Improved Insect Protein Production with Ultrasonics
Insects are a sustainable, easy-to-grow source for high-quality nutritional proteins and lipids. In order to separate proteins and lipids from the insects, ultrasonic extraction is used as highly efficient and reliable technology. Ultrasonication has been proven for high extraction rates, high protein and lipid yields, and rapid processing of prime quality insect ingredients.
Why Extract Insect Proteins with Power Ultrasound?
Insect protein extract is typically considered to be of higher quality than insect meal because it contains a higher percentage of protein and a lower percentage of other unwanted materials such as chitin and fats.
Insect meal is typically made by grinding whole insects into a powder, which can contain a significant amount of indigestible materials such as chitin, exoskeletons, and other non-nutritive components. In contrast, insect protein extract is typically made by extracting the protein from the insects, which results in a purer and more concentrated protein product. Ultrasonic extraction has been proven to be a highly efficacious production technique for high-quality insect protein.
The higher protein concentration in insect protein extract means that it can provide more protein per gram than insect meal, making it a more efficient protein source. In addition, the removal of non-nutritive components can make insect protein extract more easily digestible and may reduce the risk of digestive issues in animals and humans that consume it.
Furthermore, insect protein extract may have a milder flavor and odor compared to insect meal, making it more appealing to consumers. It also has a more versatile application, as it can be used as an ingredient in a wide range of food and feed products.
Ultrasonic Extraction of Insect Proteins
Ultrasonic extraction can be easily implemented into the regular insect meal processing and allows to upgrade to final product. Ultrasonically extracted insect protein is of superior quality than insect meal offering higher nutritional values, improved flavour and better functionalities.
General Protocol for Insect Protein Extraction using an Probe-Type Ultrasonicator
general protocol for extracting food-grade proteins from soldier fly larvae using an ultrasonic probe:
Materials and Equipment:
- Soldier fly larvae or other insect species such as mealworm larvae (Tenebrio molitor), cricket adults (Gryllus bimaculatus), and silkworm pupae (Bombyx mori) – previously cultured and harvested
- Probe-type ultrasonicator
- Blender or food processor
- Distilled water containing 9.46 mM ascorbic acid or other solvent of choice
- Glass or plastic containers
- Filter paper or mesh filters
Step-by-Step-Instruction for Insect Protein Extraction
Preparation of Insect Larvae:
- Harvest the soldier fly larvae from the rearing system.
- Wash the larvae thoroughly with distilled water to remove any debris or impurities.
- Freeze the larvae at -20°C or lower to deactivate enzymes and preserve protein quality.
- Thaw the frozen larvae and transfer them into a blender or food processor.
- Add a suitable volume of distilled water or buffer solution to achieve a desired protein concentration (e.g., 10% w/v).
- Blend or process the larvae until a homogenous slurry is obtained.
- Transfer the slurry to a glass or plastic container.
- Defatting of the insect meal is an optional step that helps to increase protein yield and quality. The fat content of the insect meal is reduced via hexane treatment. Overall, for most insect protein extracts for human consumption, defatting is recommended in order to enhance the protein quality. The conventional hexane defatting process is time-consuming. Ultrasonication can accelerate the defatting of insect meal significantly!
- Immerse the probe of the ultrasonicator, e.g., UIP2000hdT, into the larval slurry.
- Set the ultrasonicator parameters, e.g., 100% amplitude and sonication time in accordance with the volume and slurry.
- Apply ultrasonic waves to the larval slurry while maintaining a constant temperature to avoid denaturation of proteins.
- The ultrasonication process helps in disrupting the cells and releasing the proteins from the larvae.
- Monitor the temperature during sonication. Hielscher ultrasonicators are equipped with a temperature sensor and temperature control.
- After ultrasonication, transfer the sonicated larval slurry to centrifuge tubes.
- Centrifuge the tubes at a suitable speed and duration to separate the protein-containing supernatant from solid debris and unbroken cells.
- Collect the supernatant, which contains the extracted proteins, and transfer it to a clean container.
- Optionally, repeat the centrifugation step if necessary to remove any remaining solid particles. Alternatively, filtration can be used as a protein separation technique.
Protein Analysis and Storage:
- Perform protein analysis to assess the quality and composition of the extracted proteins.
- Store the extracted proteins in suitable containers at a cool, dry, and dark place.
