Changes in Functionality of Tenebrio molitor Larvae Fermented by Cordyceps militaris Mycelia

Jaiswal D.K., Krishna R., Chouhan G.K., de Araujo Pereira A.P., Ade A.B., Prakash S., Verma S.K., Prasad R., Yadav J., Verma J.P.

Minerals are the key factor determining human beings’ optimum growth and development. The deficiencies of minerals and vitamins hinder the human normal growth and development and economic status. In the 21st century, macro and micronutrient deficiencies are significant challenges to improving the nutritional value of foods at the socio-economic level. Bio-fortification is a simple strategy to improve the nutritional value of the human diet. Several bio-fortification strategies, including traditional breeding, transgenic, agronomic, and modernized agriculture practices, were employed to biofortify crops to meet nutritional needs. However, these strategies are also lacking sustainability due to the specific crop species and micronutrients, provision of long-term monitoring and assistance, long term high cost of special chemical fertilizers, losses of crop yield due to chemical fertilizers-induced alterations of plant metabolism, environmental and health impact originating from incorporation new minerals elements like Se and Cu. Therefore, microbial bio-fortification can promote human health and agriculture sustainability. This review highlights; the phyto-availability of micronutrients (Fe, Zn, Mg, Ca, Se, I, & Cu) for human diets; availability of micronutrients value in a stable in the edible part of plants; plant uptakes of micronutrients from the soil system; & strategies of crops fortification and its importance. At present, microbial bio-fortification should be emphasized by exploring the macro and micronutrients regulatory mechanisms through plant-microbe interaction with specific soil systems and climate change.

Wunjuntuk K., Ahmad M., Techakriengkrai T., Chunhom R., Jaraspermsuk E., Chaisri A., Kiwwongngam R., Wuttimongkolkul S., Charoenkiatkul S.

• Tested mushrooms were high in protein and dietary fibre and low in fat content. • Astraeus odoratus contained higher total dietary fibre and soluble fibre than others. • Schizophyllum commune showed high beta-glucan anti-alpha-amylase activity. • Lentinus edodes showed the most potent inhibition of alpha-glucosidase and lipase. This study aimed to determine the proximate composition, dietary fibre content, beta-glucan content, and inhibitory activities of starch- and lipid-digesting enzymes for cultivated local and wild mushrooms in Thailand. The protein, fat, and carbohydrate content of the mushrooms ranged from 13.1‒32.8, 0.410‒6.38 and 2.79–44.3 % dry weight (DW). The total dietary fibre, soluble fibre and beta-glucan content of Astraeus odoratus were highest among the wild mushrooms with 77.1, 72.3, and 24.9 g/100 g DW, whilst Schizophyllum commune had the highest value among the cultivated mushrooms with 68.2, 66.6 and 43.0 g/100 g DW, respectively. Among the cultivated mushrooms, the hexane extract of Schizophyllum commune showed the highest anti-alpha-amylase activity (IC 50 = 15.3 mg/mL). Lentinus edodes showed the highest anti-alpha-glucosidase activity (IC 50 = 12.9 mg/mL) in hexane extract and the highest anti-lipase activity (IC 50 = 8.85 mg/mL) in 80 % ethanol (v/v) extract. Among the wild mushrooms, the hexane extract of Phaeogyroporus portentosus showed the highest anti-alpha-amylase (IC 50 = 15.7 mg/mL) and anti-lipase activity (IC 50 = 33.6 mg/mL), while the 80 % ethanol (v/v) extract of Craterellus aureus showed the highest anti-alpha-glucosidase activity (IC 50 = 25.9 mg/mL). The present study results help recommend mushrooms rich in protein, dietary fibre, beta-glucan, and inhibitory enzyme activities associated with diabetes and obesity.

Czarnowska-Kujawska M., Paszczyk B.

