PDF(Pubmed)
Abstract：
Almond trees are the most cultivated nut tree in the world. The production of almonds generates large amounts of by-products, much of which goes unused. Herein, this study aimed to develop a green chemistry approach to identify and extract potentially valuable compounds from almond by-products. Initially, a screening was performed with 10 different Natural Deep Eutectic Solvents (NADESs). The mixture lactic acid/glycerol, with a molar ratio 1:1 (1:50 plant material to NADES (w/v) with 20% v/v of water) was identified as the best extraction solvent for catechin, caffeoylquinic acid, and condensed tannins in almond hulls. Subsequently, a method was optimized by a Design of Experiment (DoE) protocol using a miniaturized extraction technique, Microwave-Assisted Extraction (MAE), in conjunction with the chosen NADESs. The optimal conditions were found to be 70 °C with 15 min irradiation time. The optimal extraction conditions determined by the DoE were confirmed experimentally and compared to methods already established in the literature. With these conditions, the extraction of metabolites was 2.4 times higher, according to the increase in total peak area, than the established literature methods used. Additionally, by applying the multiparameter Analytical Greenness Metric (AGREE) and Green Analytical Process Index (GAPI) metrics, it was possible to conclude that the developed method was greener than the established literature methods as it includes various principles of green analytical chemistry.
摘要：
杏仁树是世界上栽培最多的坚果树。生产杏仁会产生大量的副产品,其中大部分未使用。在这里，这项研究旨在开发一种绿色化学方法来鉴定和提取潜在有价值的化合物从杏仁副产品。最初，用10种不同的天然深共晶溶剂(NADES)进行筛选。乳酸/甘油的混合物，摩尔比为1:1（1:50植物材料与NADES（w/v），水含量为20％v/v）被确定为儿茶素的最佳提取溶剂，咖啡酰奎宁酸，和浓缩的杏仁壳中的单宁。随后，通过使用小型化提取技术的实验设计（DoE）协议对方法进行了优化，微波辅助萃取(MAE),与所选的NADES一起使用。发现最佳条件为70°C，辐照时间为15分钟。通过实验确认了由DoE确定的最佳提取条件，并与文献中已经建立的方法进行了比较。在这些条件下，代谢物的提取量高2.4倍，根据总峰面积的增加，而不是使用的既定文献方法。此外,通过应用多参数分析绿色度量(AGREE)和绿色分析过程指数(GAPI)度量，可以得出结论，所开发的方法比已建立的文献方法更绿色，因为它包括绿色分析化学的各种原理。
