Debranched unacetylated and acetylated potato starches with two degrees of substitution, 0.041 (low) and 0.078 (high), combined with or without β-amylase hydrolysis were prepared to form soluble and insoluble complexes with stearic acid. The effects of modifications on the complexation, thermal properties, and X-ray patterns of soluble and insoluble complexes were investigated. Acetylation decreased the recovery of insoluble complexes but increased that of soluble complexes. Low acetylated, β-amylase-treated starch had a significantly increased amount of complexed stearic acid (123.1 mg/g) for insoluble complexes; high acetylated, β-amylase-treated starch had the highest complexed stearic acid (61.2 mg/g) for the soluble complexes. The melting temperature of the complexes decreased with acetylation. All β-amylase-treated acetylated complexes displayed the V-type diffraction pattern with peaks at 2θ = 7.4°, 12.9°, and 20°. These results suggest that starch can be modified by acetylation, debranching, and/or β-amylase to produce significant quantities of soluble starch-stearic acid complexes.

Reports from chicken conjugated linoleic acid (CLA) feeding trials are limited to yolk total fatty acid composition, which consistently described increased saturated fatty acids and decreased monounsaturated fatty acids. However, information on CLA triacylglycerol (TAG) and phospholipid (PL) species is limited. This study determined the fatty acid composition of total lipids in CLA-rich egg yolk produced with CLA-rich soy oil, relative to control yolks using gas chromatography with flame ionization detection (GC-FID), determined TAG and PL fatty acid compositions by thin-layer chromatography-GC-FID (TLC-GC-FID), identified intact PL and TAG species by TLC-matrix-assisted laser desorption/ionization mass spectrometry (TLC-MALDI-MS), and determined the composition of TAG and PL species in CLA and control yolks by direct flow infusion electrospray ionization MS (DFI ESI-MS). In total, 2 lyso-phosphatidyl choline (LPC) species, 1 sphingomyelin species, 17 phosphatidyl choline species, 19 TAG species, and 9 phosphatidyl ethanolamine species were identified. Fifty percent of CLA was found in TAG, occurring predominantly in C52:5 and C52:4 TAG species. CLA-rich yolks contained significantly more LPC than did control eggs. Comprehensive lipid profiling may provide insight on relationships between lipid composition and the functional properties of CLA-rich eggs.

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Total or crude fat determination is commonly measured in lipid chemistry by traditional methods such as Soxhlet or Goldfisch extraction. These methods require hours of solvent reflux extraction, which may be necessary when lipids are well embedded into tissues and the surface area to weight ratio is low. However, many food materials may have oil that can be readily extracted without such exhaustive solvent extraction. Simple, practical, rapid extraction techniques are more cost effective when dealing with large number of samples if the lipids can be readily extracted from the food matrix.Clark and Snyder [1] developed a rapid, 1-min equilibrium extraction method of a 1-2-g soy flour sample with hexane at ambient temperature that produced results similar to those obtained by Goldfisch extraction to allow rapid screening of soybean cultivars. Subsequently, we developed a rapid, 1-min method for total lipid extraction with hexane and isopropanol of 2 g of rice bran samples for free fatty acid determination that produced the same results as the Goldfisch extraction [2]. Similarly, the oil contents of milled rice and potato chips were determined by rapid solvent extraction [3,4].However, we have not developed any rapid animal lipid extraction methods. We anticipate incorporating CLA-rich oil [5] in eggs through poultry feed. Therefore, a rapid egg yolk lipid extraction technique would be invaluable prior to egg fatty acid analysis by FAMES GC-FID analysis. The Folch method [6] is a commonly used procedure for total lipid extraction from eggs, but uses chloroform-methanol (2:1, v/v) to extract the lipids, followed by a water wash using 0.2 times the volume of sample. This method is both time consuming and constitutes a significant health hazard because of the use of chloroform. The development of a practical, simple, rapid extraction technique would be more cost effective, particularly when dealing with a large number of samples. Hara and Radin [7] described an efficient 1-min extraction procedure that is particularly adapted to nervous tissues using hexane/isopropanol (3:2, v/v). Using this method, the whole liquid phase is evaporated, eliminating a phase separation step. The objective of this study was to determine if a rapid hexane/isopropanol extraction would extract the same amount of lipid and have the same fatty acid profile as lipids obtained by the Folch method.Six eggs were collected from the University of Arkansas Poultry Science Department. Egg yolks were separated, combined and well mixed in a beaker with a stir-bar. Yolk samples were then diluted with distilled water to obtain 100, 75, 50 and 25 % dilutions of the original yolk mixture. Duplicate extractions of each dilution were made by the Folch method [6] and the following rapid extraction method. Duplicate 4-g samples were accurately weighed and vortexed with ten times the volume of hexane/isopropanol (1:1, v/v) for 5 min at room temperature. Homogenate was filtered using a funnel with Whatman no. 4 110-mm filter paper to recover only the liquid phase...

This paper presents the use of simple, outcome-based assessment tools to design and evaluate the first semester of a new introductory laboratory program created to teach green analytical chemistry using environmental samples. This general chemistry laboratory program, like many introductory courses, has a wide array of stakeholders within and beyond the major. Among the stakeholders, there was low-level yet widespread apprehension that changes in the introductory level content would weaken student preparation. Because of this unease, it was important to prove to faculty and students alike that the new laboratory program could effectively help students reach the new laboratory learning goals without sacrificing technical content. A set of simple assessment tools, student precision and accuracy data from experiments during the semester, and a laboratory practical and a student survey from the end of the semester were used as both formative and summative program assessments. This article establishes the power of these simple, course-embedded tools to yield insights into program strengths and weaknesses and, ultimately, to demonstrate to all faculty and students the effectiveness of this first-semester program.