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Showing 3 results for Gas Chromatography Mass Spectrometry
Effects of planting times on the chemical compositions, antioxidant activity and nutritional properties of Allium jesdianum Boiss. & Buhse leaves in Lorestan province

Volume 11, Issue 3 (9-2023)
Abstract
Aims: The aim of this study was to investigate nutritional and phytochemical changes of A. jesdianum leaves on different planting dates.
Materials and methods: The same wild bulbs were cultivated in the October/January 2017 and harvested  on 25 April, 2018. Essential oils were analyzed by Gas Chromatography (GC)and Gas chromatography mass spectrometry (GC-MS). Also, total protein, vitamin C, non-structural sugars, antioxidant activity and nutritional elements of the shoots were measured. Findings: The main compounds of the leaf essential oil in October, November, December and January were Dimethyl trisulfide (12.11%, 15.1%, 12.4% and 10.2%). The results showed that the morphological traits of A. jesdianum in different planting dates have a significant difference(P > 0.05). The highest germination (68.33%), shoot height (31.33 cm), root leagth (16.33 cm), aerial dry weight (3.50 g), bulb diameter (3.76 cm), bulb fresh weight (12.66 g), bulb dry weight (6.40 g), leaf length (24.4 cm) and leaf width (1.43 cm) were recorded in November plants. As well as bulbs cultivated in November had the highest , amount of potassium (13.7 mg.g-1 DW), iron (2.5 μg.g-1 DW), copper (0.43 μg.g-1 DW), zinc (2.1 μg.g-1 DW) and manganese (2 μg.g-1 DW) compared to other planting dates. The highest amount of vitamin C (86.33 mg.100g-1 FW), antioxidant potency (IC50=37.00 μg.mL-1 , phenolic (77.00 mg galic acid.100 mg-1 DW), flavonol (66.66 mg rutin.100 mg-1 DW), and flavonoid (136.33 mg rutin.100 mg-1 DW) were obtained in the planted samples in November.
Antibacterial Activity and Chemical Composition of Ajowan (Carum copticum Benth. & Hook) Essential Oil

Volume 13, Issue 2 (3-2011)
Abstract
Gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS) were employed to determine the chemical composition of essential oil obtained from dry fruits of Carum copticum. Thymol (36.7%), -terpinene (36.5%) and -cymene (21.1%) were found to be the major constituents of the oil. The anti-bacterial activities of the oil were mainly investigated against food poisoning bacteria (Salmonella thyphimorium, Pseudomonas aeruginosa, Entero-pathogenic Escherichia coli, and Staphylococcus aureus) by broth microdilution and agar diffusion methods. The oil exhibited significant anti-bacterial activities against all the examined bacteria. In conclusion, the results of this study showed that the oil of Ajowan is rich in monoterpenes and it may be used as a natural anti-bacterial agent in drug and food industries.
Evaluation of the effect of olive, sesame and sunflower pulp for fatty acids production in semi-open culture Yarrowia lipolytica
Helia Ramezani, Mohaddeseh Larypoor, Minoo Sadri,
Volume 13, Issue 2 (1-2023)
Abstract
Among the sources of oils (vegetable, animal, microorganism), microbial oil has attracted the attention of many researchers. Oily microorganisms are able to accumulate 20 to 80% of lipids in each dry biomass. Among various microorganisms (bacterias, microalgae, fungal species including yeasts), some yeasts are considered to be the superior source of oil production. Yarrowia lipolytica is an excellent example of oily microorganisms with high fat production efficiency. By using cheap, native and available pulp as a production medium, the cost of oil produced by yeasts can be reduced. The microbial oil produced is used for medicinal, food and cosmetic purposes. In this study, the pleomorphism of Yarrowia lipolytica (ATCC 18942) was examined microscopically in different culture media. After culturing the  yeast in media containing olive, sesame and sunflower pulp, in semi-open culture conditions, the fatty acids produced were analyzed using GC-MS and FTIR techniques. After reviewing the results, the medium containing olive pulp was selected and the microbial lipid produced in this medium was extracted. Then dry weight of biomass and microbial fat were measured. The results showed that the fatty acids extracted from the medium containing olive oli cake included oleic acid, palmitic acid, linoleic acid and stearic acid, which had the best production of fatty acids among the pulp. The content of  microbial fat and dry weight were 4.07 and 7.83 g/l, respectively, and microbial fat production efficiency was 51.97%.

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