Study of Brewer's Spent Grain Environmentally Friendly Processing Ways

Area of Science:

• Food Science and Technology
• Biochemistry
• Green Chemistry

Background:

• Brewer's spent grain (BSG) is a rich plant-based byproduct with potential for valuable compound extraction.
• Electrolytically activated water (EAW), specifically catholyte (pH 9.3), is explored as a sustainable extraction medium.

Purpose of the Study:

• To investigate the efficacy of catholyte for extracting diverse organic compounds from BSG.
• To determine optimal extraction parameters (pressure, time, temperature) for different compound classes.

Main Methods:

• Brewer's spent grain was processed via mashing, filtration, and washing.
• Extraction experiments were conducted using catholyte under atmospheric and excess pressure (0.5-1 atm).
• High-Performance Liquid Chromatography (HPLC) was used for quantitative analysis of extracted compounds.
• Mathematical analysis and correlation methods were applied to interpret results and identify formation regularities.

Main Results:

• Catholyte extraction at atmospheric pressure and 50°C for 120 min yielded superior results for β-glucan, sugars, nitrogenous, and phenolic compounds compared to water extraction.
• Excess pressure conditions (0.5-1 atm) increased non-starch polysaccharide and nitrogenous compound accumulation but decreased sugars and phenolics with longer extraction times.
• Ultrasonic treatment with catholyte effectively extracted β-glucan and nitrogenous fractions, but not sugars or phenolics.
• Syringic and vanillic acids were identified as key influencers in furan compound formation under different pressure conditions.

Conclusions:

• Catholyte facilitates efficient extraction of carbohydrate, nitrogenous, and monophenolic compounds, particularly under pressure.
• Flavonoid extraction efficiency is improved by reducing extraction time under pressure conditions.
• The study highlights catholyte as a promising green solvent for valorizing brewer's spent grain.