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Showing total 786 results
Start Over Publication Year Range Last 50 years Journal journal of the american oil chemists' society Publisher springer berlin heidelberg
786 results

2. Supercritical Fluid Extraction and Chromatography of Lipids in Bilberry

Author

Margareta Sandahl, Firas Jumaah, and Charlotta Turner

Subjects
chemistry.chemical_classification, Wax, Original Paper, Chromatography, General Chemical Engineering, Organic Chemistry, Extraction (chemistry), Supercritical fluid extraction, Fatty acid, Supercritical fluid chromatography, Lipids, Sterol, Solvent, chemistry, visual_art, Chemical Engineering(all), visual_art.visual_art_medium, Bilberry, GC–MS, Gas chromatography–mass spectrometry, Fatty acids
Abstract

A supercritical fluid extraction (SFE) method has been developed for the extraction of lipids in bilberry. Experimental design was used to optimize pressure, temperature and extraction time using CO2 as solvent. Best SFE condition for total lipids was 450 bar, 60 °C and 45 min. The SFE method was compared to conventional Bligh & Dyer (B&D) extraction. The amount of fatty acid methyl esters (FAME) was found to be 4.84 ± 0.06 mg and 4.564 ± 0.003 mg per g of the freeze-dried bilberry sample for the developed SFE and B&D methods, respectively, while the amount of total lipids was found to be 54.40 ± 6.06 mg and 65.70 ± 0.67 mg per g of sample for SFE and B&D, respectively. This discrepancy between FAME and total lipids could be explained by the presence of wax esters, sterol esters, carotenoids and phospholipids, as determined by supercritical fluid chromatography. Electronic supplementary material The online version of this article (doi:10.1007/s11746-015-2680-x) contains supplementary material, which is available to authorized users.

Published
2015

3. Antioxidant Capacity of Rapeseed Extracts Obtained by Conventional and Ultrasound-Assisted Extraction

Author

Aleksandra Szydłowska-Czerniak and Agnieszka Tułodziecka

Subjects
Original Paper, ABTS, Chromatography, Rapeseed, Antioxidant, DPPH, General Chemical Engineering, medicine.medical_treatment, Organic Chemistry, Extraction (chemistry), Extraction, Antioxidant capacity, chemistry.chemical_compound, chemistry, Botany, Ultrasound, Chemical Engineering(all), medicine, Ferric, Cultivar, Trolox, medicine.drug
Abstract

Ultrasound-assisted extraction (UAE) and conventional solid–liquid extraction were applied to extract total antioxidants from two rapeseed varieties. The antioxidant capacities (AC) of winter and spring rapeseed cultivars were determined by four different analytical methods: ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), 2,2′-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The average AC of the studied rapeseed cultivars ranged between 4.21–10.03 mmol Trolox (TE)/100 g, 7.82–10.61 mmol TE/100 g, 8.11–51.59 mmol TE/100 g, 22.48–43.13 mmol TE/100 g for FRAP, CUPRAC, DPPH and ABTS methods, respectively. There are positive correlations between total phenolics (TPC = 804–1625 mg sinapic acid (SA)/100 g) and AC of the studied rapeseed extracts (r = 0.2650–0.9931). Results of the principal component analysis (PCA) indicate that there are differences between the total amounts of antioxidants in rapeseed samples extracted by different extraction techniques. Rapeseed extracts obtained after 18 min of ultrasonication revealed the highest content of total antioxidants. The UAE is a very useful, efficient and rapid technique of oilseed samples preparation for determination of AC by different analytical methods.

Published
2014

4. γ-Oryzanols of North American Wild Rice (Zizania palustris)

Author

Magdalena Rudzińska, Roman Przybylski, Felix Aladedunye, and Dorota Klensporf-Pawlik

Subjects
chemistry.chemical_classification, Hydroxylated steryl ferulate, Original Paper, Oryza sativa, γ-Oryzanol, General Chemical Engineering, Organic Chemistry, Rice bran oil, food and beverages, Wild rice, Biology, Steryl cinnamate, Steryl caffeate, Ferulic acid, chemistry.chemical_compound, chemistry, Triterpene, Botany, Regular brown rice, Chemical Engineering(all), Brown rice, Composition (visual arts), Food science, γ oryzanol, Zizania palustris
Abstract

γ-Oryzanol, a natural mixture of ferulic acid esters of triterpene alcohols and sterols, are an important bioactive components present in rice bran oil. In light of the recent increase in the popularity of wild rice among consumers, and the possibility of a direct relationship between γ-oryzanol composition and its bioactivity, the oryzanol profile of major wild rice (Zizania palustris) grown in North America was studied and compared to regular brown rice (Oryza sativa L.). A total of twenty-three γ-oryzanol components were separated, identified and quantified by HPLC coupled to an Orbitrap MS. The distribution of individual γ-oryzanols was similar for all the wild rice but significantly different from those of the regular brown rice. Unlike in the regular brown rice, a significant amount of steryl caffeate and cinnamate were found in the wild rice samples. Generally, the amounts of γ-oryzanol in the wild rice were higher compared to the regular brown rice, 1,352 vs. 688 μg/g. The results from this study showed that wild rice had a more diverse γ-oryzanol composition and the higher amounts compared to the regular brown rice.

Published
2013