Kirusnaruban Kemashalini, Gasparre Nicola, Nandasiri Ruchira, Eskin Michael N A, Rosell Cristina M
Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, Canada.
St. Boniface Hospital Research, Winnipeg, Canada.
J Food Sci. 2025 May;90(5):e70225. doi: 10.1111/1750-3841.70225.
Phenolic acids are important secondary metabolites in wheat, existing in free, conjugated, and bound forms. Traditional extraction methods use organic solvents like ethanol and acetone and are labor-intensive procedures. This study examined the extraction of phenolic acids from wheat using microwave-assisted extraction (MAE) with water as the green extractant. The extraction of phenolic acids was performed on whole grain flour and on wheat kernels. MAE conditions were solvent type (water vs. 80% (v/v) ethanol), temperature (140, 160, 170, and 180°C), and extraction time (2, 5, 10, and 15 min). MAE with 80% (v/v) ethanol effectively extracted phenolic acids directly from wheat kernels, although the amount (0.96 ± 0.03 mg/g DW) was much lower than that obtained from the flour (3.52 ± 0.24 mg/g DW). Water, however, proved to be the most efficient solvent for extracting phenolic compounds (5.41 ± 0.25 mg/g flour DW) compared with 80% (v/v) ethanol (3.52 ± 0.24 mg/g flour DW) at 170°C for 10 min. Kernel extracts extracted with water or 80% (v/v) ethanol at 170°C for 15 min yielded 2.21 ± 0.22 mg/g DW and 0.96 ± 0.03 mg/g DW, respectively. The analysis of the phenolic acids revealed that gallic acid was the most abundant acid, ranging from 1802.56 to 92.02 µg/g DW, depending on the extraction conditions. Overall, an efficient extraction of the phenolic acids, even from wheat kernels, was achieved using MAE with water as the green extractant.
酚酸是小麦中重要的次生代谢产物，以游离、结合和束缚形式存在。传统提取方法使用乙醇和丙酮等有机溶剂，且操作繁琐。本研究考察了以水作为绿色提取剂，采用微波辅助萃取（MAE）从小麦中提取酚酸的方法。酚酸的提取分别在全麦粉和小麦籽粒上进行。MAE的条件包括溶剂类型（水与80%（v/v）乙醇）、温度（140、160、170和180℃）以及提取时间（2、5、10和15分钟）。用80%（v/v）乙醇进行MAE能直接从小麦籽粒中有效提取酚酸，尽管其含量（0.96±0.03mg/g干重）远低于从面粉中获得的含量（3.52±0.24mg/g干重）。然而，与在170℃下10分钟用80%（v/v）乙醇（3.52±0.24mg/g面粉干重）相比，水被证明是提取酚类化合物最有效的溶剂（5.41±0.25mg/g面粉干重）。在170℃下15分钟用水或80%（v/v）乙醇提取的籽粒提取物分别产生2.21±0.22mg/g干重和0.96±0.03mg/g干重。酚酸分析表明，没食子酸是含量最高的酸，根据提取条件，其含量在1802.56至92.02μg/g干重之间。总体而言，以水作为绿色提取剂，采用MAE即使从小麦籽粒中也能有效提取酚酸。
