# Nutritional Profiling of Underutilised _Citrullus lantus mucosospermus_ Seed Flour
## 1 Introduction  
Egusi seed, originating from the Egusi melon (_Citrullus lantus mucosospermus_), holds substantial promise as a staple food crop in tropical regions [1]. Indigenous to tropical Africa and Asia, the Egusi melon thrives in warm climates, making it well-suited for cultivation in these areas. The seed, commonly used in traditional cuisines across these regions, presents numerous nutritional and economic opportunities [1].  
In tropical areas where food security is often a concern, Egusi seeds are a valuable food source due to its rich nutrient profile [2]. The seeds are renowned for their high protein content, essential fatty acids, vitamins, and minerals, making them a significant component of local diets. Egusi seeds offer versatility in culinary applications, utilised as a primary ingredient in soups, stews, and various traditional dishes [3].  
Moreover, Egusi cultivation holds economic potential for tropical farmers. The demand for Egusi seeds transcends local markets, with the potential for export to international markets and a growing interest in exotic and nutritious food products [1]. Furthermore, the Egusi melon plant exhibits resilience to specific environmental conditions prevalent in tropical regions, making it a viable crop choice for small-scale farmers [4].  
Egusi melon (_Citrullus lanatus mucosospermus_) seeds, known for their bitter pulp, are principally used to extract oil, which is widely used in Africa and Asia [5]. This oil, high in omega-6 fatty acids like linoleic acid, has the potential for use as a biodiesel source. Conventional defatting processes, such as heat pressing and chemical extraction, frequently produce flour with undesired properties such as discolouration, off-flavours, and lower nutritional value [6]. Furthermore, using harmful solvents in these processes risks customers' health. To solve these restrictions, this work used supercritical fluid extraction (SFE), which elevates carbon dioxide (CO2) above its critical temperature and pressure, converting it into a supercritical fluid state. This change increases CO2's solvating potency, making it an excellent medium for defatting processes [7]. Defatted egusi flour is a versatile and healthy alternative to traditional egusi flour, with potential uses in commercial food manufacturing and nutritional interventions. Continued research and development in processing techniques and product innovation can help to extend its use and advantages in the food business and public health programmes.  
Supercritical CO2 extraction, which was developed in the 1980s, has been used successfully in a variety of seed defatting procedures, including grape seed, rapeseed, and coriander [8]. This approach is versatile in seed processing, with applications including green coffee, black tea, decaffeination, hop extract, and essential oil extraction [9]. The resulting defatted meal from SFE shows potential as a functional ingredient, owing to its beneficial amino acid profile, which makes it suitable for inclusion into malnutrition programmes and promoting diversification in the food processing industry [10].  
Despite their underutilisation when compared to other oilseeds, egusi seeds have inherent nutritional benefits, particularly protein content, which improves food system functionality [11]. Previous research has shown that protein isolates from Egusi flour may be prepared using water and NaOH extractions, with the ensuing functional qualities including water- and oil-holding capabilities. Furthermore, the effect of NaCl concentrations on heat stability highlights the potential of Egusi flour as an essential material in combating malnutrition [12].  
This study assesses the nutritional and technological aspects of Egusi flour derived via supercritical CO2 extraction, shining light on its potential as a helpful resource in nutritional programmes and the food processing industry.