Antioxidant Activity and Metabolomic Analysis of Cagaitas (Eugenia dysenterica) using Paper Spray Mass Spectrometry

Cagaita is a fruit from Brazilian cerrado, belongs to Myrtaceae family, and has important economic value. This work aimed to determine the total antioxidant capacity (extractable and non-extractable fractions) by different methods and to evaluate the use of paper spray mass spectrometry to obtain fingerprints of cagaita from different regions with the aid of principal components analysis. Cagaitas had higher antioxidant activity than those found in other fruits mentioned in literature, and the non-extractable fraction was 18.90 to 21.05% of the antioxidant capacity. The analysis of paper spray mass spectrometry in positive and negative ionization modes identified several substances, including organic acids, sugars, amino acids and several other classes of phenolic compounds. Analysis of the main components of cagaita samples permitted discrimination of the major constituents such as sugars and different kinds of phenolic compounds. Thus, this study demonstrated that paper spray mass spectrometry is a simple and ultrafast method with minimum sample preparation that allows the analysis of the chemical profile of cagaita.

凯加伊塔果（Cagaita）是源自巴西塞拉多（Cerrado）生态区的果实，隶属于桃金娘科（Myrtaceae），具备重要的经济价值。本研究兼具两个核心目标：一是通过多种方法测定凯加伊塔果的总抗氧化能力（涵盖可提取与不可提取组分）；二是借助主成分分析（principal components analysis），评估利用纸喷雾质谱（paper spray mass spectrometry）获取不同产区凯加伊塔果化学指纹图谱的可行性。研究结果显示，凯加伊塔果的抗氧化活性高于文献中报道的其他果实，且其不可提取组分贡献的抗氧化能力占总抗氧化能力的18.90%至21.05%。通过正、负两种电离模式下的纸喷雾质谱分析，共鉴定出多种物质，包括有机酸、糖类、氨基酸以及多类酚类化合物。对凯加伊塔果样本开展主成分分析，可实现对其主要组成成分（如糖类与不同种类酚类化合物）的有效区分。综上，本研究证实，纸喷雾质谱是一种操作简便、超快速且样本制备流程极简的分析方法，可用于解析凯加伊塔果的化学组成特征。