Anthocyanins and color degradation in ozonated grape juice

Area of Science:

• Food Science
• Chemistry

Background:

• Ozonation is a potential preservation technique for fruit juices.
• Understanding its impact on juice quality is crucial for processors.

Purpose of the Study:

• To investigate the effects of ozone processing variables on grape juice color and anthocyanin content.
• To determine the kinetic models governing these changes.

Main Methods:

• Grape juice samples were ozonated with varying ozone concentrations and treatment times.
• Color values (L, a, b) and anthocyanin concentrations were measured.
• Kinetic analysis was performed using zero-order, first-order, and fraction conversion models.

Main Results:

• Ozonation significantly affected grape juice color (L, a, b) and anthocyanin content.
• Lightness (L) and total color difference (TCD) followed zero-order kinetics, while a and b followed first-order kinetics.
• Cyanidin-3-O-glucoside (Cy3Gl) was more stable than delphinidin-3-O-glucoside (Dy3Gl) and malvidin-3-O-glucoside (My3Gl) during ozonation, with Cy3Gl changes fitting a fraction conversion model.

Conclusions:

• Ozone processing impacts grape juice color and anthocyanin profiles.
• The stability of anthocyanins varies, with Cy3Gl being relatively stable.
• Processors should carefully consider ozonation's effects before adopting it for grape juice preservation.