Alves Izabel de Paula Duarte, Almeida Maria Carolina de, Souto Luciana Reis Fontinelle, Oliveira Tatianne Ferreira de
Food Technology Department, School of Agronomy, Federal University of Goiás - UFG, Goiânia-Goiás, Brazil.
Acta Sci Pol Technol Aliment. 2021 Jul-Sep;20(3):325-336. doi: 10.17306/J.AFS.0894.
The use of natural plant antioxidants has been an alternative approach to synthetic antioxidants for food applications. This study investigated the antioxidant properties of the leaves of Curcuma longa L. against the oxidation of soybean oil using leaf extracts obtained from seven different types of organic solvents and compared to the action of efficient synthetic antioxidants which are widely used and low cost but with toxicity risk. The application of natural alternatives from sources still little studied is a proposal and the extraction of compounds with high antioxidant capacity may vary according to the type of solvent, its mixture, its polarity and other factors that burden or harm the health of the consumer.
The leaf extracts were sanitized, dried, and obtained for solvent selection. The quantification of total phenolic compounds (TPC) and antioxidants was performed by using different combinations and proportions of solvents: water (100%), ethanol (100%), methanol (100%), ethanol/water (70%:30%), methanol/water (70%:30%), methanol/acetic acid (99.5%:0.5%), and acetone/water/acetic acid (70%:28:2%). The solvent selected was the one that extracted the highest content of phenolic and antioxidant compounds (using the free radical DPPH scavenging method and FRAP assay). It used an accelerated storage test and experimental design to assess oxidative stability (using peroxide index (PI), thiobarbituric acid reactive substances (TBARS), dienes (DC) and triple conjugates (TC) and statistical analysis).
The ethanol/water solvent was efficient in the extraction of TPC (2422 mg GAE 100 g-1). The mixture of solvents extracted an average of 23.65% more TPC when compared to the single solvents. Regarding the antioxidant capacity, the ethanol/water solvent showed 1847 mg TE 100 g-1 using the DPPH and 217 μmol of FeSO4 100 g-1 using the FRAP assays. In addition, the oxidation of soybean oil was delayed by the accelerated storage test showing equivalent results to BHT at 0.02% for the values of PI, TBARS and DC/TC.
The E/W extract showed the highest yield in the extraction of phenolic compounds and is a safe solvent for food. The addition of Curcuma longa L. leaf extract to soybean oil caused reductions in PI, TBARS, CD and CT values. The leaf extract of C. longa L. is considered to be a good alternative to synthetic antioxidants against the oxidative degradation of soybean oil.
在食品应用中，使用天然植物抗氧化剂已成为合成抗氧化剂的一种替代方法。本研究使用从七种不同类型有机溶剂中获得的叶片提取物，研究了姜黄叶片对大豆油氧化的抗氧化性能，并与广泛使用且成本低廉但存在毒性风险的高效合成抗氧化剂的作用进行了比较。从仍鲜少研究的来源应用天然替代品是一项提议，具有高抗氧化能力的化合物的提取可能会因溶剂类型、其混合物、极性以及其他对消费者健康有负担或危害的因素而有所不同。
对叶片提取物进行消毒、干燥，并用于溶剂选择。通过使用不同的溶剂组合和比例：水（100%）、乙醇（100%）、甲醇（100%）、乙醇/水（70%:30%）、甲醇/水（70%:30%）、甲醇/乙酸（99.5%:0.5%）和丙酮/水/乙酸（70%:28:2%），对总酚类化合物（TPC）和抗氧化剂进行定量。所选溶剂是提取酚类和抗氧化剂化合物含量最高的溶剂（使用自由基DPPH清除法和FRAP测定法）。它采用加速储存试验和实验设计来评估氧化稳定性（使用过氧化值（PI）、硫代巴比妥酸反应性物质（TBARS）、二烯（DC）和三共轭物（TC）以及统计分析）。
乙醇/水溶剂在提取TPC方面效率较高（2422毫克没食子酸当量/100克）。与单一溶剂相比，溶剂混合物提取的TPC平均多23.65%。关于抗氧化能力，乙醇/水溶剂使用DPPH法显示为1847毫克TE/100克，使用FRAP测定法显示为217微摩尔硫酸亚铁/100克。此外，加速储存试验表明大豆油的氧化被延迟，在PI、TBARS和DC/TC值方面显示出与0.02%的丁基羟基甲苯相当的结果。
乙醇/水提取物在酚类化合物提取中产量最高，是一种用于食品的安全溶剂。向大豆油中添加姜黄叶片提取物导致PI、TBARS、CD和CT值降低。姜黄叶片提取物被认为是对抗大豆油氧化降解的合成抗氧化剂的良好替代品。
