J. Nutrition and Food Processing Copy rights@ Jacob Olalekan Arawande. Auctores Publishing LLC – Volume 7(1)-187 www.auctoresonline.org ISSN: 2637-8914 Page 1 of 7 Phytochemical Screening and Quantitative Determination of Antioxidant Properties of Watermelon Rinds and Seeds Jacob Olalekan Arawande 1,2 *, Olamide Racheal Orimoloye 2 , Adekemi Racheal Adeleke 2 , Mulikat Adenike Adewole 3 , Adenirann Olusanya Aladejimokun 4 and Kehinde Funto Ajogbolo 4 1 Department of Science Laboratory Technology, University of Medical Sciences, PMB 536 Ondo-City, Ondo State, Nigeria 2 Department of Chemistry, University of Medical Sciences, PMB 536 Ondo, Ondo State, Nigeria. 3 Department of Biochemistry, University of Medical Sciences, PMB 536 Ondo, Ondo State, Nigeria. 4 Department of Science Laboratory Technology, Rufus Giwa Polytechnic PMB 1019 Owo, Ondo State, Nigeria. *Corresponding author: Jacob Olalekan Arawande, Department of Science Laboratory Technology, University of Medical Sciences, PMB 536 Ondo-City, Ondo State, Nigeria. Received date: November 20, 2023; Accepted date: January 19, 2024; Published date: January 30, 2024 Citation: Jacob O. Arawande, Olamide R. Orimoloye, Adekemi R. Adeleke, Mulikat A. Adewole, Adenirann O. Aladejimokun, et al, (2024), Phytochemical Screening and Quantitative Determination of Antioxidant Properties of Watermelon Rinds and Seeds, J. Nutrition and Food Processing, 7(1); DOI:10.31579/2637-8914/187 Copyright: © 2024, Jacob Olalekan Arawande. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract: In this present age of food insecurity, it is essential to source for agricultural waste that can be nutritionally beneficial to humans and animals. Watermelon rinds and seeds are regarded as agricultural wastes which need to be utilized for human and animal nutrition. This research work is aimed at examining the extractive values, qualitative and quantitative determination of phytochemicals and antioxidants properties in watermelon rinds and seeds and their solvent extracts using six different solvents. The rinds and seeds of watermelon fruits were obtained, rinsed, cut into smaller pieces, air-dried, ground into powdery sample, and sieved with 40 mm mesh size. 20 g each of sample was extracted using 200 mL of six different solvents (acetone, chloroform, ethyl acetate, ethanol, methanol and water) for 72 h. Each solvent extract was screened for twelve phytochemicals (flavonoid, phenol, reducing sugar, tannin, saponin, alkaloid, volatile oil, quinone, cardiac glycoside terpenoids, steroids and phlobatannin). The extractive values of watermelon rinds ranged from 1.51±0.26% to 13.56±0.20% while that of watermelon seeds ranged from 3.54±0.16% to 10.17±0.19% in all the six solvents used. Acetone and methanol had the higher extractable phytochemicals (41.67%) in watermelon rinds while methanol, ethyl acetate and ethanol (58.33 – 66.67%) had the highest extractable phytochemicals in watermelon seeds. Water and methanol extracts of watermelon rinds had higher total phenol, DPPH and Iron (Fe2+) chelation assay than raw sample of watermelon rinds. Water and methanol extracts of watermelon rinds had higher iron (Fe2+) chelation assay and ferric reducing antioxidant power (FRAP) than raw sample of watermelon seeds. Methanol extract of watermelon seeds had higher total flavonoid, total phenol and DPPH than raw sample of watermelon seeds. Key words: phytochemicals; antioxidant properties; solvent extracts; watermelon rinds and seeds Introduction Watermelon belongs to the cucurbitaceae or gourd family. It is an herbaceous trailing plant with stems as long as 400 cm. the roots are shallow (40-50 cm) and extensive (60-90 cm), with taproot and many lateral roots (ITFNET, 2021). Temperature range of 24-27 0C is considered as optimum for the growth of the vines (Kumar et al, 2020). They are characterized by five-angled stems, coiled tendrils, and alternate leaves. Curcurbits are usually monoecious meaning they produce separate male and female flowers on the same plant (IUE, 2021). The juice or pulp from watermelon is used for human consumption while rind and seeds are major solid wastes. Different carotenoids patterns were observed in red- fleshed and yellow-fleshed watermelon. The red-fleshed watermelon varieties contain high lycopene and varying amount of β-carotene (Tadmor et al. 2005). Watermelon is a warm season crop grown mainly in sub-tropical and hot-arid regions. It requires a long growing season in the subtropics, but fast growing in the tropical regions (ITFNET, 2021). Watermelon (Citrullus lanatus) botanically considered as the fruit is belonging to the family Cucurbitaceae (Edwards et al., 2003). Watermelon rind is also high in citrulline, an amino acid the body uses to make another amino acid, arginine (used in the urea cycle to remove ammonia from the body). Watermelon seeds are known to be highly nutritional; they are rich sources of protein, vitamins B, minerals and fat among others as well as phytochemicals (Braide et al., 2012). Open Access Research Article Journal of Nutrition and Food Processing Jacob Olalekan Arawande * AUCTORES Globalize your Research