Study on the Emulsifying Properties of Pomegranate Peel Pectin from Different Cultivation Areas
Key Laboratory of Fermentation Engineering, Ministry of Education; Glyn O. Phillips Hydrophilic Colloid Research Center, Faculty of Light Industry; School of Food and Biological Engineering, Hubei University of Technology, Wuhan, 430068, Hubei Province, China
Production & Construction Group Key Laboratory of Special Agricultural Products Further Processing in Southern Xinjiang, College of Life Sciences, Tarim University; Alar 843300, China
Wuhan Xudong Food Co., Ltd., Wuhan 430040, Hubei Province, China
Author to whom correspondence should be addressed.
These authors contributed equally to this work.
Academic Editors: Mingfu Wang and Yueliang Zhao
Molecules 2019, 24(9), 1819; https://doi.org/10.3390/molecules24091819
Received: 10 April 2019 / Revised: 1 May 2019 / Accepted: 8 May 2019 / Published: 10 May 2019
(This article belongs to the Special Issue Natural Products Used as Foods and Food Ingredients)
Pomegranate peel pectin is an important acidic anionic plant polysaccharide which can be used as a natural emulsifier. In order to study its emulsifying properties, this paper systematically analyses pomegranate peel pectin samples from Chinese Xinjiang, Sichuan and Yunnan provinces, through rheometer, interfacial rheometer, Zetasizer Nano-ZS and mastersizer. It is shown that pomegranate peel pectin can effectively reduce the oil-water interfacial tension, reaching an emulsion droplet size of only 0.507 μm, 0.669 μm and 0.569 μm, respectively, while the pectin concentration is 1.5% and the oil phase (MCT) is 10%. It has also shown that the extreme conditions of pH and ion strength can not significantly change its emulsion stability. However, freeze-thaw cycles can cause the pomegranate peel pectin emulsion to become less stable. Furthermore, the effects of decolourization, protein removal and dialysis on the emulsifying properties of pomegranate peel pectin are investigated using mastersizer rheometer and interfacial rheometer. It is found that the protein and pigment in pomegranate peel pectin have little effect on its emulsifying properties, while the results from dialyzed pectin show that the small molecule substances can reduce the emulsion particle size and increase the emulsion stability. The research outcomes of this study provide technical support for the further application of pomegranate peel pectin in the food industry.