ANTIOXIDANT ACTIVITIES OF ENDEMIC SIDERITIS LEPTOCLADA AND MENTHA DUMETORUM AQUEOUS EXTRACTS USED IN TURKEY FOLK MEDICINE

Total phenolic contents, hydroxyl radicals and one 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activities, antioxidant capacities and reducing powers of Sideritis leptoclada, which is an endemic plant to Turkey, and Mentha × dumetorum were investigated in water extracts. Total phenolic contents were detected to be 0.32 µg gallic acid/µg dry biomass in the presence of 1.33 and 9.82 µg/mL, respectively. Fifty percent scavenging activities of hydroxyl and DPPH radical were determined with 0.03 and 0.16 mg/mL extracts of S. leptoclada and 0.21 and 1.6 mg/mL extracts of Mxdumetorum. In addition, total antioxidant capacities of S. leptoplada were also higher than Mxdumetorum and there was a significant difference between the controls. The result of this study suggests that extracts of S. leptoclada and Mxdumetorum can be used as potential source of natural antioxidants and as a possible food supplement or in the pharmaceutical industry.

PRACTICAL APPLICATIONS

The research is focused on the determination of new potential plant sources of antioxidants that can be used as food. Antioxidants are vital substances that possess the ability to protect the body from damage caused by reactive oxygen species induced oxidative stress. In this study, infusions in boiled water of Sideritis leptoclada , which is a plant endemic to Turkey, and Mentha x dumetorum have high levels of antioxidant capacity. The results of the study show that extracts of S. leptoclada and Mxdumetorum can be used as a supplement agent to increase in quality of food and for the pharmaceutical industry.     

Effect of operating conditions on physical characteristics of extruded rice starch

The effect of screw speed, flow rate, barrel temperature and added moisture on physical characteristics of high moisture extruded rice starch was studied. the product physical characterization was made by measuring density, final moisture content and the maximum load force in a puncture test. Rice flour containing approximately 1.5% protein and 6% moisture was mixed with 55–65% (w/w) water and extruded in a co-rotating twin screw extruder with a slit die. A two level factorial design was used to analyse each parameter. It was found that added moisture was the most important variable affecting the force-deformation curve maxima, with the interaction between added moisture and barrel temperature exhibiting a less significant effect. Added moisture and flow rate each affected density, with the interaction between added moisture and screw speed showing a less significant effect. Temperature and flow rate affected final moisture interactively with added moisture, which was evidently the most important variable.