Fruits chlorophylls, extraction

For other plant food samples, appropriate sample sizes will depend on chlorophyll content and water content. Samples with low chlorophyll content may require 100 to 200 mg per replicate. For samples with low chlorophyll content and high water content (e.g., in florescences, fruit tissues, fruit juices), it is necessary to start with 2 to 3 g fresh weight sample and freeze dry it before extraction. Frozen food samples should also be freeze dried before extraction. 

Presents redetermined absorption coefficients for chlorophylls and total carotenoids, which allows the determination of all three in the same pigment extract of leaves or fruits... 

It is important to purify proanthocyanidins, particularly for determining their conversion yield. It is also advantageous to do so to eliminate extraneous material that might otherwise react with the proanthocyanidins. A combination of liquid-liquid extraction and adsorption chromatography is effective in removing impurities. The use of chloroform in liquid-liquid extraction is very effective in removing fat-soluble compounds such as carotenoids, chlorophyll, oils, and waxes. These compounds would be expected in leafy plant tissues (carotenoids and chlorophyll) as well as seeds and fruits (oils and waxes). Ethyl acetate is effective in the selective removal of flavan-3-ol monomers, which are also typically present with proanthocyanidins. 

Because of the varied nature of the plant tissues from which the proanthocyanidin extracts are derived, it is difficult to anticipate the expected outcome. As an example of how these procedures can be adapted to specific tissues and analyses, using grape tissues, fruit is harvested and the tissues of interest (e.g., skins and seeds) are removed from the remainder of the berry. They are rinsed well and then extracted as whole tissues using the conditions described in these protocols. For grape skins, aliquid-liq-uid extraction with chloroform has been successful in the removal of chlorophyll and waxes, yet no extraction with ethyl acetate has been performed because of the small proportion of flavan-3-ol monomers (Kennedy et al., 2001). For grape seeds, these protocols have... 

Oleoresin Black Pepper Obtained by the solvent extraction of the dried fruit of Piper nigrum L. (Fam. Piperaceae) as a dark green, olive green, or olive drab extract usually consisting of an upper oily layer and a lower crystalline layer. It may appear as a homogeneous emulsion if examined shortly after the oleoresin has been homogenized, but the product separates on standing. It may be decolorized by partial removal of chlorophyll. 

Oleoresin Pimenta Berries Obtained by the solvent extraction of the dried fruit of Pimenta officinalis Lindl (Fam Myrtaceae) as a brown-green to dark green liquid. Oleoresin Rosemary Obtained by the solvent extraction of the dried leaves of Rosmarinus officinalis L. (Fam. Labiatae). It is a thick, green paste that can be diluted with food-grade water- or oil-dispersible solvents. It may have a reduced chlorophyll content. The volatile oil content varies depending on its intended effect from a highly camphoraceous note to a subtle herbal note. 

Straight Long Chain Alcohols. Linear long-chain alcohols with carbon numbers between C22 and C32 are present in olive oil both free and esterihed (waxes). The components are abundant in the epicarp of the fruit and concentrate in solvent extracted oil. Phytol, probably derived from biodegradation of chlorophyll, is also present along with geranyl (38). 

In order to remove chlorophylls, stilbenoids, less polar flavonoids and other non-polar compoimds, the extract of Cornus alba fruits was partitioued with ethyl acetate [Bjoroy et al., 2007]. 

Saponification is the technique most used for the removal of fatty matter and other components such as chlorophylls (when their analysis is not required). In addition, saponification hydrolyzes the fatty acid esters of xanthophylls present in many ripe fruits, facilitating subsequent stages of analysis (such as isolation, identification, and quantification). The general procedure of pigment extract saponification is usually preceded by a step of transfer to diethyl ether, which is immiscible with water and has a low boiling point (below 35°C), simplifying water removal and its own removal by evaporation. This transfer not only helps saponification, but also prevents the formation of saponification artifacts, above all by reaction between ketones (usually because of the presence of acetone in the extract) and apocarotenal aldehyde groups. 

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