**1. Introduction**

The size of the world population and its accelerated growth are the greatest threat to humanity in terms of sustainability. The world population is expected to increase to 9.8 billion people by 2050 [1], requiring a 70–100% increase in food production to feed the world. Population growth could soon outstrip food production [2, 3]. Among the foods produced to feed humans and animals, those of animal origin are recognized as the least sustainable. For example, the production of 1 kg of beef protein has a carbon footprint between 45 and 640 kg CO2 equivalents and a land use of 37–2100 m2 [4, 5]. Enteric-derived methane from ruminant livestock accounts

for 17–37% of the methane emitted to the atmosphere from human activities [6–8]. Ingredients of animal origin are the most complex to replace in animal and human diets in terms of nutritional needs because: i) They have high crude protein content (20–23% for meat and fish and 40–70% for animal meals); ii) have highly digestible amino acids (close to 85–90% for meals and even higher for meat) [9–13]; iii) have a high content of essential amino acids [14, 15], iv) have highly bioavailable organic minerals, such as heme iron and zinc [14, 16], and v) have a high concentration of vitamins. Vitamin B12 is only found in foods of animal origin [17]. Several of these characteristics are not present in plant sources [18–21]. In addition, projections indicate that the price of animal-derived meat and meals will increase steadily [22].

For these reasons, there is an urgent search for new sustainable and moderate-cost protein ingredients with nutritional properties similar to those from an animal origin. Among the available alternatives are protein ingredients obtained from non-conventional raw vegetable materials such as chickpeas, lentils, beans, peas, broad beans, and others [23–25]. However, they do not always meet the demanding amino acid requirements (in terms of digestibility and essential amino acid supply) of animals and humans [26, 27]. Other alternatives are the development of protein ingredients from microalgae, algae, yeasts, fungi, microorganisms, and the re-processing of animal or marine waste [28–33]. The drawback of these alternatives is their low productive volume, which is extremely variable, and their high cost. Technological strategies have also been applied to protein ingredients, such as fermentation [34] and hydrolysis [35, 36], which increase protein digestibility, but do not modify the amino acid profile [26, 37].

The Food and Agriculture Organization of the United Nations (FAO) has proposed insects as food ingredients of the future to feed humans and animals [38]. Their use is based on the fact that insects have similar nutritional characteristics to ingredients of animal origin, in terms of protein contribution, amino acid profile, amino acid digestibility, and the presence of minerals and vitamins [39–44]. The most widely used insects worldwide for the development of food ingredients for humans and animals are black soldier fly larvae (BSFL, *Hermetia illucens*), mealworm larvae (ML, *Tenebrio molitor*), and adult house crickets (*Acheta domesticus*) [45–48], because they are produced industrially in mini-farms. From these, basic ingredients, commodities such as whole meal, defatted meal, and insect oil are obtained using simple technologies commonly used in the food industry [48–50]. However, there is great potential for obtaining other food ingredients from insects, with better sensory, and technological and even functional properties that have only been scarcely studied and have few existing industrial applications. The objective of this chapter is to analyze the potential of transforming insect flour and oil commodities into food/functional ingredients with improved sensory, technological and functional properties for massification and use as food ingredients for the future.
