scholarly journals Análise comparativa do perfil de compostos voláteis pela técnica de HS-SPME em amostras comerciais de chá verde e avaliação do efeito da infusão e da adição de sal

ForScience ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. e00769
Author(s):  
Priscila Ferreira de Sales ◽  
Lidiany Mendonça Zacaroni Lima

A qualidade sensorial do chá está relacionada com a presença de voláteis que são formados nas etapas do processamento, assim o objetivo desse trabalho consistiu em investigar o perfil de Compostos Orgânicos Voláteis (COV´s) em amostras de chá comerciais com menta (amostra 1) e sem menta (amostras 2 e 3), por meio do emprego da técnica de microextração em fase sólida (SPME) e detecção por Cromatografia Gasosa acoplada à espectrometria de massas (CG-MS). As amostras foram submetidas ao tratamento por infusão, sendo avaliado o efeito da adição de sal (NaCl) para a extração dos compostos. As amostras exibiram uma alta complexidade, sendo detectados aproximadamente 68 compostos.  Empregando o reconhecimento de padrões, o qual envolveu os algoritmos de PCA e HCA, verificou-se que a amostra 1 se diferiu das demais por apresentar picos comuns com maior intensidade e por possuir compostos orgânicos voláteis característicos da referida amostra. Os resultados também permitiram inferir que o efeito dos tratamentos foi mais expressivo nessa amostra, visto que o processo de infusão atuou na diminuição dos compostos voláteis detectados pela técnica. A adição de sal favoreceu a extração dos analitos, em que se verificou que as amostras em infusão com NaCl apresentaram maior similaridade com aquelas na forma comercial. A mesma tendência foi observada nas amostras submetidas aos tratamentos. Palavras-chave: Cromatografia. Extração de analitos. Qualidade sensorial.   Comparative analysis of the profile of volatile compounds by HS-SPME in commercial samples of green tea and assessing the effect of infusion and addition salt Abstract As the sensory quality of the tea is related to the presence of volatile compounds that are formed in the processing steps, the objective of this work was to investigate the profile of volatile organic compounds (VOC's) in commercial mint tea samples (sample 1) and without mint (samples 2 and 3) through the use of microextraction technique of solid phase extraction (SPME) and detection by gas chromatography-mass spectrometry (GC-MS). The samples were subjected to treatment by infusion, being evaluated the effect of the addition of salt (NaCl) for the extraction of compounds. The samples exhibited a high complexity, about 68 compounds were detected. Employing the pattern recognition algorithms which involved PCA and HCA, it was found that sample 1 is differed from the others because it presents common peaks with greater intensity and having volatile organic compounds characteristic of said sample. The results also possible to infer that the treatment effect was more significant in this sample, because the infusion process worked at reduction of volatile compounds. Adding salt favored the extraction of analytes in which it was found that the samples infused with NaCl were similar to those in commercial form. The same trend was observed in all the samples submitted to treatments. Keywords: Chromatography. Extraction of analytes. Sensory quality.

2020 ◽  
Vol 9 (10) ◽  
pp. e5069108880
Author(s):  
Paulo Herbesson Pereira de Sousa ◽  
Cláudia Inês da Silva ◽  
Breno Magalhães Freitas ◽  
Tigressa Helena Rodrigues Soares ◽  
Isac Gabriel Abrahao Bomfim ◽  
...  

This study tested three types of Solid-Phase Microextraction fibers in developing a method to extract volatile organic compounds present in the diet of immature Centris analis. Samples were placed in glass vials with metal lids and added with 3g NaCl and 8 ml deionized water. Extraction and characterization were carried out using a Headspace – Solid Phase Microextraction (HS-SPME) with Gas Chromatography – Mass Spectrometry, and the three types of fibers were polydimethylsiloxane (PDMS), divinylbenzene/ carboxen/ polydimethylsiloxane (DVB/CAR/PDMS) and carboxen/ polydimethylsiloxane (CAR/PDMS). Each type of fiber was exposed to volatiles for 30 min and analyzed in a chromatograph Agilent GC-MS equipped with a quadrupole detector (MSD 5977A), containing a HP-5MS (30 m x 0.25 mm x 0.25 µm) column and Helium as the carrier gas (1 ml.min-1). The CAR / PDMS fiber favored the extraction of volatile compounds to semi-volatile compounds, followed by DVB / CAR / PDMS, while PDMS presented a lower number of extracted compounds, which can be attributed to its apolar nature. The volatile compounds identified in the diet included alcohols, aldehydes, esters, ketones, and terpenes. The SPME technique has proven effective in the extraction of volatile organic compounds from immature of Centris analis diet, being the CAR/PDMS the most suitable fiber for this.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2365 ◽  
Author(s):  
Siti Zakaria ◽  
Norashikin Saim ◽  
Rozita Osman ◽  
Zaibunnisa Abdul Haiyee ◽  
Hafizan Juahir

This study analyzed the volatile organic compounds (VOCs) of three mango varieties (Harumanis, Tong Dam and Susu) for the discrimination of authentic Harumanis from other mangoes. The VOCs of these mangoes were extracted and analysed nondestructively using Head Space-Solid Phase Micro Extraction (HS-SPME) coupled to Gas Chromatography-Mass Spectrometry (GC-MS). Prior to the analytical method, two simple sensory analyses were carried out to assess the ability of the consumers to differentiate between the Harumanis and Tong Dam mangoes as well as their preferences towards these mangoes. On the other hand, chemometrics techniques, such as principal components analysis (PCA), hierarchical clustering analysis (HCA), and discriminant analysis (DA), were used to visualise grouping tendencies of the volatile compounds detected. These techniques were successful in identifying the grouping tendencies of the mango samples according to the presence of their respective volatile compounds, thus enabling the identification of the groups of substances responsible for the discrimination between the authentic and unauthentic Harumanis mangoes. In addition, three ocimene compounds, namely beta-ocimene, trans beta-ocimene, and allo-ocimene, can be considered as chemical markers of the Harumanis mango, as these compounds exist in all Harumanis mango, regardless the different sources of the mangoes obtained.


