1. AVEQ WP 8 Antioxidants in Oats Lena Dimberg and Rita Redaelli

2. Outline  Why antioxidants?  Antioxidants in oats  Tocopherols /tocotrienols/avenanthramides Bioactivities Effects of processing Effects of cultivation measures  Concluding remarks

3. Oxidation Oxidation of lipids generates free radicals which are very reactive –may results in reduction of shelf-life of foods –may cause damage to various body tissues, and may thereby initiate various diseases

4. Antioxidants Antioxidants effectively retard the onset of lipid oxidation with different mechanisms –may protect food from rancidity –may protect the body from free radical damages

5. Antioxidants  Ascorbic acid (Vitamin C)  Carotenoids (Vitamin A precursors)  Tocopherols/tocotrienols (Vitamin E)  Phenols

6.  Color  Flavor and aroma  Texture  Keeping qualities  Pharmacological effects Phenols in Foods

7. Tocopherols/ tocotrienols tocopherols tocotrienols IsomersR'R'' αCH3 β H γH δHH

8. Pisacane et al. 2004 NP-HPLC OF TOCOLS

9. Preventive of foetuses' death Membrane stabilizer Tocopherols/tocotrienols -bioactivities- Antioxidants structure-activity relationship

10. Tocopherols- in germ Tocotrienols – in endosperm Genetic variability Tocotrienols are positively related to the oil content Tocopherols/tocotrienols

11. Range of variation in tocol content Content (mg/kg) Cultivar originAuthors 19-3012 USPeterson & Qureshi, 1993 25-6725 high-oil linesPeterson & Wood, 1997 14-257 SwedishBryngelsson et al. 2002 21-548 ItalianRedaelli et al. 2004

12. Avenanthramides R= H, OH or OCH 3 n= 1 or 2

13. Phytoalexin/Antifungal Antioxidative Structure- activity relationship Anti-atherosclerotic Anti-inflammatory Avenanthramides -bioactivities Cooling sensation Tranilast look alike

14. Mainly bran constituents Not related to the oil content Avenanthramides Unique to oats

15. Tranilast Metabolites Oat avenanthramide Tranilast

16. Supression of vascular stenosis by Tranilast Control Tranilast Fukuyama et. al. 1996. European Journal of Pharmacology, 318, 327-332

17. Storage stable in whole grains Increase during germination Instable in raw oat flour soaked in water Avenanthramides -effects of processing- Heat stable

18. Effect of germination

19. Nitrogen/Light/Irrigation Conventional /Organic Farming Susceptible/Resistance Genotype/Site/Year Avenanthramides -effects of cultivation measures- Developmental stage

20. Avenanthramides - the same variety different year-

21. Concluding remarks Whole grain vs flour Processing Bioavalability Groats Flour