos , Temperatura AltaRESUMO
iMole is a platform that automatically extracts images and captions from biomedical literature. Images are tagged with terms contained in figure captions by means of a sophisticate text-mining tool. Moreover, iMole allows the user to upload directly their own images within the database and manually tag images by curated dictionary. Using iMole the researchers can develop a proper biomedical image database, storing the images extracted from paper of interest, image found on the web repositories, and their own experimental images. In order to show the functioning of the platform, we used iMole to build a 2DE database. Briefly, tagged 2DE gel images were collected and stored in a searchable 2DE gel database, available to users through an interactive web interface. Images were obtained by automatically parsing 16,608 proteomic publications, which yielded more than 16,500 images. The database can be further expanded by users with images of interest trough a manual uploading process. iMole is available with a preloaded set of 2DE gel data at http://imole.biodigitalvalley.com.
Assuntos
Mineração de Dados/métodos , Sistemas de Gerenciamento de Base de Dados , Bases de Dados Factuais , Internet , Software , Eletroforese em Gel Bidimensional , Processamento de Imagem Assistida por Computador , Armazenamento e Recuperação da InformaçãoRESUMO
Although coffee silverskin (CS) has recently been used as a food ingredient, no knowledge has been reported on the effects of species or different post-harvest treatments on its chemical composition. Therefore, the fibre, volatile compounds, phenolic acid content, and antioxidant capacity of CS samples obtained at three roasting intensities (light, medium, and dark) from the Coffea arabica and C. canephora species, each subjected to a washing or a sun-drying ("natural") post-harvest treatment, were studied. Obtained results showed that the chemical composition of CS is due to species, roasting, post-harvest treatment, and interaction. In particular, natural Arabica CS showed the highest content of volatile compounds of Maillard and varietal origin, whereas washed Arabica CS showed the highest content of soluble dietary fibre and chlorogenic derivatives. Pyrroles, sulphur compounds, and pyridines contents were higher in Canephora CS than in Arabica CS. The dark-roasted washed Arabica CS showed the highest content of 5-O- and 3-O-caffeoylquinic acids, while the natural Arabica CS highlighted the highest antioxidant capacity. The effect of post-harvest treatments seemed to be emphasised in Arabica CS, independent of roasting, which did not significantly affect the antioxidant capacity of CS from either species.
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Salame Piemonte is a dry-fermented meat product typical of the Piedmont region in Italy, manufactured using commercial starter cultures. This study aimed to select autochthonous starter cultures (ASCs) that could be used for sausage fermentation in order to strengthen the link with the geographical area of production and improve the sensory properties of the final product. A culture-dependent approach was adopted during three different spontaneous sausage fermentation processes to isolate and characterise the main bacterial resources involved. Dominant lactic acid bacteria (LAB) in each batch were Pediococcus pentosaceus, Latilactobacillus sakei, and Latilactobacillus curvatus; Staphylococcus xylosus was the most dominant coagulase-negative staphylococci (CNS) in all the studied batches. LAB and presumptive CNS isolates were further evaluated for their physiological properties and biotechnological potential. Thereafter, 11 strains were selected and evaluated for safety. Five selected strains (two P. pentosaceus, two L. sakei, and one S. xylosus strain) were used for pilot-scale Salame Piemonte production with seven different strain combinations. Based on the liking test, three ASC combinations led to the highest liking score compared to industrial products. These three ASCs were then used for the second pilot-scale sausage production confirming the high liking score. In summary, the use of P. pentosaceus and S. xylosus ASC significantly improved product sensory properties compared with that obtained using commercial starter cultures.
Assuntos
Lactobacillales , Latilactobacillus sakei , Produtos da Carne , Pediococcus pentosaceus , BiotecnologiaRESUMO
Biochemical, volatile and textural profiles during manufacture and ripening were determined in samples of Castelmagno PDO cheese obtained from three different batches in the main artisan cheese plant of Castelmagno PDO production area. At the end of manufacture, samples were characterised by a pH of 6.57% and 52.4% moisture content. The HPLC analysis of organic acids and sugars showed the exhaustion of lactose content, while Urea-PAGE indicated extensive primary proteolysis of both ß-casein and αs1-casein. During ripening, cheeses were characterised by high degradation of ß-casein and αs1-casein, due to bacterial action. RP-HPLC profiles showed a high production of peptides eluted between 20 and 30min. In total, 92 volatile compounds were identified in cheese headspace. Texture profiles showed an increase in hardness, gumminess, chewiness and adhesiveness values, as well as a decrease in cohesiveness during ripening.
