Purification, composition analysis and antioxidant activity of a polysaccharide from the fruiting bodies of Ganoderma atrum

Reactive oxygen species (ROS) are a class of highly reactive molecules derived from the metabolism of oxygen. ROS, including superoxide radicals, hydroxyl radical and hydrogen peroxide molecules are often generated as by products of biological reactions or from exogenous factors. There is extensive evidence to involve ROS in the development of degenerative diseases. Evidence suggests that compounds especially from natural sources are capable of providing protection against free radicals. This has attracted a great deal of research interest in natural antioxidants. It is necessary to Screen out medicinal plants for their antioxidant potential. Therefore an attempt has been made to review different in vitro models for estimating antioxidant properties of natural products from medicinal plants. All the models are described along with the different standards that can be used for estimation. In the end, a large number of plants showing in vitro antioxidant activity are listed but in vivostudies are lacking. 

	 

	Key words: Antioxidant assay, in vitro models, antioxidant medicinal plants.

In vitro models for antioxidant activity evaluation and some medicinal plants possessing antioxidant properties: An overview

Antibacterial and antioxidant activities of Mentha piperita L.

Isolation, chemical composition and antioxidant activities of a water-soluble polysaccharide from Cyclocarya paliurus (Batal.) Iljinskaja

The recovery process of the phenolic compounds from the coffee industry by-products and their antioxidant activity were investigated in this work. The coffee by-products (coffee pulp, husk, silver skin, and spent coffee) were obtained from coffee processing industry. The phenolic conserves were extracted using solvent mixture of isoproponal and water. The yield of the conserve was highest in case of silver skin (25%) followed by spent waste (19%) and cherry husk (17%) when pretreated with viscozyme. The conserve enclosed chlorogenic acid as major component when analyzed with high-performance liquid chromatography. The bioactive conserves prepared from coffee by-products possessed 65%–70% antioxidant activity. Apart from these, the coffee by-products encompassed total dietary fiber of 40%–80%. Whereas the soluble and insoluble fiber proportion of the coffee by-product ranged between 16–35% and 18–64%, respectively. The antioxidant activity of coffee by-product fiber ranged from 1.5 to 2.0 mmol trolox/100 g and is analogous to that of widespread fruits and fresh vegetables. The hydration properties such as water holding capacity of each by-product was strictly related to the amount of insoluble fiber and to the granulometry. This is the first report on the isolation of bioactive and functional compounds from coffee by-products and can be a source of new value-added products such as phenolic antioxidant adjunct for food processing.

K Yahara

Papers

Antioxidative properties of xanthone on the auto oxidation of soybean in cylcodextrin emulsion