Oryza sativa L. ‘Violet Nori’ is an Italian cultivar of spontaneous growing aromatic purple rice which is particularly rich in polyphenolic compounds, especially anthocyanins, conferring it an excellent antioxidant capacity. The present study aimed at increasing the extraction yields of its antioxidant compounds with green strategies and it is divided into two steps. The first step concerned a solubility study of the targeted polyphenols in different ethanol:water mixtures by means of a theoretical prediction method, using the simulation program COSMO-RS, and the subsequently confirmation of the computational results by practical experiments. Once the best extraction mixture was identified, the second step of the work was performed, with the purpose of intensifying the extraction yield. Therefore, various innovative green extraction techniques, including ultrasound, using both the probe system and the ultrasonic bath, bead milling, microwave and accelerated solvent extractions were tested and compared to conventional maceration.

Results, expressed in terms of total phenolic and total monomeric anthocyanin contents, showed that the best extracting solvent for ‘Violet Nori’ rice was the mixture ethanol:water (60:40 v/v), being COSMO-RS computational predictions in good correlation with the experimental results. Moreover, the most efficient techniques to extract the antioxidant compounds resulted to be both ultrasound-assisted extraction probe and bead milling, that in only 5 min got the same extractive efficiency obtained after 3 h of conventional maceration.

水稻L.'Violet Nori'是一种自发种植的芳香紫色大米的意大利栽培品种，它特别富含多酚类化合物，尤其是花色苷，使其具有出色的抗氧化能力。本研究旨在通过绿色策略提高其抗氧化剂化合物的提取率，该研究分为两个步骤。第一步涉及使用模拟程序COSMO-RS通过理论预测方法对目标多酚在不同乙醇：水混合物中的溶解度进行研究，随后通过实际实验确认计算结果。一旦确定了最佳的提取混合物，便进行了第二步工作，目的是提高提取率。因此，各种创新的绿色提取技术，

以总酚和总单体花色苷含量表示的结果表明，“紫罗兰色”大米的最佳提取溶剂是乙醇：水（60:40 v / v）的混合物，这与COSMO-RS计算预测具有良好的相关性与实验结果。而且，最有效的提取抗氧化剂化合物的技术是超声辅助提取探针和珠磨，这两种提取方法仅用5分钟即可获得与常规浸渍3小时相同的提取效率。