Author(s):  
Antonia Flores ◽  
Silvia Sorolla ◽  
Concepció Casas ◽  
Rosa Cuadros ◽  
Anna Bacardit

Volatile organic compounds (VOCs) and Semi-Volatile Organic Compounds (SVOCs) arise from the chemicals used in the various stages of the leather manufacturing process. An important aim of the tanning industry is to minimize or eliminate VOCs and SVOCs, without lowering the quality of leather.   This paper shows the development of a new headspace-solid phase micro extraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS) method for the identification of VOCs and SVOCs emitted by newly designed polymers for the leather finishing operation. These new polymers are polyurethane resins designed to reduce the VOC and SVOC concentration. This method enables a simple and fast determination of the qualitative and semi-quantitative content of VOCs and SVOCs in polyurethane-type finishing resins. The chemicals that are of concern in this paper are the following: Dipropylene glycol Monomethyl Ether (DPGME), DBE-3 (a mixture of dibasic esters) and Triethylamine (TEA). The test conditions that have been determined to carry out the HS-SPME assay are the following: incubation time (2 hours), extraction temperature and time (40°C; 5 minutes) and the desorption conditions (280°C, 50 seconds).  Ten samples of laboratory scale resins were tested by HS-SPME followed by gas chromatography (GC-MS). DPGME and DBE-3 (a mixture of dimethyl adipate, dimethyl glutarate and dimethyl succinate) have been identified effectively. The compounds are identified by a quantitative method using external calibration curves for the target compounds. The technique is not effective to determine the TEA compound, since the chromatograms shown poor resolution peaks for the standard. 


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kristen L. Reese ◽  
Carolyn L. Fisher ◽  
Pamela D. Lane ◽  
James D. Jaryenneh ◽  
Matthew W. Moorman ◽  
...  

Abstract Algae ponds used in industrial biomass production are susceptible to pathogen or grazer infestation, resulting in pond crashes with high economic costs. Current methods to monitor and mitigate unhealthy ponds are hindered by a lack of early indicators that precede culture crash. We used solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) to identify volatiles emitted from healthy and rotifer infested cultures of Microchloropsis salina. After 48 hours of algal growth, marine rotifers, Brachionus plicatilis, were added to the algae cultures and volatile organic compounds (VOC) were sampled from the headspace using SPME fibers. A GC-MS approach was used in an untargeted analysis of VOCs, followed by preliminary identification. The addition of B. plicatilis to healthy cultures of M. salina resulted in decreased algal cell numbers, relative to uninfected controls, and generated trans-β-ionone and β-cyclocitral, which were attributed to carotenoid degradation. The abundances of the carotenoid-derived VOCs increased with rotifer consumption of algae. Our results indicate that specific VOCs released by infected algae cultures may be early indicators for impending pond crashes, providing a useful tool to monitor algal biomass production and pond crash prevention.


Author(s):  
Dalma Radványi ◽  
András Geösel ◽  
Zsuzsa Jókai ◽  
Péter Fodor ◽  
Attila Gere

Button mushrooms are one of the most commonly cultivated mushroom species facing different risks e.g.: viral, bacterial and fungal diseases. One of the most common problems is caused by Trichoderma aggressivum, or ‘green mould' disease. The presence or absence of mushroom disease-related moulds can sufficiently be detected from the air by headspace solid-phase microextraction coupled gas chromatography-mass spectrometry (HS SPME GC-MS) via their emitted microbial volatile organic compounds (MVOCs). In the present study, HS SPME GC-MS was used to explore the volatile secondary metabolites released by T. aggressivum f. europaeum on different nutrient-rich and -poor media. The MVOC pattern of green mould was determined, then media-dependent and independent biomarkers were also identified during metabolomic experiments. The presented results provide the basics of a green mould identification system which helps producers reducing yield loss, new directions for researchers in mapping the metabolomic pathways of T. aggressivum and new tools for policy makers in mushroom quality control.


2009 ◽  
Vol 4 (12) ◽  
pp. 1934578X0900401 ◽  
Author(s):  
Marisa Piovano ◽  
Juan A. Garbarino ◽  
Elizabeth Sánchez ◽  
Manuel E. Young

The compounds responsible for the characteristic odor of eight fresh non-edible Basidiomycetes fungi were evaluated. The volatile organic compounds from the fresh samples present in the headspace of a sealed vial were determined by solid-phase microextraction gas chromatography-mass spectrometry, using a PDMS/DVB fiber. A total of twenty-eight components were identified, the most frequent being 1-octen-3-ol and 3-octanone.


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