Effect of glow discharge plasma technology on the phenolic content and antioxidant capacity of four tropical juices with different phenolic composition

Cold plasma is a potential alternative to traditional thermal conservation methods. It presents itself as a promising technique for retaining several sensory parameters while improving fruit juices' phenolic content and antioxidant capacity. This research evaluates the application of glow discharge plasma on the total phenolic content and antioxidant capacity of four tropical juices (acai, guava, caja, and sapota). Glow discharge plasma operating with nitrogen plasma flowrates between 10 and 30 ml/min for 5 to 15 min were evaluated. Plasma treatment promoted a significant increment of phenolic content on sapota (<= 91%) and slightly changes in the phenolic content of acai (<= 9%), caja (<= 2%), and guava (<= 17%) juices. Glow discharge plasma improved the antioxidant capacity in acai (<= 101%), guava (<= 116%), and sapota (<= 261%) juices while decreased the antioxidant capacity in caja (<= 32%). Application of plasma for extended periods (15 min) resulted in a decrease of bioactive compounds compared with shorter processing times. Novelty impact statement This work shows that the main bioactive compounds of different fruits play a significant role in determining how cold plasma technology will influence fruit juices' antioxidant capacity and total phenolic content. This work shows that cold plasma application can increase the total phenolic content of fruit juices and antioxidant capacity. This increase greatly depends on the fruit's major constituents with total phenolics increasing by 9% to 90%, and antioxidant capacity increasing by 7% to 302%. The knowledge of the juice's main constituents could help to predict the suitability of cold plasma application.

Automated summary

The study demonstrates that application of glow discharge plasma can significantly increase the total phenolic content and antioxidant capacity of fruit juices, with sapota showing the highest improvement. However, longer processing times may result in a decrease in bioactive compounds.