To meet the growing interest of utilizing microalgae biomass in the production of biofuels and nutraceutical and pharmaceutical lipids, we need suitable analytical methods and a comprehensive database for their lipid components. The objective of the present work was to demonstrate methodology and provide data on fatty acid composition, lipid class content and composition, characteristics of the unsaponifiables, and type of chlorophylls of five microalgae. Microalgae lipids were fractionated into TAG, FFA, and polar lipids using TLC, and the composition of fatty acids in total lipids and in each lipid class, hydrocarbons, and sterols were determined by GC-MS. Glyco-and phospholipids were profiled by LC/ESI-MS. Chlorophylls and their related metabolites were qualified by LC/APCI-MS. The melting and crystallization profiles of microalgae total lipids and their esters were analyzed by DSC to evaluate their potential biofuel applications. Significant differences and complexities of lipid composition among the algae tested were observed. The compositional information is valuable for strain selection, downstream biomass fractionation, and utilization. ABSTRACT: To meet the growing interest of utilizing microalgae biomass in the production of biofuels and nutraceutical and pharmaceutical lipids, we need suitable analytical methods and a comprehensive database for their lipid components. The objective of the present work was to demonstrate methodology and provide data on fatty acid composition, lipid class content and composition, characteristics of the unsaponifiables, and type of chlorophylls of five microalgae. Microalgae lipids were fractionated into TAG, FFA, and polar lipids using TLC, and the composition of fatty acids in total lipids and in each lipid class, hydrocarbons, and sterols were determined by GC-MS. Glyco-and phospholipids were profiled by LC/ESI-MS. Chlorophylls and their related metabolites were qualified by LC/APCI-MS. The melting and crystallization profiles of microalgae total lipids and their esters were analyzed by DSC to evaluate their potential biofuel applications. Significant differences and complexities of lipid composition among the algae tested were observed. The compositional information is valuable for strain selection, downstream biomass fractionation, and utilization.

Polyacrylonitrile (PAN) was electrospun in dimethylformamide as a function of electric field, solution flow rate, and polymer concentration (C). The fiber diameter increased with C and ranged from 30 nm to 3.0 mm. The fiber diameter increased with the flow rate and decreased when the electric field was increased by a change in the working distance; however, it did not change significantly when the electric field was varied by a change in the voltage at a given working distance. The fibers below about 350 nm diameter contained beads, whereas above this diameter, bead-free fibers were obtained. For PAN with a molecular weight of 100,000 g/mol, the fiber diameter scaled as C , consistent with De Gennes's scaling concepts. In the semidilute unentangled regime (0.5-3.1 wt %), where the viscosity scaled as C 1.3 , microscopic or nanoscopic particles rather than fibers were obtained. Concentrationdependent electrospinning studies were also carried out for higher molecular weight PAN (250,000 and 700,00 g/mol). The results of these studies are also presented and discussed.

Antioxidant activity of phytosterols, oryzanol, ferulic acid ester of sterols, corn fiber oil, and rice bran oil was investigated. Commercial soybean oil and distilled soybean oil FAME were used as substrates for both oxidative stability determination and viscosity analysis after the oil was oxidized. At low concentration, these materials did not improve the oxidative stability of the oil substrates, although the viscosity tended to be reduced slightly. The antipolymerization activity of steryl ferulate was higher at higher concentration than at lower concentration, and steryl ferulate was more effective than oryzanol. Rice bran oil showed very good antioxidant and antipolymerization activities. RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/fshn_ag_pubs/16 ABSTRACT: Antioxidant activity of phytosterols, oryzanol, ferulic acid ester of sterols, corn fiber oil, and rice bran oil was investigated. Commercial soybean oil and distilled soybean oil FAME were used as substrates for both oxidative stability determination and viscosity analysis after the oil was oxidized. At low concentration, these materials did not improve the oxidative stability of the oil substrates, although the viscosity tended to be reduced slightly. The antipolymerization activity of steryl ferulate was higher at higher concentration than at lower concentration, and steryl ferulate was more effective than oryzanol. Rice bran oil showed very good antioxidant and antipolymerization activities.

Egg-yolk lecithin has phospholipid (PL) classes and a FA composition that differ from soybean lecithin and may have unique functional properties. The purposes of this research were to develop an effective method for extracting a sufficient amount of lecithin from fresh egg yolks and to evaluate its functional properties. Ethanol was used to dehydrate and partially extract the PL, after which hexane was used to extract the total lipids. A phase separation of the combined extracts resulted in neutral and polar lipid fractions. An acetone precipitation of PL from the final polar lipid fraction was necessary to remove the residual neutral lipids, especially cholesterol. The purity of PL in the lecithin product was 95%. Surface tension reduction, emulsion stability, and oxidative stability studies were conducted to characterize the functional properties of egg-yolk lecithin. Egg-yolk lecithin and soy lecithin had similar surface activities, as evaluated by the surface tension reduction in an aqueous system and the critical micelle concentration. Soybean lecithin created a more stable emulsion than egg-yolk lecithin. However, egg-yolk lecithin was more oxidatively stable than soybean lecithin.Paper no. J11030 in JAOCS 82, 571-578 (August 2005). KEY WORDS:Egg-yolk lecithin, emulsion stability, functionality, phospholipids, oxidative stability, surface tension.Egg yolks are a good source of phospholipids (PL). PL represent approximately 10% of the wet weight of the egg yolk (1), equivalent to about 22% of the total egg yolk solids. The main components of egg-yolk lecithin are PC (80.5%) and PE (11.7%). Egg-yolk lecithin also contains lysophosphatidylcholine, sphingomyelin, and neutral lipids in minor quantities. The extraction of the total lipids or the PL from yolks is desirable because of the unique properties and valuable applications of these products (2). Yolk lecithin is used in the pharmaceutical and cosmetic industries as an emulsifier, and it is not as commonly used in foods as soy lecithin, because of its commercial availability and unfamiliar functional properties. It was recently reported that dietary egg-yolk PC can significantly lower cholesterol absorption in rats compared with soybean PC (3). In addition, egg-yolk lecithin contains relatively more saturated FA than does soybean lecithin, and it may have better oxidative stability than soybean lecithin. Therefore, yolk lecithin may have certain unique applications in foods. According to the limited information available in the literature, egg-yolk lecithin is primarily extracted with solvents such as diethyl ether, hexane, chloroform, and ethanol. However, some of these solvents are considered undesirable because of environmental and health concerns (2,4). Earlier research focused mainly on total lipid extraction and cholesterol removal. Sequential extractions with various solvents or a multisolvent system were investigated (5,6). Other PL fractionation techniques, such as ethanol extraction and then low-temperature crystallization to remove the solidified...

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