title: The pressure-induced, lactose-dependent changes in the composition and size of casein micelles.
abstract: The effects of lactose on the changes in the composition and size of casein micelles induced by high-pressure treatment and the related mechanism of action were investigated. Dispersions of ultracentrifuged casein micelle pellets with 0-10% (w/v) lactose were subjected to high pressure (400 MPa) at 20 °C for 40 min. The results indicated that the level of non-sedimentable caseins was positively related to the amount of lactose added prior to pressure treatment, and negatively correlated to the size. A mechanism for the pressure-induced, lactose-dependent changes in the casein micelles is proposed. Lactose inhibits the hydrophobic interactions between the micellar fragments during or after pressure release, through the hydrophilic layer formed by their hydrogen bonds around the micellar fragments. In addition, lactose does not favour the association between calcium and the casein aggregates after pressure release. Due to these two functions, lactose inhibited the formation of larger micelles after pressure treatment.
authors.affiliation: Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, PR China; Beijing Laboratory for Food Quality and Safety, Beijing, PR China.
authors.forename: Pengjie
authors.initials: P
authors.lastname: Wang
authors.affiliation: Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, PR China; Beijing Laboratory for Food Quality and Safety, Beijing, PR China.
authors.forename: Shaoming
authors.initials: S
authors.lastname: Jin
authors.affiliation: Beijing Higher Institution Engineering Research Center of Animal Product, Beijing, PR China.
authors.forename: Huiyuan
authors.initials: H
authors.lastname: Guo
authors.affiliation: Beijing Higher Institution Engineering Research Center of Animal Product, Beijing, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, PR China; Beijing Laboratory for Food Quality and Safety, Beijing, PR China. Electronic address: renfazheng@263.net.
authors.forename: Fazheng
authors.initials: F
authors.lastname: Ren
mesh_terms: D002118:Calcium / Q000378:metabolism; D002364:Caseins / Q000737:chemistry* / Q000378:metabolism; D003611:Dairy Products; D005511:Food Handling / Q000379:methods; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions / Q000187:drug effects; D007785:Lactose / Q000494:pharmacology*; D008823:Micelles; D010316:Particle Size; D011312:Pressure
chemical_list: D002364:Caseins; D008823:Micelles; D007785:Lactose; D002118:Calcium
keywords: Casein micelles; High pressure; Lactose; Physicochemical properties