A simplified HPLC method for determination of tryptophan in some cereals and legumes.

In the present study, a simple analytical method is proposed for determining tryptophan, and method is validated on some cereal and legume samples. In the method alkaline hydrolysis of proteins was used due to the destruction of tryptophan structure during acid hydrolysis. Following alkaline hydrolysis (120°C for 12h), hydrolysates are filtered through ashless filter paper and pH values are adjusted with hydrochloric acid solution. Separation and detection of tryptophan are performed on a reversed-phase column with fluorescence detection within 10min by using a mobile phase of acetonitrile and acetate buffer of pH 6.3 (1:9, v/v). For determination of tryptophan content, the procedure described in the study offers an alternative analysis method by enabling high speed analysis and the use of simple extraction process to the other available methods.

Effects of a traditional fermented grape-based drink 'hardaliye' on antioxidant status of healthy adults: a randomized controlled clinical trial.

BACKGROUND: The antioxidative effects of the traditional grape-based beverage, hardaliye, were investigated with a 40-day randomized controlled clinical trial on 89 healthy adults. Subjects were randomly divided into three groups: high hardaliye (HH), low hardaliye (LH) and control group. HH and LH groups consumed 500 mL and 250 mL hardaliye per day, respectively, and the control group did not consume any hardaliye. Dien conjugate (DC), malondialdehyde (MDA), vitamin C, total antioxidant capacity (TAC) and homocysteine concentrations were measured in fasting blood samples collected at baseline and after intervention. RESULTS: Significant decreases in DC, MDA and homocysteine concentrations were observed in HH and LH groups (P < 0.001) after intervention, whereas the control group showed no change. The reduction in homocysteine was significantly different between HH and LH groups (P < 0.001), except for DC and MDA. TAC and vitamin C were slightly increased; however, the change was not statistically significant. CONCLUSION: Dietary supplementation with hardaliye affect the MDA, DC and homocysteine levels in blood, possibly due to the presence of antioxidant compounds. Dose response was only observed for homocysteine. Further studies need to be performed to assess the effects on antioxidant capacity.