Controllable synthesis of hydrogen bubbles via aeration method for efficient antioxidant process

Hydrogen as a potential reductive gas has selective antioxidant capacity to remove the reactive oxygen species (ROS) which is harmful to human body. Introducing hydrogen to human body through hydrogen-rich water (HRW) is an effective strategy to alleviate the oxidation process dominated by ROS. Here, aeration method was adopted to prepare the hydrogen-rich water, and the effects of hydrogen pressure, injected water volume and temperature on the hydrogen concentration and bubble size were overall investigated to achieve the controllable synthesis of hydrogen bubbles. It was found that hydrogen-rich water with a concentration higher than 1000 ppb and nanoscale bubbles (300–600 nm) can be obtained by the present aeration processing method. Altering processing parameters can lead to various hydrogen solubilities and bubble sizes acquired. The hydrogen bubbles showed a high stability in the as-prepared water by keeping it in room temperature condition until 5 h. The scavenging experiments exhibited that the hydrogen-rich water showed a good antioxidant ability on different free radicals (DPPH, ·OH and ·O2−). In comparison to the conventional antioxidant of vitamin C (VC), the scavenging rate of hydrogen-rich water on ·O2− free radical is 4.3 times that of VC. Such hydrogen-rich water with a high hydrogen concentration and stability may play an important role in the field of hydrogen molecular medical therapy.