Eurasian water milfoil: Composition, recovery of phenolics and anthocyanins, and saccharification

Abstract

AbstractEurasian water milfoil (Myriophyllum spicatum; EWM) is an invasive aquatic weed that has spread worldwide but remains unstudied as a potential source of bioenergy and valuable chemicals. In this study, the composition of EWM biomass is characterized by determining the monosugar and lignin content, ash, and extractives. EWM extractives contain beneficial phenolic compounds, among them anthocyanin pigments. Following the biorefinery concept, a stepwise treatment of this aquatic plant was carried out toward integrating the extraction of phenolics with the saccharification of carbohydrates for viable biomass utilization. The recovery of phenolics and anthocyanin pigments was studied, in which different extracting compositions and conditions were applied. The antioxidant capacity of the extracts was evaluated. Saccharification was carried out using autoclaving, followed by hydrolysis using common cellulase enzyme. Different media were studied. Under the best condition, the carbohydrates contained were hydrolyzed to reducing sugars, and the conversion rate to glucose reached 90%. The yield of glucose was 0.245 g g−1 dried plant. This study demonstrates the potential of EWM as a source of antioxidants comparable to some phenolics‐rich algae, and as a bioenergy resource comparable with other sugar‐rich macrophytes.