Savić Ivan M, Savić Gajić Ivana M
Faculty of Technology in Leskovac, University of Niš, Bulevar oslobodjenja 124, 16000 Leskovac, Serbia.
Foods. 2025 Jan 27;14(3):409. doi: 10.3390/foods14030409.
The ultrasound-assisted extraction process with microwave pretreatment was modeled and optimized to maximize the yield of antioxidants from green walnut husks using a response surface methodology with Box-Behnken design. In this design, the ultrasound-assisted extraction time (10-40 min), ultrasound-assisted extraction temperature (40-60 °C), and microwave pretreatment time (20-60 s) were selected as the factors, while the total antioxidant content was defined as the response. The solvent of choice for extracting antioxidants was 50% (/) ethanol. After optimization using the desirability function, an ultrasound-assisted extraction time of 23 min, ultrasound-assisted extraction temperature of 60 °C, and microwave pretreatment time of 60 s were proposed as the optimal conditions and their validity was verified. Under these conditions, the experimentally determined total antioxidant content was 3.69 g of gallic acid equivalent per 100 g of dry matter. In addition to phenolics, UHPLC-ESI-MS/MS analysis indicated the presence of lipids, quinones, terpenoids, and organic acids in the extract. After the antioxidant extraction, the solid residue was further processed to isolate cellulose in line with the concept of sustainable manufacturing. The structural characterization and hydration properties of cellulose were analyzed to identify its key features and assess its potential for value-added applications. The results demonstrate that green walnut husks are a valuable and cost-effective agro-industrial byproduct for extracting antioxidants and isolating cellulose. This aligns with the principles of a circular economy and the sustainable production of natural compounds.
采用Box-Behnken设计的响应面法，对微波预处理的超声辅助提取工艺进行了建模和优化，以最大限度地提高从青皮核桃壳中提取抗氧化剂的产率。在该设计中，选择超声辅助提取时间（10 - 40分钟）、超声辅助提取温度（40 - 60℃）和微波预处理时间（20 - 60秒）作为因素，而将总抗氧化剂含量定义为响应值。提取抗氧化剂的首选溶剂是50%（/）乙醇。使用期望函数进行优化后，提出超声辅助提取时间为23分钟、超声辅助提取温度为60℃、微波预处理时间为60秒作为最佳条件，并验证了其有效性。在这些条件下，实验测定的总抗氧化剂含量为每100克干物质3.69克没食子酸当量。除了酚类物质外，超高效液相色谱-电喷雾串联质谱（UHPLC-ESI-MS/MS）分析表明提取物中存在脂质、醌类、萜类和有机酸。抗氧化剂提取后，根据可持续制造的理念，对固体残渣进行进一步处理以分离纤维素。分析了纤维素的结构特征和水化性质，以确定其关键特性并评估其增值应用的潜力。结果表明，青皮核桃壳是提取抗氧化剂和分离纤维素的一种有价值且经济高效的农业工业副产品。这符合循环经济原则和天然化合物的可持续生产。
