title: Polymeric complexes of cornstarch and waxy cornstarch phosphates with milk casein and their performance as biodegradable materials.
abstract: Complexes of phosphated cornstarch and waxy cornstarch with casein were prepared and characterised. They were prepared from casein in defatted milk and corn and waxy corn starches phosphated to degree of substitution values (DS) of 0.0637 and 0.0968, respectively. The components were blended in starch to casein ratios of 2:1, 1:1, and 1:2, then precipitated with hydrochloric acid. Aqueous solubility, water binding capacity, IR spectra, and thermal analysis (thermogravimetry, TG, and differential thermogravimetry, DTG) of the precipitates revealed that they were not simple physical mixtures of the components. The components interact with one another electrostatically with involvement of the starch phosphate groups and the peptide bonds of casein as documented by the IR spectra. Because of their insolubility in 7 M aqueous urea solution they might also be considered as complexes in which the components were chemically bound. Enzymatic studies showed that they are biodegradable materials.
authors.affiliation: Department of Animal Product Technology, Agricultural University, Cracow, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Najgebauer
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Grega
authors.forename: Marek
authors.initials: M
authors.lastname: Sady
authors.forename: Piotr
authors.initials: P
authors.lastname: Tomasik
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D002364:Caseins / Q000737:chemistry*; D002417:Cattle; D004055:Differential Thermal Analysis; D008892:Milk / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D012995:Solubility; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D013818:Thermogravimetry; D014867:Water
chemical_list: D002364:Caseins; D010710:Phosphates; D014867:Water; D013213:Starch