Extraction of hydrocolloids from Pereskia Aculeata Miller: reuse of process residue as activated carbon for the pigment-removal phase

Abstract Hydrocolloids of Pereskia aculeata Miller (OPNH) are potential ingredients in food industry as emulsifiers and stabilizers. The extraction process of OPNH requires the removal of pigments with activated carbon. Because this step is critical to the quality of the ingredient and has an impact on costs, a new activated carbon has been developed with residues from the same process. Residues activated with NaOH and H3PO4 (300 °C, 1 h) were subjected to batch adsorption tests in model solutions of malachite green (MG), carbohydrate and protein. Residue treated with 85% H3PO4 (OPNAC) had higher productivity and MG adsorption capacity, displaying a predominantly microporous surface (MEV/BET) with chemical activation confirmed by TG/FTIR. OPNAC showed higher MG and protein adsorption capacity than the commercial activated carbon (CAC) did. Results for MG-adsorption capacity by OPNAC did not show significant differences in the presence of protein and carbohydrate, presenting the higher affinity of the adsorbent for the dye. Adsorption isotherms showed OPNAC to be more favorable to MG adsorption than CAC, and to have a good fit to Langmuir-Freundlich model. OPNAC made it possible to reduce costs and allowed the sustainability of the process, leading to increased efficiency in selective pigment removal compared with CAC.

摘要：木麒麟（Pereskia aculeata Miller）源亲水胶体（Hydrocolloids）OPNH作为乳化剂与稳定剂，具备食品工业应用潜力。OPNH的提取工艺需通过活性炭（activated carbon）脱除色素。由于该步骤对产品品质与生产成本均至关重要，研究人员利用同工艺副产物开发了新型活性炭。经氢氧化钠（NaOH）与磷酸（H₃PO₄）（300 ℃、1 h）活化的工艺副产物，于孔雀石绿（malachite green, MG）、碳水化合物与蛋白质模拟溶液中开展批量吸附实验。经85% H₃PO₄处理的副产物（OPNAC）具备更高的产率与孔雀石绿吸附性能，其表面以微孔为主（经MEV/BET法表征），热重-傅里叶变换红外光谱联用（TG/FTIR）证实其具备化学活化特性。OPNAC对孔雀石绿与蛋白质的吸附性能优于商业活性炭（commercial activated carbon, CAC）。在蛋白质与碳水化合物共存条件下，OPNAC对孔雀石绿的吸附性能无显著差异，表明该吸附剂对染料具有更高的亲和性。吸附等温线结果显示，相较于商业活性炭，OPNAC更利于孔雀石绿的吸附，且其吸附行为与朗缪尔-弗伦德里希模型（Langmuir-Freundlich model）拟合度良好。相较于商业活性炭，OPNAC可降低生产成本并提升工艺可持续性，同时优化了选择性脱除色素的效率。