Cereals antioxidant activity

WANG s M and zhao j f (1997) Antioxidant activities of tea polyphenol on edible oils . Western Cereal and Oil Technology, 11, 44-6. 

There are also more complex hydroxycinnamic acids in cereals and other members of the Poaceae. These are cell wall-bound mono-, di- and tri-ferulates. Although they appear to have significant antioxidant activity, their bioavailability (release from cell walls and subsequent absorption in humans) is very low. 

Stratil P, Klejdus B and Kuban V. 2007. Determination of phenolic compounds and their antioxidant activity in fruits and cereals. Talanta 71 (4) 1741—1751. 

Siwela, M., Taylor, J. R. N., de Milliano, W. A. J., and Duodu, K. G. (2007). Occurrence and location of tannins in finger millet grain and antioxidant activity of different grain types. Cereal Chem. 84,169-174. 

Zielinski, H. and Kozlowska, H., Antioxidant activity and total phenolics in selected cereal grains and their different morphological fractions, J. Agric. Food Chem., 48, 2008-2016, 2000. 

Peterson, D.M. Emmons, C.L. Flibbs, A.H. 2001. Phenolic antioxidants and antioxidant activity in pearling fractions of oat groats. J. Cereal Sci. 33 97-103. 

Huang, C.J. Xu, Z. Godber, J.S. 2009. Potential antioxidant activity of gamma-oryzanol in rice bran as determined using an in vitro-mouse lymph axilliary endothelial model. Cereal Chem. 86 679-684. 

Tocopherols and tocotrienols, collectively known as tocols, are monophenolic and lipophilic compounds that are widely distributed in plant tissues (7). The main commercial source of natural tocopherols is the soybean oil. Tocotrienols, less common than tocopherols, are present in palm oil, rice bran oil, as well as cereals and legumes (11). Tocopherols and tocotrienols are classified into a-, (3-, y-, and 5-, depending on their chemical structures (Figure 7). In general, tocotrienols have a stronger antioxidant effect on lipid oxidation than tocopherols. The antioxidant activity of tocopherols is dependent on temperature and is in the order of 5- > y->P-> oc-tocopherol (7). Tocopherols (mixed natural concentrate) are a golden... 

The antioxidant activity of different food products has been linked to their preventive role in cardiovascular disease [68 86 98 99]. Many of them are fruit and vegetables, although cereals, herbs and spices also show important antioxidant activity. Processed fruit products also provide important antioxidant protection as has been described for orange and lemon juice, [100], grape juice [91], grape pomace [101] and red wines [102-107]. Very pronounced in vitro antioxidant activity has been demonstrated in tea [99 108] and olives [27]. Many herbs and spices containing antioxidant constituents can be useful to prevent rancidity of meat and fish products [109-112]. Fibre also has antioxidant activity, mainly due to the presence of phenolic metabolites linked to the polysaccharides [87]. Thus, the antioxidant activity of barley leaves [93], pineapple peel fibre [113] and rice-hull [114] have been described. 

Phenolic compounds, a major group of phytochemicals, are naturally present in both edible (fruits, vegetables, cereal grains, and nuts, among others) and nonedible plant parts. They play important roles in human health due to their antioxidant activity, which is based on their ability to donate a hydrogen atom to free radicals [3], Nuts and their by-products are able to reduce risk of cancer, diabetes, and other chronic diseases [32]. 

Phytic acid and camosine (histidine-containing dipeptide), obtained from cereal and meat by-products, are effective inhibitors of hpid oxidation by several mechanisms, including metal inactivation and free radical quenching. Uric acid obtained from the decomposition of adenosine triphosphate in muscle also inhibits lipid oxidation by the same mechanisms. However, the importance of uric acid as an endogenous antioxidant in muscle foods is not clear. Various protein concentrates from soybeans, cottonseed and peanuts inhibit hpid oxidation in muscle foods. In addition to their iron binding activity, these crade extracts contain complex polyphenolic flavonoids that have potent antioxidant activity. 

Expansion is desirable for snacks and breakfast cereals, but the increased surface area formed by the numerous air cells favors oxidation. However, antioxidants derived from Maillard reaction products may help reduce oxidation rates. Oatmeal cookies containing potato peels showed lower peroxide values than control cookies, and extruded peels had greater antioxidant activity than did non-extruded peels (Arora and Camire, 1994). 

Beta T, Nam S, Dexter JE, Sapirstein HD (2005) Phenolic content and antioxidant activity of pearled wheat and roller-milled fractions. Cereal Chem 82 390-393. doi 10.1094/CC-82-0390... 

Many fruits and vegetables (e.g., grape, citrus, olive, black pepper, spices, soya, cereals) and the derived foods and beverages are a good source of phenolic antioxidants and constitute an important part of our daily diet [4,5,25,26,107-109,111-115]. A good correlation between phenolic content and antioxidant activity is often observed, as reported for monomeric and dimeric hydroxycinnamates of rye bran [75] and various caffeoyl quinic esters in peach puree [116],... 

Among cereals, sorghum and maize had higher antioxidant activity compared to wheat, oats, and rice. Sorghum is known to contain the highest content of phenolic compounds, reaching up to 6% in some varieties (Dicko et al. 2006). The wide array... 

Naturally occurring vitamin E comprises a series of compounds called tocopherols. Among the richest sources are cereal germs and most oilseeds. a-Tocopherol (molecular weight 430.7 daltons), which possesses the highest vitamin E activity, is a yellow oil, insoluble in water, but soluble in organic solvents. It is readily oxidized and, therefore, is also used as an antioxidant. A vitamin E deficiency disease has... 

---