The application of bacterial cultures in food fermentation is a novel strategy to increase the “natural” levels of bioactive compounds. The unique ability of lactic acid bacteria (LAB) to produce folate, B vitamins, and conjugated linolenic acid cis9trans11 C18:2 (CLA) during cold storage up to 21 days was studied. Although some species of LAB can produce folates and other important nutrients, little is known about the production ability of yogurt starter cultures. Pasteurized milk samples were inoculated with four different combinations of commercially available yogurt vaccines, including starter cultures of Bifidobacterium bifidum. Both the type of vaccine and the time of storage at 8 °C had a significant effect on the folate and CLA contents in the tested fermented milks. The highest folate content (105.4 µg/kg) was found in fresh fermented milk inoculated with Lactobacillus delbrueckii, Streptococcus thermophilus, and Bifidobacterium bifidum. Only the mix of Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, and Bifidobacterium bifidum showed potential (59% increase) to synthesize folate during seven days of storage. A significant increase in the content of CLA, when compared to fresh fermented milk, was observed during cold storage for up to 21 days in products enriched with Bifidobacterium bifidum.

Samtiya M., Aluko R.E., Puniya A.K., Dhewa T.

Plant-based foods are rich sources of vitamins and essential micronutrients. For the proper functioning of the human body and their crucial role, trace minerals (iron, zinc, magnesium, manganese, etc.) are required in appropriate amounts. Cereals and pulses are the chief sources of these trace minerals. Despite these minerals, adequate consumption of plant foods cannot fulfill the human body’s total nutrient requirement. Plant foods also contain ample amounts of anti-nutritional factors such as phytate, tannins, phenols, oxalates, etc. These factors can compromise the bioavailability of several essential micronutrients in plant foods. However, literature reports show that fermentation and related processing methods can improve nutrient and mineral bioavailability of plant foods. In this review, studies related to fermentation methods that can be used to improve micronutrient bioavailability in plant foods are discussed.

Hong J., Han T., Kim Y.Y.

Edible insects have been used as an alternative protein source for food and animal feed, and the market size for edible insects has increased. Tenebrio molitor larvae, also known as mealworm and yellow mealworm, are considered a good protein source with nutritional value, digestibility, flavor, and a functional ability. Additionally, they are easy to breed and feed for having a stable protein content, regardless of their diets. Therefore, T. molitor larvae have been produced industrially as feed for pets, zoo animals, and even for production animals. To maintain the nutrient composition and safety of T. molitor larvae, slaughtering (heating or freezing) and post-slaughtering (drying and grinding) procedures should be improved for animal feed. T. molitor larvae are also processed with defatting or hydrolysis before grinding. They have a high quality and quantity of protein and amino acid profile, so are considered a highly sustainable protein source for replacing soybean meal or fishmeal. T. molitor has a chitin in its cuticle, which is an indigestible fiber with positive effects on the immune system. In studies of poultry, the supplementation of T. molitor larvae improved the growth performance of broiler chickens, without having negative effects on carcass traits, whereas some studies have reported that there were no significant differences in the growth performance and carcass yield of broiler chickens. In studies of swine, the supplementation of T. molitor larvae improved the growth performance and protein utilization of weaning pigs. Furthermore, 10% of T. molitor larvae showed greater amino acid digestibility than conventional animal proteins in growing pigs. However, there are some challenges regarding the biosafety, consumer’s acceptance, and price for the use of T. moiltor larvae in animal feed. Consequently, T. molitor larvae could be used as an alternative or sustainable protein source in monogastric animal feed with a consideration of the nutritional values, biosafety, consumer’s acceptance, and market price of T. molitor larvae products.

Borremans A., Bußler S., Sagu S.T., Rawel H., Schlüter O.K., Leen V.C.

The aim of this study was to determine the effect of blanching followed by fermentation of mealworms (Tenebrio molitor) with commercial meat starter cultures on the functional properties of powders produced from the larvae. Full fat and defatted powder samples were prepared from non-fermented and fermented mealworm pastes. Then the crude protein, crude fat, and dry matter contents, pH, bulk density, colour, water and oil binding capacity, foaming capacity and stability, emulsion capacity and stability, protein solubility, quantity of free amino groups, and protein composition of the powders were evaluated. Regardless of the starter culture used, the blanching plus fermentation process reduced the crude and soluble protein contents of the full fat powders and in general impaired their water and oil binding, foaming, and emulsifying properties. Defatting of the powders improved most functional properties studied. The o-phthaldialdehyde assay revealed that the amount of free amino groups was higher in the fermented powders while sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that the soluble proteins of the fermented powders were composed of molecules of lower molecular mass compared to non-fermented powders. As molecular sizes of the soluble proteins decreased, it was clear that the protein structure was also modified by the fermentation process, which in turn led to changes in functional properties. In general, it was concluded that fermentation of mealworms with blanching as a pre-treatment does not contribute to the functional properties studied in this work. Nevertheless, the results confirmed that the properties of non-fermented powders are comparable to other food protein sources.

