Effect of acoustically assisted treatments on vitamins, antioxidant activity, organic acids and drying kinetics of pineapple

The effects of the application of an acoustically assisted treatment on the vitamins (C, B-1, B-2, B-3, and B-5), the antioxidant activity (DPPH, FRAP), the polyphenol and flavonoid contents, the organic acid contents (citric and malic) and drying kinetics of pineapple (Ananas comosus var. Perola) have been studied. Treatments were carried out using two different soaking media: distilled water and pineapple juice at 30 degrees C during 10, 20 and 30 min without and with acoustic assistance (23.2 W/L). After treatment, samples were dried at 60 degrees C and 0.5 m/s during 8 h. The quality parameters were determined in untreated, treated, and treated-dried samples. The acoustic assistance promoted an increment of vitamins B-1, B-2, B-3 and B5, total flavonoid and malic acid contents, and a reduction of vitamin C, total polyphenol content, antioxidant activity and citric acid content in treated samples. However, in all treated-dried samples the final content of those quality parameters was higher than the observed in the untreated dried sample. (C) 2016 Elsevier B.V. All rights reserved.