Corncobs are generated in large quantities during corn processing but are commonly discarded, burned, or used as low-value animal feed. Rich in cellulose, hemicellulose, lignin, and phenolic acids, they have considerable potential as renewable feedstocks for biorefineries. FA and pCA are especially valuable because of their antioxidant and anti-inflammatory properties. However, these compounds are tightly bound within the dense lignocellulosic structure of corncobs through ester and ether linkages. Conventional alkaline extraction can release them effectively but requires substantial quantities of solvents and produces alkaline wastewater. Enzymatic extraction offers milder and more selective processing, yet enzymes often cannot penetrate the compact biomass matrix. Therefore, an effective pretreatment combined with synergistic enzymes is needed to improve compound recovery without relying on harsh chemicals.
A study (DOI: 10.48130/fia-0026-0002) published in Food Innovation and Advances on 02 March 2026 by Guangsen Fan's team, Key Laboratory of Geriatric Nutrition and Health (Beijing Technology and Business University), Ministry of Education, reports that optimized hydrothermal pretreatment followed by synergistic enzymatic hydrolysis substantially increased phenolic acid and XOS production from corncobs.
The researchers first characterized the corncob material and found that it contained 34.34% cellulose, 22.19% hemicellulose, and 16.26% lignin, together with 17.8 mg/g FA and 11.29 mg/g pCA. They then evaluated the effects of autohydrolysis temperature, treatment time, solid-to-liquid ratio, and particle size through single-factor experiments. A Box-Behnken response surface design was subsequently used to identify the optimal pretreatment conditions. Corncob particles of 40–60 mesh were autohydrolyzed at 165 °C for 34 min using a solid-to-liquid ratio of 1:90.8. Under these conditions, the total FA and pCA yield reached 46.19%, 1.76 times the pre-optimization level. The pretreated material was then hydrolyzed using the feruloyl esterase BpFaeT132C-D143C and xylanase SrXyn10AR. A second response surface model optimized temperature, hydrolysis time, and enzyme concentration. The final enzymatic conditions were 43 °C, pH 5.5, 90 rpm, and 2.5 h, with each enzyme supplied at 1.1 U/mL. The resulting total FA and pCA yield reached 63.42%, closely matching the model prediction and approaching the highest previously reported recovery from corncobs while reducing hydrolysis time to approximately one-tenth of that required in an earlier study. Tests using the enzymes individually and in combination confirmed their synergistic action: xylanase opened the hemicellulose structure, enabling feruloyl esterase to access and cleave phenolic acid ester bonds. The combined treatment also raised total XOS production to 303.31 mg/g, 5.23 times the amount produced by autohydrolysis alone. Scanning electron microscopy showed that the initially smooth, compact corncob surface became porous after autohydrolysis and extensively fragmented after enzymatic treatment. Fourier-transform infrared spectroscopy further confirmed the disruption of ester bonds, lignin structures, and hemicellulose components.
Overall, the study demonstrates that autohydrolysis and complementary enzyme activities can be integrated into a rapid, low-chemical process for the comprehensive utilization of corncobs. Simultaneously recovering phenolic acids and XOS improves resource efficiency and creates multiple high-value product streams from a single agricultural residue. With further optimization and scale-up assessment, this approach could contribute to cleaner biorefining, agricultural waste reduction, and the development of sustainable ingredients for the food, pharmaceutical, and cosmetic industries.
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References
DOI
10.48130/fia-0026-0002
Original Source URL
https://doi.org/10.48130/fia-0026-0002
Funding information
This research was supported by Beijing Natural Science Foundation (Grant No. 6222003) and Open Research Fund Program of Guangxi Key Lab of Agricultural Resources Chemistry and Biotechnology (Grant No. 2024KF05).
About Food Innovation and Advances
Food is essential to life and relevant to human health. The rapidly increasing global population presents a major challenge to supply abundant, safe, and healthy food into the future. The open access journal Food Innovation and Advances (e-ISSN 2836-774X), published by Maximum Academic Press in association with China Agricultural University, Zhejiang University and Shenyang Agricultural University, publishes high-quality research results related to innovations and advances in food science and technology. The journal will strive to contribute to food sustainability in the present and future.