ABSTRACT

A growing worldwide population, an ever-increasing need for food on a global scale, and environmental problems relating to the production of (animal) food have all pointed to the possibility of using edible insects as a sustainable and nutritious food and feed source. There have been an increasing number of studies that relate insects as a source of food; nevertheless, very little is known about the makeup of the nutrients and functional compounds that they contain. The potential of edible insects for their wide range of nutraceutical characteristics, their production and processing as functional foods, and their acceptability and growth in market trends in the global context are the primary topics of this article. Previous studies on edible insects reveal they can be a source of nutraceuticals and protein. Most edible insects provide protein, energy, vitamins, vital fatty acids, and minerals. In addition to these benefits, insects can be a source of bioactive substances, particularly peptides, which have potential applications in the sector of functional foods. There are possible applications for edible insects beyond as a food source or animal feed. In addition, the development of multi-purpose applications will make the mass production of edible insects more intriguing.

INTRODUCTION

One of the most fundamental needs of any living thing is food, which supplies our bodies with every vital nutrient we require to live a long and healthy life. There is mounting evidence that edible insects have the potential to develop into an important source of protein that can help meet the growing need for food and feed on a worldwide scale. Another of the ecological services insects may provide is decomposition of organic waste, and this attribute is one of the advantages of the insect food and feed sector. The global insect food and feed industry uses around 2300 different insect species. Insects are primarily consumed as food or livestock feed in the developing areas of tropical Southeast Asia, Africa, and South America. The insects currently reared as food and feed are: black soldier fly (Hermetia illucens), the domestic fly (Musca domestica), mealworm (Tenebrio molitor), superworm (Zophobas morio), lesser mealworm/  Buffaloworm (Alphitobius diaperinus), house cricket (Acheta domesticus), the tropical domestic cricket (Gryllodes sigillatus), Jamaican field cricket (Gryllus assimilis), Desert locust (Schidtocerca gregaria), Silkworm (Bombyx mori) and Greater wax moth (Galleria mellonella).

Particularly in Europe, insects represent a substantial biological resource that has not yet been properly exploited to its full potential. There are a wide variety of insect species, each one of which might provide a useful and wholesome component of a food product. The bodies of insects are packed with a wide variety of nutrients, including protein, amino acids, fat, carbs, and numerous vitamins. Other than for use in food and animal feed, edible insects have a lot of potential applications. Due to the increased interest in nutraceuticals, biotechnology has been used to create modern modified food from nutritious edible insects. This article considers the inestimable benefits of edible insects to highlight their potential as a source of functional food and high-value nutraceuticals.

INSECTS’ NUTRIENTS AND BIOACTIVE COMPONENTS PROTEIN AND AMINO ACIDS

The protein content of edible insect’s ranges from about 7% to 80% of the dry matter, depending on the species, however, several different species contain an average of 60-65% protein. Comparatively, insect protein content (40-80 g/100 g dry weight) is similar to that of widely accepted meats like chicken, beef, and pork. Insect proteins appear to be easily digested by humans and eating them may increase protein intake and diet quality (Belluco et al., 2013). Moreover, insects are well recognized as a good source of protein since they contain all nine essential amino acids, including methionine, cysteine, lysine, and threonine (Köhler et al., 2019). Edible insects can provide the essential amino acids that the human body needs for its metabolic processes but cannot produce itself.

TECHNOLOGICALLY-FUNCTIONAL CHARACTERISTICS

Proteins’ techno-functional qualities are significant for food composition and ingredient replacement. The solubility, emulsification capacity and stability, foamability, gel formation, water-holding capacity, and oil-holding capacity of edible insect proteins will be investigated of their technological functionalities. In beverages and food powders, solubility is a key quality. Strong emulsifiers are used in sausage formulation to prevent water loss, making them excellent for the meat sector because of their good emulsion stability and capacity, moreover, for shakes and desserts, foaming is an essential quality. For dairy products like cheese or cream to have the proper texture and minimize syneresis, an appropriate matrix formation as a gel is required. Furthermore, isolated proteins from black soldier fly pupae, when dissolved in water and glycerine, exhibit promising properties as a polymer matrix for film development (Barbi et al., 2019). To encourage the use of insect proteins in a larger variety of food and feed items, it is essential to understand their technological and functional features.

FAT AND FATTY ACIDS

A cell’s ability to maintain its structure and carry out its biological functions depends on the availability of energy, which is provided by lipids. Insects vary widely in their total lipid, cholesterol, saturated, unsaturated, and polyunsaturated fatty acid composition depending on species, developmental stage as well as diet (Mishyna & Glumac, 2021; Rehman et al., 2022). But if you compare insects to meats like beef and pork, you’ll find that some species contain as much as 65% unsaturated fatty acids (Payne et al., 2016; Zielińska et al., 2015).

