Abstract Resveratrol (2,5,4′-trihydroxystilbene) is a naturally occurring phytoalexin produced by some spermatogphytes and it has recently attracted the increasing attention of agronomists and pharmacologists owing to its satisfactory bioactivities. The objective of this work was to develop a cost-effective technology of foam fractionation to recover trans-resveratrol (trans-Res) from the leaching solution of muscat grape pomace on the assistance of molecular imprinting modified SiO2 nanoparticles. First, trans-Res was leached from muscat grape pomace through the method of alkaline extraction. Under the suitable leaching conditions, the leaching yield of trans-Res reached 84.34%. Adsorption experiments were performed for describing the adsorption behavior of trans-Res on the molecular imprinting modified SiO2 nanoparticles. Results indicated that their adsorption could be fairly described by Freundlich model and fitted well with the pseudo-second-order kinetics model. Moreover, the molecular imprinting modified SiO2 nanoparticles could effectively maintain the stability of trans-Res through avoiding the cis-trans photo-isomerization and oxidative degradation. Finally, foam fractionation was carried out for recovering trans-Res from the leaching solution, in which the concentration of trans-Res was as high as 29.09 mg/L. The molecular imprinting modified SiO2 nanoparticles were used as the collector. Under the suitable conditions of loading liquid volume 250 mL, particle size of molecular imprinting modified SiO2 nanoparticles 436.0 nm, sapindus saponin concentration 0.075 g/L, volumetric gas flow rate 100 mL/min and pore diameter of gas distributor 0.180 mm, the enrichment ratio and the recovery percentage of trans-Res reached 13.68 ± 1.03 and 89.73 ± 3.57%, respectively. This work is expected to provide a new technology for selectively recovering non-surface-active materials from the solution with their isomers or analogues, and to facilitate the industrialization of foam fractionation.

中文翻译：

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开发泡沫分馏新技术从麝香葡萄渣浸出液中有效回收反式白藜芦醇

摘要 白藜芦醇（2,5,4'-三羟基芪）是一种由某些精子植物产生的天然植物抗毒素，由于其令人满意的生物活性，近年来越来越受到农学家和药理学家的关注。这项工作的目的是开发一种经济高效的泡沫分馏技术，在分子印迹改性 SiO2 纳米粒子的帮助下，从麝香葡萄渣的浸出液中回收反式白藜芦醇 (trans-Res)。首先，通过碱提法从麝香葡萄渣中浸出反式Res。在合适的浸出条件下，反式Res的浸出率达到84.34%。进行吸附实验以描述反式 Res 在分子印迹改性 SiO2 纳米粒子上的吸附行为。结果表明，它们的吸附可以用 Freundlich 模型来描述，并且与拟二级动力学模型很好地吻合。此外，分子印迹修饰的SiO2纳米粒子可以通过避免顺反光异构化和氧化降解有效地保持反式Res的稳定性。最后对浸出液进行泡沫分馏回收反式Res，其中反式Res的浓度高达29.09 mg/L。分子印迹改性的 SiO2 纳米颗粒用作收集器。在上样液体积250 mL、分子印迹改性SiO2纳米粒子粒径436.0 nm、无患子皂苷浓度0.075 g/L、气体体积流量100 mL/min、气体分布器孔径0.180 mm的适宜条件下，trans-Res的富集率和回收率分别达到13.68±1.03和89.73±3.57%。这项工作有望为从溶液中选择性回收非表面活性材料及其异构体或类似物提供一种新技术，并促进泡沫分馏的工业化。