Preparation, characterization, and adsorption capacity of pyrophosphoric acid sustainable activated carbon from baijiu spent grains for risk factor mitigation

Abstract

The increasing societal concern regarding the safety of alcoholic beverages necessitates the implementation of effective and safe intervention measures to enhance their safety. This study aims to repurpose the substantial spent grains generated during Baijiu production, which have a significant environmental impact, into sustainable activated carbon (as an adsorbent) by pyrophosphoric acid to alleviate these concerns directly. Precise optimization strategies were employed for simulated and authentic Baijiu samples to determine ideal conditions for carbon synthesis suitable for different alcoholic beverages (with fewer flavor compounds and rich in flavor compounds). Characterization via FT-IR and SEM confirmed the porous structure of the activated carbon. The adsorption experiments indicate that calcination temperature significantly influences adsorption efficiency, favoring selective adsorption of higher alcohols, acetaldehyde, and methanol, while simultaneously reducing acid adsorption. Compared to commercial activated carbon, spent grain carbon exhibited superior acid retention effects. Through sensory evaluation to determine application parameters, activated carbon can reduce acetaldehyde and higher alcohols in Baijiu by 9.67 % and 14.94 %, respectively, without compromising aroma. Thus, this research not only provides a novel recycling strategy for the significant waste generated in Baijiu production but also offers a green and sustainable assurance measure for the quality and safety of alcoholic beverages.