Effects of ultrasound treatments on antioxidants content of cider, enriched previously with natural extracts

Abstract

The cider obtained in laboratory conditions was enriched in valuable and natural bio compounds using several extracts (obtained from blueberry juice and an colorant obtained from black carrot "Black Carrot HC Red-Blue Colored Concentrate" in 2% citric acid solution) and ultrasounds treatments.Compared with the untreated cider, all the cider variants enriched with both types of extracts had higher values for total polyphenols and flavonoids content. This increase in values, from one measurement to another is due to the increase in the amplitude of the ultrasound in the propagation medium (cider + liquid extract). This reveals the importance of increasing the amplitude, in the efficiency of extraction of anthocyanins, demonstrating that a similar application time, but at different amplitude, influences the content of polyphenols and flavonoids, respectively.To assess the antioxidant activity of the cider variants tested in the experimental study, it was estimated the diphenylpicrylhydrazyl (DPPH) free inhibition percentage (DPPH inhibition) by the enriched cranberry extracts obtained from the forest fruits (blueberries) in 2% citric acid, respectively by those obtained by using black carrot juice (0.03% concentration).