Phenolics, such as phenolic acids and anthocyanins, can be destructed
by physical factors during food processing or enzyme activity
in vegetables and fruits stored in different conditions (Kader,
Irmouli, Nicolas, & Metche, 2002; Rossi et al., 2003). The conditions
of food processing can cause a discoloration of polyphenols present
in raw material into yellowish or brownish pigments (Clifford,
2000) found in the colour of ready-made products.