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, itâs significantly less susceptible to fungus. Secondly, heartwood contains far less moisture than sapwood and will have far less shrinkage when itâs dried.hat 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.
Food that is reheated must reach a minimum internal temperature of at least 165Â°F for 15 seconds. Reheating must be done rapidly and the minimum temperature must be reached within two hours. Steam tables, warmers, or similar equipment do not heat food quickly enough and must not be used for reheating food.
Primary Heating Systems LTHW (maximum temperatures of 100Â°C) Low temperature hot water is the most common means ofheating. Flows are usually based on a temperature drop of 11Â°C(from 82â71Â°C). MTHW (100Â°Câ120Â°C) Medium temperature hot water systems are generally designed ona temperature drop of 30Â°C (from 120â90Â°C).