Şahin Selin, Samli Ruya, Tan Ayşe Seher Birteksöz, Barba Francisco J, Chemat Farid, Cravotto Giancarlo, Lorenzo José M
Department of Chemical Engineering, Engineering Faculty, Istanbul University, 34320 Avcilar, Istanbul, Turkey.
Department of Computer Engineering, Engineering Faculty, Istanbul University, 34320 Avcilar, Istanbul, Turkey.
Molecules. 2017 Jun 24;22(7):1056. doi: 10.3390/molecules22071056.
Response surface methodology (RSM) and artificial neural networks (ANN) were evaluated and compared in order to decide which method was the most appropriate to predict and optimize total phenolic content (TPC) and oleuropein yields in olive tree leaf () extracts, obtained after solvent-free microwave-assisted extraction (SFMAE). The SFMAE processing conditions were: microwave irradiation power 250-350 W, extraction time 2-3 min, and the amount of sample 5-10 g. Furthermore, the antioxidant and antimicrobial activities of the olive leaf extracts, obtained under optimal extraction conditions, were assessed by several in vitro assays. ANN had better prediction performance for TPC and oleuropein yields compared to RSM. The optimum extraction conditions to recover both TPC and oleuropein were: irradiation power 250 W, extraction time 2 min, and amount of sample 5 g, independent of the method used for prediction. Under these conditions, the maximal yield of oleuropein (0.060 ± 0.012 ppm) was obtained and the amount of TPC was 2.480 ± 0.060 ppm. Moreover, olive leaf extracts obtained under optimum SFMAE conditions showed antibacterial activity against and , with a minimum inhibitory concentration (MIC) value of 1.25 mg/mL.
为了确定哪种方法最适合预测和优化无溶剂微波辅助萃取（SFMAE）后获得的橄榄树叶提取物中的总酚含量（TPC）和橄榄苦苷产量，对响应面法（RSM）和人工神经网络（ANN）进行了评估和比较。SFMAE的工艺条件为：微波辐射功率250 - 350W，萃取时间2 - 3分钟，样品量5 - 10g。此外，通过几种体外试验评估了在最佳萃取条件下获得的橄榄叶提取物的抗氧化和抗菌活性。与RSM相比，ANN对TPC和橄榄苦苷产量具有更好的预测性能。回收TPC和橄榄苦苷的最佳萃取条件为：辐射功率250W，萃取时间2分钟，样品量5g，与用于预测的方法无关。在这些条件下，获得了橄榄苦苷的最大产量（0.060±0.012ppm），TPC含量为2.480±0.060ppm。此外，在最佳SFMAE条件下获得的橄榄叶提取物对金黄色葡萄球菌和大肠杆菌具有抗菌活性，最低抑菌浓度（MIC）值为1.25mg/mL。
