Zannini Domenico, Monteforte Martina, Gargiulo Luca, Marino Tiziana, Gomez d'Ayala Giovanna, Santagata Gabriella, Dal Poggetto Giovanni
Institute of Chemical Sciences and Technologies "G. Natta" (SCITEC), National Council of Research, Via De Marini 6, 16149 Genova, Italy.
Institute for Polymers, Composites and Biomaterials (IPCB), National Council of Research, Via C. Flegrei 34, 80078 Pozzuoli, Italy.
Polymers (Basel). 2025 Feb 28;17(5):659. doi: 10.3390/polym17050659.
In this paper, citrus pomace was used as a source of pectin and polyphenols extracted in one pot solution by microwave-assisted extraction (MAE) and conventional extraction (CE) methods. MAE parameters were optimized to maximize yield and adjust in situ final physicochemical properties of extracted pectins, such as the methylation degree (DM), significantly influencing pectin functionality and application. Citric acid (CA) and acetic acid (Hac) were employed as solvents to mitigate pectin degradation. Extracted pectins were structurally (GPC and FTIR-ATR), morphologically (SEM), and thermally (TGA) characterized. From the reaction batch, the bioactive compounds (AOs) were separated and recovered, and their yield and antioxidant activities were evaluated with a DPPH assay. Moreover, by strategically selecting pH and solvents, this research enabled precise control over the final properties of pectin. The various characterization techniques employed show that the extraction conditions significantly influence the physicochemical and morphological properties of the material. Molecular weight (Mw) values range from 218 kDa to 567 kDa, surface morphology varies from compact/aggregated structures to three-dimensional network-like formations, and the DM spans from 34% (low DM) to 83% (high DM). This highlights a novel approach for predicting and tailoring in situ characteristics of extracted pectin to meet specific application requirements.
在本文中，柑橘渣被用作果胶和多酚的来源，通过微波辅助萃取（MAE）和传统萃取（CE）方法在一锅溶液中进行萃取。对MAE参数进行了优化，以实现产量最大化，并原位调整所提取果胶的最终物理化学性质，如甲基化程度（DM），这对果胶的功能和应用有显著影响。使用柠檬酸（CA）和乙酸（Hac）作为溶剂来减轻果胶降解。对所提取的果胶进行了结构表征（凝胶渗透色谱法和傅里叶变换红外光谱衰减全反射法）、形态表征（扫描电子显微镜）和热稳定性表征（热重分析法）。从反应批次中分离并回收了生物活性化合物（AO），并通过DPPH测定法评估了它们的产量和抗氧化活性。此外，通过策略性地选择pH值和溶剂，本研究实现了对果胶最终性质的精确控制。所采用的各种表征技术表明，萃取条件对材料的物理化学和形态性质有显著影响。分子量（Mw）值范围为218 kDa至567 kDa，表面形态从致密/聚集结构到三维网络状结构各不相同，DM跨度从34%（低DM）到83%（高DM）。这突出了一种预测和定制所提取果胶原位特性以满足特定应用要求的新方法。
