Laboratory of Food Technology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M2S), KU Leuven, Kasteelpark Arenberg 22, PB 2457, 3001 Leuven, Belgium.
Laboratory of Food Technology and Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M2S), KU Leuven, Kasteelpark Arenberg 22, PB 2457, 3001 Leuven, Belgium.
Food Res Int. 2021 Mar;141:110087. doi: 10.1016/j.foodres.2020.110087. Epub 2020 Dec 29.
The presented research studied the emulsifying and emulsion stabilizing capacity of pectin samples isolated from different plant origin: apple, carrot, onion and tomato. The acid extracted pectin samples showed distinct structural properties. Specifically, apple pectin showed a high degree of methylesterification (78.41 ± 0.83%), carrot pectin had the lowest concentration of other co-eluted cell wall polymers, onion pectin displayed a bimodal molar mass distribution suggesting two polymer fractions with different molar mass and tomato pectin was characterized by a high protein content (16.48 ± 0.05%). The evaluation of the emulsifying and emulsion stabilizing potential of the pectin samples included investigating their ability to lower the interfacial tension next to a storage stability study of pectin stabilized o/w emulsions. Creaming behavior as well as the evolution of the oil droplet size were thoroughly examined during storage using multiple analytical techniques. Overall, smaller oil droplet sizes were obtained at pH 2.5 compared to pH 6.0 indicating better emulsifying capacity at lower pH. The lowest emulsion stability was observed in emulsions formulated with tomato pectin in which weak flocculation and relatively fast creaming affected emulsion stability. Onion pectin clearly showed the most promising emulsifying and emulsion stabilizing potential. At both pH conditions, emulsions stabilized by the onion pectin sample displayed highly stable oil droplet sizes during the whole storage period. The presence of the two polymer fractions in this sample can play an important role in the observed stability. In future work, it could be evaluated if both fractions contribute to emulsion stability in a synergistic way. In conclusion, this work showed that pectin samples extracted from different plant origin display diverse structural properties resulting in varying emulsifying and emulsion stabilizing potential. Polymer molar mass potentially plays a major role in the structure-function relation.
本研究探讨了从不同植物源（苹果、胡萝卜、洋葱和番茄）中分离得到的果胶样品的乳化和乳化稳定能力。酸提取的果胶样品表现出明显的结构特性。具体而言，苹果果胶表现出高度的甲酯化程度（78.41±0.83%），胡萝卜果胶的其他共洗脱细胞壁聚合物浓度最低，洋葱果胶表现出双峰分子量分布，表明存在两种具有不同分子量的聚合物级分，而番茄果胶的蛋白质含量较高（16.48±0.05%）。果胶样品乳化和乳化稳定潜力的评估包括研究其降低界面张力的能力，以及研究果胶稳定的 o/w 乳液的储存稳定性。在储存过程中，使用多种分析技术彻底检查了乳状液的流变性以及油滴尺寸的演变。总体而言，在 pH 2.5 下获得的油滴尺寸较小，表明在较低 pH 下具有更好的乳化能力。在 pH 6.0 下，番茄果胶稳定的乳液表现出最差的乳液稳定性，其中弱絮凝和相对较快的乳析影响了乳液稳定性。洋葱果胶明显表现出最有前途的乳化和乳化稳定潜力。在两种 pH 条件下，由洋葱果胶样品稳定的乳液在整个储存期间显示出高度稳定的油滴尺寸。该样品中两种聚合物级分的存在可能在观察到的稳定性中发挥重要作用。在未来的工作中，可以评估这两种级分是否以协同的方式对乳液稳定性做出贡献。总之，本工作表明，从不同植物源提取的果胶样品具有不同的结构特性，从而具有不同的乳化和乳化稳定能力。聚合物分子量可能在结构-功能关系中起着重要作用。
