Changes of Antioxidant Compounds in a Fruit Juice-Stevia rebaudiana Blend Processed by Pulsed Electric Technologies and Ultrasound

The purpose of this study was to compare the effects of the non-thermal technologies of pulsed electric fields (PEF), high-voltage electrical discharges (HVED) and ultrasound (USN) on bioactive compounds (ascorbic acid, total carotenoids, total phenolic compounds and total anthocyanins) and antioxidant capacity of a fruit juice (papaya and mango) blend sweetened with Stevia rebaudiana. Experiments were carried out at two equivalent energy inputs (32-256 kJ/kg) for each technology. Principal component analysis (PCA) was used to understand the contribution of ascorbic acid, total carotenoids and oxygen radical absorbance capacity (ORAC) values. These parameters were better retained with PEF treatments. Nevertheless, the use of HVED and USN technologies cannot be ruled out, as they may enhance the contents of other bioactive compounds such as total phenolic compounds when HVED technology is applied at an energy input of 256 kJ/kg. The obtained data can contribute to the determination of optimum processing conditions for production of high nutritional quality liquid foods.