{"title":"Alkaline treatment for targeted lignin breakdown in rice straw: Maximizing phenolic content and product characterization","authors":"","doi":"10.1016/j.fbp.2024.10.012","DOIUrl":null,"url":null,"abstract":"<div><div>Lignin is a significant renewable source for the production of phenolics and aromatic compounds for use as functional materials. Rice straw (RS), a lignocellulosic biomass was given alkaline treatment, to breakdown lignin into methoxyphenols and heterocyclic compounds, leaving behind carbohydrate rich residue. Process parameters such as NaOH (M), time (min) and liquid to solid (L:S) ratio (mL/g) were optimized using Response Surface Methodology (RSM) to enhance the extraction of phenolics. The maximum phenolic content (13.98 mg/g RS) was obtained after treatment with 3 M NaOH for 30 min with L: S ratio of 20:1 mL/g at 121°C. GC-MS revealed the presence of 14 compounds, primarily methoxyphenols like acetosyringone (32.44 %), 2-methoxy-4-vinyl phenol (23.71 %), vanillin (1.25 %) and 2, 6-dimethoxyphenol (1.49 %). Additionally, a significant proportion of a heterocyclic compound, 2, 3-dihydrobenzofuran (31.72 %), was also present. The extract exhibited considerable levels of 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (IC<sub>50</sub> (half-maximal inhibitory concentration) = 0.45 mg/mL) radical scavenging activity, which was comparable to ascorbic and gallic acids. With substantial conversion (60.17 %) of rice straw lignin to phenols and simultaneous recovery of both cellulose (45.7 %) and hemicellulose (14.6 %), this process can be useful in biorefining of lignocellulosic biomass to phenolic chemicals for application in food and pharmaceutical industry.</div></div>","PeriodicalId":12134,"journal":{"name":"Food and Bioproducts Processing","volume":null,"pages":null},"PeriodicalIF":3.5000,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Food and Bioproducts Processing","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0960308524002116","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Lignin is a significant renewable source for the production of phenolics and aromatic compounds for use as functional materials. Rice straw (RS), a lignocellulosic biomass was given alkaline treatment, to breakdown lignin into methoxyphenols and heterocyclic compounds, leaving behind carbohydrate rich residue. Process parameters such as NaOH (M), time (min) and liquid to solid (L:S) ratio (mL/g) were optimized using Response Surface Methodology (RSM) to enhance the extraction of phenolics. The maximum phenolic content (13.98 mg/g RS) was obtained after treatment with 3 M NaOH for 30 min with L: S ratio of 20:1 mL/g at 121°C. GC-MS revealed the presence of 14 compounds, primarily methoxyphenols like acetosyringone (32.44 %), 2-methoxy-4-vinyl phenol (23.71 %), vanillin (1.25 %) and 2, 6-dimethoxyphenol (1.49 %). Additionally, a significant proportion of a heterocyclic compound, 2, 3-dihydrobenzofuran (31.72 %), was also present. The extract exhibited considerable levels of 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (IC50 (half-maximal inhibitory concentration) = 0.45 mg/mL) radical scavenging activity, which was comparable to ascorbic and gallic acids. With substantial conversion (60.17 %) of rice straw lignin to phenols and simultaneous recovery of both cellulose (45.7 %) and hemicellulose (14.6 %), this process can be useful in biorefining of lignocellulosic biomass to phenolic chemicals for application in food and pharmaceutical industry.
期刊介绍:
Official Journal of the European Federation of Chemical Engineering:
Part C
FBP aims to be the principal international journal for publication of high quality, original papers in the branches of engineering and science dedicated to the safe processing of biological products. It is the only journal to exploit the synergy between biotechnology, bioprocessing and food engineering.
Papers showing how research results can be used in engineering design, and accounts of experimental or theoretical research work bringing new perspectives to established principles, highlighting unsolved problems or indicating directions for future research, are particularly welcome. Contributions that deal with new developments in equipment or processes and that can be given quantitative expression are encouraged. The journal is especially interested in papers that extend the boundaries of food and bioproducts processing.
The journal has a strong emphasis on the interface between engineering and food or bioproducts. Papers that are not likely to be published are those:
• Primarily concerned with food formulation
• That use experimental design techniques to obtain response surfaces but gain little insight from them
• That are empirical and ignore established mechanistic models, e.g., empirical drying curves
• That are primarily concerned about sensory evaluation and colour
• Concern the extraction, encapsulation and/or antioxidant activity of a specific biological material without providing insight that could be applied to a similar but different material,
• Containing only chemical analyses of biological materials.