Study of prebiotic potential and antioxidant activity in <i>Plantago</i> spp. leaves after enzymatic hydrolysis with hemicellulase and xylanase

Abstract

The leaves of <i>Plantago</i> species have been known as a rich source of polysaccharides, polyphenols, and iridoids. In the recent years, some authors have examined the relative influence of carbohydrate compositions and polyphenols on their antioxidant and prebiotic activity. In this study enzymatic hydrolysis of <i>Plantago major</i>, <i>Plantago lanceolata</i>, and <i>Plantago media</i> leaves with hemicellulase and xylanase was carried out. The chemical composition of the enzyme-derived hydrolysis products was determined. Their antioxidant activity was evaluated using 2,2-diphenyl-2-picryl-hydrazyl-hydrate, ferric reducing antioxidant power, and cupric reducing antioxidant capacity assays. The utilization of the carbohydrate complex from the obtained hydrolysates to stimulate the production of certain glycohydrolases from <i>Lactobacillus plantarum</i> probiotic strains was investigated. The HPLC analysis of the hydrolysis products showed the presence of galactose and arabinose in 1:3 and 1:4 ratios. The highest concentration of total sugars was determined in <i>P. major</i> hydrolysates with hemicellulase (386.71 mg/g dry weight). The antioxidant activity according to the three methods was the highest in <i>P. media</i> hydrolysates, which correlated with their total phenolic concentration. <i>L. plantarum</i> S27 showed the highest values of α-galactosidase activity at the 24-h fermentation process when it was cultivated in a broth with the presence of <i>P. major</i> hydrolysates with hemicellulase and xylanase (0.129 U/mg and 0.133 U/mg, respectively).