Unravelling the nutritional and health benefits of marketable winged termites (Macrotermes spp.) as sustainable food sources in Africa.

Termites are widely distributed globally and serve as a valuable food source in many countries. However, information on the myriad nutritional benefits of processed termite products in African markets remain largely unexploited. This study evaluated the phytochemicals, fatty acids, amino acids, minerals, vitamins and proximate composition of the edible winged termites (Macrotermes spp.) from three major Counties of Kenya. A total of 9 flavonoids, 5 alkaloids, and 1 cytokinin were identified. The oil content varied from 33 to 46%, exhibiting significant levels of beneficial omega 3 fatty acids, such as methyl (9Z,12Z,15Z)-octadecatrienoate and methyl (5Z,8Z,11Z,14Z,17Z)-eicosapentaenoate, ranging from 82.7-95.1 to 6.3-8.1 µg/g, respectively, across the different regions. Four essential and cereal-limiting amino acids lysine (1.0-1.3 mg/g), methionine (0.08-0.1 mg/g), leucine (0.6-0.9 mg/g) and threonine (0.1-0.2 mg/g), were predominant. Moreover, termites had a rich profile of essential minerals, including iron (70.7-111.8 mg/100 g), zinc (4.4-16.2 mg/100 g) and calcium (33.1-53.0 mg/100 g), as well as vitamins A (2.4-6.4 mg/kg), C (0.6-1.9 mg/kg) and B12 (10.7-17.1 mg/kg). The crude protein (32.2-44.8%) and fat (41.2-49.1%) contents of termites from the various Counties was notably high. These findings demonstrated the promising nutrients potential of winged termites and advocate for their sustainable utilization in contemporary efficacious functional food applications to combat malnutrition.

Unlocking the Potential of Substrate Quality for the Enhanced Antibacterial Activity of Black Soldier Fly against Pathogens.

Globally, antibiotics are facing fierce resistance from multidrug-resistant bacterial strains. There is an urgent need for eco-friendly alternatives. Though insects are important targets for antimicrobial peptides, it has received limited research attention. This study investigated the impact of waste substrates on the production of antibacterial agents in black soldier fly (Hermetia illucens L.) larvae (HIL) and their implications in the suppression of pathogens [Bacillus subtilis (ATCC 6051), Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853), and Escherichia coli (ATCC 25922)]. The 20% acetic acid (AcOH) extract from market waste had the highest antibacterial activity with an inhibition zone of 17.00 mm, followed by potato waste (15.02 mm) against S. aureus. Hexane extract from HIL raised on market waste also showed a significant inhibitory zone (13.06 mm) against B. subtilis. .Minimum inhibitory concentration (MIC) values recorded were 25 mg/mL against all test pathogens. The fastest time-kill of 20% AcOH extract was 4 h againstB. subtilis, E. coli, ,andP. aeruginosa. Lauric acid was also identified as the dominant component of the various hexane extracts with concentrations of 602.76 and 318.17 µg/g in HIL reared on potato and market waste, respectively. Energy from the market waste substrate correlated significantly (r = 0.97) with antibacterial activities. This study highlights the key role of substrate quality and extraction methods for enhancing the production of antibacterial agents in HIL, thus providing new insights into the development of potential drugs to overcome the alarming concerns of antimicrobial resistance.

Unravelling the nutritional and health benefits of wheat bread enriched with meat powder from laying hen fed diet with insect (Hermetia illucens) meal.

Wheat bread is among stable foods that are nutritionally imbalanced, thus enrichment is crucial. We evaluated the nutritional impact of high-valued wheat bread enriched with varying levels of meat powder from hen fed diet with insect (Hermetia illucens)-based meal. Crude protein and ash in bread increased with increasing inclusion of meat powder. Limiting amino acids like lysine and threonine in enriched bread products increased by 3.0-4.5 and 1.8-3.1-folds, respectively. Omega 3 fatty acids were significantly enhanced in bread fortified with meat powder. Vitamins (retinol, nicotinic acid, and pantothenic acid) were significantly increased in supplemented bread products. Iron, zinc, and calcium increased by 1.1, 1.2 and 3.0-folds in enriched bread with 30% meat powder. Colour, flavour and overall acceptability of breads prepared with 25 and 30% meat powder were highly ranked. Our findings demonstrate that meat powder (i.e., from hen fed insect-based diets) enrichment would provide added health and nutritional benefits to bread products without having adverse effects on any functional or sensory properties. Thus, this could be a novel strategy and trend for improving bread products, that might generate increasing demand for a healthier consumer-oriented lifestyle.