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Metagenomics is a powerful tool to study and understand the microbial dynamics that occur during food fermentation and allows to close the link between microbial diversity and final sensory characteristics. Each food matrix can be colonized by different microbes, but also by different strains of the same species. In this study, using an innovative integrated approach combining culture-dependent method with a shotgun sequencing, we were able to show how strain-level biodiversity could influence the quality characteristics of the final product. The attention was placed on a model food fermentation process: Salame Piemonte, a Protected Geographical Indication (PGI) Italian fermented sausage. Three independent batches produced in February, March and May 2018 were analysed. The sausages were manufactured, following the production specification, in a local meat factory in the area of Turin (Italy) without the use of starter cultures. A pangenomic approach was applied in order to identify and evaluate the lactic acid bacteria (LAB) population driving the fermentation process. It was observed that all batches were characterized by the presence of few LAB species, namely Pediococcus pentosaceus, Latilactobacillus curvatus and Latilactobacillus sakei. Sausages from the different batches were different when the volatilome was taken into consideration, and a strong association between quality attributes and strains present was determined. In particular, different strains of L. sakei, showing heterogeneity at genomic level, colonized the meat at the beginning of each production and deeply influenced the fermentation process by distinctive metabolic pathways that affected the fermentation process and the final sensory aspects.
Assuntos
Lactobacillus , Metagenômica , Fermentação , Microbiologia de Alimentos , ItáliaRESUMO
In heat-shocked human cells, heat shock factor 1 activates transcription of tandem arrays of repetitive Satellite III (SatIII) DNA in pericentromeric heterochromatin. Satellite III RNAs remain associated with sites of transcription in nuclear stress bodies (nSBs). Here we use real-time RT-PCR to study the expression of these genomic regions. Transcription is highly asymmetrical and most of the transcripts contain the G-rich strand of the repeat. A low level of G-rich RNAs is detectable in unstressed cells and a 10(4)-fold induction occurs after heat shock. G-rich RNAs are induced by a wide range of stress treatments including heavy metals, UV-C, oxidative and hyper-osmotic stress. Differences exist among stressing agents both for the kinetics and the extent of induction (>100- to 80.000-fold). In all cases, G-rich transcripts are associated with nSBs. On the contrary, C-rich transcripts are almost undetectable in unstressed cells and modestly increase after stress. Production of SatIII RNAs after hyper-osmotic stress depends on the Tonicity Element Binding Protein indicating that activation of the arrays is triggered by different transcription factors. This is the first example of a non-coding RNA whose transcription is controlled by different transcription factors under different growth conditions.
Assuntos
DNA Satélite/química , RNA não Traduzido/biossíntese , Ativação Transcricional , Animais , Células CHO , Estruturas do Núcleo Celular/química , Estruturas do Núcleo Celular/ultraestrutura , Cricetinae , Cricetulus , Proteínas de Ligação a DNA/metabolismo , Células HeLa , Fatores de Transcrição de Choque Térmico , Resposta ao Choque Térmico , Humanos , Fatores de Transcrição NFATC/fisiologia , Pressão Osmótica , RNA não Traduzido/análise , RNA não Traduzido/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/metabolismoRESUMO
The ability of hemp (Cannabis sativa L.) inflorescence extract to counteract lipid oxidation was studied in stripped linseed oil. The ethanolic extract was characterized in terms of terpenes (6.00 mg/mL), cannabidiol (4.99% w/w), phenolic compounds (1.80 mg gallic acid equivalents (GAE)/mL), antiradical, and metal ion-chelating activities (50% effective concentration (EC50) of 2.47 mg/mL and 0.39 mg/mL, respectively). The stripped linseed oil, used as control (CO), was mixed with hemp extract (HO) or α-tocopherol (EO) at a ratio of 0.6% (w/w) and stored for 7 days in darkness at 40 °C. Hemp extract reduced the oxidation and lipolysis processes. At the end of the storage, HO showed a significantly higher level of α-linolenic acid (ALA; 26.64 g/100 g), lower peroxide value (PV) (21.19 meq O2/kg oil), and lower hexanal content (7.67 mmol/kg oil) than those found in the control. In contrast, EO showed a marked lipolysis (the free fatty acids increased by 42.57%) and a noticeable oxidation, since the ALA content decreased by 2.10% and a PV of 50 meq O2/kg oil was observed. This study demonstrates that hemp inflorescences can be used as a source of natural antioxidants in vegetable oils and lipid products to retard their oxidation, especially those characterized by a high degree of unsaturation.
