Effect of a variety of polyphenols compounds and antioxidant properties of rhubarb (Rheum rhabarbarum)

Rhubarb (Rheum spp.) is a plant characterized by very high antioxidant properties. It is very rich in many compounds that have a pro-health effect on the human body. Polyphenols are natural plant substances that can be a very important component in the prevention of various diseases. Therefore, the use of rhubarb as an interesting plant material in various industries has recently increased. The aim of the study was to determine the effect of the harvest date and rhubarb variety on the content of polyphenolic compounds. The quantitative determination of polyphenols was performed by liquid chromatography-mass spectrometry with quadrupole time-of-flight mass spectrometry. Rhubarb stalks of two Polish varieties Viktoria and Red Malinowy were used in the study. It was found that rhubarb is a source of flavan-3-ols (86.57-195.98 mg/100 g(dm)), flavonols (49.79-73.49 mg/100 g(dm)), anthocyanins (4.33-96.20 mg/100 g(dm)), and gallotannin (6.32-1356 mg/100 g(dm)). Red Malinowy rhubarb from spring harvest was characterized by the highest and VA rhubarb was characterized by the lowest total antioxidant activity. It should be emphasized that the content of individual compounds depended on the variety and the date of harvest of rhubarb. Furthermore, the study revealed a high correlation between the polyphenol content and the total antioxidant capacity.