Encyclopedia
Please note this is an old version of this entry, which may differ significantly from the current revision.
Subjects:
Food Science & Technology
Edible insects are abundant in protein content, encompassing all essential amino acids required for a balanced diet. This is a viable alternative protein source for feeding options to the expanding world population. It has significant potential for enhancing food security, offering a sustainable and environmentally conscious alternative to conventional protein sources.
- insects
- protein
- bioactive peptides
- alternative protein
- functional properties
- kosher
- Halal
1. Edible Insects
Insect-based food sources are frequently consumed in tropical and subtropical regions, whereas their acceptance is notably limited in Western countries [1]. Insects have a high amount of protein, fat, and minerals, positioning them as a promising food source and ingredient option for enhancing the quality of various food products, including bread, pasta, protein bars, snacks, and processed meat products. In addition, insects have significant potential as a sustainable solution for future nutrition demands because they are renewable natural resources available all year round and have low environmental impacts with enhanced food safety [2,3].
In contrast to conventional primary protein sources utilized for human food and animal feed, insects exhibit high protein content and well-balanced amino acids. Notably, insect farming demands reduced land, water, and gas emissions compared to traditional protein sources (Table 1) [4,5].
Table 1. Environmental impact of farming on common protein sources.
| Insect | Chicken | Pig | Cow | |
|---|---|---|---|---|
| Greenhouse gases released per kg of live weight, g | 2 | NA | 1130 | 2850 |
| Feed required per kg of live weight, kg | 1.7 | 2.5 | 5 | 10 |
| Land required per g of protein | 18 | 51 | 63 | 254 |
| Water required per g of protein, liter | 23 | 34 | 57 | 112 |
Cadinu, Barra, Torre, Delogu and Madau [5], Aiello, et al. [6], Alexander, et al. [7], Agnieszka de Sousa [8].
The main obstacles to the expanding insect production industries are inadequate consumer acceptance and the need for well-defined regulations governing insect-based food and feed. Such impediments could hinder the widespread production and promotion of insects as a viable food source, as specific stakeholders perceive the associated processes to be both costly and time-consuming [9]. According to Johnson [10], insect-eating seems to be culturally universal; the only factors that change are the location, the population of insects, and ethnicity. Notably, ancestral human populations in Africa likely incorporated insects into their diets, a tradition observed in present-day primates that exhibit an enthusiastic inclination towards insect consumption. These food sources are likely served as routine, ritual, or emergency. Forest insects are commonly gathered from various regions to be part of human diets. Unfortunately, in conjunction with the exploitation of forest insects, the oversight of forest plant management has been minimal in most cases. Furthermore, it is worth noting that the domestication of insects has been limited primarily to a select few species, such as silkworms and bees. Larvae and pupae are the most often consumed insects, typically undergoing minimal processing prior to consumption.
2. Insects Nutritional Value of Edible Insects
2.1. Protein Content of Edible Insects
The nutritional value of insects varies significantly across species, developmental stage, diet, growth environment, sex, and measurement methods [21]. However, researchers generally agree that insects are extremely rich in protein. On average, the protein content of edible insects ranges from 35–60% dry weight or 10–25% fresh weight [24,25,26], and the content found in certain insects is higher than some plant-based proteins. Therefore, insect-derived protein presents itself as a viable and premium protein source, particularly beneficial for individuals struggling with inadequate nutritional intake due to protein deficiencies. Indeed, nutritionists are the dominant research group on food insects, driven by a desire to solve protein-deficient dietary concerns [14]. Table 3 shows an overview of the protein content in select edible insects on a dry-weight basis.
