背景:果汁行业的废物副产品对于循环经济概念似乎很有价值,考虑到果皮几乎占水果总重量的一半。因此,从相关生物废弃物中回收这些非常有价值的成分已经成为一个非常有趣的研究课题。
目的:本研究旨在开发一种基于统计实验设计方法的与疏水性深共晶溶剂(DES)集成的提取工艺。
方法:使用均质器-辅助提取(HAE)从柠檬皮中回收富含柠檬烯(挥发性混合物的主要成分)的柑橘提取物。基于薄荷醇的低共熔混合物伴随着羧酸(甲酸,乙酸,和丙酸)。在以不同摩尔比(1/1、1/2和2/1)制备的溶剂中得到最高效率(就柠檬烯含量而言)的组合上继续优化。通过响应面法(RSM)的中心组合设计,对工艺参数进行了分析,以优化工艺。使用固相微萃取(SPME)技术,通过气相色谱-质谱法(GC-MS)定量D-柠檬烯产率。还通过体外生物活性测定(酚类含量和2,2-二苯基-1-吡啶酰肼[DPPH]自由基清除活性)评估了柠檬皮提取物的质量。
结果:通过2mg固体/30mLDES实现了最大产量(每克新鲜样品3.80mg-柠檬烯),~53秒,和~8500转/分钟。统计上最有效的变量被确定为固体质量,然后是混合速度和提取时间的二次幂,p<0.0001。
BACKGROUND: Waste by-products of the juice industry appear valuable for the circular economy concept, considering that the peel accounts for almost half of the total fruit weight. Therefore, the recovery of these highly valuable components from relevant biowaste has become a very interesting research topic.
OBJECTIVE: The current study aims to develop an extraction process integrated with hydrophobic deep eutectic solvent (DES) based on statistical experimental design approach.
METHODS: Homogenizer-assissted extraction (HAE) was used to recover the citrus extract rich in limonene (the main component of the volatile mixture) from lemon peels. Menthol-based deep eutectic mixtures were accompanied by carboxylic acids (formic, acetic, and propionic acids). Optimization continued on the combination that gave the highest efficiency (in terms of limonene content) among the solvents prepared at different molar ratios (1/1, 1/2, and 2/1). Process parameters were analyzed to optimize the process through central composite design with response surface method (RSM). D-Limonene yield was quantified with gas chromatography-mass spectrometry (GC-MS) with solid-phase microextraction (SPME) technique. The quality of the lemon peel extracts was also evaluated with respect to in vitro bioactivity assays (phenolic content and 2,2-diphenyl-1-picrylhydrazyl [DPPH] free radical scavenging activity).
RESULTS: The maximum yield (3.80 mg-limonene per g fresh sample) was achieved by 2 mg solid/30 mL DES, ~53 sec, and ~8500 rpm. Statistically most effective variable was identified as solid mass, followed by second powers of mixing speed and extraction time at p < 0.0001.