Effect of tehina processing and storage in the physical-chemical quality

The effect of tehina processing and storage during six months at 25℃and 35℃on total phenolics,antioxidant activity,anthocyanins,and fatty acid analysis was evaluated.Tehina processing,storage period and temperature significantly(p≤0.05)decreased total phenolics,antioxidant activity and anthocyanins contents.The results showed that raw sesame seeds had the highest total phenolics(99.98 mg GAE/100 g)and lower levels were found in dehulled unroasted sesame seeds,tehina at zero time and roasted sesame seeds(62.53,60.61 and 47.03 mg GAE/100 g,respectively).In addition,tehina during storage showed a significant decrease in total phenolics(60.61 to 42.45 mg GAE/100 g).Raw sesame seeds had the highest antioxidant activity(0.51 mg/mL),while the tehina,dehulled unroasted and roasted sesame had antioxidant activity values of 1.21,1.35 and 1.79 mg/mL,respectively.Also,antioxidant activity of tehina at zero time was highest(1.21 mg/mL)and lowest was in tehina stored for six months(1.70 mg/mL).Sesame seeds and tehina had low levels of anthocyanins(1.26 and 0.50 mg cya-3-glu/100 g).Fatty acid analysis showed that sesame seeds(raw,dehulled unroasted and roasted)and tehina samples contain high percent of unsaturated fatty acid oleic(C18:1)and linoleic(C18:2).

Effects of drying process on total phenolics,antioxidant activity and flavonoid contents of common Mediterranean herbs

Four different fresh and dried herb species(sage,thyme,mint and lemonbalm)were evaluated to study the effect of drying process on the total phenolics,antioxidant activity,flavonoid contents and color properties.Fresh mint had the highest contents of total phenolics(335.4 mg GAE/100 g),whereas lower levels were respectively found in sage(316.4 mg GAE/100 g)followed by lemonbalm(303.2 mg GAE/100 g)and thyme(299.2 mg GAE/100 g).Dry processing significantly decreased the phytochemical contents of all investigated herbs.Compare to air drying,total phenolics,antioxidant activity and flavonoids content in herbs decreased apparently by oven dried.Fresh mint had the highest antioxidant activity(87.46%)and flavonoids content(298.51 mg CE/100 g),while the fresh sage,thyme and lemonbalm were found to have antioxidant activity values of 86.81%,86.56% and 85.26%,respectively.Results showed that air drying herbs contained more total phenolics,antioxidant activity,and flavonoids than oven drying herbs.