Globally, the broad-spectrum antimicrobial activity of chitin and chitosan has been widely documented. However, very little research attention has focused on chitin and chitosan extracted from black soldier fly pupal exuviae, which are abundantly present as byproducts from insect-farming enterprises. This study presents the first comparative analysis of chemical and biological extraction of chitin and chitosan from BSF pupal exuviae. The antibacterial activity of chitosan was also evaluated. For chemical extraction, demineralization and deproteinization were carried out using 1 M hydrochloric acid at 100 °C for 2 h and 1 M NaOH for 4 h at 100 °C, respectively. Biological chitin extraction was carried out by protease-producing bacteria and lactic-acid-producing bacteria for protein and mineral removal, respectively. The extracted chitin was converted to chitosan via deacetylation using 40% NaOH for 8 h at 100 °C. Chitin characterization was done using FTIR spectroscopy, while the antimicrobial properties were determined using the disc diffusion method. Chemical and biological extraction gave a chitin yield of 10.18% and 11.85%, respectively. A maximum chitosan yield of 6.58% was achieved via chemical treatment. From the FTIR results, biological and chemical chitin showed characteristic chitin peaks at 1650 and 1550 cm−1—wavenumbers corresponding to amide I stretching and amide II bending, respectively. There was significant growth inhibition for Escherichia coli, Bacillus subtilis,Pseudomonas aeruginosa,Staphylococcus aureus, and Candida albicans when subjected to 2.5 and 5% concentrations of chitosan. Our findings demonstrate that chitosan from BSF pupal exuviae could be a promising and novel therapeutic agent for drug development against resistant strains of bacteria.

The need for mass-production of crickets is increasing with continued awareness. Cricket farming has been introduced with considerable success among small-holder farmers in the warmer, low altitude Lake Victoria regions of Kenya. Efforts are however on-going to introduce the farming in cooler, higher altitude areas in the interest of expanding the enterprise and increase mass production. A pilot farm was established at a farm located 1,519 meters above sea level with a temperature range of 17-22 °C. Initial egg stock was incubated at the farm under room conditions in the month of November to December. Different agricultural side streams and farm weeds were tested as probable cricket feed. Hatch rate, duration of hatching, preferred food types, mortality, weight gain and nutrient content at different ages were assessed. The hatch rate averaged 60%, mortality for hatchlings (pinheads) was below 2% while a steady weight gain was observed over a 12 weeks growth period with highest maximum weight being 2.03 grams per cricket. All agricultural side streams were accepted by the crickets and the wandering Jew weed was among the preferred feed and a source of significant nutrient for the crickets. Protein content ranged from 36-60% while fat content was 12-25%. Cricket production can therefore be promoted in the higher altitude, cooler areas in order to promote industrial exploitation of the crickets in combating food and nutrition insecurity.

Globally, Ralstonia solanacearum (Smith) is ranked one of the most destructive bacterial pathogens inducing rapid and fatal wilting symptoms on tomatoes. Yield losses on tomatoes vary from 0 to 91% and most control measures are unaffordable to resource-poor farmers. This study investigated the antimicrobial activities of chitin and chitosan extracted from black soldier fly (BSF) pupal exuviae against R. solanacearum. Morphological, biochemical, and molecular techniques were used to isolate and characterize R. solanacearum for in vitro pathogenicity test using disc diffusion technique. Our results revealed that BSF chitosan significantly inhibited the growth of R. solanacearum when compared to treatments without chitosan. However, there was no significant difference in the antibacterial activities between BSF and commercial chitosan against R. solanacearum. Soil amended with BSF-chitin and chitosan demonstrated a reduction in bacterial wilt disease incidence by 30.31% and 34.95%, respectively. Whereas, disease severity was reduced by 22.57% and 23.66%, when inoculated tomato plants were subjected to soil amended with BSF chitin and chitosan, respectively. These findings have demonstrated that BSF pupal shells are an attractive renewable raw material for the recovery of valuable products (chitin and chitosan) with promising ability as a new type of eco-friendly control measure against bacterial wilt caused by R. solanacearum. Further studies should explore integrated pest management options that integrate multiple components including insect-based chitin and chitosan to manage bacterial wilt diseases, contributing significantly to increased tomato production worldwide.