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The cocoa bean shell (CBS) is a main by-product of cocoa processing, with great potential to be used as an ingredient for functional foods because of its nutritional and flavour properties. This study aimed to characterise and classify CBSs obtained from cocoa beans of diverse cultivars and collected in different geographical origins through their volatile profile assessed using headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME/GC-qMS) and E-nose combined with principal component analysis (PCA). The study provides, for the first time in a representative set of samples, a comprehensive fingerprint and semi-quantitative data for >100 volatile organic compounds (VOCs), such as aldehydes, ketones, pyrazines, alcohols, and acids. Through PCA, a clear separation of the Criollo cultivar from the other cultivars was achieved with both GC-qMS and E-nose analytical techniques because of the high content of key-aroma VOCs. Several biomarkers identified by GC-qMS, such as 2-hepanol, 2-methylpropanoic acid, and 2,3,5-trimethylpyrazine, recognized as key-aroma compounds for cocoa beans, were found suitable for the classification of CBSs according to their quality and origin. GC-qMS and E-nose appeared to be suitable analytical approaches to classify CBSs, with a high correlation between both analytical techniques. The volatile fingerprint and classification of CBSs could allow for the selection of samples with a specific flavour profile according to the food application and, therefore, constitute an interesting approach to valorise this by-product as a food ingredient.
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Cacau/química , Nariz Eletrônico , Análise de Alimentos/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Extratos Vegetais/análise , Microextração em Fase Sólida/métodos , Compostos Orgânicos Voláteis/análise , Álcoois/análise , Aldeídos/análise , Cetonas/análise , Odorantes/análise , Análise de Componente Principal/métodos , Pirazinas/análise , PaladarRESUMO
This data article describes the analysis of volatile organic compounds (VOCs) in 44 samples of cocoa bean shells (CBS) obtained from cocoa beans of diverse cultivars and collected in different geographical origins. The volatile compounds were extracted by headspace solid-phase microextraction (HS-SPME) method and then analyzed by gas chromatography coupled to a quadrupole mass spectrometry GC-qMS. The retention times, identification and semi-quantification of 101 VOCs are reported. Data collected on the volatile profile of CBS samples using E-nose analysis are also available. Additional data related to physicochemical characteristics and color analysis for CBS samples are reported. Further interpretation and discussion on these datasets can be found in the related article entitled "Assessment of volatile fingerprint by HS-SPME/GC-qMS and E-nose for the classification of cocoa bean shells using chemometrics" (Barbosa-Pereira et al., 2019).
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Thermal and chemical stresses induce the formation in human cells of novel and transient nuclear structures called nuclear stress bodies (nSBs). These contain heat shock factor 1 (HSF-1) and a specific subset of pre-mRNA processing factors. Nuclear stress bodies are assembled on specific pericentromeric heterochromatic domains containing satellite III (SatIII) DNA. In response to stress, these domains change their epigenetic status from heterochromatin to euchromatin and are transcribed in poly-adenylated RNAs that remain associated with nSBs. In this article, we describe the cloning, sequencing, and functional characterization of these transcripts. They are composed of SatIII repeats and originate from the transcription of multiple sites within the SatIII arrays. Interestingly, the level of SatIII RNAs can be down-regulated both by antisense oligonucleotides and small interfering RNAs (siRNA). Knockdown of SatIII RNA by siRNAs requires the activity of Argonaute 2, a component of the RNA-induced silencing complex. Down-regulation of satellite III RNAs significantly affects the recruitment of RNA processing factors to nSBs without altering the association of HSF-1 with these structures nor the presence of acetylated histones within nSBs. Thus, satellite III RNAs have a major role in the formation of nSBs.
