Carpentieri Serena, Ferrari Giovanna, Pataro Gianpiero
Department of Industrial Engineering, University of Salerno, Fisciano, SA, Italy.
ProdAl Scarl - University of Salerno, Fisciano, SA, Italy.
Front Nutr. 2023 Mar 17;10:1158019. doi: 10.3389/fnut.2023.1158019. eCollection 2023.
The application of Pulsed electric fields as a mild and easily scalable electrotechnology represents an effective approach to selectively intensify the extractability of bioactive compounds from grape pomace, one of the most abundant residues generated during the winemaking process.
This study addressed the optimization of the pulsed electric fields (PEF)-assisted extraction to enhance the extraction yields of bioactive compounds from red grape pomace using response surface methodology (RSM).
The cell disintegration index (Z ) was identified as response variable to determine the optimal PEF processing conditions in terms of field strength (E = 0.5-5 kV/cm) and energy input (W = 1-20 kJ/kg). For the solid-liquid extraction (SLE) process the effects of temperature (20-50°C), time (30-300min), and solvent concentration (0-50% ethanol in water) on total phenolic content (TPC), flavonoid content (FC), total anthocyanin content (TAC), tannin content (TC), and antioxidant activity (FRAP) of the extracts from untreated and PEF-treated plant tissues were assessed. The phenolic composition of the obtained extracts was determined HPLC-PDA.
Results demonstrated that the application of PEF at the optimal processing conditions (E = 4.6 kV/cm, W = 20 kJ/kg) significantly enhanced the permeabilization degree of cell membrane of grape pomace tissues, thus intensifying the subsequent extractability of TPC (15%), FC (60%), TAC (23%), TC (42%), and FRAP values (31%) concerning the control extraction. HPLC-PDA analyses showed that, regardless of the application of PEF, the most abundant phenolic compounds were epicatechin, p-coumaric acid, and peonidin 3-O-glucoside, and no degradation of the specific compounds occurred upon PEF application.
The optimization of the PEF-assisted extraction process allowed to significantly enhance the extraction yields of high-value-added compounds from red grape pomace, supporting further investigations of this process at a larger scale.
脉冲电场作为一种温和且易于扩展的电技术，是一种有效方法，可选择性增强从葡萄皮渣中提取生物活性化合物的能力，葡萄皮渣是酿酒过程中产生的最丰富的残渣之一。
本研究采用响应面法（RSM）对脉冲电场（PEF）辅助提取进行优化，以提高从红葡萄皮渣中提取生物活性化合物的产率。
将细胞破碎指数（Z）确定为响应变量，以确定在电场强度（E = 0.5 - 5 kV/cm）和能量输入（W = 1 - 20 kJ/kg）方面的最佳PEF处理条件。对于固液萃取（SLE）过程，评估了温度（20 - 50°C）、时间（30 - 300分钟）和溶剂浓度（水中0 - 50%乙醇）对未处理和PEF处理的植物组织提取物中总酚含量（TPC）、类黄酮含量（FC）、总花青素含量（TAC）、单宁含量（TC）和抗氧化活性（FRAP）的影响。通过高效液相色谱 - 光电二极管阵列检测法（HPLC - PDA）测定所得提取物的酚类组成。
结果表明，在最佳处理条件（E = 4.6 kV/cm，W = 20 kJ/kg）下应用PEF可显著提高葡萄皮渣组织细胞膜的通透程度，从而相对于对照提取提高了TPC（15%）、FC（60%）、TAC（23%）、TC（42%）和FRAP值（31%）的后续可提取性。HPLC - PDA分析表明，无论是否应用PEF，最丰富的酚类化合物为表儿茶素、对香豆酸和芍药素3 - O - 葡萄糖苷，并且在应用PEF后特定化合物未发生降解。
PEF辅助提取工艺的优化能够显著提高从红葡萄皮渣中提取高附加值化合物的产率，支持对该工艺进行更大规模的进一步研究。
