Saha Ajoy, Basak B B, Manivel P, Kumar Jitendra
ICAR-Directorate of Medicinal and Aromatic Plants Research, Anand, Gujarat 387310 India.
Present Address: Research Centre of ICAR-Central Inland Fisheries Research Institute, Bangalore, Karnataka 560089 India.
J Food Sci Technol. 2021 Jan;58(1):255-266. doi: 10.1007/s13197-020-04538-8. Epub 2020 May 28.
Solid residues obtained after essential oil extraction from Jowitt (Java citronella) was explored as a potential source of phenolics/antioxidant. Both the non-distilled plant materials and their solid residues were extracted with Soxhlet extraction method using solvents of various polarity viz. petroleum ether, chloroform, ethyl acetate, acetone, ethanol, methanol, water and various combination of (50% and 75%) of methanol, ethanol, and acetone in water. Different antioxidant assays like 2,2-diphenyl-1- picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), superoxide anion (SO) radical scavenging assay, ferric-reducing antioxidant power (FRAP) and iron chelating ability along with total phenol (TPC) and flavonoid content (TFC) was measured to evaluate the extract. Compared to distilled materials, the non-distilled plant materials had significantly higher TPC/TFC content and also exhibited higher antioxidant activities. 50% aqueous methanol showed the highest extractive yield, whereas 75% aqueous methanol exhibited the highest TPC and TFC content. The 50% or 75% aqueous methanolic extract also exhibited the highest DPPH, ABTS and SO scavenging activity and ferric-reducing antioxidant power activity. However, ethyl acetate and 75% aqueous acetone extract of non-distilled and distilled plant materials, respectively showed the highest iron chelating activity. The half maximal effective concentration (IC = µg/mL) for DPPH, ABTS, SO and metal chelating ability in non-distilled plant extract ranged from 64-387, 92-761, 285-870, and 164-924, respectively, and corresponding value of distilled materials ranged from 144-865, 239-792, 361-833 and 374-867, respectively. The EC (µg/mL) for FRAP assay ranged from 118-840 and 151-952 for non-distilled and distilled materials, respectively. The findings of this study indicate the potential of these by-products as a natural antioxidants source.
对从爪哇香茅（Jowitt）中提取香精油后得到的固体残渣作为酚类/抗氧化剂的潜在来源进行了探索。采用索氏提取法，使用各种极性的溶剂，即石油醚、氯仿、乙酸乙酯、丙酮、乙醇、甲醇、水以及甲醇、乙醇和丙酮在水中的各种（50%和75%）组合，对未蒸馏的植物材料及其固体残渣进行提取。通过不同的抗氧化测定方法，如2,2-二苯基-1-苦基肼（DPPH）、2,2'-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）（ABTS）、超氧阴离子（SO）自由基清除测定、铁还原抗氧化能力（FRAP）和铁螯合能力，以及总酚（TPC）和黄酮含量（TFC）的测定来评估提取物。与蒸馏后的材料相比，未蒸馏的植物材料具有显著更高的TPC/TFC含量，并且还表现出更高的抗氧化活性。50%甲醇水溶液的提取率最高，而75%甲醇水溶液的TPC和TFC含量最高。50%或75%甲醇水溶液提取物还表现出最高的DPPH、ABTS和SO清除活性以及铁还原抗氧化能力活性。然而，未蒸馏和蒸馏植物材料的乙酸乙酯提取物和75%丙酮水溶液提取物分别表现出最高的铁螯合活性。未蒸馏植物提取物中DPPH、ABTS、SO和金属螯合能力的半数有效浓度（IC₅₀ = μg/mL）分别为64 - 387、92 - 761、285 - 870和164 - 924，蒸馏材料的相应值分别为144 - 865、239 - 792、361 - 833和374 - 867。FRAP测定的EC₅₀（μg/mL）未蒸馏材料为118 - 840，蒸馏材料为151 - 952。本研究结果表明这些副产品作为天然抗氧化剂来源的潜力。