TECHNOLOGICALLY-FUNCTIONAL CHARACTERISTICS 

Typically, vegetable oil is utilized to make skin care and protection products. However, it is also possible to employ insect-derived lipids for this purpose. There are already on the market skincare products that have been made by employing pure BSFL fat (Franco et al., 2022). The high quantities of phospholipid and free fatty acids, as well as the odor and color, present certain issues that may need to be address by research and development. BSFL fats could be a potential alternative to palm kernel or coconut oil for glycine-acyl surfactant production (used in detergents, wetting agents, emulsifiers, and foaming agents) (Verheyen et al., 2020). The creation of biodiesel from the fats of BSFL has been the subject of a significant research. Rehman et al., 2018 investigate the production of biodiesel from BSFL fat body by transesterification with methanol and fueled diesel engine with insect biodiesel. The research validates the production biodiesel from BSFL and compare it with EU biodiesel standard and validate that insect biodiesel have the potential to be used in diesel engine. The biodiesel also produces by utilizing the crop residues from yellow mealworm by Wang and Reman et al., 2017 and the highest yield of the insect biodiesel from BSFL develop on organic wastes streams were recorded 80-90%. 

EDIBLE INSECT-DERIVED BIOACTIVE FUNCTIONAL COMPOUNDS

A major source of protein for the future has been proposed as edible insects. In addition to having a high nutritional value, edible insects also include a variety of valuable metabolites that may offer humans several beneficial effects. Edible insects include a wide variety of useful compounds that may have numerous applications in human health. These include antimicrobial peptides, interferon, sex attractant hormones, cordycepin, polysaccharides, microelements, chitin/chitosan, steroidal material, vitamins, lecithin, and other nutrients (Fig.1). These particular functional compounds have the potential to help people strengthen their immunity, fight tumors, control intestinal function, regulate intestinal function, relieve fatigue, fight oxidation, protect against colds, improve sleeping, promote growth and development, and lower blood sugar and blood pressure, among other benefits (Fig. 1). Exploration and use of functional compounds in edible insects must be scaled up for sustainable industry growth.

BIOTECHNOLOGY APPLICATION FOR EXPLORATION OF FUNCTIONAL COMPOUNDS

Biotechnological methods are typically used on edible insects to enhance the product’s functional characteristics. In our opinion the enzymatic hydrolysis and insect product fermentation may be the approaches which have been applied for the increasing the functional properties. The inclusion of enzymes is what drives the process known as enzymatic hydrolysis, which breaks down the macromolecules in food. Proteolytic enzymes have been used to improve the functional qualities and reduce the antinutritional features of protein-rich edible insects. Insect proteins have been hydrolyzed enzymatically to produce bioactive peptides that improve the antioxidant, antihypertensive, solubility, emulsifying, foaming, thermal stability, and interfacial characteristics.

Proteinase-mediated peptide synthesis: Bioactive peptides are defined as peptides with a biological activity or specific protein fragments that have a beneficial effect on bodily functions or conditions, and it could possibly impact health. In our opinion due to the high protein content of edible insects, their hydrolysis may yield bioactive peptides. There are some previous reports for hydrolysis of insect proteins that revealed the presence of bioactive peptides with potential antihypertensive, antibacterial, and antioxidant effects, all of which work to lower health risks and boost the immune system (de Castro et al., 2018; Roos & van Huis, 2017). Fig. 2, illustrates the biopeptide preparation based on the enzymatic hydrolysis of the insect proteins

Insect-derived bioactive compounds: Natural antimicrobial peptides and proteins found in insects are a prime example of the bioactive substances that insects provide (AMPs). The naturally present antimicrobial peptide presents in various species of insects i.e., Hermetia illucens, Musca domestica, Tenebrio molitor, Zophobas morio, Schidtocerca gregaria, Bombyx mori and Galleria mellonella. Fig. 3 represents the natural antimicrobial peptides and proteins found in insects.

Edible insect fermentation: Fermentation is a method of food processing that involves changing a substrate through the actions of microorganisms in order to create a new and improved product. This can include changes to the taste, texture, color, nutritional content, and other sensory attributes. There is a need to investigate the fermentation process of edible insects to improve their functional qualities. The quality of the fermented product can also be affected by factors like the starter used and the length of time it is treated. In our opinion the fermentation of edible insects could be a useful method of preventing harmful microorganisms from multiplying in edible insect products with other beneficial effects in the development of insect product. The fermentation process and its possible application in edible insects’ industry briefed in Fig. 4.