Table 3. Protein content of common and edible insects on a dry weight basis.
| Insect’s Name | Protein Content Range (%) | Reference |
|---|---|---|
| Larvae | 26–45 | [27,28,29,30,31] |
| Cricket, Grasshoppers, Locusts | 6–77 | [27,28] |
| Grasshopper | 20–56 | [28,29] |
| Beetles, Grubes | 8–69 | [28,32,33] |
| Termites | 20–43 | [28,29,33] |
| Bees, Ants | 5–66 | [28,33] |
| Dragonfly | 26–54 | [34] |
| Cockroaches | 43–66 | [33] |
| Flies | 35–64 | [33] |
| True Bugs | 27–71 | [33] |
| Butterflies, Moths | 18–60 | [33] |
| Dragonflies, Damselflies | 54–56 | [33] |
Values are expressed on dry dry-weight basis.
One crucial factor needs to be considered while analyzing the insect’s protein content. Considering the possible overestimation linked to the commonly used 6.25 nitrogen-to-protein conversion factor is essential when assessing insect protein content. This component, which was first found to be appropriate for meat, might not apply to insects because of the substantial amount of fibrous chitin that is present in their cuticles.
2.2. Amino Acid Composition
Insects often compare well with conventional sources of protein, for example, soy and fish. A large percentage of the protein within the exoskeleton is chemically tied and thus may not be accessible. Furthermore, exoskeletons include polysaccharide chitin containing nitrogen, which can potentially lead to an overestimation of the overall protein composition of insects when evaluated based on nitrogen content. To address this, a nitrogen-to-protein conversion factor of 5.60 for a range of insect species may be more suitable than the standard ratio of 6.25. Alternately, by removing the nitrogen contained in the chitin exoskeleton, the protein composition of insects may be reassessed. Insects are usually considered an essential source of the essential amino acid (EAA). The amino acid content of selected insect species (Milligrams per gram of protein), fish, and beef protein content are presented in Table 4. Even though species-developed levels vary with EAA at particular levels, they generally compare well with conventional protein sources used in animal feed and high-quality sources of human protein such as meat, milk, and fish [38].
Table 4. Amino acid content comparison (mg/g protein) among various edible protein sources including insects, beef, and fish (on dry weight, mg/g protein).
| Source | Lys * | His ** | Arg ** | Asp | Thr * | Ser | Glu | Pro | Gly | Ala | Met * | Cys | Val * | Ile * | Leu * | Phe * | Tyr ** | Trp * | AAS *** (%) | Reference |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Zonocerus variegatus | 48.4 | 39.2 | 60.6 | 81.9 | 30.7 | 46.7 | 133.7 | 43.0 | 44.9 | 36.6 | 18.9 | 6.5 | 35.4 | 36.7 | 50.6 | 30.5 | 25.3 | - | 66.4 | [43] |
| Periplaneta americana L.a | 40.0 | 20.0 | 51.0 | - | 36.0 | 45.0 | 130 | 65.0 | 71.0 | 61.0 | 36.0 | 20.0 | 65.0 | 31.0 | 56.0 | 31.0 | 69.0 | 6.0 | 76.3 | [44] |
| Rhynchophoris phoenicis (larvae) | 45.0 | 38.9 | 79.2 | 30.6 | 39.0 | 156.0 | 50.1 | 47.2 | 52.5 | 19.7 | 20.2 | 35.0 | 39 | 54.2 | 47.5 | 29.0 | - | 71.9 | [45] | |
| Sciphophorus acupunctatus (larvae) | 53.5 | 14.7 | 44.0 | - | 40.4 | - | - | - | - | - | 20.2 | 26.7 | 62.0 | 48.2 | 78.2 | 46.1 | 63.5 | 8.1 | 83.4 | [46,47] |
