scholarly journals Leaf epicuticular waxes of eleven Euphorbia species (Euphorbiaceae) from the Central Balkans: Impact on chemotaxonomy

2019 ◽  
Vol 71 (1) ◽  
pp. 21-26
Author(s):  
Gordana Krstic ◽  
Ivana Aljancic ◽  
Jovana Stankovic ◽  
Mirjana Cvetkovic ◽  
Petar Marin ◽  
...  

The presence of n-alkanes, free alcohols and free acids in leaf epicuticular wax extracts of 22 samples of 11 Euphorbia L. species belonging to the sections Paralias, Esula, Myrsiniteae and Helioscopia, 10 of which were never examined before, were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS), and n-alkane C27 was detected as the principal component of leaf epicuticular waxes in the majority of the examined species, while the most abundant free alcohol was C26. Three Euphorbia species belonging to section Helioscopia were characterized by a predominance of alcohol C28. Free acid (C16) was the major component in 21 investigated samples. The usefulness of n-alkanes and free alcohols and free acids as potential chemotaxonomic markers is briefly discussed.

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1180
Author(s):  
Xiaoyu Yin ◽  
Qian Chen ◽  
Qian Liu ◽  
Yan Wang ◽  
Baohua Kong

Smoking is mainly used to impart desirable flavour, colour and texture to the products. Various food smoking methods can be divided into traditional and industrial methods. The influences of three different smoking methods, including traditional smouldering smoke (TSS), industrial smouldering smoke (ISS) and industrial liquid smoke (ILS), on quality characteristics, sensory attributes and flavour profiles of Harbin red sausages were studied. The smoking methods had significant effects on the moisture content (55.74–61.72 g/100 g), L*-value (53.85–57.61), a*-value (11.97–13.15), b*-value (12.19–12.92), hardness (24.25–29.17 N) and chewiness (13.42–17.32). A total of 86 volatile compounds were identified by headspace solid phase microextraction combined with comprehensive two-dimensional gas chromatography mass spectrometry (GC × GC-qMS). Among them, phenolic compounds were the most abundant compounds in the all sausages. Compared with sausages smoked with smouldering smoke, the ILS sausages showed the highest content of volatile compounds, especially phenols, alcohols, aldehydes and ketones. Principal component analysis showed that the sausages smoked with different methods had a good separation based on the quality characteristics and GC × GC-qMS data. These results will facilitate optimising the smoking methods in the industrial production of smoked meat products.


2016 ◽  
Vol 78 (2) ◽  
Author(s):  
Nurrulhidayah Ahmad Fadzlillah ◽  
Abdul Rohman ◽  
Arieff Salleh Rosman ◽  
Farahwahida Mohd Yusof ◽  
Amin Ismail ◽  
...  

Butter is high priced product; as a consequence, butter can be subjected for adulteration with low price components such as lard. The presence of lard in any products is not allowed for Muslim and Jewish, therefore, its presence must be identified. Gas chromatography-mass spectrometry was successfully used to detect and discriminate butter from adulterated with lard. Results were presented in the form of chromatogram. Principal component analysis (PCA) was used to interpret the data and provided a good grouping of samples with 55.8% of the variation accounted for by PC 1 and 21.5% were accounted for by PC 2. All the lard containing samples formed a separate group from the samples that were free of lard. This method can be developed into a rapid method for detecting the presence of lard in food samples for Halal authentication.


2021 ◽  
Vol 117 (11/12) ◽  
Author(s):  
Pabalala M. Mthembi ◽  
Ellen M. Mwenesongole ◽  
Michael D. Cole

Nyaope, a Tswana word for a mixture or ‘mish-mash’, describes a drug cocktail consisting of heroin, cannabis, and on occasion other controlled substances and warfarin. It is highly addictive with extremely unpleasant side effects caused by withdrawal from the drug. It is a problem drug especially in townships in South Africa. However, its prevalence in neighbouring southern African states and further afield is not yet known. There is currently no validated method for the analysis and comparison of nyaope. We describe a validated method for the gas chromatography – mass spectrometry analysis of nyaope so that within-batch and between-batch comparisons of nyaope can successfully be made for the first time. The validated method managed an accuracy within the range 80–120%, the precision was less than 20% for all analytes and managed linearity with R2≥0.99. The detection limits for diamorphine, efavirenz, nevirapine and Δ9-tetrahydrocannabinol were 14.2, 18.6, 18.7 and 9.94 pg on column, respectively, and the limits of quantitation were 43.1, 56.3, 56.6 and 30.1 pg on column, respectively. The simulated and casework samples were successfully discriminated into original batches using the identified nyaope components, the unsupervised chemometric methods principal component analysis and hierarchical clustering, as well as chromatographic profiles.


Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 572 ◽  
Author(s):  
Qin Long ◽  
Zhong Li ◽  
Bin Han ◽  
Hamid Gholam Hosseini ◽  
Huaying Zhou ◽  
...  

Background: Alpinia officinarum Hance is both an herbal medicine and a condiment, and generally has different cultivars such as Zhutou galangal and Fengwo galangal. The appearance of these A. officinarum cultivars is similar, but their chemical composition and quality are different. It is therefore important to discriminate between different A. officinarum plants to ensure the consistency of the efficacy of the medicine. Therefore, we used an electronic nose (E-nose) to explore the differences in odor information between the two cultivars for fast and robust discrimination. Methods: Odor and volatile components of all A. officinarum samples were detected by the E-nose and gas chromatography-mass spectrometry (GC-MS), respectively. The E-nose sensors and GC-MS data were analyzed respectively by principal component analysis (PCA), the correlation between E-nose sensors and GC-MS data were analyzed by partial least squares (PLS). Results: It was found that Zhutou galangal and Fengwo galangal can be discriminated by combining the E-nose with PCA, and the E-nose sensors S2, S6, S7, S9 were important sensors for distinguishing different cultivars of A. officinarum. A total of 56 volatile components of A. officinarum were identified by the GC-MS analysis, and the composition and content of the volatile components from the two different A. officinarum cultivars were different, in particular the relative contents of 1,8-cineole and α-farnesene. The classification result by PCA analysis based on GC-MS data was consistent with the E-nose results. The PLS analysis demonstrated that the volatile terpene, alcohol and ester components primarily interacted with the sensors S2 and S7, indicating that particular E-nose sensors were highly correlated with some aroma constituents. Conclusions: Combined with advanced chemometrics, the E-nose detection technology can discriminate two cultivars of A. officinarum, with GC-MS providing support to determine the material basis of the E-nose sensors’ response.


Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1385 ◽  
Author(s):  
Dong Han ◽  
Si Mi ◽  
Chun-Hui Zhang ◽  
Juan Li ◽  
Huan-Lu Song ◽  
...  

The primary aim of this study was to investigate volatile constituents for the differentiation of Chinese marinated pork hocks from four local brands, Dahongmen (DHM), Daoxiangcun (DXC), Henghuitong (HHT) and Tianfuhao (TFH). To this end the volatile constituents were evaluated by gas chromatography-mass spectrometry/olfactometry (GC-MS/O), electronic nose (E-nose) and chemometrics. A total of 62 volatile compounds were identified and quantified in all pork hocks, and 24 of them were considered as odour-active compounds because their odour activity values (OAVs) were greater than 1. Hexanal (OAV at 3.6–20.3), octanal (OAV at 30.3–47.5), nonanal (OAV at 68.6–166.3), 1,8-cineole (OAV at 36.4–133.3), anethole (OAV at 5.9–28.3) and 2-pentylfuran (OAV at 3.5–29.7) were the key odour-active compounds contributing to the integral flavour of the marinated pork hocks. According to principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) of GC-MS/O and E-nose data, the results showed that the marinated pork hocks were clearly separated into three groups: DHM, HHT, and DXC-TFH. Nine odour-active compounds, heptanal, nonanal, 3-carene, d-limonene, β-phellandrene, p-cymene, eugenol, 2-ethylfuran and 2-pentylfuran, were determined to represent potential flavour markers for the discrimination of marinated pork hocks. This study indicated the feasibility of using GC-MS/O coupled with the E-nose method for the differentiation of the volatile profile in different brands of marinated pork hocks.


Author(s):  
Tengku Fazarina Tengku Ab Ghani ◽  
Hasmerya Maarof ◽  
Mohamed Noor Hassan

Perfume is a mixture of fragrant essential oils and aroma compounds, fixatives, and solvents used to give human body, objects, and living spaces a pleasant odour. Perfume compositions are mixture of natural and synthetic sources which consist of 100 or more components. The difference in composition of perfume is the  main characteristics which can classify the perfume into several groups such as animal and plant sources. Therefore, correct identification of each perfume product composition is crucial in order to do the classification. The perfume products have been analyzed using gas chromatography mass spectrometry and chemometric technique. There are 34 samples of perfume products used in this article which is taken from different brand available around Skudai. Chemometric technique was applied in this research to simplify data obtained by allowing them to form classes to their respective groups. Two unsupervised pattern recognition technique namely principal component analysis (PCA) and cluster analysis were used. The perfume product samples investigated in this research can be classified into two main groups namely animal and plant sources. Principal component analysis (PCA) and cluster analysis were successfully used in classifying the perfume product according to their respective groups based on the compositional information from the chromatogram of each samples.________________________________________GRAPHICAL ABSTRACT


Sign in / Sign up

Export Citation Format

Share Document