Enzymatic hydrolysis of fractionated products from oils thermally oxidized in the laboratory

Enzymatic hydrolysis of the acylglycerol products obtained from thermally oxidized vegetable oils was studied. Corn, sunflower and soybean oils were heated in the laboratory at 180 C for 50, 70 and 100 hr with aeration and directly fractionated by silicic acid column chromatography. By successive elution with 20%, then 60% isopropyl ether inn-hexane, and diethyl ether, the thermally oxidized oils were separated into three fractions: the nonpolar fraction (monomeric compounds), slightly polar fraction (dimeric compounds), and polar fraction comprising oligomeric compounds. Enzymatic hydrolysis with pancreatic lipase showed that the monomers were hydrolyzed as rapidly as the corresponding unheated oils, the dimers much more slowly, and the oligomeric compounds barely at all. Overall, the hydrolysis of the dimers was less than 23% of that for the monomers, with small differences among the oils. Longer heating periods resulted in greater reductions in hydrolysis of the dimeric compounds. These results suggest that the degree of enzymatic hydrolysis of the fractionated acylglycerol compounds is related to differences in the thermal oxidative deterioration, and amounts of polar compounds in the products.     

Alcoholic extraction of vegetable oils. Part IV. Solubilities of vegetable oils in aqueous 2-propanol

Summary Solubilities of 14 vegetable oils in four different concentrations of aqueous 2-propanol at various temperatures were determined by a direct and simple method. Comprehensive solubility data of these oils and the critical solution temperatureversus 2-propanol composition data are presented in tabular form. Solubility of each oil in aqueous 2-propanol increases with temperature until the critical solution temperature is reached, at and above which oil and the solvent are miscible in all proportions. Further the critical solution temperatures of all the oils with aqueous 2-propanol solutions increased with the increase in water content of 2-propanol solutions. There appears to be a general relation between fatty acid contents of the oils and critical solution temperatures which needs further study. Presented at the 30th fall meeting, American Oil Chemists' Society, September 24–26, 1956, Chicago, Ill.     

Quantitative extraction of pecan oil from small samples with supercritical carbon dioxide

A procedure to determine total oil content of pecan was developed for samples weighing 500 and 10 mg by supercritical fluid extraction (SFE) with carbon dioxide as the extraction solvent, and chilled hexane as the trapping solvent. Fatty acid methyl esters (FAMEs) were prepared from the total lipid fraction by using either an aliquot (500 mg starting weight) or the entire extract (10 mg starting weight). Total oil content obtained for either sample size with SFE was similar to that obtained with an organic solvent extraction technique. The fatty acid composition for the total lipid fraction of oils extracted with SFE was the same as for oils extracted with organic solvents, and oil composition did not change during SFE. Both oil yield and fatty acid composition were similar to those reported previously for pecan. Samples could be extracted and placed into FAME-derivatizing reagents in one day, and fatty acid composition of the total lipid fraction could be determined by gas-liquid chromatography the next day. The procedure, as demonstrated for pecan, should be suitable for other oilseeds, especially those containing low amounts of water.     

The use of natural essential oils as antimicrobial solutions in paper packaging. Part II

We have assessed the antimicrobial, vapor-phase activity of the following natural essential oils (EOs) when used in paraffin-based “active coatings” for paper packaging materials intended to come into contact with foods: clove (Sygzium aromaticum), cinnamon (Cinnamomum zeylanicum), and oregano (Origanum vulgare) EOs, and cinnamaldehyde-enriched cinnamon EO. To our knowledge, this is the first time that such an approach has been presented for consideration by the scientific community.     

Keeping properties of edible oils. Part II. Refining by treatment with alumina

A new refining technique is described in which the normal earth-bleaching process is replaced by a treatment of the neutral oil, in light petroleum solution, on a column of activated alumina. The products are generally of somewhat improved color and have considerably longer keeping times compared with conventional oils. The application of the process on the semi-large seale is described. Paper presented at the 5th Congress of the International Society for Fat Research, Gdansk, September, 1960.     

Gas-liquid chromatography of triglycerides from erucic acid oils and fish oils

By critically selecting optimum operating conditions, quantitative gas-liquid chromatography of triglycerides has been extended to molecules containing substantial amounts of C₂₀, C₂₂, and C₂₄ fatty acids. The triglycerides of four erucic acid oils (water cress, rapessed, nasturtium, andLunaria annua) and two fully hydrogenated fish oils (menhaden and tuna) have been quantitatively analyzed by this technique. The average fatty acid chain length calculated from the triglyceride composition of each oil agreed closely with that determined by GLC of its respective methyl esters. Several conclusions about the triglyceride composition of the fats analyzed are discussed. Winner, AOCS Bond Award. Presented at the AOCS Meeting in Cincinnati, October 1965.     

