Modification of the Intensity of Compounds Biosynthesis in the Petioles of Rhubarb (Rheum rhaponticum L.) Induced by the Ozonation Process

Abstract

Abstract Rhubarb (Rheum rhaponticum L.) is a vegetable that, despite many health-promoting properties, contains large amounts of oxalic acid, which has a negative impact on human health. Treatment of rhubarb petioles with gaseous ozone is one way to improve their quality by changing their chemical properties. As part of the research, an analysis of the mechanical and chemical properties of rhubarb petioles was performed. The analyzes showed that the applied doses of ozone of 10 ppm during 1, 3 and 5 minutes lowered the concentration of oxalic acid during 5 days of tests performed after the ozonation treatment. The most favorable effect on the reduction of oxalic acid, amounting to 36%, was caused by gaseous ozone at a concentration of 10 ppm during 5 minutes compared to the control. In addition, it was noted that on the 1st and 3rd day after using ozone gas, the antioxidant activity of the tested raw material increased significantly. Also on the same days of testing, the total amount of polyphenols increased as a result of the use of ozone fumigation. The largest increase in the total amount of polyphenols, amounting to 12%, was observed for a dose of 10 ppm 5 minutes on the 1st day after the ozonation treatment compared to the control variant. In turn, no positive effect of the ozonation process on the content of vitamin C and the value of destructive force during three-point bending of rhubarb leaf petioles was noted.