Green Downstream Processing By Using Hydrothermal Extraction For Recovering Flavonoid, Phenolic And Antioxidant Activity From Moringa Oleifera Leaves

Well known as rich in phenolic compounds, Moringa oleifera mature leaf extract show significant antioxidant activity both in vitro and in vivo. It has been widely used at cosmetic, medicine, and functional food sector. Hydrothermal extraction, one of the green environmentally friendly method that fit to M. oleifera feedstock for recovering natural antioxidant namely flavonoid, phenolic, and antioxidant activity. Three parameters were used at this study such as sample-solvent ratio, running temperature and extraction time. Flavonoids were evaluated with 2.4 Dinitrophenyl hydrazine colorimetric, whereas phenolics were measured by tanat acid which react with Foulin ciocealteu reagent. Antioxidant activity was measured by DPPH. The optimum result was obtained at 15 minutes with 140 0C for total flavonoid content (TFC) 18.98 mg/g whereas 170 0C for total phenolic content (TPC) and antioxidant activity 48.73 mg tanat acid/dried extract; 44.76 mg/L respectively

Comparison of Alkaline/Oxidative and Hydrothermal Extraction of Wheat Bran Arabinoxylans

The bran accounts for approximately 25% of the wheat kernel but is currently only a by-product, used as animal feed. However, due to its high arabinoxylan content it could be a valuable raw material for food production. Arabinoxylans cannot be digested in the human intestine but are intensely studied for their health-beneficial properties. These include glycemic control by formation of a highly viscous gel in the intestine, and hence delaying starch digestion, alongside an increase in short chain fatty acids. To apply sufficient amounts of arabinoxylan for health-beneficial effects, extraction and concentration is required. Alkaline/oxidative conditions are commonly used, but for potential food applications more cost-efficient methods, without hazardous chemicals, are required. Therefore, this study aimed to optimize the conditions for hydrothermal extraction (extraction time and temperature) at laboratory-scale and to compare the results to an established alkaline/oxidative method. The resulting extracts were characterized for yield, purity, arabinoxylan molecular mass, arabinose/xylose ratio, and viscosity to evaluate the quality of the method. For the hydrothermal extraction, an extraction time of 1 h at 160 °C and 6.5 bar gave the best results. However, even these optimized conditions resulted in lower extract purity and severely degraded arabinoxylans. Although further optimization of the hydrothermal process is required, the present work builds an important foundation for the development of an industrial hydrothermal extraction method.

Optimization of Extraction Conditions for Antioxidant Activity of Acer tegmentosum Using Response Surface Methodology

Extraction from edible plants is a highly important process that has various biological functions. To maximize biological activity, extraction methods should facilitate optimal extraction of functional phytochemicals. In this study, the optimal hydrothermal extraction conditions of Acer tegmentosum were determined using response surface methodology (RSM), and HepG2 cells were treated with optimized extract and hydrogen peroxide. In a central composition design, the independent variables were extraction temperature (X1: 70–90 °C), extraction time (X2: 2–6 h), and solvent-to-solid ratio (X3: 50–150). The maximum total phenolic contents (276.70 ± 10.11 mg GAE/g) and DPPH (2,2-diphenyl-1-pictylhydrazyl) activity (33.45 ± 2.20%) of A. tegmentosum were estimated at optimized extraction conditions, as follows: X1: 89.34 °C, X2: 7.36 h, X3: 184.09. Using the calculated extraction conditions, functional phytochemicals were extracted by hydrothermal extraction and freeze-dried. A. tegmentosum treatment (>10 μg/mL) of HepG2 cells remarkably attenuated hydrogen-peroxide-inducible hepatic cellular death and reactive oxygen species production in vitro.