scholarly journals Fatty Acids Analysis of Photosynthetic Sulfur Bacteria by Gas Chromatography

Author(s):  
Mara Teresa



2016 ◽  
Vol 36 (03) ◽  
pp. 308 ◽  
Author(s):  
Moh Taufik ◽  
Hanifah Nuryani Lioe ◽  
Nancy Dewi Yuliana

The fatty acid composition of palm oil is the major factor influencing its physical and chemical properties. The purpose of this research was to evaluate the analytical performance of major fatty acids (palmitic acid, stearic acid, oleic acid, and linoleic acid) analysis in palm oil. Triglycerides of palm oil were derivatized to fatty acid methyl esters (FAMEs) by using boron trifluoride (BF3) in methanol. FAMEs were determined by gas chromatography-flame ionization detection (GC-FID) using DB-23 capillary column as stationary phase. The studied parameters were instrument performance analysis, the efficiency of fatty acid derivatization, stability of derivatized analytes, accuracy, repeatability, intra-lab reproducibility, ruggedness, and method uncertainty. The evaluation results showed the instrument linearity at a working range of 5 to 40 mg/mL marked by coefficient of determination (R2) between 0.991-0.995. Instrument limits of detection (LOD) and instrument limits of quantification (LOQ) for 4 major fatty acids analysis were 26-35 µg/mLand 86-128 µg/mL, respectively. The increase of fatty acid concentration led to the decrease of derivatization efficiency in the fatty acids analysis. The result also showed that derivatized analytes were stable during 24 h storage at freeze temperature. The average recovery values by spiking method with the spiking concentration at 50 and 90 mg/g sample were at 75-94 % for stearic and linoleic acids analysis, however those for palmitic and oleic acids analysis were considered very low (<40 %), due to their low derivatization efficiency. Repeatability and intra-lab reproducibility of 4 major fatty acids analysis were at acceptable ranges, 0.45-1.38 % and 1.15-2.03 %, respectively. Determination by varying the volume of derivatizing agent showed the rugged method. Uncertainty of repeatability (Ur) and uncertainty of reproducibility (Ur) were ranged at 1.84-9.02 mg/g and 1.40-10.65 mg/g, respectively. This method was considerably reliable for the analysis of less abundance fatty acids in palm oil, stearic and linoleic acids.



ChemPlusChem ◽  
2015 ◽  
Vol 80 (5) ◽  
pp. 839-850 ◽  
Author(s):  
Petr Žáček ◽  
Jiří Kindl ◽  
Kateřina Frišonsová ◽  
Markéta Průchová ◽  
Alena Votavová ◽  
...  


2021 ◽  
pp. 1-5
Author(s):  
Tayanna Bernardo Oliveira Nunes Messias ◽  
Susana Paula Alves ◽  
Rui José Branquinho Bessa ◽  
Marta Suely Madruga ◽  
Maria Teresa Bertoldo Pacheco ◽  
...  

Abstract In this research communication we describe the composition of fatty acids (FA) present in the milk of the Nordestina donkey breed, and how they differ during lactation. Milk samples were taken from 24 multiparous lactating Nordestina donkeys that grazed the Caatinga, comprising 5 animals at each of around 30, 60 and 90 d in milk (DIM) and a further 9 animals ranging from 120 to 180 DIM. The milk fat content was analysed by mid infrared spectroscopy and the FA profile by gas chromatography. The milk fat percentage ranged from 0.45 to 0.61%. The main FA found in milk were 16:0 and 18:1c9. These did not differ among DIM classes and comprised 23% and 25% of total FA. Notably, the α-Linolenic acid (18:3 n-3) was the third most abundant FA and differed (P < 0.05) with DIM, being lowest in the 30 and 60 DIM samples (around 10.7% of total FA) and highest in the 60 and 90 DIM classes (around 14.6% of total FA). The low-fat content and the FA profile of the donkey milk gives it potential as a functional ingredient, which could help to preserve the commercial viability of the Nordestina donkey breed.



2011 ◽  
Vol 6 (11) ◽  
pp. 1934578X1100601 ◽  
Author(s):  
Ali Shafaghat

The hexane extracts of flower, leaf, stem, and seed of Hypericum scabrum, which were collected from northwestern Iran, were obtained by extraction in a Soxhlet apparatus. The fatty acids were converted to methyl esters and determined by gas chromatography/flame ionization detector (GC/FID) and gas chromatography/mass spectrometry (GC/MS) systems. The hexane extract from the flower, leaf, stem, and seed contained 39.1%, 43.2%, 29.0%, and 37.6% of omega-3 fatty acids, respectively. The other main components of the flower extract were tetracosane (12.2%) and palmitic acid (9.3%), and that of the leaf extract was palmitic acid (7.4%). The stem and seed extracts contained bis(2-ethylhexyl)phthalate (18.7% and 35.7%), nonacosane (11.7% and 3.9%) and linoleic acid (6.5% and 6.9%) as major components. The hexane extracts of different parts from H. scabrum represent an important source of omega-3 fatty acids in several Hypericum species. The antioxidant activity of all hexane extracts was evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The results indicate that hexane extracts from different parts of H. scabrum possess considerable antioxidant activity. The highest radical scavenging activity was detected in seed, which had an IC50 = 165 μg/mL. The antimicrobial activity of the extracts of those samples were determined against seven Gram-positive and Gram-negative bacteria ( Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, S. epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae), as well as three fungi ( Candida albicans, Saccharomyces cerevisiae, and Aspergillus niger). The bioassay showed that the oil exhibited moderate antimicrobial activity. This study reveals that the all parts of this plant are attractive sources of fatty acid components, especially the essential ones, as well as of effective natural antioxidants.



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