BACKGROUND Red beet plants are cultivated worldwide for the consumption of their roots, generating large amounts of unexploited by-products. In particular, beet leaves (BL) represent about 50% of the whole plant and are usually discarded as waste. This constitutes not only an economic issue, since multiple resources invested in the production will be wasted, but also an environmental problem because of the pollution associated with their disposal. However, BL comprise an important source of functional compounds (polyphenols and betalains) that could be recovered from the raw material, representing a sustainable solution for the underutilisation of this by-product. This study proposes the recovery of polyphenols and betalains using an aqueous ultrasound-assisted extraction (UAE) process at different powers (35, 50, and 100 W) that was characterised and optimised. RESULTS UAE significantly enhanced the recovery of bioactive compounds and shortened the time required for extraction in comparison to traditional macerations (35<50<100 W). During UAE the temperature of the systems increased as a function of the power applied, favouring the recovery of these phytochemicals. Additionally, Box-Behnken design and Response Surface Methodology were employed to optimise UAE conditions (90 W ultrasound power, 1:20 solid-liquid ratio, 16 min extraction time), under which the yields were 14.9 mg/g (polyphenols), 949.1 μg/g (betaxanthins), and 562.2 μg/g (betacyanins), consistent with the values predicted by the models. CONCLUSION This study enabled the development of a green-solvent UAE process that constitutes an effective post-harvest by-products strategy to minimize losses and increase biomass utilisation through the recovery of bioactive compounds from BL, promoting sustainability in the agri-food chain. This article is protected by copyright. All rights reserved.

中文翻译：

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从甜菜叶中提取生物活性化合物的水相超声辅助提取工艺的开发：减少损失和增加生物质利用的建议

背景红甜菜植物在世界范围内种植以消耗其根，产生大量未开发的副产品。特别是，甜菜叶 (BL) 约占整个植物的 50%，通常作为废物丢弃。这不仅构成经济问题，因为投入生产的多种资源将被浪费，而且由于与它们的处置相关的污染而构成环境问题。然而，BL 包含可从原材料中回收的功能化合物（多酚和甜菜碱）的重要来源，代表了这种副产品未充分利用的可持续解决方案。本研究建议使用不同功率的水性超声辅助提取 (UAE) 工艺回收多酚和甜菜碱 (35, 50, 和 100 W) 进行了表征和优化。结果 与传统浸渍法 (35<50<100 W) 相比，UAE 显着提高了生物活性化合物的回收率并缩短了提取所需的时间。在阿联酋期间，系统的温度随着施加的功率而增加，有利于这些植物化学物质的回收。此外，采用 Box-Behnken 设计和响应面方法来优化阿联酋条件（90 W 超声功率，1:20 固液比，16 分钟提取时间），在该条件下，产量为 14.9 mg/g（多酚），949.1 μg/g（甜菜黄素）和 562.2 μg/g（甜菜花青素），与模型预测的值一致。结论 本研究促成了一种绿色溶剂阿联酋工艺的开发，该工艺构成了一种有效的收获后副产品策略，通过从 BL 中回收生物活性化合物来最大程度地减少损失并增加生物质利用，促进农业食品链的可持续性。本文受版权保护。版权所有。