Abstract

Rapeseed meal is a by-product of oil producing industry which contains a high amount of protein (37–42%). To prepare protein isolates, suitable for human nutrition, the industrial rapeseed meal is often subjected to a pre-treatment with aqueous ethanol solution. The aim of the study was to investigate the phytochemical profile and bioactivity of the ethanol-wash solutes (EWS) obtained as a waste product of the main process of the protein isolate preparation from industrial rapeseed meal. Proximate composition analysis revealed that total carbohydrates were more than half of the product (60.63%). The content of hydrolysable reducing sugars was 44.13%, while glucose was 7.22%. The total phenols amounted 13.38%. EWS contained 1.63% total flavonoids and 242.05 µmol/g dry weight glucosinolates. The major components, as determined by GC–MS analysis, were sucrose, turanose and melibiose with 22.68%, 4.08% and 3.97% of total ion current (TIC) of polar compounds, respectively; cetyl alcohol (2.45% of TIC) and methyl oleate (2.08% of TIC) representing nonpolar compounds, and sinapic acid (73.71% of TIC) which was the prevailing substance of the phenolic acids identified in the EWS. The 0.2% EWS, prepared in aqueous 70% ethanol solution, exhibited 70.68% scavenging capability of DPPH radicals and 585.11 µmol Fe²⁺/g EWS (dry weight) reducing capacity. The product demonstrated limited antibacterial but broad antifungal activity which was expressed against Aspergillus niger (ATCC 1015), Aspergillus flavus, Penicillium sp., Rhizopus sp. and Fusarium moniliforme (ATCC 38932) as determined by the agar-well diffusion assay. Overall, EWS exhibited bioactive capacity, which revealed its potential application as a value-added product in the food and nutraceutical industries or agriculture. The broad-spectrum antifungal activity makes the product a prospective agent for food biopreservation or plant bioprotection.

Graphic Abstract

中文翻译：

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工业油菜粕乙醇洗涤溶质的植物化学特征和生物活性

摘要

菜籽粕是石油生产工业的副产品，含有大量蛋白质（37-42%）。为了制备适合人类营养的蛋白质分离物，工业菜籽粕通常用乙醇水溶液进行预处理。该研究的目的是研究乙醇洗涤溶质 (EWS) 的植物化学特征和生物活性，该乙醇洗涤溶质 (EWS) 作为工业油菜籽粕分离蛋白制备主要过程的废物产物。近似成分分析显示，总碳水化合物占产品的一半以上 (60.63%)。可水解还原糖的含量为44.13%，而葡萄糖为7.22%。总酚为13.38%。EWS 含有 1.63% 的总黄酮和 242.05 µmol/g 干重的硫代葡萄糖苷。通过 GC-MS 分析确定的主要成分，蔗糖、松二糖和蜜二糖分别占极性化合物总离子流 (TIC) 的 22.68%、4.08% 和 3.97%；鲸蜡醇（TIC 的 2.45%）和油酸甲酯（TIC 的 2.08%）代表非极性化合物，芥子酸（TIC 的 73.71%）是 EWS 中确定的酚酸的主要物质。在 70% 乙醇水溶液中制备的 0.2% EWS 对 DPPH 自由基和 585.11 µmol Fe 的清除能力为 70.68%²⁺ /g EWS（干重）还原能力。该产品表现出有限的抗菌但广泛的抗真菌活性，该活性针对黑曲霉(ATCC 1015)、黄曲霉、青霉属、根霉属。和念珠菌镰刀菌(ATCC 38932) 通过琼脂孔扩散试验测定。总体而言，EWS 表现出生物活性能力，这表明其作为增值产品在食品和营养品行业或农业中的潜在应用。广谱抗真菌活性使该产品成为食品生​​物防腐或植物生物保护的前瞻性试剂。

图形摘要