Volarization of valuable compound from watermelon by-product using ultrasound-assisted extraction

Abstract

The aim of this study was to develop an efficient, reliable, and sustainable technology for the recovery of value-added compounds from by-product, in this case, is watermelon rinds. The properties of the watermelon rinds obtained from innovative ultrasound-assisted extraction (UAE) were evaluated. In regard to this, the pectin content, degree of esterification, and galacturonic acid content of the watermelon rind extracts were determined in order to verify the efficiency of the UAE. Initially, the UAE were conducted using two types of acid: citric and hydrochloric. The highest pectin content was obtained using citric acid. Additional UAE was then performed with citric acid at 50, 60, or 70°C for 10, 20, or 30 mins. Both UAE temperature and time significantly influenced the pectin extracts and galacturonic acid. The best findings for a high galacturonic acid content (47.41%) when the watermelon rinds were extracts at 70°C for 20 mins. According to the findings, the extraction process lasted 10 or 20 mins at all temperatures was mainly high-methoxyl pectin, which can form gels under acidic conditions. This suggests that pectins derived from watermelon rinds using UAE may be especially useful as an additive in some confectionery products.