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In this study, cricket chitosan was used as a prebiotic. Lactobacillus fermentum, Lactobacillus acidophilus, and Bifidobacterium adolescentis were identified as probiotic bacteria. Cricket chitin was deacetylated to chitosan and added to either De Man Rogosa and Sharpe or Salmonella/Shigella bacterial growth media at the rates of 1%, 5%, 10%, or 20% to obtain chitosan-supplemented media. The growth of the probiotic bacteria was monitored on chitosan-supplemented media after 6, 12, 24, and 48 h upon incubation at 37 °C. Growth of Salmonella typhi in the presence of probiotic bacteria in chitosan-supplemented media was evaluated under similar conditions to those of the growth of probiotic bacteria by measuring growth inhibition zones (in mm) around the bacterial colonies. All chitosan concentrations significantly increased the populations of probiotic bacteria and decreased the populations of pathogenic bacteria. During growth, there was a significant pH change in the media with all probiotic bacteria. Inhibition zones from probiotic bacteria growth supernatant against Salmonella typhi were most apparent at 16 mm and statistically significant in connection with a 10% chitosan concentration. This study suggests cricket-derived chitosan can function as a prebiotic, with an ability to eliminate pathogenic bacteria in the presence of probiotic bacteria.

House cricket is currently introduced for scaled-up production in farming systems in Kenya and other parts of the world, as an alternative source of animal proteins. The aim of this study was to assess the nutritional composition in farmed cricket as influenced by age in order to ascertain the optimal harvesting time for possible utilization of crickets in improving child nutrition in Kenya. Sampling was carried out between weeks 4 and 13. The moisture content was analysed by drying method, chitin by sodium hydroxide digestion, protein content by estimation of total nitrogen, crude fat by soxhlet extraction method, ash by muffle furnace incineration, available carbohydrates by subtraction, and energy by calculation method. The crude protein mean ranged from 36.00 to 60.00 g/100 g, chitin 2.20 to 12.40 g/100 g, total lipids 12.00 to 25.00 g/100 g, over the 13 weeks period. Minerals concentration was optimum at week 9, with magnesium 1.30 to 11.30 mg/100 g, calcium 1.40 to 19.70 mg/100 g, and zinc 0.20 to 16.60 mg/100 g. Findings from this study indicate that farmed cricket would be best harvested between weeks 9 and 11, when the protein and mineral content is optimum. Nutrients available in farmed crickets show that farmed crickets can be used in child food ingredients to improve child nutrition.

The consumption of insects as an alternative protein source is acceptable as a sustainable alternative to mainstream protein sources. Apart from containing a high protein content, insects also have dietary fiber in the form of chitin, which helps to enrich gut microbiota. The importance of the gut microbiome in general health has recently been underlined for humans, farm animals, pets, poultry, and fish. The advances in 16S RNA techniques have enabled the examination of complex microbial communities in the gastrointestinal tract, shedding more light on the role of diet in disease and immunity. The gut microbiome generates signals influencing the normal nutritional status, immune functions, metabolism, disease, and well-being. The gut microbiome depends on dietary fiber; hence, their diversity is modulated by diet, a relevant factor in defining the composition of gut microbiota. Small shifts in diet have demonstrated an enormous shift in gut microbiota. Edible insects are an excellent source of protein, fat, and chitin that could influence the gut microbiota as a prebiotic. Chitin from insects, when consumed, contributes to a healthy gut microbiome by increasing diversity in fecal microbiota. Moreover, a high fiber intake has been associated with a reduced risk of breast cancer, diverticular disease, coronary heart disease, and metabolic syndrome. This review presents edible insects with a focus on fiber found in the insect as a beneficial food component.

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