This study was on the comparison of hydrothermal treatments at 170 °C (steam injection) and 220 °C (steam explosion) to solubilize the organic matter contained in residual strawberry extrudate, focusing on phenolic compounds that were susceptible to be extracted and on sugars. After the extraction step, the remaining strawberry extrudate phases were subjected to anaerobic digestion to generate biogas that would compensate the energy requirements of the suggested hydrothermal treatments and to stabilize the remaining waste. Hydrothermal treatment at 220 °C allowed the recovery of 2053 mg of gallic acid eq. per kg of residual strawberry extrudate. By contrast, after hydrothermal treatment at 170 °C, only 394 mg of gallic acid eq. per kg of residual strawberry extrudate was recovered. Anaerobic digestion processes were applied to the de-phenolized liquid phase and the solid phase together, which generated similar methane productions, i.e., around 430 mL CH₄/g volatile solids, after both 170 °C and 220 °C hydrothermal treatments. Considering the latest observation, hydrothermal treatment at 220 °C is a preferable option for the valorization of residual strawberry extrudate (RSE) due to the high solubilization of valuable phenolic compounds that can be recovered.

中文翻译：

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通过高温水热处理和蒸汽爆炸进行高附加值的化合物回收，以及随后的残留草莓挤出物的生物甲烷化作用。

这项研究是对在170°C（蒸汽注入）和220°C（蒸汽爆炸）下进行水热处理以溶解残余草莓挤出物中所含有机物的比较，重点是易提取的酚类化合物和糖类。在提取步骤之后，将剩余的草莓挤出物相进行厌氧消化，以产生沼气，该沼气将补偿建议的水热处理的能量需求并稳定剩余的废物。在220°C的水热处理可以回收2053 mg没食子酸当量。每公斤残余草莓挤出物。相比之下，在170°C进行水热处理后，只有394 mg没食子酸当量。每公斤残余草莓挤出物被回收。经过170°C和220°C的水热处理后，挥发性固体含量为₄ / g。考虑到最新的观察结果，在220℃下进行水热处理是使残留草莓挤出物（RSE）增值的首选方法，因为有价值的酚类化合物可以高度溶解，因此可以回收。