Free absorbency capacity

Generally, when the terms of swelling or absorbency are used without specifying its conditions, they imply uptake of distilled water while the sample is freely swollen, that is, no load is put on the testing sample. The free absorbency capacity can be tested by the following methods. 

CAO G, ALESSio H M and CUTLER R G (1993) Oxygen-radical absorbance capacity assay for antioxidants, Free Rad Biol Med, 14, 303-11. 

N9. Ninfali, R, and Aluigi, G., Variability of oxygen radical absorbance capacity (ORAC) in different animal species. Free Radio. Res. 29, 399-408 (1998). 

In 2004, food scientists with the U.S. Department of Agriculture (USDA) published a list of antioxidant capacity for one hundred common foods consumed in the United States. This test was branded as ORAC, the oxygen radical absorbance capacity, determined by measuring in a test tube the ability of a food to neutralize free radicals—highly reactive, unstable... 

Properties Soft, silver-white solid oxidizing rapidly in air waxlike at room temperature, brittle at low temperatures. Store in airtight containers or in naphtha or similar liquid that does not contain water or free oxygen. D 0.9674 (25C), mp 97.6C, bp 892C. Decomposes water on contact, with evolution of hydrogen to form sodium hydroxide insoluble in benzene, kerosene, and naphtha. Has excellent electrical conductivity and high heat-absorbing capacity. 

At present it appears that there are two major carbon monoxide sinks. The first is provided by the soil surface. Thus, laboratory experiments show that the CO absorbing capacity of different soils can be very important (see Seiler, 1974). The generalization of the results of these laboratory works gives a value of 450 x 1061 yr 1 for the global sink intensity (see Table 7). An other possibility is the reaction of carbon monoxide with OH radicals which removes CO rapidly from the air. In the previous section we have discussed the chemical destruction of CH4 by OH. One end product of these processes is carbon monoxide (see [3.2]) which also reacts with free radicals to form carbon dioxide in the following way (e.g. Bortner et al. 1974)... 

Recently, an indirect method to measure the free radical scavenging activity of extracts and, thus, their antioxidant activity has been developed using HPLC coupled to a coulometric array detector system [61]. This was developed to characterise the overall antioxidant activity status of fruit and vegetables. A significant positive linear correlation was demonstrated between the total antioxidant activity determined by using the oxygen radical absorbance capacity assay and that measured using the electrochemical data obtained from the coulometric array detectors. 

Free radical scavengers are molecules that react with free radicals and render them harmless. There is considerable interest in foods rich in vitamins A, C and E (Chapters 51, 52 and 56) and those with an abundance of phytochemicals such as the phenols, polyphenols and flavonoids, which have high oxygen radical absorbance capacity (ORAC) values. These are potent free radical scavengers that are thought to reduce the risk of several chronic degenerative disorders. 

High absorbent capacity and absorption rate, which promote free flow of body fluids and prevent fluid pooling at the wound site thus reducing the risk of bacterial infection and wound maceration. 

Hyaluronic acid (HA), discussed in detail in Section IILA.l.e, is a component of human skin that occurs in the interstitial fluids of the epidermis and, because of its water-absorbing capacity, lends turgidity, viscolasticity, and firmness to the skin. Changes in HA concentrations have been noted in skin as tlie body ages (196). In aging skin free of chronic sun... 

Capacity = amount of water absorbed speed = rate of water removal intensity = level of water remaining after drying, that is, high means that the smallest amount of free water remains after drying. 

---