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Grape seed and green tea extracts are reported to produce antioxidant scavenging activities against free radical toxicity. This study aimed to investigate the hypothesis that a specific combination of these extracts presents a synergistic antioxidant scavenging activities. The extracts of grape seed, green tea and their mixtures were characterized by phytochemical studies and tested for phenolics and flavonoids. In vitro antioxidant activity for individual extract and its mixtures was determined by DPPH, hydroxyl and superoxide free radical scavenging methods. The amount of total phenolics varied among the different extracts and ranged from 43.74 to 67.68 mg of gallic acid equivalents (GAE) / g dry weight, whereas total flavonoids content ranged from 4.25 to 11.66 mg of quercetin equivalents (QU) /g dry weight. The present results suggest that both extracts reported a highly contents of total phenolic and flavonoids compounds, also the mixtures of these extracts can synergistically enhance antioxidant activity. Antioxidant potential from mixture 2 (grape seed extract 200 mg: green tea extract 100 mg) was comparable to that of standard. HPLC results showed that the most abundant components in the mixture 2 extract were epigallocatechingallate while the lowest was the procyanidine.

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At present, the major body of research is focused on weaning the world from fossil fuels. The problem is that the world is running out of fossil fuel. Therefore, an alternative source must be identified. The biofuels are promising alternatives. In the case of petrodiesel, a promising alternative is biodiesel production from algae. The ability of microalgae to generate large quantities of lipids with a fast growth rate made them superior biodiesel producers. Using light-emitting diodes (LEDs) as an energy source in microalgal cultivation was recently increased owing to its large spectrum, endurance, and low-energy utilization. Changes in cultivation conditions, limited capabilities of harvesting light, and self-shading of microalgae were the most important problems. Therefore, the photobiostimulation of algae using LEDs radiation led to an increase in algal growth rate which results in increased lipid production. This research investigated the influence of monochromatic LEDs on the growth of Chlorella sorokiniana microalga. At the first phase, microalgae growth and algal biomass significantly increased under red LEDs [2.3 g/L], blue LEDs [1.8 g/L], green LEDs [0.7 g/L], and white LEDs (0.6) g/L as a control, respectively. At the second phase, microalgal growth and algal biomass significantly increased under red LEDs [2.9 g/L], blue LEDs 2.3 g/L, and white LEDs (1.5) g/L as a control, respectively. The percentage of extracted oil (%) or the yield of extracted oil of microalgae was 10.38 % (white LEDs), 16.94 % (blue LEDs), and 15.55 % (red LEDs) respectively. It was concluded that the photobiostimulation of algae using LEDs led to the enhanced weight of algal biomass, therefore increased of lipids and biodiesel production. The red LEDs were the best one in terms of increasing the weight of algal biomass. The blue LEDs were the best one in terms of increasing the percentage of extracted oil. However, the green LEDs were not effective.