The extraction effect of the skin of dragon fruit (Hylocereus polyrhizus) to its phenolic compounds and its antioxidants: A review

Abstract Dragon fruit contains various nutrients and functional values both in the flesh and skin. The skin of dragon fruit contains 30-35% water. It has lots of phenolic compounds and antioxidants, of which the higher amount of antioxidants are in the skin. These compounds are very easily damaged due to the extraction process especially if done incorrectly. This article is written to be a guide in selecting the extraction process in order to preserve the compounds. Based on the review, it is found the modern UAE (Ultrasound Assisted Extraction) process provides better quality than the other various conventional and modern extraction processes. UAE is an extraction process that does not use a heating process in its extraction which can damage the phenolic compounds and antioxidants. The results of the analysis of phenolic compounds using the UAE system have found betacyanin 17.64 mg, phenolic compounds 65.16 mg, flavonoid compounds 195 mg and antioxidants 620 mol. Thus, the recommended treatment to do is to use UAE extraction.