DEVELOPMENT AND VALIDATION OF ANALYTICAL METHOD FOR PALM OIL DETERMINATION IN MICROCAPSULES PRODUCED BY COMPLEX COACERVATION

The microencapsulation of palm oil may be a mechanism for protecting and promoting the controlled release of its bioactive compounds. To optimize the microencapsulation process, it is necessary to accurately quantify the palm oil present both external and internal to the microcapsules. In this study, we developed and validated a spectrophotometric method to determine the microencapsulation efficiency of palm oil by complex coacervation. We used gelatin and gum arabic (1:1) as wall material in a 5% concentration (w/v) and palm oil in the same concentration. The coacervates were obtained at pH 4.0 ± 0.01, decanted for 24 h, frozen (−40 ºC), and lyophilized for 72 h. Morphological analyzes were then performed. We standardized the extraction of the external palm oil through five successive washes with an organic solvent. We then explored the best method for rupturing the microcapsules. After successive extractions with hexane, we determined the amount of palm oil contained in the microcapsules using a spectrophotometer. The proposed method was shown to be of low cost, fast, and easy to implement. In addition, in the validation step, we confirmed the method to be safe and reliable, as it proved to be specific, accurate, precise, and robust.

棕榈油的微囊化（microencapsulation）可作为保护其生物活性成分并实现控释的有效手段。为优化微囊化工艺，需精准定量微胶囊内外的棕榈油含量。本研究开发并验证了一种基于复凝聚法（complex coacervation）测定棕榈油微囊包封率的分光光度法。实验采用质量浓度为5%（w/v）的明胶（gelatin）与阿拉伯胶（gum arabic）按1:1比例复配作为壁材，芯材为同浓度的棕榈油；凝聚反应的pH值控制在4.0±0.01，经24小时倾析后，先于-40℃冷冻，再经72小时冷冻干燥。随后开展形貌表征分析。研究人员通过有机溶剂连续洗涤五次，实现了微胶囊表面游离棕榈油的标准化提取；并探索了最优的微胶囊破壁方法。经正己烷（hexane）连续萃取后，采用分光光度计定量微胶囊内包封的棕榈油含量。所提出的方法具有成本低廉、操作快速简便的优势。此外，验证实验结果表明该方法专属性强、准确度高、精密度良好且耐用性佳，证实其安全可靠。