Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal.
Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal.
Food Res Int. 2019 Dec;126:108572. doi: 10.1016/j.foodres.2019.108572. Epub 2019 Jul 23.
This study aims to give an unprecedented contribution on the chemical composition and bioactivities of the most produced and appreciated Portuguese fig variety ("Pingo de Mel") with the view of expanding the knowledge on its potentialities. An advanced characterization of its peel and pulp parts was carried out. Four free sugars (glucose, fructose, trehalose and sucrose), 5 organic acids (oxalic, quinic, malic, citric, and succinic acids), tocopherols in all their 4 forms, besides 23 fatty acids were detected in the samples. Fifteen different phenolic components were found in the peel hydroethanolic extract; whereas 12 were detected in the pulp hydroethanolic extract. Quercetin-3-O-rutinoside (rutin) was the major constituent of the peel, accounting for 33.8% of its phenolic content, followed by 5-O-caffeoylquinic acid and vanillic acid malonyl di-deoxyhexoside. Caffeic acid derivatives, such as caffeic acid hexosides, were the major components of pulp, followed by vanillic acid derivatives and O-caffeoylquinic acid. Both extracts displayed promising antioxidant capacities in all methods used, namely the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging, the reducing power, the inhibition of β-carotene bleaching assays, the thiobarbituric acid reactive substances assay and the oxidative haemolysis inhibition assay; however, the peel presented significantly lower IC values than pulp. The extracts showed practically identical antibacterial capacities, being effective against methicillin-sensitive Staphylococcus aureus (MICs = 2.5 mg/mL), besides methicillin-resistant S. aureus, Escherichia coli and Morganella morganii (MICs = 5 mg/mL). The obtained results evidence that the fig peel is superior to the corresponding pulp as it relates to nutritional and phenolic profiles as well as bioactivities, endorsing the urgency in valorising and exploiting this usually discarded industrial by-product.
本研究旨在对最常生产和最受欢迎的葡萄牙无花果品种（“Pingo de Mel”）的化学成分和生物活性进行前所未有的研究，以期扩大其潜力的认识。对其果皮和果肉部分进行了深入的特征描述。在样品中检测到四种游离糖（葡萄糖、果糖、海藻糖和蔗糖）、五种有机酸（草酸、奎宁酸、苹果酸、柠檬酸和琥珀酸）、所有四种形式的生育酚以及 23 种脂肪酸。在果皮的水乙醇提取物中发现了 15 种不同的酚类成分；而在果肉的水乙醇提取物中检测到 12 种。在果皮中，槲皮素-3-O-芸香糖苷（芦丁）是主要成分，占其酚类含量的 33.8%，其次是 5-O-咖啡酰奎宁酸和香草酸丙二酰二脱氧己糖苷。咖啡酸衍生物，如咖啡酸己糖苷，是果肉的主要成分，其次是香草酸衍生物和 O-咖啡酰奎宁酸。两种提取物在所有使用的方法中都表现出了有前景的抗氧化能力，即 2,2-二苯基-1-苦基肼自由基清除能力、还原能力、β-胡萝卜素漂白抑制试验、硫代巴比妥酸反应物质试验和氧化溶血抑制试验；然而，果皮的 IC 值明显低于果肉。提取物表现出几乎相同的抗菌能力，对甲氧西林敏感的金黄色葡萄球菌（MICs = 2.5mg/mL）有效，此外对耐甲氧西林的金黄色葡萄球菌、大肠杆菌和摩根摩根菌（MICs = 5mg/mL）也有效。研究结果表明，与营养成分、酚类成分和生物活性相关，无花果果皮优于相应的果肉，支持对这一通常被丢弃的工业副产品进行增值和开发的紧迫性。
