Stability improvement of natural food colors: Impact of amino acid and peptide addition on anthocyanin stability in model beverages

Food Chem. 2017 Mar 1:218:277-284. doi: 10.1016/j.foodchem.2016.09.087. Epub 2016 Sep 14.

Abstract

Anthocyanins are prone to chemical degradation and color fading in the presence of vitamin C. The potential of three amino acids (l-phenylalanine, l-tyrosine, l-tryptophan) and a polypeptide (ε-poly-l-lysine) in prolonging the color stability of purple carrot anthocyanins (0.025%) in model beverages (0.05% l-ascorbic acid, citric acid, pH 3.0) stored at elevated temperature (40°C/7 days) was examined. In the absence of amino acids or peptides, anthocyanin degraded at first-order reaction rate. Addition of amino acids or peptide (0.1%) increased the color stability of anthocyanins, with the most significant improvement observed for l-tryptophan. The average half-life of anthocyanin color increased from 2 days to 6 days with l-tryptophan addition. Fluorescence quenching measurements revealed that the l-tryptophan interacted with anthocyanins mainly through hydrogen bonding, although some hydrophobic interaction may also have been involved. Overall, this study suggests that amino acid or peptide addition may prolong the color stability of anthocyanin in beverage products.

Keywords: Anthocyanin; Beverage system; Color stability; Peptides; Tryptophan.

MeSH terms

  • Amino Acids / chemistry*
  • Anthocyanins / chemistry*
  • Ascorbic Acid / chemistry
  • Citric Acid / chemistry
  • Color
  • Daucus carota / chemistry
  • Food Coloring Agents / chemistry*
  • Fruit and Vegetable Juices / analysis*
  • Half-Life
  • Hydrogen-Ion Concentration
  • Peptides / chemistry*
  • Phenylalanine / chemistry
  • Polylysine / chemistry
  • Tryptophan / chemistry
  • Tyrosine / chemistry

Substances

  • Amino Acids
  • Anthocyanins
  • Food Coloring Agents
  • Peptides
  • Polylysine
  • Citric Acid
  • Tyrosine
  • Phenylalanine
  • Tryptophan
  • Ascorbic Acid