Recovery of sugars and amino acids from brewers' spent grains using subcritical water hydrolysis in a single and two sequential semi-continuous flow-through reactors

Author(s)

Sganzerla, William Gustavo ; Vigano, Juliane ; Castro, Luiz Eduardo Nochi ; Maciel-Silva, Francisco Weshley ; Rostagno, Mauricio A. ; Mussatto, Solange I. ; Forster-Carneiro, Tania

• Document type: Journal article
• Source: Food Research International; v. 157, p. 11-pg., 2022-06-10.

Abstract

This study evaluated the subcritical water hydrolysis (SWH) of brewer's spent grains (BSG) to obtain sugars and amino acids. The experimental conditions investigated the hydrolysis of BSG in a single flow-through reactor and in two sequential reactors operated in semi-continuous mode. The hydrolysis experiments were carried out for 120 min at 15 MPa, 5 mL water min-1, at different temperatures (80 - 180 degrees C) and using an S/F of 20 and 10 g solvent g-1 BSG, for the single and two sequential reactors, respectively. The highest monosaccharide yields were obtained at 180 degrees C in a single reactor (47.76 mg g-1 carbohydrates). With these operational conditions, the hydrolysate presented xylose (0.477 mg mL-1) and arabinose (1.039 mg mL-1) as main sugars, while low contents of furfural (310.7 mu g mL-1), 5-hydroxymethylfurfural (<1 mg L-1), and organic acids (0.343 mg mL-1) were obtained. The yield of proteins at 180 degrees C in a process with a single reactor was 43.62 mg amino acids g-1 proteins, where tryptophan (215.55 mu g mL-1), aspartic acid (123.35 mu g mL-1), valine (64.35 mu g mL-1), lysine (16.55 mu g mL-1), and glycine (16.1 mu g mL-1) were the main amino acids recovered in the hydrolysate. In conclusion, SWH pretreatment is a promising technology to recover bio-based compounds from BSG; however, further studies are still needed to increase the yield of bioproducts from lignocellulosic biomass to explore two sequential reactors. (AU)

• FAPESP's process: 19/26925-7 - Development of an automated system for biofuel precursor production using sub-critical technology
• Grantee: William Gustavo Sganzerla
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 20/15774-5 - Development of methods of extraction, separation and two-dimensional analysis of phenolic compounds in natural products
• Grantee: Juliane Viganó
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/05999-0 - Waste2energy: integration of the supercritical and anaerobic digestion technologies for the management of water and food waste
• Grantee: Tânia Forster Carneiro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/13496-0 - Multi user equipment approved in grant 2018/14582-5: ultra-high pressure liquid chromatography system (UHPLC), composed by a quaternary pump, autoinjector, oven with selection valve and detector (PDA)
• Grantee: Maurício Ariel Rostagno
• Support Opportunities: Multi-user Equipment Program