Hwang J., Choe J.Y.

Although edible insects are getting attention all over the world, consumers are still reluctant to visit edible insect restaurants. Thus, the objective of this research is to explore what risks customers perceive in edible insect restaurants and how those risks affect the image of edible insect restaurants. More specifically, First, the results of principal components analysis showed that 21 perceived risk items were divided into seven factors: quality, psychological, health, financial, environmental, time-loss, and social risks. Second, five sub-dimensions of perceived risk had a negative effect on image, with the exception of financial and environmental risks. Lastly, image was found to increase intention to use, word-of-mouth intention, and willingness to pay more.

Wei C., Yao X., Jiang Z., Wang Y., Zhang D., Chen X., Fan X., Xie C., Cheng J., Fu J., Leung E.L.

Lung cancer is the most commonly diagnosed cancer worldwide and it is also the most leading cause of cancer-related deaths. Although multiple generations of targeted therapeutic drugs such as gefitinib and afatinib specifically targeting the epidermal growth factor receptor (EGFR) pathway are currently available for lung cancer treatment, none of them can escape their eventual drug-resistance. As a key component of Cordyceps Sinensis and widely used in traditional Chinese medicines (TCM), cordycepin (CD) has attracted increasing attention to both scientists and clinicians. We aimed to explore the potential in developing cordycepin (CD) as an anti-lung cancer drug. A systematic analysis was conducted on a panel of non-small cell lung cancer (NSCLC) cell lines to identify the cells sensitive to CD. We found that CD can affect different aspects of lung cancer development including proliferation, migration, invasion, cell cycle, and apoptosis. We then explored the underlying molecular mechanisms of CD-mediated NSCLC cell apoptosis by conducting a series of in vitro and in vivo experiments. We found that in addition to affecting different stages of NSCLC development including tumor growth, migration, and invasion, the CD is capable of inhibiting NSCLC cell cycle progression and inducing cancer cell apoptosis without apparent adverse effect on normal lung cells. Furthermore, we found that the cells containing EGFR mutations are more sensitive to CD treatment than those without. Mechanistically, CD induces NSCLC cell apoptosis by interacting with and activating AMP-activated protein kinase (AMPK). More importantly, we found that the potency of CD's anticancer effect both in vitro and in vivo is comparable to afatinib and even better than gefitinib. Our findings suggest that CD either by itself or in combination with the currently available targeted therapeutic drugs might be additional therapeutic options for drug-resistance NSCLC treatment.

Park S.J., Jang H., Hwang I., Kim J.M., Jo E., Lee M., Jang I., Joo J.C.

The ubiquitous transcription factor, NF-κB, has been reported to inhibit apoptosis and induce drug resistance in cancer cells. Cordyceps militaris extract (CME) is involved in the regulation of the NF-κB signaling pathway. However, the detailed role of CME in the suppression of the NF-κB signaling pathway is unclear. We found that CME dose-dependently inhibited tumor necrosis factor-α (TNF-α)-induced NF-κB activation in TK-10 human renal cell carcinoma. CME prevented NF-κB from translocating to the nucleus, which resulted in the downregulation of GADD45B, upregulation of MKK7, and phosphorylation of JNK (p-JNK). The increased activation of Bax led to pronounced CME-induced apoptosis, which occurred through caspase-3. Furthermore, the siRNA-mediated knockdown of GADD45B inhibited MKK7 expression, whereas the siRNA-mediated inhibition of MKK7 downregulated p-JNK and the JNK inhibitor, SP600125, inhibited Bax expression. Thus, these results indicated that CME inhibited the activation of GADD45B via the inhibition of NF-κB activation, which upregulated the MKK7-JNK signaling pathway to induce apoptosis in TK-10 cells. Thus, this study reveals a novel anticancer function of CME.

