Abstract
The extraction of xylose, glucose, fructose, and other sugars in different brown juice (BJ) biomasses in a green biorefinery may be used on a large scale for fermentation and biobased production. A comparative study of different BJ obtained in a biorefinery demonstration platform was conducted employing white clover, red clover, grass-clover mixture, alfalfa, festulolium, and ryegrass as feedstock. In the green biorefinery, the biomass was submitted to mechanica wetl fractionation in which a green juice (GJ) and a fiber cake fraction were separated. The protein was extracted from the GJ by using heat precipitation at 85 °C and, sent to a decanter centrifugation, where a leaf protein concentrate was separated from the BJ. Total sugar content varied between 29.10 g/L to 10.82 g/L, in BJ from the different feedstocks. Glucose constitutes the carbohydrate with the highest concentration in BJ of festulolium, ryegrass, red clover, and grass-clover feedstock. Among all the remaining carbohydrates in the BJ, xylose is the major sugar in BJ from alfalfa and white clover. However, the highest xylose concentration was in red clover with 7.04 g/L. Ryegrass showed a higher concentration of fructose with 9.17 g/L. In general, fructose was extracted in all the BJ biomasses with quantities up to 4.73 g/L, except alfalfa with 1.81 g/L. Ryegrass and festulolium exhibited a majority concentration with 5.19 and 8.43 g/L of sucrose. Maltose and galactose presented low sugar concentrations and arabinose had the lower concentrations in BJ biomasses.