| Ephydra hians (larvae) | 55.0 | 10.0 | - | 49.0 | - | - | - | - | - | 19.0 | - | 61.0 | 40.0 | 74.0 | 54.0 | 51.0 | 7.1 | 74.3 | [48] | |
| Hoplophorion monograma | 55.0 | 15.0 | - | 45.0 | - | - | - | - | - | 19.0 | - | 74.0 | 41.0 | 77.0 | 47.0 | 90.0 | 9.6 | 84.1 | [48] | |
| Atta mexicanah | 49.0 | 25.0 | - | 43.0 | - | - | - | - | - | 34.0 | - | 64.0 | 53.0 | 80.0 | 88.0 | 47.0 | 6.0 | 89.3 | [48] | |
| Liometopum apiculatumd | 58.0 | 29 | 50.0 | 42.0 | - | - | - | - | - | 18.0 | 14.0 | 60.0 | 49.0 | 76.0 | 39.0 | 68.0 | 8.0 | 88.0 | [48] | |
| Macrotermes bellicosus | 54.2 | 51.4 | 69.4 | 27.5 | - | - | - | - | - | 7.5 | 18.7 | 73.3 | 51.1 | 78.3 | 43.8 | 30.2 | 14.3 | 97.3 | [46] | |
| Bombyx mori (larvae) | 47.3 | 25.8 | 41.9 | - | 31.2 | 36.6 | 100.0 | 34.4 | 60.2 | 45.2 | 14.0 | 8.6 | 40.9 | 32.3 | 52.7 | 29.0 | 31.2 | 7.5 | 64.8 | [49] |
| Acheta domesticus (adults) | 53.7 | 23.4 | 61.0 | - | 36.1 | 49.8 | 104.9 | 56.1 | 50.7 | 87.8 | 14.6 | 8.3 | 52.2 | 45.9 | 100.0 | 31.7 | 48.8 | 6.3 | 78.2 | [49] |
| Boopedon flaviventrish | 55.0 | 24.0 | - | 44.0 | - | - | - | - | - | 18.0 | - | 57.0 | 47.0 | 88.0 | 41.0 | 74.0 | 6.0 | 83.1 | ||
| Fish (Clarias anguillaris) | 50.2 | 11.8 | 47.8 | 70.4 | 20.8 | 19.2 | 118 | 24.5 | 31.1 | 24.8 | 23.4 | 7.3 | 28.0 | 25.8 | 64.7 | 38.7 | 24.6 | - | - | [50] |
| Beef | 45 | 20 | 33 | 52 | 25 | 27 | 90 | 28 | 24 | 30 | 16 | 5.9 | 20 | 16 | 42 | 24 | 22 | - | - | [51] |
* Denotes essential amino acids. ** Denotes semi-essential amino acids. *** Average Amino acid Score based on the egg’s amino acids as reference.
2.3. Fatty Acids Composition
As Table 5 illustrates, the quantity of insect-related fat within and across species may vary considerably. Typically, larval invertebrates exhibit significantly higher fat levels than adults on a dry-matter basis. Triacylglycerol and phospholipids in various forms represent 80% and 20% of the total fat content, respectively. Compared to fish or soy meal, to utilize insects in animal feeds, a part of the fat content will have to be removed. This extracted fat can be utilized as an additional component. Table 5 summarizes the reported fatty acids compositions of several insect species.
Generally, insects have a spectrum equal to other animal species in saturated and monounsaturated fatty acids and polyunsaturated fatty acids (PUFA). Among saturated fatty acids, palmitic acid (C16:0) is the primary constituent, often accompanied by varying proportions of stearic acid (C18:0). The principal monounsaturated fatty acid is oleic acid (C18:1); however, certain species can have a considerable accumulation of palmitoleic acid (C16:1) in rare cases. In general, insects with lower levels of n-3 alpha-linolenic acid are relatively high in n-6 PUFA (n-6 C18:2) and linoleic acid (C18:3). However, few indications show that insects can manufacture long-chain N-3-PUFAs, such as Eicosapentaenoic, EPA (C20:5), and DHA (C22:6), which are oily fish-related acids. Alterations in food can change the total fat and fatty acid content of different insect species. For instance, introducing rich PUFA sources into the diet of mealworms has been demonstrated to yield a significant increase in their PUFA content, as observed in the study by Hawkey, Lopez-Viso, Brameld, Parr, and Salter [38].
