Project Abstract

Abstract
The extraction of oil from watermelon seeds is a promising area of research due to the potential health benefits of watermelon seed oil and its various applications in the food and cosmetic industries. This study aimed to investigate and optimize the oil extraction process from watermelon seeds using different methods such as solvent extraction, cold pressing, and supercritical fluid extraction. The oil content of watermelon seeds was found to be around 20-30%, making them a viable source for oil extraction. Various parameters such as extraction temperature, time, seed particle size, and solvent type were optimized to determine their effects on oil yield and quality. The solvent extraction method using hexane showed the highest oil yield compared to cold pressing and supercritical fluid extraction. However, concerns regarding solvent residues in the extracted oil raise environmental and health issues. Cold pressing, on the other hand, is a more environmentally friendly method that retains the natural characteristics of the oil but yields lower amounts compared to solvent extraction. Supercritical fluid extraction, utilizing carbon dioxide as a solvent, showed promising results in terms of oil yield and quality. This method is considered safe, environmentally friendly, and capable of producing high-quality oil without solvent residues. Optimization of extraction parameters such as pressure, temperature, and CO2 flow rate led to increased oil yield and quality. The extracted watermelon seed oil was analyzed for its physicochemical properties, fatty acid composition, antioxidant activity, and thermal stability. The oil was found to be rich in unsaturated fatty acids, particularly linoleic acid, which is known for its health benefits. The oil also exhibited good antioxidant activity and thermal stability, making it suitable for use in food products and cosmetics. Overall, this study provides valuable insights into the extraction of oil from watermelon seeds and the potential applications of watermelon seed oil in various industries. Further research could focus on scaling up the extraction process, exploring the use of different solvents, and investigating the bioactive compounds present in watermelon seed oil for potential health benefits.

Project Overview

1.0 INTRODUCTION

The edible fruit of watermelon (Citrullus lanatus) belongs to the family Cubitaceae. The fruit contains many obovate, smooth compressed seeds thickened at the margin and of a black or yellowish white colour. Watermelon plays a very important role in Africa as it is used to quench thirst when there is shortage of water. The seed of watermelon (Citrullus lanatus) can be bruised and rubbed up with water to form an emulsion, which can be used to cure catarrhal infections, disorders of the bowels, urinary passage and fever. It is also being used as worm expeller, in recent years it has been used to expel tape worm (Abiodun and Adeleke, 2010). In Nigeria, the watermelon seed is often discarded after the juicy part has been eaten. The seed constitutes a public nuisance because the sellers of watermelon do not dispose of these in a hygienic manner. Therefore, this project work when successfully completed will convert waste into wealth. From previous studies on watermelon seed oil, it is light penetrating and rich in essential fatty acids (Abiodun and Adeleke, 2010). As a result of importance of drying techniques, this research was designed to observe the effect of two drying methods on the physico-chemical properties of the seed oil and also to determine its edibility and effectiveness in soap making. In Africa, Watermelon seeds have been prized for the highly nutritive oil that they contain. Traditionally, the seeds are removed from the rind and then allowed to dry outside in the sun. Once dried, the seeds are then pressed to extract the beneficial oil. Natural Sourcing provides the most superior watermelon seed oil available. It is carefully processed and packaged to maintain the purity, freshness and beneficial properties of this exceptional watermelon seed oil.

The fatty acid profile of edible oils plays an important role in their stability and nutritional value. Monounsaturated (18:1) and polyunsaturated (18:2) fatty acids have been found to be effective replacements for saturates as part of cholesterol-lowering diets (Mattson and Grundy, 1985). However, it is also known that the oils with substantial amounts of unsaturation, particularly 18:2 fatty acids, are susceptible to oxidation and may produce products that contribute to arteriosclerosis and carcinogenesis. Some studies with experimental animals indicate that excessive amounts of linoleic acid promote carcinogenesis

(Kubow, 1990).Watermelon seed oil, rich in linoleic acid (~64.5 %), is used for frying and cooking in some African and Middle Eastern American countries owning to its unique flavour (Akoh and Nwosu, 1992). Much research has been published on the oxidative stability of some vegetable or fruit oils, but a little has been reported on the stability of watermelon seed oil. The modification of watermelon seed oil fatty acid composition by incorporation of oleic acid (18:1) has been explored (Charment et al., 1997). The modified watermelon seed oil was produced with the better balance of monounsaturated (18:1) and essential Fatty acids (18:2), and also improved the seed oil oxidative stability and nutritional value (Charment et al., 1998).The watermelon family Cucurbitaceae is the most popular fruit in Serbia, with a traditional name ″lubenica″. Unfortunately, there is no information of domestic application or medicinal values of this seed oil for cooking and or frying as useful source of oil with good nutritional value. Thus, watermelon seed oil composition (physical and chemical) shall be evaluated in this present study, which has not been previously investigated. The data generated in the work may help in the future selection of watermelon seed oil for use in human diet.

The light texture, moisturizing capabilities and stable shelf life of watermelon seed oil makes it a highly suitable emollient in natural baby care formulations and light body emulsions. Unlike mineral oil that is a common ingredient in commercial skin projects, watermelon seed oil does not clog pores or prevent the body from natural elimination of toxins through the skin. The rich composition of essential fatty acid contained in watermelon seed oil nourishes and restores elasticity to the skin (Akoh and Nwosu, 1992). It may be recommended for use in skin care formulations for all skin types including dry, oily and maturing skin. Watermelon seed oil may also be a perfect choice for inclusion in hair care formulations as it is non greasy yet highly moisturizing. Grinding the dry seed, flaking or rolling of the seeds to carry out extraction of oil, this is then subjected to mechanical processing to liberate the oil or the use of chemical solvent.

1.1 Aims and Objectives

The aims and objectives of the project are;

Ø Determine the oil content in the watermelon seed using soxhlet extractor.

Ø Determine the physico-chemical characteristic properties of the extracted oil.

Ø Use of normal hexane and petroleum ether as an extractive solvent.

Ø Effect of two drying methods on the physico-chemical properties of the watermelon seed oil.

Ø Determine its edibility and effectiveness in soap making.

Ø Determine the proximate analysis of the seed.

1.2 Scopes

Ø Collection of the watermelon seeds from road side hawkers.

Ø Drying and removal from the shell.

Ø Drying proper (oven drying and sun drying).

Ø Cleaning of the seed.

Ø Weighing of the watermelon seed.

Ø Grinding of the seed.

Ø Proximate analysis of the seed.

Ø Sieving to obtain particle sizes of varying dimensions.

Ø Extraction using soxhlet method, petroleum ether and hexane as solvent.

Ø Characterization of the oil (physical and chemical).

1.3 Problem Statement

In Nigeria, the watermelon seed is often discarded after the juicy part has been eaten. The seed constitutes a public nuisance because the sellers of watermelon do not dispose of these in a hygienic way. Therefore, this project work when completed will succ