Thirteenth International Conference on Food Studies

Abstract

Cellulose, the most abundant polymer on the earth, is the main compound of wheat straw with approximately 32%. This compound and its derivatives like cellulose nanofibers are promising materials for various applications in the food industry. However, to date, corrosive and toxic solvents have commonly been implemented in the isolation of cellulose. The main objective of this study is to evaluate the effect of pressurized water + ethanol mixtures at different concentrations at optimum processing conditions of temperature and time to hydrolyze non-cellulosic material from wheat straw. Pressurized aqueous ethanol (PAE) treatment of wheat straw was performed in a semi-continuous flow type subcritical fluid system. The experiments were conducted at 180°C, 50 bar, and ethanol concentrations of 0–100% (v/v) for 60 min. Total sugars and total phenolic contents in the hydrolysates were analyzed according to the phenol-sulfuric acid and Folin Ciocalteu methodologies, respectively. SCW and PAE at 20% ethanol treatments significantly reduced wheat straw’s ash, crude protein, and fat contents. These hydrolysis treatments also showed the highest carbohydrate content, followed by 60% and 100% ethanol treatments, which may be due to the higher production of H+ and OH-, inducing structural carbohydrates hydrolysis. Total phenolics obtained from the hydrolysis treatment indicated rupture of lignocellulosic complexes. Samples treated with PAE up to 60 % ethanol show no significant difference in phenolic content. In conclusion, pressurized fluid treatments successfully produce hydrolysates with value-added products such as sugars and phenolic compounds along with a cellulose-enriched solid residue.