Table 5. Fat and fatty acids composition of some insects based on dry weight (g/100 g dry-weight basis).
| Common Name | Fat Content |
Saturate d Fatty Acids (SFA) | Monounsaturated Fatty Acids (MUFA) | Polyunsaturated Fatty Acids (PUFA) | Linoleic Acid (18:2) | Alfa Linolenic Acid (18:3) | Arachidonic Acid (18:4) |
Reference |
|---|---|---|---|---|---|---|---|---|
| Winged termite | 44.82 | 35.05 | 52.77 | 12.18 | 10.75 | 1.43 | [55,56] | |
| White spotted flower beetle | 26.70 | 23.61 | 95.20 | 10.40 | 9.10 | 0.40 | 0.70 | [27,57] |
| Desert locust | 13.00 | 25.30 | 39.35 | 26.28 | 14.04 | 11.35 | [58] | |
| Dung beetle * | 13.50 | 733.46 | 85.65 | 1514.32 | - | 39.82 | 934.95 | [59,60] |
| Black soldier fly larvae | 35.00 | 36.20 | 28.70 | 35.00 | 13.00 | 1.70 | - | [61,62,63] |
| Sugarcane termite | 46.00 | 32.17 | 56.10 | 11.73 | 11.54 | 0.20 | - | [56] |
| Tropical house cricket | 20.00 | 33.74 | 34.33 | 31.91 | 29.78 | 2.13 | - | [58] |
| Guizhou black ant |
15.20 | 23.90 | 72.40 | 3.70 | 2.10 | 1.00 | 0.20 | [64] |
* Values for dung beetle is mg/100 g of dry weight basis.
2.4. Micronutrient and Vitamin Composition Variability
The composition of micronutrients and vitamins in insects depends on their dietary intake and exhibits variations across species, orders, and seasons. There are also significant variations in the literature accessible for particular species, which might be attributed to analysis at various phases. Insects often have adequate mineral levels to fulfill most animals’ nutritional needs. Insects with remarkably high levels of iron and zinc can offer substantial calcium, magnesium, manganese, phosphorus, and selenium. Despite the variable ranges of reported mineral content in insects, they consistently emerge as a valuable mineral resource. According to the Weru, Chege, and Kinyuru [40] review, phosphorus values ranged from 2.74 to 1443 mg/100 g, while magnesium varied from 1.54 to 1009.26 mg/100 g. This value for calcium was 0.27 mg/100 g in palm weevils at the late larval stage, while the highest value was for termites (Trinervitermes germinates).
3. Production of Protein, Protein Hydrolysate, and Peptides
The efficient extraction of proteins from insects, similar to protein extraction from other sources, needs a method that maximizes surface area exposure of the raw material to achieve optimal yields of both protein and fat/oils. In this sense, the insects should be dried first and then ground/sieved to obtain a homogenous insect flour. De-fatting the ground insect sample will facilitate the extraction of protein efficiently and proficiently. However, insect flour also could be used as a food ingredient for the formulation of different food products [66,67,68,69,70,71]; the European Commission also has recently approved the use of specific insect flours as food ingredients, in keeping with the need to identify alternative high-quality sources of protein for human nutrition [72]. The next step in protein extraction after de-fatting is the solubilization of protein. In order to separate the slurry and residue, centrifugation/filtration is typically used. The last steps to extract protein from insects as a protein source are the precipitation of protein and then the separation of the supernatant and protein sediment by another centrifugation procedure to produce protein concentrate/isolate from insects [38,40,42,67,73].
De-fatting the insect flour is a crucial step for extracting the protein because it improves the extraction yield and enhances the efficiency of the extraction process. It also prevents the interference of the fat/oil content with the protein and the problems resulting from interactions between the hydrophobic amino acids and fat, which appear to be the potential reasons for non-significant functional properties [24,67,71]. Different researchers have previously reported various solvents to de-fat insect flour or insect proteins in which hexane, ethanol, petroleum ether, and isopropanol were widely used as solvents [74,75].
