title: Impact of pH, freeze-thaw and thermal sterilization on physicochemical stability of walnut beverage emulsion.
abstract: The effects of environment stresses on the stability of walnut emulsion were investigated. The physical stability of walnut emulsion was characterized by droplet size, zeta potential and chemical stability of walnut oil in the emulsion was evaluated by determining the peroxide concentration during the storage. The results showed that emulsion in the presence of xanthan gum and mixed emulsifiers exhibited better stability after 4 freeze-thaw cycles. At pH 3-10, the mixed emulsifiers could improve the stability through their absorption on the oil-water interface. However, xanthan gum couldn't protect the droplets against the aggregation in high acid environment, but greatly enhanced the physical stability at pH 6-10. During the thermal sterilization process, the physical stability of walnut emulsion was decreased with a rise of sterilization temperature and the extension of sterilization time. The sterilization temperature above 121 °C and time over 25 min led to the poor physical and oxidative stability.
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Liu
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China.
authors.forename: Cuixia
authors.initials: C
authors.lastname: Sun
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Beijing Key Laboratory of Functional Food from Plant Resources, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China. Electronic address: gyxcau@126.com.
authors.forename: Yanxiang
authors.initials: Y
authors.lastname: Gao
mesh_terms: D001628:Beverages / Q000032:analysis*; D055598:Chemical Phenomena; D004355:Drug Stability; D004655:Emulsions; D005511:Food Handling; D005615:Freezing; D006863:Hydrogen-Ion Concentration; D031324:Juglans / Q000737:chemistry*; D009754:Nuts / Q000737:chemistry*; D010316:Particle Size; D011135:Polysaccharides, Bacterial / Q000737:chemistry; D013242:Sterilization
chemical_list: D004655:Emulsions; D011135:Polysaccharides, Bacterial; C002563:xanthan gum
keywords: Freeze–thaw; Mixed emulsifiers; Stability; Thermal sterilization; Walnut beverage emulsion; Xanthan gum