Insects as food source: Insects such as crickets, worms, flies and larvae are rich in proteins. In order to fulfil the growing demand for high-quality proteins, insects have got valued as a healthy, sustainable, and environmental-friendly protein source, which is used for human food, pet food and livestock feed. Insects are ectothermic (which means they are cold-blooded and do not waste energy to produce heat to increase their body temperature), they do not require a lot of space, and they can be fed using waste as growth substrate. This makes insect proteins and lipids a promising food source, which can help to fill the “protein gap”, which has to be overcome to feed a rising world population and its demand for high-quality nutrients, especially protein.
Insect Farming: Insects are bred on insect farms, where they are grown in containers or reactors. With the advantage of being fast growing organisms, they require relatively low care, can be fed with organic waste, and are quickly cultivated to harvest size or ripeness. Especially fly larvae, mealworms and crickets are easy to breed. Regarding efficiency, the larvae of the black soldier fly is recognized for its excellent transformation of organic waste into high-quality protein. this is why the black soldier fly is also known as “queen of waste transformation” under insect farmers.
Processing Steps of Insect Meal: When the insects have reached their targeted size or stadium, they are harvested. This means they are ready to be processed into food ingredients. Before processing, the insects are washed in water, sieved and stored alive at 4℃ for about one day without any feed.
Afterwards, the insects are cooked, and then dried by very hot air or by heating them in a container. Heat treatment is also required to kill bacteria. Finally, the insects are milled into a dry insect meal (also known as insect flour). The insect meal can be used as a food ingredient or additive in animal feed. But in order to refine and upgrade the insect meal, the most valuable ingredients, i.e. proteins and lipids, are extracted. Especially pure insect protein is valued as highly nutritional ingredient, which is used in protein bars, protein powders and as additive into many food products such as baked goods, chips, crackers etc.
Use ultrasonic probe-type extractors to produce high-quality insect protein!
Ultrasonic Extraction of High-Quality Proteins from Insects:
Ultrasonic extraction is used to produce protein powders, hydrolysates, and protein isolates from many insect forms, including flies, worms, bugs, crickets, and larvae. By extracting high-quality proteins from insect meal, ultrasonication produces functional food ingredients with superior nutritional profile.
Advantages of Ultrasonic Protein Extraction from Insects
Ultrasonication is widely applied to extract and treat proteins from various sources such as botanicals (e.g., from soy, rice, rapeseed, sunflower, pumpkin seeds etc.), dairy (e.g., whey protein concentrate (WPC), whey protein, milk protein retentates, calcium caseinate), algae (e.g., seaweed), seafood (e.g., fish by-products and seafood waste), and insects (e.g. worms, larvae, flies, maggots, beetles, crickets, cockroaches etc.).
As a highly efficient, and green extraction technology, ultrasonic extraction of insect protein has been found its place in the production of insect protein powders, hydrolysates and isolates. Due to high process reliability, repeatability and linear up-scaling, ultrasonication is used to extract protein from insects, to modify protein structures and to improve physicochemical properties of protein.
For instance, Mintha et al. (2020) applied ultrasonic extraction to black soldier fly larvae (H. illucens). They report that sonication improved protein structure, altered protein functionality, and as thereby beneficial for the production of H. illucens protein / hydrolysates. Especially, zeta potential, dispersibility, and thiol values were increased by ultrasonication. Furthermore, turbidity and particle size of protein decreased after sonication. Ultrasonication significantly increased lightness (L*) of protein isolates by x ¯ 7.46% compared to the non-sonicated control.
High-Performance Ultrasonicators for Insect Protein Processing
Ultrasonic extraction and homogenisation is a reliable processing technology, which facilitates and accelerates the production of high-quality insect proteins. Hielscher Ultrasonics portfolio covers the full range from compact lab ultrasonicators to industrial extraction systems. Thereby, we at Hielscher can offer you the most suitable ultrasonicator for your envisaged process capacity. Our long-time experienced staff will assist you from feasibility tests and process optimisation to the installation of your ultrasonic system on final production level.
The small foot-print of our ultrasonic extractors as well as their versatility in installation options make them fit even into small-space insect protein processing facilities. Ultrasonic processors are installed worldwide in food and nutritional supplement production facilities as well as for the production of pet and livestock feed. Furthermore, ultrasonic high shear mixers are ideal to formulate insect proteins into human food products as well as into pet food for accompanying animals and livestock feed for farm animals.