4. Hydrolysis of Insect Proteins
Recently, there has been growing interest in producing protein hydrolysates and peptides from various insect species, which is due to some issues related to insect proteins, including allergenicity and weak functional properties. As Zarei, et al. [79] explained, there are three different techniques of enzymatic hydrolysis of proteins based on how enzymes are added to the protein-containing buffer solution system. The methods are categorized into three different enzyme addition systems: multiple-enzyme digestion systems, simultaneous enzyme addition, and consecutive enzyme addition systems. In the single-addition systems, only one enzyme is added to the protein substrate, and hydrolysis will be carried out based on the respective enzyme. However, more than one enzyme (≥2) is added in the multiple-enzyme digestion and consecutive enzyme addition. According to the literature, most of the studies on enzymatic protein hydrolysis used the single-enzyme addition method.
In their study, Leni, et al. [80] used the protease derived from Bacillus licheniformis to facilitate protein extraction and improve the techno-functional properties of proteolysate from lesser mealworms. They also investigated the effect of the degree of hydrolysis (DH) on functional properties of the protein hydrolysate during a 3 h hydrolysis period. Their findings showed that the DH enhanced the solubility and oil-holding ability, whereas a reduced emulsifying ability was observed. Notably, the use of protease-assisted extraction has been applied by researchers worldwide.
Furthermore, in a study performed by Vercruysse, et al. [85], the proteins of four insects, including cotton leafworm (Spodoptera littoralis), silkworm/domestic silk moth, desert locust, and buff-tailed bumblebee or large earth bumblebee (Bombus terrestris), were hydrolyzed using three proteolytic enzymes including gastrointestinal proteases, alcalase, and thermolysin. Although hydrolysis of the insect proteins resulted in increased ACE inhibitory activity, the highest ACE inhibitory activity was observed after gastrointestinal digestion.
5. Bioactive Peptides
Once the structure, characteristics, and functions of a specific insect protein are comprehended, chemical synthesis emerges as a valuable technique for producing and researching the desired peptide. Insect protein extraction for human food holds the potential as a practical customer acceptance approach. The development, recognition, and accomplishments associated with a particular insect peptide with bioactive effects such as antioxidants, antimicrobials, and antihypertensives could catalyze increased investment and expanded research into the extraction and supplementation of insect proteins [9].
As shown in Table 7, different enzymes have been used for the enzymatic hydrolysis of insect proteins [9]. The simulation of the human gastrointestinal digestive system with pepsin, trypsin, and R-chymotrypsin has also been studied. These investigations have demonstrated the ACE inhibitory effects of insect proteins, suggesting that silkworm/domestic silk moth hydrolysates revealed 100% ACE inhibitory activity while the parent protein (un-hydrolyzed protein) showed 50% ACE inhibitory activity. The in vitro ACE inhibitory activity of small peptides was found using protein from cotton leafworm edible insects. After fractionation in two steps using RP-HPLC and gel filtration, a tripeptide, Ala-Val-Phe, was identified and sequenced. The in vitro ACE inhibitory activity of the peptide showed an IC50 value of 2123 μM [95].
Table 7. The Bioactive peptides from various insects and their potential health benefits.
