Characterization of anthocyanin-rich waste from purple corncobs (Zea mays L.) and its application to color milk.
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.
Jing
Pu
P
University of Maryland, College Park, MD, USA.
Giusti
M Mónica
MM
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*
D000872:Anthocyanins; D005505:Food Coloring Agents; D010860:Pigments, Biological