Hielscher Ultrasonics – Sophisticated Extraction Equipment
Hielscher Ultrasonics product portfolio covers the full range of high-performance ultrasonic extractors from small to large scale. Additional accessories allow for the easy assembly of the most suitable ultrasonic device configuration for your insect protein process. The optimal ultrasonic setup depends on the envisaged capacity, volume, raw material, batch or inline process and timeline.
Ultrasonic Insect Extraction – Batch and Inline Processing
Hielscher ultrasonicators can be used for batch and continuous flow-through processing. Ultrasonic batch processing is ideal for process testing, optimisation and small to mid-size production level. For a producing large volumes of insect proteins, inline processing might be more advantageous. Whilst batching requires only a very simple setup, it is more time- and labour-intensive. A continuous inline mixing process requires sophisticated setup – consisting in a pump, hoses or pipes and tanks -, but it is more efficient, faster and requires significantly less labour. Hielscher Ultrasonics has the most suitable extraction setup for your extraction volume and process goals.
Ultrasonic Extractors for Every Product Capacity
Hielscher Ultrasonics product range covers the full spectrum of ultrasonic processors from compact lab ultrasonicators over bench-top and pilot systems to fully-industrial ultrasonic processors with the capacity to process truckloads per hour. The full product range allows us to offer you the most suitable ultrasonic extractor for your raw material, process capacity and production targets.
Ultrasonic benchtop systems are ideal for feasibility tests and process optimization. Linear scale-up based on established process parameters makes it very easy to increase the processing capacities from smaller lots to fully commercial production. Up-scaling can be done by either installing a more powerful ultrasonic extractor unit or clustering several ultrasonicators in parallel. With the UIP16000, Hielscher offers the most powerful ultrasonic extractor worldwide.
Precisely Controllable Amplitudes for Optimum Results
All Hielscher ultrasonicators are precisely controllable and thereby reliable work horses in production. The amplitude is one of the crucial process parameters that influence the efficiency and effectiveness of ultrasonic extraction of nutrients from insects.
Insect material such as larvae and flies require milder sonication and lower amplitude settings, whilst crickets and insects with a thick exoskeleton shell require sonication at higher amplitudes to release the targeted nutrients. All Hielscher Ultrasonics processors allow for the precise setting of the amplitude. Sonotrodes and booster horns are accessories that allow to modify the amplitude in an even wider range. Hielscher industrial ultrasonic processors can deliver very high amplitudes and deliver the required ultrasonic intensity for demanding applications. Amplitudes of up to 200µm can be easily continuously run in 24/7 operation.
Precise amplitude settings and the permanent monitoring of the ultrasonic process parameters via smart software give you the possibility to treat your seeds with the most effective ultrasonic conditions. Optimal sonication for best extraction results!
The robustness of Hielscher ultrasonic equipment allows for 24/7 operation at heavy duty and in demanding environments. This makes Hielscher ultrasonic equipment a reliable work tool that fulfils your extraction requirements.
Easy, Risk-free Process Testing
Ultrasonic processes can be completely linear scaled. This means every result that you have achieved using a lab or bench-top ultrasonicator, can be scaled to exactly the same output using the exactly same process parameters. This makes ultrasonication ideal for risk-free feasibility testing, process optimization and subsequent implementation into commercial manufacturing. Contact us to learn how sonication can increase your insect protein production!
Highest Quality – Designed and Manufactured in Germany
As a family-owned and family-run business, Hielscher prioritizes highest quality standards for its ultrasonic processors. All ultrasonicators are designed, manufactured and thoroughly tested in our headquarter in Teltow near Berlin, Germany. Robustness and reliability of Hielscher ultrasonic equipment make it a work horse in your production. 24/7 operation under full load and in demanding environments is a natural characteristic of Hielscher high-performance mixers.
The table below gives you an indication of the approximate processing capacity of our ultrasonicators:
|Batch Volume||Flow Rate||Recommended Devices|
|1 to 500 mL||10 to 200 mL/min||UP100H|
|10 to 2000 mL||20 to 400 mL/min||UP200Ht, UP400St|
|0.1 to 20 L||0.2 to 4 L/min||UIP2000hdT|
|10 to 100 L||2 to 10 L/min||UIP4000hdT|
|15 to 150 L||3 to 15 L/min||UIP6000hdT|
|n.a.||10 to 100 L/min||UIP16000|
|n.a.||larger||cluster of UIP16000|
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Facts Worth Knowing
The use of insect as nutritional compound to feed humans and animal is termed “entomophagy”. The Oxford Online Dictionary defines the term “entomophagy” as “the practice of eating insects, especially by people.” Since insects are a sustainable source rich in high-quality proteins and lipids, insects such as crickets, flies, larvae, worms, maggots, beetles and cockroaches are grown and processed for the production of proteins and fatty acids for human and animal nutrition.