Unraveling the physicochemical attributes of three cricket (Gryllus bimaculatus)-enriched biscuit products and implications on consumers' preference and willingness to pay.

Disgust and neophobia elicited by whole insect products, has necessitated the need to mask insect-based food products. The physico-chemical parameters, sensory acceptance, and willingness to pay (WTP) for wheat biscuits supplemented with cricket powder was evaluated. The biscuits' color intensity correlated with the cricket inclusion levels. Spread ration of cricket-enriched-biscuits increased (1.0-1.2-folds), while the hardness and fracturability decreased (1.0-1.3-folds and 1.0-1.2 folds, respectively) compared to the control biscuit. Cricket-biscuits exhibited 1.2-1.7, 1.1-3.7, 1.2-3.0 and 1.1-1.2-folds higher (p < 0.05) protein, ash, fiber, and fat, respectively. Ca, Fe, and Zn were 1.1-3.7, 1.1-1.2 and 1.4-4.0-folds higher, respectively, for cricket-based biscuits. Monounsaturated and polyunsaturated fatty acids proportionally increased with increasing cricket flour. On a likert scale, 71.4%, 71.9%, 38.4% and 57.5% of the caregivers and 38.6%, 58.3%, 40.0% and 34.0% for children (3-5 years) strongly preferred the color, texture, taste and aroma, respectively, of the cricket-based biscuits. Forty-seven (47%) of the caretakers were WTP a premium of 37 Kenyan shillings (0.34 USD) for cricket-based biscuits. Our findings demonstrated that integration of cricket flour into existing market-driven consumer familiar food products significantly increased acceptability and WTP, thus promising potential to contribute to improved food and nutritional security.

Aroma characterization and consumer acceptance of four cookie products enriched with insect (Ruspolia differens) meal.

This research aims to advance knowledge on the impact of four processing methods on volatile compounds from insect-based baked products (cookies) to provide insights on consumer acceptance. Samples were exposed to double step enzyme digestive test, volatiles characterized through headspace analysis, while semi-trained panelists were recruited for the sensory test. Blanched and boiled samples of R. differens had considerably higher digestibility (83.42% and 81.61%, respectively) (p < 0.05) than toasted and deep-fried samples. Insect-based cookie products integrated with blanched and boiled R. differens meal expressed higher digestibility (80.41% and 78.73%, respectively) that was comparable to that of commercial cookie products (control cookies-CTRC with 88.22%). Key volatile compounds common between the various cookie products included, nonanal, octanal, methyl-pyrazine, hexanal, tetradecane, 2-pentylfuran, 2-heptanone, 2E-octenal, 2E-heptenal and dodecane. Among the volatile compounds, pleasant aromas observed were 2E,4E-dodecadienal, pentanal, octanal, methyl pyrazine, furfurals, benzaldehyde, and 2-pentyl furan, which were more pronounced in cookies fortified with boiled, toasted and deep-fried R. differens meal. There was a greater resemblance of sensory characteristics between control cookies and those fortified with deep-fried R. differens. These findings underscore the significant influence of aroma compounds on consumer acceptability and preference for insect-based baked food products, which allows for future process-modification of innate aromas of insect-based meals to produce high-valued pleasant consumer driven market products.

Dynamics in nutrients, sterols and total flavonoid content during processing of the edible Long-Horned grasshopper (Ruspolia differens Serville) for food.

Long-horned grasshopper (Ruspolia differens Serville) is a tasty delicacy in over 20 African countries. This study evaluated the impact of diverse post-harvest thermal treatment (blanching, boiling, toasting, and deep-frying) on the nutrients, total flavonoid content and sterols preservation of R. differens products. Crude protein, ash, and fibre of R. differens was drastically reduced by deep-frying technique. There was increase in Omega-3 (α-linolenic acid), Omega-6 fatty acid (linoleic and arachidonic acids) and sterols [(22Z)-27-Norergosta-5,22-dien-3ß-ol, cholesterol, campesterol, cholest-4-ene-3-one and ß-sitosterol] and flavonoids (2-3 folds) during blanching compared to other techniques. The iron and zinc content increased significantly in blanched and boiled products of R. differens. Thus, losses of nutrients, total flavonoid content and sterols during processing of R. differens for food can be mitigated by employing blanching technique, which is cheaper and least time-consuming. The implications of these dietary and therapeutic compounds on human nutrition and health are discussed.