# Exploring the Potential of Yellow Mealworm (_Tenebrio molitor_) Oil as a Nutraceuticalal Ingredient
## 1 Introduction  
The use of edible insects has frequently been linked to their use as feed for animal consumption. However, in recent years, due to the increase in world population and the growing demand for proteins of animal origin in developing countries, its possible use as food for human consumption has acquired great relevance, representing one of the possible responses with lower environmental impact [1]. The Food and Agriculture Organization (FAO) has remarked that insects are a very nutritious and healthy food source with high protein content and good nutritional value [2]. Additionally, its production entails a smaller ecological footprint and is more sustainable than conventional livestock farming since itproduces less greenhouse gases, requires less land and water use, and its feed can be based on byproducts [3; 4]. Although demand for insect products is expected to increase greatly in the next decades, its consumption as a whole dried insect in Western countries is not widely accepted among consumers, mainly for cultural reasons. Therefore, the introduction into the European market should focus on products derived from insects as ingredients, in which the anatomy of the animal is not perceived, such as flour or oils. It is estimated that there are more than 2000 species of edible insects that have traditionally been consumed throughout the world. Among them are the larvae of _Tenebrio molitor_, also called yellow mealworm. This insect has aroused special interest due to its rapid production and nutritional value since it has a very high content of proteins (52%) with high biological value and unsaturated lipids, compared with other insects, as well as other interesting components such as antioxidant compounds, chitosan, or bioactive peptides [5; 6; 7]. Yellow mealworm was the first insect species to receive a positive opinion from the European Food Safety Authority (EFSA) as a novel food in 2021 [8]. Currently, frozen and dried yellow mealworms (whole or powder) commercialization is allowed in the European market [9]. Interest in _Tenebrio molitor_ has been mainly focusing on its protein fraction value, such as defatted mealworm powder, and its potential uses for feeding animals, but more recently for human consumption as a bakery ingredient or protein bars [10]. Defatted mealworm powder is also a potential functional ingredient in food production due to its high antioxidant capacity [11]. During the production of defatted mealworm powder, _Tenebrio molitor_ oil is obtained as a by-product. Different methods could extract this oil. The traditional and most common method is the mechanical pressing of dried larvae. However, this method requires further refining steps to avoid solid residues of undesirable particles present in the oil. Alternative approaches, such as organic solvents or supercritical carbon dioxide extraction, have been employed [12] to improve efficiency. The previous study indicated insect oil as a source of unsaturated fatty acids, including essential belonging to \(\omega\)-6 and \(\omega\)-3 families and certain bioactive compounds with antioxidant properties, such as tocopherols and polyphenols [12]. Thus, insect oils can be considered an alternative source of valuable lipids in human nutrition [6; 12]. The potential benefit of insect oil use in human consumption has not been widely studied, and its production is mainly intended for feed enrichment or as a biofuel component despite its low toxicity and interesting nutritional profile [13]. The results of a study by [PERSON] et al. [7] suggest a suppression of hyperlipidemia and hepatic steatosis in mice in which part of the fat in their diet had been partially replaced with _Tenebrio molitor_ oil [7]. Other studies suggested the antimicrobial activity of the oil, retarding the growth of both Gram-positive and Gram-negative pathogenic bacteria and improving the intestinal barrier and maintenance of intestinal health in rabbits [14]. These results point to possible health benefits if this type of oil is incorporated into the human diet.