PubMed · 13394585
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
F M HUNTER, W G UNGLAUB. 1957. Essential fatty acids.. https://doi.org/10.1097/00000441-195701000-00016
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Fatty acids play critical roles in biological systems. Imbalances in fatty acids are related to a variety of diseases, which makes the measurement of fatty acids in biological samples important. Many analytical strategies have been developed to investigate fatty acids in various biological samples. Due to the structural diversity of fatty acids, many factors need to be considered when developing analytical methods including extraction methods, derivatization methods, column selections, and internal standard selections. This review focused on gas chromatography-mass spectrometry (GC-MS)-based methods. We reviewed several commonly used fatty acid extraction approaches, including liquid-liquid extraction and solid-phase microextraction. Moreover, both acid and base derivatization methods and other specially designed methods were comprehensively reviewed, and their strengths and limitations were discussed. Having good separation efficiency is essential to building an accurate and reliable GC-MS platform for fatty acid analysis. We reviewed the separation performance of different columns and discussed the application of multidimensional GC for improving separations. The selection of internal standards was also discussed. In the final section, we introduced several biomedical studies that measured fatty acid levels in different sample matrices and provided hints on the relationships between fatty acid imbalances and diseases.
Protein, fat content, and beany odor affect consumers' choice of soy foods. Our objective was to characterize protein, lipid, and lipoxygenase activities and fatty acid compositions in food soybeans and to determine how chemical composition and enzyme activities related to the generation of beany odor components, including hexanal, hexanol, trans-2-nonenal, 1-octen-3-ol, and trans-2,trans-4-decadienal in soymilk. Protein, lipid, and fatty acid compositions and lipoxygenase activities of five soybean materials, including Proto, IA2032, IA 2064, IA3017, and L-Star varieties, were analyzed. Soymilk was prepared by a traditional method involving soaking, grinding, and cooking processes. Selected odor compounds in raw and cooked soymilk were analyzed by solid-phase microextraction and gas chromatography. Results showed that soybeans differed in crude protein and lipid content, lipoxygenase activities, and fatty acid compositions. L-Star had the highest and Proto the lowest lipid content among the five soybean cultivars. Protein content, lipoxygenases, and linoleic acid were positively correlated with beany odor content in soymilk made from the selected soybean materials. After boiling for 20 min, the soymilk made from L-Star and IA2032 retained the lowest odor profiles among the soymilk products made from the five selected materials.
Seeds of different cultivars of Glycine max (L.) Merr. (soybean) have strikingly different rates of water imbibition. Seeds that readily imbibe water are termed 'soft', while those that remain non-permeable, even after several days in water, are referred to as 'hard', 'stone', or 'impermeable' seeds. What prevents soybean hard seeds from taking up water? Previous work established that the initial imbibition of soft soybean seeds correlates with the presence of small cracks in the outermost cuticle that covers the seed coat, prompting a detailed analysis of soybean seed coat cutin. In this paper, it is shown that the outermost cuticle of the seed coat has an unusual chemical composition, lacking typical mid-chain-hydroxylated fatty acids but being relatively rich in other types of hydroxylated fatty acids. The cuticle of the impermeable cultivar studied contained a disproportionately high amount of hydroxylated fatty acids relative to that of the permeable ones. Moreover, a brief treatment with hot alkali released the omega-hydroxy fatty acid component of the outermost cuticle and created holes in it that caused the seeds to become permeable. This demonstrates that the outermost cuticle of the seed is the critical structure that prevents water uptake by hard seeds.