| Insect Source | Enzyme Used | Identified Peptides | Bioactivity | Reference |
|---|---|---|---|---|
| Silkworm/domestic silk moth (Bombyx mori) | Pepsin, trypsin, R-chymotrypsin | simulated the human gastrointestinal hydrolysate | ACE inhibitory effects, with 100% activity in hydrolysates | [85] |
| Cotton leafworm (Spodoptera littoralis) | Pepsin, trypsin and α-chymotrypsin | Ala-Val-Phe | In vitro ACE inhibitory activity (IC50: 2123 μM) | [95] |
| Mealworm larva (Tenebrio molitor) | Alcalase | Tyr–Ala–Asn | ACE inhibitory activity (IC50: 0.017 mg/mL) | [89] |
| Silkworm pupae (Bombyx mori) | Alcalase, Prolyve, Flavourzyme, Brewers Clarex | SWFVTPF, NDVLFF | Antioxidant activity (ROS reduction, superoxide dismutase (SOD) expression and glutathione (GSH) production activity) | [90] |
| Tropical house crickets (Gryllodes sigillatus) | Alcalase-generated protein hydrolysates | YKPRP, PHGAP, VGPPQ | Anti-hypertensive, anti-glycemic, anti-inflammatory activities | [91] |
| Black soldier fly (Hermetia Illucens) | -------------------------- | Hill-Cec1, Hill-Cec10 | Antimicrobial activity against various pathogens | [96] |
| Silkworm pupae (Bombyx mori) | Acidic protease, Neutral protease | FKGPACA, SVLGTGC | Antioxidant activity, ABTS radical scavenging | [97] |
| Crickets (Gryllus bimaculatus) | Alcalase | TEAPLNPK, EVGA, KLL, TGNLPGAAHPLLL, AHLLT, LSPLYE, AGVL, VAAV, VAGL, QLL | Antioxidant activity | [98] |
| White-spotted flower chafer larva (Protaetia brevitarsis) | Flavourzyme | Ser-Tyr, Pro-Phe, Tyr-Pro-Tyr, Trp-Ile | ACE inhibitory activity, NO production in cells | [99] |
| Brown seaweed (Laminaria digitate) | Hydrolysates, fermentation generated peptides or generated from high-pressure processing | YIGNNPAKGGLF, IGNNPAKGGLF, and others (130 in total) | ACE-1 inhibitory activity, Potential DPP-IV inhibition | [100] |
6. Bioactive Peptides from Insect Proteins: Functional Potential and Applications
6.1. Protein Solubility
Zielińska, Karaś, and Baraniak [69] studied the functional properties of proteins isolated from three species of edible insects including the tropical house cricket, desert locust, and mealworm, and evaluated the solubility of the isolated proteins. Their research found that the proteins exhibited their lowest solubility at a pH level of approximately 5 across all three protein samples, while the highest solubility was achieved at around pH 11. A high protein solubility was also shown within the pH range of 2 to 4. Similar results have been reported for larvae of an edible insect, the black soldier fly, in which the lowest solubility was shown at pH values of 4 to 5. However, the solubility increased beyond this range [78]. Mexican fruit fly protein also showed the minimum protein solubility at pH 5 whereas its maximum solubility was at pH 10 [66].
6.2. Edible Insect Proteins as Emulsifiers
Zielińska, Karaś, and Baraniak [69] compared the emulsifying properties of three insect species in which the highest value was noted in the tropical house cricket protein preparation (72.62%) with an emulsion stability of 38.3%. Similarly, Omotoso [103] reported an emulsion activity of 75% for silkworms but with a lower emulsion stability (23%). The emulsion activities for the whole insects in the Zielińska, Baraniak, Karaś, Rybczyńska, and Jakubczyk [58] study were found to have consistent values ranging from 62% to 69.17%. Moreover, pretreatment with pulsed-field electricity (PFE) could improve the emulsifying capacity (EC) of proteins extracted from the house cricket flour. The highest intense PFE increased the emulsifying capacity to 74.7%, while the lowest increase in the EC was 22.1%.
6.3. Foaming Properties of Insect Proteins
Egg-white proteins are the most widely utilized proteins in spray applications. Furthermore, milk proteins such as whey proteins and caseins or soy proteins are also utilized for spray utilization. The characteristics of foam inherent to these proteins have been investigated, especially within the most popular edible insect proteins. These protein sources exhibit potential for integration into food formulations for foaming purposes under specific pH and ionic strength conditions [101]. The foaming activity and stability are different among various insects, even when subjected to a similar processing approach. One of the main factors affecting the foaming properties is the amino acid composition of insect proteins, as shown in Kim, et al. [107]. In that study, the salt-soluble protein fraction of mealworms revealed significantly higher foamability than water-soluble fractions. Having a polar water-soluble group (amphiphilicity) is a critical parameter in foaming properties. No foam activity was observed in the African migratory locust flours at a pH of less than 3, while a significant foam formation of around 200% was shown at pH 5 [108].