Assuntos
Estruturas do Núcleo Celular/metabolismo , RNA não Traduzido/química , RNA não Traduzido/metabolismo , Estresse Fisiológico/genética , Transcrição Gênica , Animais , Proteínas Argonautas , Fusão Celular , Núcleo Celular/genética , Núcleo Celular/metabolismo , Técnicas de Cocultura , DNA Satélite/química , DNA Satélite/metabolismo , Proteínas de Ligação a DNA , Relação Dose-Resposta a Droga , Regulação para Baixo , Eucromatina/genética , Eucromatina/metabolismo , Fator de Iniciação 2 em Eucariotos , Células HeLa , Fatores de Transcrição de Choque Térmico , Resposta ao Choque Térmico , Heterocromatina/genética , Heterocromatina/metabolismo , Humanos , Camundongos , Células NIH 3T3 , Oligonucleotídeos Antissenso/farmacologia , Fatores de Iniciação de Peptídeos/metabolismo , RNA Interferente Pequeno/farmacologia , RNA não Traduzido/genética , Complexo de Inativação Induzido por RNA , Análise de Sequência de RNA , Estresse Fisiológico/metabolismo , Fatores de TranscriçãoRESUMO
The microbial contamination that occurs during the slaughtering process and during handling of the meat results in a shortening of the shelf-life of meat. In this study, which has had the aim of extending the shelf life of beefsteaks, pilot-scale treatments were carried out with aqueous ozone (AO) and electrolyzed water (EW) before vacuum packaging (VP). The development of the potentially active microbiota and the associated volatilome were followed over 15days of storage under refrigerated conditions (4°C), in order to define the potential long-term effects of the treatments and storage condition on microbiota. The targeted RNA-based amplicon sequencing identified Pseudomonas fragi as the most frequent species before and after the treatments with AO and EW, as well as in the untreated control. The tested treatments did not reduce the overall presence of this species, but they affected the intra-species distribution of its oligotypes, albeit slightly. With the progression of the refrigerated storage and the reduction of the oxygen availability, Lactobacillus sakei, Leuconostoc gasicomitatum and Lactococcus piscium became the dominant, potentially active, beef microbiota, as confirmed by microbiological data. When the OTU abundances and volatilome were coupled, a significant association was observed between the organic acids, esters and aldehydes and these lactic acid bacteria species. In spite of the limited effectiveness of the treatments over the short and long term, this study has provided a detailed view of beef spoilage using RNA as the sequencing target, strengthening and confirming the current knowledge based on DNA-amplicon sequencing.
Assuntos
Fenômenos Fisiológicos Bacterianos , Microbiologia de Alimentos , Embalagem de Alimentos/normas , Carne/microbiologia , Animais , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Biodiversidade , Bovinos , Oxigênio/farmacologia , Ozônio/farmacologia , Vácuo , Água/farmacologiaRESUMO
Roasted hazelnuts can be consumed as whole nuts, or as an ingredient in the confectionary and bakery industries and are highly appreciated for their typical taste, aroma and crunchy texture. In this work, two hazelnut types (TGT, Ordu) from two harvests were roasted using two different systems (hot air, infrared) at different time/temperature combinations, and the evolution of oxidative stability, the total phenolic content (TPC), the antioxidant capacity, the mechanical and acoustic properties and the sensory perception were determined during storage. The results showed that the oxidative stability was increased by roasting hazelnuts at 120°C for 40min with hot air system. Similar overall trends were not found for the TPC, the antioxidant capacity and the mechanical-acoustic properties. However, for the maintenance of high antioxidant activity, a storage time of 6months at 4°C is recommended. The two roasting systems gave hazelnuts with significant sensory differences only at high roasting temperature.