Effect of domestic processing and microwave heating on phenolic compounds and tannins in some oil seeds [electronic resource]

Includes bibliographic reference

Oilseeds contain different constituents with antioxidant activity especially phenolic compounds and tannins,
this study was conducted to evaluate the possible effects of some domestic processes such as dehulling,
soaking, ordinary and pressure cooking, germination, fermentation and microwave heating on the contents
of phenolic compounds and tannins in some oilseeds. The data revealed that oil seeds could be considered
as a rich source of oils and proteins. Phenolic compounds contents of raw oil seeds were; 978.4, 968.0,
862.75, 915.0 and 1063.4 mg/100 g, while, tannin contents were; 510.0, 490.0, 457.0, 457.0 and 440.0 mg/100 g
on dry weight basis in peanut, sesame, soybean, safflower and sunflower, respectively. All processing treatments
reduced the phenolic compounds except dehulling of sunflower seeds which was increased by 9.6%. Dehulling of
oil seeds reduced tannin content by 9-26.5%, while during cooking processes, tannin leaching out in cooking
water resulted in a reduction in its content by 4.5-19.6% for ordinary cooking and 5.2-20.2% for pressure cooking.
Germination and fermentation processes decreased tannin by 12.5-34.7 and 13.6-49.0%, respectively. Microwave heating
treatment had an effect in removal of tannins from seeds than other cooking methods. The reduction ranged between
8.8-24.4% of its initial content in raw oil seeds. The study concluded that all processing treatments used in the
study had an effect on the oilseeds content from both phenolic compounds and tannins.

Key words: Phenolic Compounds, microwave Heating, Domestic processing.

Summary in Arabic