title: Short communication: Effects of nanofiltration and evaporation on the physiochemical properties of milk protein during processing of milk protein concentrate.
abstract: The aim of this work was to evaluate the effects of nanofiltration and evaporation concentration technologies on the physiochemical properties of milk protein concentrate (MPC) during processing. Skim milk, ultrafiltered milk, evaporated milk, nanofiltered milk, evaporated MPC, and nanofiltered MPC samples were collected at different processing stages. Chemical composition, microstructure of casein micelles, free sulfhydryl content, and surface hydrophobicity of the samples were determined. The insolubility index of MPC was also determined. Casein micelles aggregated compactly after evaporation while surface hydrophobicity increased and free sulfhydryl content decreased in evaporated milk compared with skim milk. However, the microstructure of the casein micelles was relatively undisturbed after nanofiltration, with reduced surface hydrophobicity and free sulfhydryl content. No significant difference was found in chemical composition between the 2 MPC preparations: approximately 61.40% protein and 28.49% lactose. In addition, the particulate microstructures of both MPC were similar. However, the insolubility index of evaporated MPC was significantly (0.58mL) higher than that of nanofiltered MPC. Nanofiltration may be an effective way to improve the solubility of MPC products.
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Synergetic Innovation Center of Food Safety and Nutrition, Northeast Agricultural University, Harbin 150030, China.
authors.forename: Jialu
authors.initials: J
authors.lastname: Cao
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Shaozong
authors.initials: S
authors.lastname: Wu
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: School of Food Science and Chemical Engineering, Beijing Technology and Business University, Beijing 100048, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China. Electronic address: 18611994355@163.com.
authors.forename: Haimei
authors.initials: H
authors.lastname: Li
authors.affiliation: College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Synergetic Innovation Center of Food Safety and Nutrition, Northeast Agricultural University, Harbin 150030, China. Electronic address: liebzhang@gmail.com.
authors.forename: Liebing
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002364:Caseins / Q000032:analysis; D005260:Female; D005374:Filtration / Q000662:veterinary; D005511:Food Handling / Q000379:methods*; D005524:Food Technology; D057927:Hydrophobic and Hydrophilic Interactions; D007785:Lactose / Q000032:analysis; D008823:Micelles; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods
chemical_list: D002364:Caseins; D008823:Micelles; D008894:Milk Proteins; D007785:Lactose
keywords: evaporation; milk protein concentrate; nanofiltration; physiochemical properties