Original Articles
Hayam M. Abbas1, Ahmed M. S. H
Abstract
The evaluation of yoghurt samples fortified with 1% (w/v) rice bran (RB) and follow up the changes during storage for two weeks at refrigerator was carried out. The evaluation was based on total free fatty acids, phenolic contents, antioxidants activity and volatile compounds. Yoghurt samples were analyzed at zero time and after 5,7 and 14 days. The results showed a significant increase in total phenolic content during storage until 7 days of storage and a decrease had occurred in both control and supplemented yoghurt samples. The fortification with RB at 1% showed a remarkable increase in phenolic content compared to control sample. The fortified sample exhibited nearly double concentration (35.9 mg/mL) of phenolic content compared to (17.8 mg/ml) in control sample at the end of storage. The antioxidant activity increased significantly (P <0.05) during storage compared to zero time and in fortified sample with rice bran at 1% compared to control. A total of 19 volatile compounds were identified in control sample, only 18 were found in fortified yoghurt due to the absence of limonene. The major volatile compounds were, acetaldehyde, dimethyl sulfide, propanal and 2-propanol which represented 20.6%, 15.5%, 9.27% and 7.27%, respectively in fresh control sample while their corresponding values in fortified yoghurt were 21.52%, 16.4 3%, 9.18% and 6.18 % respectively. It could be concluded that fortification of yoghurt- milk with 1% rice bran succeed in produced functional product which had healthy properties beside its valuable nutritive value.