Purschke B., Brüggen H., Scheibelberger R., Jäger H.

Edible insects have emerged as an alternative source for feed and food. Fractionation is considered as a promising strategy to produce standardised insect-based intermediates to augment industrial applicability and consumer acceptance. So far, mainly wet fractionation techniques were studied to separate insect components and concentrate protein. This study investigated a dry fractionation approach to yield protein-enriched and differently composed fractions of mealworm larvae (Tenebrio molitor). The influence of post-harvest procedures including different pre-treatments (blanching, freezing, etc.), drying methods (oven drying, fluidized bed drying, freeze-drying, etc.), and defatting on physico-chemical properties of the larvae were studied. Furthermore, the impact of pre-processing on disintegration of larvae during roller milling was investigated via sieve classification. Applied post-harvest process chain significantly affected the colour, dimensions, apparent density, and hardness of dried larvae with an impact on fractionation behaviour and characteristics of the obtained fractions. Drying at elevated temperatures caused pronounced darkening and shrinkage due to browning reactions and tissue collapse. Mechanical properties were affected as well leading to heterogeneous particle size distributions after milling and sieving. A large fraction of particles <500 µm was determined for samples exhibiting low mechanical hardness such as freeze-dried and defatted larvae. Significant differences in macro-nutrient composition of the sieving fractions were found deviating in chitin (3.6–16.1%db), protein (52.5–58.2%db) and fat (21.4–26.6%db) content. Highest protein recovery of max 72% was determined in the particle size fraction 500–1000 µm. Concluding, these results provide insights into physico-chemical characteristics of mealworms affected by pre-treatment and drying. The potential of dry fractionation techniques for protein enrichment and delivery of a variety of differently composed mealworm fractions was demonstrated and may provide an interesting potential to optimize water and energy consumption during insect fractionation.

Chiang S., Liang Z., Wang Y., Liang C.

The effects of different light-emitting diode (LED) conditions including different LED wavelengths and LED wavelength combinations on the production of bioactive compounds of Cordyceps militaris cultivated on brown rice were investigated. The results of our study showed that the optimal illumination times for biomass (0.49 g/g dw, dry weight), cordycepin (3′-deoxyadenosine) (3.97 m g/g dw), mannitol (21.3 mg/g dw) and adenosine (0.95 m g/g dw) production were 12, 12, 12 and 8 h/day, respectively, by fluorescent lamps. Among the three different LED wavelengths tested, the greatest effect of wavelength for biomass (0.38 g/g dw), cordycepin (2.89 m g/g dw), mannitol (23.6 mg/g dw) and adenosine (0.76 m g/g dw) production were red light (619–626 nm), green light (526–531 nm), red light and blue light (467–472 nm), respectively. Among the ten LED wavelength combinations, the greatest effect of wavelength ratios for specific productivity of cordycepin (30.0), mannitol (86.5) and adenosine (5.5) were 3R:3B,2R:4B and 2R:4B, respectively. Our findings suggest that the combination of wavelengths had the greatest impact on the bioactive compounds production of C. militaris.

Grau T., Vilcinskas A., Joop G.

Abstract The farming of edible insects is an alternative strategy for the production of protein-rich food and feed with a low ecological footprint. The industrial production of insect-derived protein is more cost-effective and energy-efficient than livestock farming or aquaculture. The mealworm Tenebrio molitor is economically among the most important species used for the large-scale conversion of plant biomass into protein. Here, we review the mass rearing of this species and its conversion into food and feed, focusing on challenges such as the contamination of food/feed products with bacteria from the insect gut and the risk of rapidly spreading pathogens and parasites. We propose solutions to prevent the outbreak of infections among farmed insects without reliance on antibiotics. Transgenerational immune priming and probiotic bacteria may provide alternative strategies for sustainable insect farming.

Nowak V., Persijn D., Rittenschober D., Charrondiere U.R.