6.4. Gelling Properties of Insect Proteins
Limited research has been conducted to identify the gelling characteristics of edible insect proteins. Yi, et al. [109] investigated the gel-forming capacity of three distinct orders of five insect proteins, including mealworm, darkling beetle (Zophobas morio), lesser mealworm, house cricket, and dubia cockroach (Blaptica dubia) (Coleoptera, Orthoptera, and Blattodea). It was concluded that gels from all concentrations might be made from pH 7 or 10 at a protein concentration of 30% (w/v). However, the soluble fraction of the house cricket formed a gel at pH 7 and a concentration of 3% when it was heated at 86 °C. The gelling property of an insect’s protein concentrate is influenced by enzymatic hydrolysis. Dion-Poulin, et al. [110] indicated that enzymatic hydrolysis has a negative impact on gelation in the protein hydrolysates produced from cricket and mealworm proteins.
6.5. Water-Holding Capacity of Insect Proteins
All conditions associated with the protein matrix’s capacity to retain the maximum amount of water per gram of the sample material, even when subjected to the force of gravity, are called the water-holding capacity (WHC). Water-holding capacity (WHC), water-binding capacity (WBC), and water absorption capacity (WAC) are all the same terms used to elucidate how a protein is able to absorb water. Despite potential variations in measurement methodologies, these three terminologies are commonly employed interchangeably. This functional characteristic is indeed related to the gelation and gelling properties of proteins. Furthermore, the water-binding capacity is enhanced through thermal denaturation. This feature is also linked to a better texture and wetness that is of considerable relevance in food formulation. Certain insects like mealworm and African palm weevil (Rhynchophorus phoenicis) have greater WHC values than pulse protein flours and are similar to concentrated soy and milk protein levels. These interesting results show that specific concentrated insect protein or flour may be included as functional agents in food formulation [101].
6.6. Oil Absorption Capacity of Insect Proteins
The capacity of oil absorption (OAC), the capability to bind to oil (OBC), and the capability to maintain oil (OHC) all refer to the number of lipids absorbable by the amount of protein powder indicated. These functional property terms are significantly linked. Hydrophobic proteins and small, low-density proteins exhibit heightened lipid affinity compared to large, high-density, and hydrophilic equivalents. As protein contains different hydrophobic amino acids that have hydrophobic properties, it can interact with oil in foods. In fact, the water and oil absorption capacity depends on the availability of polar and non-polar amino acids. Less availability of polar amino acids correlates with reduced water absorption capability, and vice versa [104]. The oil absorption capacity values for black soldier fly protein obtained by a modified protocol (MP) have been evaluated using a modified protocol (MP) with conditions of 60 min, a 15:1 alkaline-solution-to-sample ratio, and 40 °C. Results showed comparable values with the tropical house cricket (3.22 g/g) and the desert locust (3.22 g/g) protein extracts [78], while that for the optimized protocol (OP) was reported to be around 2.74 g/g for mealworm. These results showed a higher value for OAC compared to the 1.08 g/g reported for the protein extract from the plant seed source [111].
7. Edible Insects and Their Proteins in Meat Analogs and Cereal Products
According to Gravel and Doyen [101], several studies have shown the inclusion of insect proteins and analogs in beef emulsions. De-fatted mealworm flour, or protein hydrolysate, has substituted 10% lean pork in emulsified sausages [112]. The meat also hardened compared to the control sausage, irrespective of the initial preparation. The added protein-rich insect meal resulted in considerable moisture loss in the emulsified sausage, thereby changing the texture. Similar research with the house cricket was carried out by the same authors, and the conclusion was that insect proteins might strengthen emulsified meats.