Insects as Nutritional Protein Source
Insects are known as a source for high quality protein, containing many essential amino acids. Therefore, numerous crickets, grasshoppers, beetles, moths, worms, flies and various other insects are bred to produce proteins for human and animal consumption. Besides being rich in proteins, insects are also a significant source of fatty acids, minerals (e.g., iron, zinc, potassium, selenium, and copper) and vitamins (mostly B vitamins). For instance, insects such as crickets and mealworms have high concentrations of complete protein, vitamin B12, riboflavin and vitamin A.
In contrast to animal derived products, insects contain also dietary fibre. Insect fibre is mainly found in form of chitin, an essential building block of the exoskeleton.
Commonly bred insects for protein production are the following species:
- The mealworm (Tenebrio Molitor L.) is the larvae form of a species of darkling beetles (Coleoptera). The optimum incubation temperature is 25 ̊C – 27 ̊C and its embryonic development lasts 4 – 6 days. It has a long larvae period of about half a year with the optimum temperature and low moisture terminates. The protein content of Tenebrio Molitor larvae and adult are 46.44% and 63.34%, respectively.
- The house cricket (Acheta domesticus) is the most common cricket type used for human consumption. The cricket is well-known to be one of the most nutritious edible insects. Crickets can be consumed dry-roasted, baked, deep-fried, boiled or used as food ingredient. To integrate crickets into functional foods, food formulations or recipes, cricket meal or flour is used. Cricket meal is a powder of dried and fine ground crickets. Crickets mature quickly and are typically full-grown within 3 -4 weeks. An individual female can lay from 1,200 to 1,500 eggs in 3-4 weeks. Due to the quick and simple growing, crickets are farmed for human nutrition as well as for animal food. Crickets are normally killed by deep freezing, where they feel no pain and are sedated before neurological death.
- The black soldier fly (Hermetia illucens) is a common and widespread fly of the family Stratiomyidae. Black soldier flies are widely farmed due to their exceptional high protein content and the low requirements during breeding and growing stages. They requiresvery few resources, which makes it possible to effectively treat bio-waste. Black soldier fly larvae (BSFL) contain up to 43% of protein, 35% fatty acids, and are rich in calcium and other micro-nutrients. Since the larvae have the highest protein content, black soldier flies are bred only for approx. 18 days until they have reached the larvae stadium and are then harvested. The complete life cycle of the black soldier fly is only 6 weeks short.
Black soldier fly (Hermetia illucens) larvae have been also successfully used as source to extract lipids, which were subsequently nano-emulsified by ultrasonication.
Literature / References
- Benjamin Kumah Mintah; Ronghai He; Mokhtar Dabbour; Jiahui Xiang; Jiang Hui; Akwasi Akomeah Agyekum; Haile Mai (2020): Characterization of edible soldier fly protein and hydrolysate altered by multiple-frequency ultrasound: Structural, physical, and functional attributes. Process Biochemistry, Volume 95, August 2020. 157-165.
- Benjamin Kumah Mintah; Ronghai He; Mokhtar Dabbour; Jiahui Xiang; Akwasi Akomeah Agyekum; Haile Mai (2019): Techno-functional attribute and antioxidative capacity of edible insect protein preparations and hydrolysates thereof: Effect of multiple mode sonochemical action. Ultrasonics Sonochemistry, Volume 58, November 2019.
- Young Deug Choi; Nathan A.K. Wong; Joong-Hyuck Auh (2017): Defatting and Sonication Enhances Protein Extraction from Edible Insects. Korean Journal of Food Science and Animal Resource. 37(6), 2017. 955-961.
- Carlos Álvarez; Brijesh K. Tiwari (2015): Ultrasound Assisted Extraction of Proteins From Fish Processing By-Products. IFT Conference Chicago 2015.
- Benjamin Kumah Mintah; Ronghai He; Mokhtar Dabbour; Akwasi Akomeah Agyekum;
Zheng Xing; Moses Kwaku Golly; Haile Ma (2019): Sonochemical action and reaction of edible insect protein: Influence on enzymolysis reaction‐kinetics, free‐Gibbs, structure, and antioxidant capacity. Journal of Food Biochmistry 2019.