Edible insects are considered rich in protein and a variety of micronutrients, and are therefore seen as potential contributors to food security. However, the estimation of the insects' contribution to the nutrient intake is limited since data are absent in food composition tables and databases. Therefore, FAO/INFOODS collected and published analytical data from primary sources with sufficient quality in the Food Composition Database for Biodiversity (BioFoodComp). Data were compiled for 456 food entries on insects in different developmental stages. A total of 5734 data points were entered, most on minerals and trace elements (34.8%), proximates (24.5%), amino acids (15.3%) and (pro)vitamins (9.1%). Data analysis of Tenebrio molitor confirms its nutritive quality that can help to combat malnutrition. The collection of data will assist compilers to incorporate more insects into tables and databases, and to further improve nutrient intake estimations.

Zhu F., Du B., Bian Z., Xu B.

One of the main active components from mushrooms was recently identified as β-glucan. Health-promoting β-glucans are an auspicious group of polysaccharides. β-Glucans from different sources such as cereals, yeast and grass have previously been documented. However, information on mushroom β-glucan is limited. This review summarizes the extraction, purification, quantification, and structural characterization of β-glucans, along with chemical and biological activities from this compound from mushrooms, and the current status of this research area with a view for future directions.

Makkar H.P., Tran G., Heuzé V., Ankers P.

A 60–70% increase in consumption of animal products is expected by 2050. This increase in the consumption will demand enormous resources, the feed being the most challenging because of the limited availability of natural resources, ongoing climatic changes and food–feed–fuel competition. The costs of conventional feed resources such as soymeal and fishmeal are very high and moreover their availability in the future will be limited. Insect rearing could be a part of the solutions. Although some studies have been conducted on evaluation of insects, insect larvae or insect meals as an ingredient in the diets of some animal species, this field is in infancy. Here we collate, synthesize and discuss the available information on five major insect species studied with respect to evaluation of their products as animal feed. The nutritional quality of black soldier fly larvae, the house fly maggots, mealworm, locusts–grasshoppers–crickets, and silkworm meal and their use as a replacement of soymeal and fishmeal in the diets of poultry, pigs, fish species and ruminants are discussed. The crude protein contents of these alternate resources are high: 42–63% and so are the lipid contents (up to 36% oil), which could possibly be extracted and used for various applications including biodiesel production. Unsaturated fatty acid concentrations are high in housefly maggot meal, mealworm and house cricket (60–70%), while their concentrations in black soldier fly larvae are lowest (19–37%). The studies have confirmed that palatability of these alternate feeds to animals is good and they can replace 25–100% of soymeal or fishmeal depending on the animal species. Except silkworm meal other insect meals are deficient in methionine and lysine and their supplementation in the diet can enhance both the performance of the animals and the soymeal and fishmeal replacement rates. Most insect meals are deficient in Ca and its supplementation in the diet is also required, especially for growing animals and laying hens. The levels of Ca and fatty acids in insect meals can be enhanced by manipulation of the substrate on which insects are reared. The paper also presents future areas of research. The information synthesized is expected to open new avenues for a large scale use of insect products as animal feed.

Al-Mekhlafi F.A., Abutaha N., Wadaan M.A., Al-Khalifa M.S.

Bread waste in Saudi Arabia is a significant environmental issue that has caused significant losses. Insects, specifically Tenebrio molitor larvae, offer potential bioconversion solutions for food waste. Larvae were fed diets comprising different proportions of leftover bread (LB) powder mixed with wheat bran (WB), and feeding trials were conducted over 50 days. Results indicated that including LB powder did not significantly affect larval survival, affirming its safety. The larvae fed the diets LB100, LB75WB25, LB50WB50, LB25WB75, and WB reached the final weights of 27.64, 95.27, 105.012, 98.74, and 67.64 mg. Similarly, the highest mean pupal weight, at 0.133 mg, was observed when larvae were reared on LB75WB25, while the lowest mean pupal weight, at 0.107 mg, was recorded on the WB diet. Protein content varied significantly among diets, with mixed diets exhibiting protein content ranging from 16.98 % to 55.26 %. The primary fatty acid found in mealworm oil was oleic acid (C18:9), which made up 54.11 % of the total fatty acid content for larvae raised on 75LB:25WB, 52.01 % for LB, and 46.942 % for WB, with LB incorporation positively impacting growth, pupal weight, protein content, and antioxidant properties. Utilizing LB powder highlights its potential for sustainable insect farming, addressing environmental concerns, and enhancing resource sustainability.