Moreover, in recent years, there has been growing interest in the incorporation of insect protein into various food products, including pasta, bread, and other pastries. In a study performed by Azzollini, et al. [114], a cereal snack incorporated with 10% and 20% mealworm flour was developed, and a comprehensive evaluation encompassing nutritional, physical, and microstructural aspects was undertaken. The results revealed that the addition of insect flour enhanced protein content and snack digestibility. The 10% mealworm flour cereal snacks displayed similar textural features as their insectless counterparts. However, those with 20% mealworm flour showed poor structural characteristics. The authors emphasized that the important stage during the formulation of protein-rich dietary products is when selecting the processing method, as the texture and nutritional characteristics may differ appropriately.
Pasta preparation from insects also has been another area of food processing and development. Duda, et al. [117] tested the use of 5% cricket powder in wheat pasta. The authors investigated the effects of insect proteins on cooking time, color, texture, and flavor, with the latter being the most distinguishing feature. In general, the sensory assessments revealed that fortified wheat pasta meets consumer needs, showing no significant differences from other wheat pasta.
8. Challenges, Food Safety, and Considerations in Utilizing Edible Insects and Their Proteins as Food Ingredients
Although the consumption of insects, insect flours, and their protein isolates and concentrates is increasing worldwide, there are still some issues and challenges that need to be considered and addressed by researchers, producers, manufacturers, and companies. Among the paramount challenges associated with insect entomophagy and the integration of insect-based flour or protein into various products, several pivotal concerns demand consideration, including consumer acceptance, processing methods, environmental impact, economic considerations, the imperative for regulatory frameworks and legislation, and the assurance of food safety to both insects and their derivative products. The detailed considerations delineated are succinctly encapsulated in Figure 2.
Figure 2. The main challenges of utilizing edible insects and their proteins as food ingredients.
9. Halal and Kosher Considerations for Insect-Based Food Products
For most Muslims, their food acceptability on a global scale is firmly dependent on religious rules, which are monitored and verified by the Halal certification bodies, especially for the food produced by companies. Based on the International Market Analysis Research and Consulting (IMARC) Group report entitled “Halal Food Market: Global Industry Trends, Share, Size, Growth, Opportunity, and Forecast 2018–2023”, the global halal food market reached a value of US$1.4 trillion in 2017. The report projected the market value to reach US$2.6 trillion by 2023, exhibiting a compound annual growth rate (CAGR) of more than 11 percent during the period between 2018 and 2023. With the growing number of Muslims worldwide and the continued agitation for healthier and trusted food products, the halal food market has emerged as one of the most profitable and influential markets in the contemporary business world [135].
However, the Islamic Canon law shows different and mostly opposing views regarding insects and their products, which mainly depend on the various Islamic branches and opinions. An example is Carmine (E-120), an insect extract that is used as a food dye in the food industry. However, Islamic scholars have different opposing views about its usage in food products. Therefore, these opposing views have significantly affected Islamic scholars, followed by the certification bodies.
Although there is ambiguity and obscurity among the Islamic scholars and branches, the Halal logo is not only a religious indication or symbol for only a specific population now. It has become a symbol of clean, hygienic, and reliable food products, acknowledged by a majority of Muslims and some non-Muslims. [135]. Therefore, it would be a contradiction when ignoring the various benefits of insect-based products, including protein, protein hydrolysates, or bioactive peptides.
In conclusion, although insects and insect-based products are not absolutely allowed or prohibited in Islam for consumption, forbidding the consumption of all insects as Haram is also a simplification and generalization of the opinion. This is evident in the consensus of the four Sunni schools and most Shia Scholars that locusts and food worms that grow out of it are halal. However, there has yet to be a consensus among them on other edible insects. Based on the juristic analysis, the opinion that allows insect consumption under some conditions is considered more evident and preponderant. However, an essential precondition before certifying an insect-based food product as halal is an evaluation that encompasses a risk analysis as well as the nutritional quality of each insect that is being marketed. It is then left to the consumer to choose such food items as a matter of individual acceptability, but such food items should not be denied halal certification [135].
This entry is adapted from the peer-reviewed paper 10.3390/foods12234243
This entry is offline, you can click here to edit this entry!