Alcoholic extraction of vegetable oils. II. Solubilities of corn,linseed, and tung oils in aqueous ethanol

Summary Solubilities of corn, linseed, and tung oils in aqueous alcoholic solutions at various temperatures have been determined by a direct and simple method. The solubility curves for the three oils in aqueous alcoholic solutions are presented. The critical solution temperatureversus alcohol composition data have been plotted for the three oils. It is observed that the critical solution temperature increases with the water content of the alcohol and that the relationship is linear in each case. Similar results were obtained for cottonseed, peanut, sesame, and soybean oils previously (1). The pressure in the system, increases with temperature; the maximum is approximately 20 p.s.i.g. Presented at the Philadelphia fall meeting, American Oil Chemists’ Society, October 11, 1955.     

Liquid-liquid extraction of BHT from vegetable oils

Partition behavior of the antioxidants BHT and BHA has been investigated betweenn-heptane and the polar phases; DMSO, DMF, acetonitrile and 80% methanol-water v/v. The distribution of four vegetable oils in these solvent pairs was also examined, as well as the influence of the oil on the partition of the antioxidants. Consideration has been given to requirements for quantitative extraction in the more promising cases.     

The pigments of crude cottonseed oils. II. Nitrogen-containing pigments derived from Gossypol

Summary Dark, crude cottonseed oil has been shown to contain a mixture of ninhydrin-sensitive substances combined with gossypol. Phenylalanine, aspartic acid, and glycine have been obtained by acid hydrolysis of the addition compound, followed by paper chromatography of the hydrolysate. The presence of other amino acids was indicated, but their identification could not be established with certainty; proline and hydroxyproline were apparently absent. The possibility that part of the color of dark, crude oils arises from gossypol-α-amino acid interaction is discussed. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

The absorption of fish oils and concentrates

Both preventive and curative therapies have created a considerable demand for eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. The most common sources for ω3 fatty acids are fish oil. The concentrations of EPA and DHA in commercial oils, after modest enrichment, reach about 300 mg/g; alternative technologies can produce reasonably priced fish oils containing 400 or even 500 mg/g of ω3 acids. When the acids are liberated from the glycerides, concentrates of ethyl esters or free acids with 65 to 70% total ω3 fatty acids (at least 50% EPA+DHA) are readily prepared. Difficulties have arisen because most clinical trials have used fish oils of unspecified composition, and some trials are now based on either ethyl esters or free acids. There are at least three different, but not mutually exclusive, absorption routes in humans, namely the preduodenal route, the lymphatic routevia chylomicrons, and the routevia the portal vein to the liver. This makes it difficult to compare results. The difficulty in obtaining dose-related clinical data may in part be due to the form in which the ω3 acids are offered and due in part to the natural presence of these fatty acids in the body. The nontriglyceride forms, especially the free acids, have been advocated for standardization of trials to facilitate interlaboratory comparisons. Based on a paper presented at the Symposium on Milk Lipids held at the AOCS Annual Meeting, Baltimore, MD, April 1990.     

Annual review of literature on fats,oils, and soaps. Part II

Journal of the American Oil Chemists' Society -     

Faster and easier methods for quantitative lipid extraction and fractionation from miniature samples of animal tissues

A less time-consuming dry-column method for total lipid extraction from tissue samples was scaled down and modified to permit the evaluation of 1-g samples of liver and muscle tissues from rats and from obese (ob/ob) and lean mice. Lipid yields obtained by the new dry-column method compared well with those obtained by the widely accepted traditional chloroform/methanol method. For subsequent separation of neutral and polar lipid classes, a solid-phase fractionation method was developed. Its performance was verified by thin-layer chromatogrphy. Both column chromatographic methods were found to be especially convenient when running multiple samples simultaneously.     

Toxicology studies. II. The laboratory animal

The laboratory animal can be thought of as the toxicologist's major instrument for use in a safety evaluation programme. Consequently, to obtain reliable results from such an ‘instrument’, the toxicologist must obtain animals of the highest quality available, and maintain as well as monitor them in such a manner that intercurrent infections or latent diseases do not produce effects leading to erroneous conclusions. The procedures described will enhance the reliability of the results obtained in toxicological studies.     

