This work examines the biorefining potential of mixed fruit and vegetable waste generated in hotels targeting recovery of high-value bioactive phytochemicals, biogas, and soil amender. Through a primary survey of 15 number of star-category hotels in the National Capital Region (NCR) in India, the organic waste management options being practiced were compiled. Phytochemicals recovery from the mixed fruit and vegetable waste was done employing a previously optimized solvent extraction process; this was followed by anaerobic digestion (AD) of the solid residue. Three different waste samples were tested for AD viz. without phytochemicals removal (NT), phytochemicals removal without dichloromethane (DCM) treatment (T-1), and phytochemicals removal with DCM treatment (T-2). The survey indicated that organic waste management practices in NCR hotels are variable covering a broad range—from complete in-house handling of the waste to disposal of the entire amount to urban local bodies. Removal of bioactive phytochemicals from mixed fruit and vegetable waste enhanced the AD process with shorter time lag in gas generation and increased production of biogas with higher methane (CH₄) content. The biomethanation potential (L/g VS) and CH₄ content (%) were, respectively, 0.198 ± 0.06 and 41 ± 3 (NT), 0.275 ± 0.36 and 57 ± 3 (T-1), and 0.303 ± 0.39 and 62 ± 3 (T-2); thus, the best AD performance was obtained with sample T-2. A combination of phytochemicals removal followed by AD is thus an alternative, biorefinery-based concept for managing mixed fruit and vegetable waste from hotels. The proposed process would involve a combination of physico-mechanical (shredding, drying), physico-chemical (solvent extraction, ultrasonication, centrifugation, filtration, vacuum distillation), and biochemical (AD) steps. Besides the option of upcycling the anaerobic digestion streams (CH₄, CO₂ and nutrients) in a bioeconomy approach, this scheme enables the recovery of high-value phytochemicals. A preliminary resource recovery estimate (per year per hotel) for sample T-2 is as follows: phytochemicals 6.2 metric tons (MT), biogas 890 m³, and digestate 78 MT. Overall, this study is expected to contribute towards efforts in the eventual transition to a sustainable biobased circular economy.

Graphical abstract

中文翻译：

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管理酒店产生的水果和蔬菜废物的生物精炼方法：印度的研究案例

这项工作研究了酒店产生的混合水果和蔬菜废物的生物精炼潜力，旨在回收高价值的生物活性植物化学物质、沼气和土壤改良剂。通过对印度首都地区 (NCR) 的 15 家星级酒店的初步调查，编制了正在实施的有机废物管理方案。使用先前优化的溶剂萃取工艺从混合水果和蔬菜废物中回收植物化学物质；随后对固体残留物进行厌氧消化 (AD)。对三种不同的废物样品进行了 AD 测试。不去除植物化学物质 (NT)、不经二氯甲烷 (DCM) 处理去除植物化学物质 (T-1) 和经 DCM 处理去除植物化学物质 (T-2)。调查表明，NCR 酒店的有机废物管理做法变化多样，涵盖范围广泛——从完全内部处理废物到将全部废物处置给城市地方机构。从混合水果和蔬菜废物中去除生物活性植物化学物质增强了 AD 过程，缩短了气体产生的时间延迟，并增加了具有更高甲烷 (CH) 的沼气产量₄）内容。生物甲烷化潜力 (L/g VS) 和 CH ₄含量 (%) 分别为 0.198 ± 0.06 和 41 ± 3 (NT)、0.275 ± 0.36 和 57 ± 3 (T-1)、0.303 ± 0.39 和 62 ± 3 (T-2); 因此，样品 T-2 获得了最好的 AD 性能。因此，去除植物化学物质和 AD 的组合是一种替代的、基于生物精炼厂的概念，用于管理酒店的混合水果和蔬菜废物。提议的工艺将涉及物理-机械（切碎、干燥）、物理-化学（溶剂萃取、超声处理、离心、过滤、真空蒸馏）和生化 (AD) 步骤的组合。除了升级循环厌氧消化流（CH ₄，CO ₂和营养素）在生物经济方法中，该方案能够回收高价值的植物化学物质。样本 T-2 的初步资源回收估计（每家酒店每年）如下：植物化学物质 6.2 公吨 (MT)、沼气 890 m ³和沼渣 78 MT。总体而言，这项研究预计将有助于最终过渡到可持续的生物循环经济。

图形概要