Crude vegetable extract

The majority of shed enterocytes collected during the perfusion are still functionally active and show no signs of apoptosis [67, 68]. On that basis, Petri et al. [19] were able to study the cellular response to phytochemicals In human enterocytes In vivo, by measuring differences in mRNA levels of phase 2 metabolizing enzymes. Indeed, the authors observed an immediate cellular response of the enterocytes to phytochemicals present in a crude vegetable extract [19]. 

FIGURE 15.38 Full mass scan TIC of a crude vegetable extract spiked with 5 ppb of a pesticides mixture on an ion trap instrument. At this low concentration level, the pesticide peaks are buried beneath the elevated baseline due to the presence of matrix. 

Once harvested, rapeseed is transported to an oil mill where vegetable oil is extracted. The crude vegetable oil is then refined. The refined vegetable oil is converted to FAME by esterification, which generates glycerol as a by-product (see Tables 7.7 to 7.9). 

Compared to refined vegetable oils, the compositions of crude vegetable oils and oil and fat products are more complicated. These samples contain proteins, carbohydrates, and minerals that interfere with HPLC separation and reduce the lifetime of the HPLC column. These compounds need to be largely eliminated from the extract before HPLC analysis. Saponification and heating are used to weaken sample matrices to allow the solvent to fully access all tocopherols and tocotrienols of the sample. Liquid/liquid extraction is used to remove these polar compounds from the organic solvent layer that contains tocopherols and tocotrienols. The normal-phase HPLC method is usually used for crude vegetable oils and vegetable oil products reversed-phase HPLC can be used for animal fat products. 

Because the PL concentration in the total lipid extract is generally rather low, a preconcentration step is generally required prior to HPLC analysis crude vegetable oils e.g., contain only 0.5-2.0% of phospholipids. 

Curare is the arrow poison of the South American Indians, and it may contain as many as 30 different plant ingredients, which may vary widely from tribe to tribe according to local custom. Curare is prepared in the rain forests of the Amazon and Orinoco, and represents the crude dried extract from the bark and stems of various plants. The young bark is scraped off, pounded, and the fibrous mass percolated with water in a leaf funnel. The liquor so obtained is then concentrated by evaporation over a fire. Further vegetable material may be added to make the preparation more glutinous so that it will stick to the arrows or darts. The product is dark brown or black, and tarlike. 

Investigation on antifeedants against a snail species that is a worldwide pest of many vegetables and several other crops, Acusta despesta, focused on the crude methanol extract from the Japanese cedar or Sugi, Cryptomeria japonica (Taxodiaceae). Two active compounds were isolated from the hexane extract (fractionated from the crude... 

Flash and Fire Point. Flash point is the temperature at which the volatile products are evolved at such a rate that they are capable of being ignited but not supporting combustion. At the fire point, the accumulated breakdown products are capable of supporting a flame on their own. A crude cottonseed oil with a fatty acid content of 1.8% was found to have a flash point of 560°F or 293.3°C. Solvent-extracted oils can have a low flash point because of a solvent residue. A flash point analysis would identify this crude oil deficiency to prevent an accidental fire or explosion in an atmosphere that was not explosion proof. Crude vegetable oil shipments received with a flash point below 250°F are rejectable by most trading rules. Figure 1 shows the relationship between free fatty acid content, smoke, flash, and fire points of processed cottonseed and peanut oils. 

Vegetable lecithins are obtained as a by-product in the vegetable oil refining process. Polar lipids are extracted with hexane and, after removal of the solvent, a crude vegetable oil is obtained. Lecithin is then removed from the crude oil by water extraction. Following drying, the lecithin may be further purified. ... 

One of the major applications of CPC is the purification of natural products from vegetal extracts (flowers, roots, etc.) or crude extracts from fermenta-... 

In solvent extraction crude vegetable oil and other useful materials are dissolved in a solvent to separate them from the insoluble meal. Many solvents have been evaluated for commereial extraction. Commercial hexane has been the main solvent for the oilseed processing industry since the 1940s because of its availability at reasonable eost and its suitable fiinetional characteristics for oil extraction. However, the interest in alternative solvents to hexane has continued and is motivated by one of a eombination of faetors desire for a nonflammable solvent, more efficient solvent, more energy efficient solvent, less hazardous and environmentally friendly solvent, solvent with improved produet quality, and solvents for niche/specialty markets. Today eommereial isohexane (hexane isomers) is replacing commercial hexane in a few oilseed extraction operations and other solvents (e.g., isopropanol, ethanol, acetone, etc.) are also being used for various extraction processes or have been evaluated for use as extracting solvents. ... 

One of the major applications of CPC is the purification of natural products from vegetal extracts (flowers, roots, etc.) or cmde extracts from fermentation broth without previous sample preparation. Hostettmann and coworkers have described many examples of isolation of natural products by CPC. Some flavonoids are, for instance, purified by using solvent systems containing chloroform, some cou-marins by using solvent systems containing HEX and EtOAc, and more polar products, such as tannins, by butanol-based systems. The main interest of this technique lies, however, in the possibility to overload its column so that all the applications of semipreparative chromatography are available. For instance, Menet and Thiebaut have separated 140 mg of an antibiotic from a crude extract of a fermentation broth. Some fractions of up to 95% purity were collected, while the original extract contained only 7% of the molecule of interest. They have also compared the performances of CPC, preparative LC, and hydrodynamic mode CCC. They finally showed that the solvent consumption is the lowest for CPC, while the enrichment is the best. 

In addition to homolipids, crude vegetable oils contain heterolipids and other components of plant material. The heteroHpids content depends on the technology used. The oil obtained through pressing contains 0.1%, while the extracted oil contains 1-2% and soybean oil contains 3-4% phospholipids. The heterolipids content of virgin oils is much lower, about 0.01%. 

Procedure Cholinesterase activity was measured according to the modified biochemical methods developed for crude preparations (Gorunef ah, 1978), using Ellman reagent 5,5"-dithio-bis(p-nitrobenzoic acid) or its red analogue 2,2-dithio-bis-(p-phenyleneazo)-bis-(l-oxy-8-chlorine-3,6) -disulfur acid in the form of sodium salt, which interact with thiocholine salt (Roshchina 2001). Water extracts of vegetative microspores of horsetail (Equisetum arvense) or Hippeastrum hybridum microspores (150 mg of microspores in 30 ml for 1 h) were used. 

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