Glucoraphanin extraction from Cardaria draba: Part 1. Optimization of batch extraction

Glucosinolates have historically been considered an anti‐nutritional component of food and feed cereal crops. Large‐scale protocols have been aimed at complete glucosinolate elimination from plants, rather than maximizing the recovery of any particular glucosinolate compound. Recently, glucoraphanin, an alkenyl glucosinolate, has been found to have nutritional value in terms of anti‐carcinogenic behavior and hypertension relief. In this work, we report on the efficient capture of glucoraphanin from the noxious weed Cardaria draba. The effect of temperature, ethanol content in the aqueous solvent, initial solvent pH, solids loading, and contact time on both glucoraphanin and glucosinalbin recovery were examined. The optimal extraction conditions, evaluated using 0.11 dm³ stirred baffled vessels, were found to be 20% aqueous ethanol solvent at 70 °C and an initial pH value of 3, extracted at a solid to liquid ratio of 50 g dm^?3 over 20 mins. The recovery achieved with the baffled vessels was up to three times greater than the glucoraphanin yield obtained using standard analytical procedures that involved the use of 8.0 × 10^?3 dm³ of hot, 80% ethanol solutions in test tubes at the same solvent loading. This corresponds to 30 mg g^?1 of glucoraphanin recovered from the dried C draba leaves, versus only 10 mg g^?1 using the analytical method. Copyright © 2005 Society of Chemical Industry     

Non-structural cracking in RC walls: Part II. Quantitative prediction model

In this paper, for a quantitative assessment of non-structural cracking in an RC wall, an improved analytical model is proposed. First of all, to quantitatively calculate the cracking potential, an analytical model that can estimate the post-cracking behavior in an RC tension member is proposed. Unlike conventional approaches that use the bond-slip relationship or the assumed bond stress distribution, in our proposed approach the tensile strength of concrete at the post-cracking stage is quantified on the basis of polynomial strain distribution functions of steel and concrete. Predictions of cracking loads and elongations of reinforcing steel in RC tension members using the proposed model show good agreement with results from previous analytical studies and from experimental data. Subsequent comparisons of analytical results with test results verify that the combined use of both the approach in this paper as well as the approach previously introduced in the companion paper to this research make it possible to accurately predict the cracking behavior of RC walls. Additionally, the influence of changes in the material properties and construction conditions on the cracking in RC walls is investigated theoretically, using the numerical model proposed in this paper.     

The dynamics of extraction processes: Part II. Comparison of dynamic testing methods and their application to an extraction process

A comparison of the theoretical and experimental difficulties and advantages of sinusoidal, pulse, and step testing procedures, as applied to a continuous stagewise extraction process, is made. An experimental extraction apparatus suitable for a variety of dynamic studies is described. For this apparatus step testing has been found to give results as reliable as those from pulse methods. The paper develops the theoretical background and describes experimental implementation of double pulse testing. The extraction column when used with the system water-acetic acid-methyl isobutyl ketone was found to behave linearly over the range of variables studied. The stages of the column were found to be “well-mixed”, and it was concluded that the column could be best represented by a lumped parameter model.     

Production of commercial dyes via impingement-sheet mixing Part II. Results of laboratory experiments

Three commercial azo dyes of Ciba-Geigy AG were produced using the industrial impingement-sheet mixer discussed in Part 1 (Chem. Eng. Process., 29 (1991) 173–177) of this paper. Relative to conventional technology, yield increases of 7%–14% were obtained for two of the dyes. Impingement-sheet mixing of the third dye, however, produced small explosions in the mixed liquid sheet that decreased the observed yield. Inability to remove heat from the liquid sheets resulted in an adiabatic temperature rise that, coupled with a high reaction, pH, led to strong decomposition of the relatively unstable diazo reactant.     

千年健挥发油微波辅助提取研究

采用微波辅助溶剂萃取法(MASE)提取千年健挥发油,并利用GC-MS技术对其化学成分进行了分析。最佳提取条件为:石油醚作溶剂,微波功率600 W,提取温度60℃,提取时间25 min,在该条件下提取的挥发油共鉴定出63种成分,主要为芳樟醇(相对质量分数23.411%,下同),7-乙酰基-2-羟基-2-甲基-5-异丙基二环[4.3.0]壬烷(5.222%),4-松油醇(3.971%)。与传统水蒸气蒸馏法(HD)比较发现,MASE法节省时间,得率更高,同时化学组成成分差异不大,是一种完全可以替代HD法提取千年健挥发油的高效、节能的提取技术。