Background: Colour and turbidity (appearance), odour and flavour, taste, and texture are
the main parameters affecting consumer’s perception of juice quality. Anthocyanins, as natural antioxidant
and water-soluble pigment, exist in red fruit juices which are extremely unstable and more
susceptible to degradation. These mainly include anthocyanins, pigments, proteins, and vitamins that
are thermally sensitive.
Objective: The present study focuses on the treatment of three different fruit juices namely red grape,
pomegranate, and sour cherry using different preservative methods and evaluation of their organoleptic
Methods: Four preservative methods including pasteurization (90°C for 30 sec), mild heat treatment
(60°C for 4, 8 and 12 min), sonication (25°C) and thermosonication (90°C) using amplitude levels of
24.4, 42.7 and 61 μm for 4, 8 and 12 min, have been used for the treatment of the three selected fruit juices.
Results: Obtained results indicate that untreated grape juice had maximum L* value (29.83) and the
pasteurized grape juice had a minimum L* value (25.77). Furthermore, while a* values of untreated
grape, pomegranate, and sour cherry juices were 39.7, 42.03 and 38.13, respectively, these pasteurized
juices had minimum a* values of 35.3, 38.47 and 36.97, respectively. In addition, results revealed
that sonication and mild heating had minimum effects on colour and appearance, odour and
flavour of all three studied juices. Furthermore, significant positive (p˂0.05) effects of thermosonication
were observed for the cloudiness parameter of the studied juices. Maximum acceptability
scores were achieved by mild heat-treated grape juice at 60°C for 8 min (8.33), thermosonicated
pomegranate juice at 60°C and amplitude of 24.4 μm for 4 min (7.33) and sonicated sour cherry juice
at 25°C and amplitude of 24.4 μm for 4 min (9.33).
Conclusion: Different preservative methods with optimum processing conditions were successfully
utilized to minimize the changes in the sensorial and physicochemical properties of the treated juices.