Asma Yaprağından Antioksidan Bileşiklerin Mikrodalga Destekli Ekstraksiyonunun Optimizasyonu

In this study, the optimum microwave assisted extraction (MAE) parameters (solid/liquid ratio,time and power) determined by Box-Behnken Design (BBD) of Response Surface Methodology(RSM) for the extraction of antioxidant compounds from grapevine leaves. The BBD was used todefine the effects of independent variables on Total Phenolic Content (TPC), DPPH radicalscavenging activity and Trolox Equivalent Antioxidant Capacity (TEAC). Second-orderpolynomial model and regression analysis were used for prediction optimum point. The optimumconditions for MAE of grapevine leaves were determined as solid/liquid ratio of 30%, power of300 W and time of 300 sec. All of the models was found valid and significant independentvariables (R2) were found as 0.9282, 0.9340 and 0.9380 and the predicted experimental value ofdesign 58.204 mg GAE/ mL extract, 95.905% and 65.123% for TPC, DPPH scavenging activityand TEAC, respectively. The results of the present showed that MAE of grapevine leaves producethe extracts with a higher antioxidant values in a shorter time when compared with solventextraction.&nbsp;</p

Optimisation of ultrasound assisted extraction of rice bran proteins: effects on antioxidant and antiproliferative properties

In this study, it was aimed to increase added value of rice bran which is a by-product of paddy processing. Optimisation of ultrasound assisted extraction produced the highest rice bran protein yield (39.85%) with the parameters as solid/liquid ratio of 0.43, power of 48.25% amplitude, and ultrasound application time of 29.89 min. Based on the optimised solid/liquid ratio and time, antioxidant and antiproliferative properties of protein isolates treated with different level of ultrasound power were determined. Total antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, total phenolic content (TPC), metal chelating activity and the effects on HepG2 cytotoxicity of rice bran protein isolates were evaluated. The highest values of TEAC (17.73%), DPPH (63.61%), TPC (297.43 mg GAE/mg), and metal chelating activity (55.34%) were obtained from samples treated with 100% ultrasound power. Th results of the study showed that the ultrasound power had significant effect (P< 0.05) on TPC, metal chelating activity, and DPPH scavenging activity of rice bran proteins