title: Alternative bleaching methods for Cheddar cheese whey.
abstract: Residual annatto colorant (norbixin) in fluid Cheddar cheese whey can be bleached. The 2 approved chemical bleaching agents for whey, hydrogen peroxide (HP) and benzoyl peroxide (BP), negatively impact the flavor of dried whey protein. The objective of this study was to evaluate alternative methods for bleaching liquid whey: ultraviolet radiation (UV), acid-activated bentonite (BT), and ozone (OZ). Colored Cheddar cheese whey was manufactured followed by pasteurization and fat separation. Liquid whey was subjected to one of 5 treatments: control (CT) (no bleaching; 50 °C, 1 h), HP (250 mg/kg; 50 °C, 1 h), UV (1 min exposure; 50 °C), BT (0.5% w/w; 50 °C, 1 h), or OZ (2.2g/h, 50 °C, 1 h). The treated whey was then ultrafiltered, diafiltered, and spray-dried to 80% whey protein concentrate (WPC80). The entire experiment was replicated 3 times. Color (norbixin extraction and measurement), descriptive sensory, and instrumental volatile analyses were conducted on WPC80. Norbixin elimination was 28%, 79%, 39%, and 15% for HP, BT, UV, and OZ treatments, respectively. WPC80 from bleached whey, regardless of bleaching agent, had lower sweet aromatic and cooked/milky flavors compared to unbleached CT (P < 0.05). The HP and BT WPC80 had higher fatty flavor compared to the CT WPC80 (P < 0.05), and the UV and OZ WPC80 had distinct mushroom/burnt and animal flavors. Volatile compound results were consistent with sensory results and confirmed higher relative abundances of volatile aldehydes in UV, HP, and OZ WPC80 compared to CT and BT WPC80. Based on bleaching efficacy and flavor, BT may be an alternative to chemical bleaching of fluid whey.
  
  
  CONCLUSIONS
  The 2 approved chemical bleaching agents for whey, hydrogen peroxide (HP) and benzoyl peroxide (BP), negatively impact flavor of dried whey protein, and restrictions on these agents are increasing. This study evaluated 3 alternatives to chemical bleaching of fluid whey: UV radiation, ozone, and bentonite.
authors: Dept of Food, Bioprocessing & Nutrition Sciences, Southeast Dairy Foods Research Center, North Carolina State Univ, Raleigh, NC 27695, USA. maryanne_drake@ncsu.edu
authors: E J
authors: EJ
authors: Kang
authors: T J
authors: TJ
authors: Smith
authors: M A
authors: MA
authors: Drake
mesh_terms: D001585:Benzoyl Peroxide / Q000737:chemistry; D031212:Bixaceae; D057886:Bleaching Agents / Q000737:chemistry*; D002338:Carotenoids / Q000032:analysis; D002611:Cheese; D003116:Color; D005511:Food Handling / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006861:Hydrogen Peroxide / Q000737:chemistry; D008894:Milk Proteins / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis; D013649:Taste; D055549:Volatile Organic Compounds; D000067816:Whey Proteins
chemical_list: D057886:Bleaching Agents; D008894:Milk Proteins; D010936:Plant Extracts; D055549:Volatile Organic Compounds; D000067816:Whey Proteins; D002338:Carotenoids; C054041:annatto; D006861:Hydrogen Peroxide; C099823:norbixin; D001585:Benzoyl Peroxide