Ultrasound application to conserve the antioxidant properties of pitahaya (#231)

Authors

Escribano-Siesquén, William Enrique

Abstract

Pitahaya fruit has a considerable content of antioxidant and nutraceutical substances. Traditional techniques and thermal treatments used in fruit processing alter the phytochemical and nutritional components and limit their utilization, so a modern and suitable technology was sought to help preserve its components, finding ultrasound as one of the techniques that favors the preservation of the nutritional properties, bioactivity and antioxidants of the fruit pulp and its derived or processed products. In the processing of pitaya, the pulp was extracted by cutting it into slices and freezing it at -50°C, then freeze-drying it for about 49 hours. The dry ground sample was macerated in methanol for 7 days, separated into portions to determine the antioxidant capacity by DPPH method and analyzed by spectrophotometer. In a filtered portion, the antioxidant capacity was determined directly, and other portions were subjected to ultrasound before analysis, evaluating the times, power and frequency of application in order to preserve the natural antioxidant and nutritional composition of the pulp; it was found that the sample to which ultrasound was applied for 20 minutes at 180 W power and 40 kHz frequency was the most relevant to preserve the antioxidant capacity of pitaya pulp.