Mun S., Jang C.J., Jo S., Park S., Sim H.B., Ramos S.C., Kim H., Choi Y., Park D., Park K., Jeong B., Kim D.H., Kang K., Kim J.

An N., Li K., Wang Y., Shen W., Huang X., Xu S., Wu L., Huang H.

In this study, Cordyceps militaris matrix was employed for the first time to fabricate a biodegradable food packaging. Carmine and Ag@CuBTC were introduced to cross-link with mycelium and were uniformly dispersed within the matrix to enhance the water resistance, antimicrobial, and antioxidant properties of the bio-films. The bio-film displayed high biodegradability, with nearly 100 % degradation achieved after three weeks. The bio-film exhibited exceptional resistance to oxidation (49.30 % DPPH and 93.94 % ABTS•+), as well as effective inhibitory capabilities against E. coli and S. aureus, respectively. The composite film maintained a high CO2/O2 selective permeability, which was advantageous for mitigating fruit metabolism and extending shelf life. Simultaneously, food preservation experiments confirmed that these bio-films can decelerate the spoilage of fruits and effectively prolong the shelf-life of food. The experimental findings indicated that the prepared Bio-R-Ag@Cu film held promise as an environmentally friendly biodegradable material for food packaging.

De Bellis P., Rizzello C.G.

The World Health Organization [...]

Siddiqui S.A., Erol Z., Rugji J., Taşçı F., Kahraman H.A., Toppi V., Musa L., Di Giacinto G., Bahmid N.A., Mehdizadeh M., Castro-Muñoz R.

AbstractFermentation is thought to be born in the Fertile Crescent, and since then, almost every culture has integrated fermented foods into their dietary habits. Originally used to preserve foods, fermentation is now applied to improve their physicochemical, sensory, nutritional, and safety attributes. Fermented dairy, alcoholic beverages like wine and beer, fermented vegetables, fruits, and meats are all highly valuable due to their increased storage stability, reduced risk of food poisoning, and enhanced flavor. Over the years, scientific research has associated the consumption of fermented products with improved health status. The fermentation process helps to break down compounds into more easily digestible forms. It also helps to reduce the amount of toxins and pathogens in food. Additionally, fermented foods contain probiotics, which are beneficial bacteria that help the body to digest food and absorb nutrients. In today’s world, non-communicable diseases such as cardiovascular disease, type 2 diabetes, cancer, and allergies have increased. In this regard, scientific investigations have demonstrated that shifting to a diet that contains fermented foods can reduce the risk of non-communicable diseases. Moreover, in the last decade, there has been a growing interest in fermentation technology to valorize food waste into valuable by-products. Fermentation of various food wastes has resulted in the successful production of valuable by-products, including enzymes, pigments, and biofuels.

Kotsou K., Chatzimitakos T., Athanasiadis V., Bozinou E., Athanassiou C.G., Lalas S.I.

The utilization of alternative and sustainable food sources has garnered significant interest as a means to address the challenges of food security and environmental sustainability. Tenebrio molitor larvae, commonly known as mealworms, have emerged as a promising candidate in this context, as they are a rich source of nutrients and can be reared with relatively low resource input. This review article presents an in-depth analysis of the diverse range of food products developed using T. molitor larvae and the distinctive properties they bestow on these products. The review encompasses an exploration of the nutritional composition of the larvae, emphasizing their rich protein content, balanced amino acid profile, fatty acids with health benefits, vitamins, and minerals. It delves into how these attributes have been harnessed to enhance the nutritional value of a variety of food items, ranging from protein-rich snacks and energy bars to pasta, bakery goods, etc. Each of these applications is discussed with regard to how T. molitor larvae contribute to the nutritional content and sensory characteristics of the final product. Furthermore, this review sheds light on the innovative techniques and processing methods employed to incorporate T. molitor larvae into different food matrices. It addresses challenges related to taste, texture, and appearance that have been encountered and the strategies devised to overcome related problems. Overall, this comprehensive review elucidates the diverse food products that have been developed utilizing T. molitor larvae as a key ingredient. Highlighting the nutritional, sensory, and sustainability aspects of these products, this review offers valuable insights to harness the potential of this alternative protein source to meet the evolving needs of modern food systems.