The heartwood, bark, and roots contain many extractives of actual and potential value in food processing, pesticide manufacturing, and dyemaking Osage-orange is used in landscape design, being picturesque rather than beautiful, and possessing strong form, texture, and character.
The heartwood, bark, and roots contain many extractives of actual and potential value in food processing, pesticide manufacturing, and dyemaking. Osage-orange is used in landscape design, being picturesque rather than beautiful, and possessing strong form, texture, and character.  Most notably, these extractives are responsible for giving the heartwood its characteristic color: the jet-black color of Ebony (Diospyros spp.) , the ruby-red of Bloodwood (Brosimum rubescens) , or the chocolate-brown of Black Walnut (Juglans nigra) —all owe their vivid hues to their respective heartwood extractives. However, it should be noted that the transition area from sapwood to heartwood, commonly referred to as the sapwood demarcation, can vary from gradual to very abrupt: this can be important in wood projects where decay resistance is needed. These compounds (including resins, phenols, and terpenes, sometimes referred to as extractives) not only help make heartwood more resistant to attack by insects and decay organisms but also tend to give this inner portion of the stem a distinctive darker color. The proportion of heartwood to sapwood in the main stem does vary with species. Black locust, for example, usually has a very narrow band – often less than an inch – of functioning sapwood, whereas maple stems often can have many inches of sapwood and relatively narrow cores of heartwood. ProteinsIII. Monosaccharides and derivatives. Summary-Extractive components are “small” molecules that can be extractedwith a solvent from wood, bark, or foliage. - Generally, extractives are present in small amounts. - Extractives vary tremendously within species, betweenspecies, and within trees. - There are thousands of different extractives present in wood Sapwood is living, outmost portion of a woody stem or branch, while heartwood is dead, inner wood,which often comprises the majority of stem cross-section.You can usually distinguish sapwood from heartwood by its lighter color. But, color in wood can be very misleading; not all heartwood is dark and not all dark-colored wood is heartwood. And, the relative amounts of sapwood and heartwood in any stem can vary greatly among individuals, species, and growing conditions. So, for a more accurate – and less specious – distinction, we need a more complete understanding of what wood is and how both sapwood and heartwood form. The proportion of heartwood to sapwood in the main stem does vary with species. Black locust, for example, usually has a very narrow band – often less than an inch – of functioning sapwood, whereas maple stems often can have many inches of sapwood and relatively narrow cores of heartwood. What occurs as moisture is no longer transported through the straw-like cells, the pores in heartwood are filled with organic material. The presence of chemicals called extractives causes the cell walls in heartwood to change color. Extractives are what create the rich color and unique character in heartwood. The functional beauty of heartwood for a woodworker is threefold. First, it’s significantly less susceptible to fungus. Secondly, heartwood contains far less moisture than sapwood and will have far less shrinkage when it’s dried.  In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In heartwood it occurs only in the first and last forms. Wood that is thoroughly air-dried retains 8–16% of the water in the cell walls, and none, or practically none, in the other forms. Even oven-dried wood retains a small percentage of moisture, but for all except chemical purposes, may be considered absolutely dry. This dead wood which forms at the center of the trunk is thus called heartwood. The transition from sapwood to heartwood is accompanied by the accumulation and buildup of various deposits and substances, commonly referred to as extractives. However, it should be noted that the transition area from sapwood to heartwood, commonly referred to as the sapwood demarcation, can vary from gradual to very abrupt: this can be important in wood projects where decay resistance is needed. The total extractive content of wood may range from less than 1% upto 30%. Water-soluble extractives are found in the heartwood of most species, but high-grade, close-grained lumberfrom larger, older trees contain greater quantities of water-soluble extractives. Sidings and trim manufactured fromsecond or third growth trees tend to have less heartwood and consequently less extractives. If caulking and end priming are not done, or are doneimproperly, moisture can infiltrate the open endgrain of the wood at those points. Cure When extractives do appear, they can sometimes be removed by cleaning with a warm water detergent solution anda soft, non-metallic bristle brush.
http://www.na.fs.fed.us/spfo/pubs/silvics_manual/volume_2/maclura/pomifera.htm http://www.wood-database.com/wood-articles/what-is-wood/ http://northernwoodlands.org/articles/article/what_is_the_difference_between_sapwood_and_heartwood/ http://chemistry.umeche.maine.edu/Green/Afternoon/Cole.pdf http://northernwoodlands.org/articles/article/what_is_the_difference_between_sapwood_and_heartwood/ http://www.wagnermeters.com/wood-moisture-meter/sapwood-and-heartwood/ https://en.wikipedia.org/wiki/Heartwood http://www.wood-database.com/wood-articles/what-is-wood/ http://www.cabotstain.com/pdf/TchBul02.pdf
does heartwood contain extractives