For several years, crickets have been proposed as a new source of nutrients in the human diet since they possess bioactive molecules, including a high content of proteins, lipids, chitin, vitamins and minerals.
In a new Italian study, published in ‘Antioxidants’,The nutritional and functional properties of a new spray-dried (SD) cricket powder were evaluated. The powder is characterized by physicochemical properties (morphology, size distribution, solid state, thermal profiles and surface zeta potential) and antioxidant properties. Moreover, preclinical properties (cytocompatibility and pro-inflammatory immune response) were evaluated.
The obtained data lead the authors to suggest that SD crickets represent an interesting medical food material with anticipated future applications in tissue engineering due to their “remarkable antioxidant and anti-inflammatory activity”.
Dimensional analysis suggests a narrow size distribution with a mean diameter of 22 µm that should improve flavor. Characterization of the solid state highlights the presence of lipids, proteins and chitin. The amount of chitin was also evaluated, since it is a bioactive polysaccharide with antioxidant and antimicrobial activity. The powder was found to have an average chitin content of 32.80 ± 7.32 g/kg which researchers say could contribute to protection against inflammatory and neurodegenerative diseases. An in vitro protein digestibility study revealed that SD cricket powder is characterized by a k-PDCAAS value of 1, which means that it is a protein source that could provide all the amino acids needed by humans for optimal nutrition. This could be related to the fine particle size that favors bioavailability. Moreover, antioxidant tests revealed an increase in both radical scavenging activity and iron ion chelating (binding) activity, suggesting that the powder possesses antioxidant activity.“This aspect could prove to be of great interest to the medical field, since free radicals generated by altered metabolic processes can cause significant injury and lead to numerous diseases including cancer, inflammation and neurological conditions.” the review states. Moreover, SD crickets show no toxic effect on cell viability towards Caco-2 cells and monocyte-derived macrophages.“In conclusion, research on SD crickets highlights their potential nutritional value as they can be considered equivalent to dairy proteins, eggs and cow’s milk, all highly nutritious foods. Moreover, the antioxidant properties, biocompatibility, thermal stability and anti-inflammatory properties support the potential use of SD crickets in to the food industry by providing health benefits in addition to their basic nutritional value.“These results were confirmed using different batches, showing a low variability in the properties of SD crickets from one batch to another. The consistency of the batches and their properties prove that SD crickets represent an interesting material and that one could imagine future applications, such as their use in tissue engineering due to their outstanding antioxidant and anti-inflammatory activity.”
New food status
In Europe, the marketing of insects as food is regulated by “novel food” legislation—Regulation (EU) no. 2015/2283, which applies to all categories of food that “were not used for human consumption to a significant extent” within the European Union before May 15, 1997, which is the case with insects. Currently (Q3 2022), four new food approvals for edible insects have entered into force, and EFSA (European Food Safety Authority) has published its sixth opinion on edible insects, emphasizing that food safety and quality are strictly related to species and production process
Crickets are highly nutritious and rich in high-quality protein, providing an excellent source of the recommended essential amino acids, with the possible exception of methionine/cysteine. They are also a good source of riboflavin, folic acid, vitamin B12, tocopherol and several minerals.
Moreover, insects have been shown to be beneficial for human health due to the presence of bioactive molecules that act as anti-inflammatory, cardioprotective, antimicrobial, antimycotic and antioxidant. In particular, chitin, a bioactive polysaccharide from the exoskeleton of insects, is characterized by remarkable antioxidant and antimicrobial activities. They could offer a wide range of applications in many sectors, helping to protect the population from diseases such as cancer, neurodegenerative and inflammatory diseases.
Nutritional benefits of spray-dried powder
A more common production method involves grinding whole crickets into a paste, followed by drying in an oven to produce a “cricket cake”, and finally undergoing particle size reduction in an industrial food processor to produce flour. The main problem with the final product obtained by this method is that the particle size often exceeds 300 µm, because the exoskeleton of the cricket made of chitin is resistant to grinding and remains largely intact.
This is not a problem in products where these particle sizes are acceptable, such as bars or some baked goods. However, this could greatly reduce sensory acceptance in other products (such as beverages or puddings), as particles larger than 100 µm could be unpleasant to the human tongue and oral palate.
To overcome this problem, other processes have been established to produce a finer cricket powder by wet mixing the cricket mass and then spray drying it. This process results in a spray-dried (SD) cricket powder that differs in color, flavor and textural properties from “cricket cake”. In fact, spray drying is a simple, easily scalable and versatile technique that allows obtaining microparticles with a size distribution from a few μm to several hundred μm, resulting in a more pleasant product for the human palate. What’s more, the process can be completed in shorter periods of time, keeping the flavor intact.
For the current study, SD crickets were donated by Alia Insect Farm. The insects are pasteurized and then crushed and ground to obtain a homogeneous mixture. This was spray dried at 200 °C (inlet temperature), yielding a fine powder with residual moisture below 5%. Ten batches were prepared and samples of 50 g each were studied.
“Nutritional and functional properties of a new Italian spray-dried cricket powder”
Ruggeri, M.; Bianchi, E.; Vigani, B.; Sánchez-Espejo, R.; Spano, M.; Totaro Fila, C.; Mannina, L.; Viseras, C.; Rossi, S.; Sandra, G.