title: Characterization of anthocyanin-rich waste from purple corncobs (Zea mays L.) and its application to color milk.
abstract: Pigment production from anthocyanin-rich purple corncobs generates a deeply colored waste precipitate. Our objectives were to characterize this anthocyanin-rich waste (ARW) and to find a suitable application in a food matrix. Composition and solubility characteristics of ARW were evaluated. Color (CIELAB) and pigment (monomeric anthocyanin and HPLC profiles) stability of ARW in milk (35 mg/100 mL) were evaluated using an accelerated test at 70 degrees C and phosphate buffer as a control. ARW provided milk an attractive purple hue (324-347 degrees ). Monomeric anthocyanin degradation followed zero-order kinetics in skim and whole milk and second-order kinetics in the control, with half-lives of 173, 223, and 44 min at 70 degrees C, respectively. ARW shows potential as a natural colorant for a pH range unusual for anthocyanin applications. A protective effect of matrix constituents on the stability of anthocyanins was evident. Anthocyanins may interact with different compounds in biological systems when the pH values are close to neutral.
authors.affiliation: University of Maryland, College Park, MD, USA.
authors.forename: Pu
authors.initials: P
authors.lastname: Jing
authors.forename: M Mónica
authors.initials: MM
authors.lastname: Giusti
mesh_terms: D000818:Animals; D000872:Anthocyanins / Q000032:analysis* / Q000737:chemistry; D004355:Drug Stability; D005505:Food Coloring Agents; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008892:Milk / Q000737:chemistry*; D010860:Pigments, Biological / Q000032:analysis; D012995:Solubility; D003313:Zea mays / Q000737:chemistry*
chemical_list: D000872:Anthocyanins; D005505:Food Coloring Agents; D010860:Pigments, Biological