Edible insects are increasingly being considered as food and feed ingredients because of their rich nutrient content. Already, edible insect farming has taken-off in Africa, but quality and safety concerns call for simple, actionable hazard control mechanisms. We examined the effects of traditional processing techniques—boiling, toasting, solar-drying, oven-drying, boiling + oven-drying, boiling + solar-drying, toasting + oven-drying, toasting + solar-drying—on the proximate composition and microbiological quality of adult Acheta domesticus and Ruspolia differens, the prepupae of Hermetia illucens and 5th instar larvae of Spodoptera littoralis. Boiling, toasting, and drying decreased the dry matter crude fat by 0.8–51% in the order: toasting > boiling > oven-drying > solar-drying, whereas the protein contents increased by 1.2–22% following the same order. Boiling and toasting decreased aerobic mesophilic bacterial populations, lowered Staphylococcus aureus, and eliminated the yeasts and moulds, Lac+ enteric bacteria, and Salmonella. Oven-drying alone marginally lowered bacterial populations as well as yeast and moulds, whereas solar-drying alone had no effect on these parameters. Oven-drying of the boiled or toasted products increased the aerobic mesophilic bacteria counts but the products remained negative on Lac+ enteric bacteria and Salmonella. Traditional processing improves microbial safety but alters the nutritional value. Species- and treatment-specific patterns exist.
13 November 2017 in Journal of Ethnobiology and Ethnomedicine
Edible insects are an important source of food to many African populations. The longhorn grasshopper, Ruspolia differens (Serville 1838), commonly known as senene in Tanzania is one of the most appreciated edible insects by societies around Lake Victoria crescent. Senene is primarily an essential treat for the tribes around the lake, e.g., the Haya of Tanzania, Luo of Kenya and Baganda of Uganda. Despite its importance as a food item and appreciation as a delicacy, there are few studies dealing with culture, beliefs and indigenous technology in connection with the senene. The main objective of this study was to survey indigenous technologies, processing methods and traditions in relation to senene consumption among the Haya tribe in Kagera region of Tanzania. Our ethnographic study was conducted through semi-structured interviews. A total of 51 locals, 26 females and 25 males aged 21 to 60 years were interviewed (with 3 female and 7 male key informants among them). Questions focused on cultures, beliefs and traditions towards senene consumption. Processing, preservation and shelf-life as well as nutritional knowledge were also investigated. Harvesting for household consumption was mainly done through wild collection. Traditionally made traps were mostly used for commercial harvesting. Deep frying was the most preferred processing method while smoking was the most preferred preservation method, with shelf-life of up to 12 months. Interesting traditions and taboos associated with senene consumption were identified, with men monopolising the insects as food by declaring the insects taboo for women and children. Deep fried senene in locally packed containers were mostly sold by street vendors, but also available from a variety of stores and supermarkets. Beyond being just an important traditional delicacy, senene is becoming increasingly popular, providing opportunity for local businesses. Indigenous technologies for harvesting, processing and preserving senene exist, but must be improved to meet food processing standards, thereby promoting commercialization. This carries economic potential essential for improving incomes and livelihoods of women and smallholder farmers, improving household level food security.
The desert locust (Schitocerca gregaria) swarms in numbers that decimate farmland, threatening an already vulnerable horn and Eastern region of Africa. The aim of this research was to assess the nutrient content and oil characteristics of the desert locust and for possible utilization as a food resource at industrial scale. The desert locusts were harvested from swarms in various regions of Kenya. Nutrient analysis was performed using standard protocols and physico-chemical characteristics of the extracted oil were evaluated. A 100 g sample contained 450Kcal energy, 46 g protein, 32 g fat and 4 g fibre. Calcium was the most abundant macro mineral (208.36 mg/100 g), iron was the most abundant trace mineral (4.83 mg/100 g) while α-tocopherol content of 267.47 µg/g was recorded. Oleic acid was the main fatty acid (30.78%) with total unsaturated fatty acids being 66.47% of the total fatty acids. The n-6:n-3 ratio of 2,4 was reported which indicated a significant nutritional quality of the locust oil. The locust oil had 0.94 specific gravity indicating potential industrial applications. Iodine value (75 g iodine/100 g oil), peroxide value (0.18 mEq/Kg) and saponification value (171 mg KOH/Kg) indicated an oil with relative stability and potential for industrial utilization in the food industry. As a result, locust control efforts could therefore include harvesting and consumption as part of the integrated management.
The aim of the study was to determine the chemical and functional properties of five Kenyan seaweed species namely; (Hypnea musciformis, Eucheuma denticulatum, Laurencia intermedia, Sargassum oligocystum, Ulva fasciata) as a potential fat replacer in chicken sausage processing. The proximate composition was investigated using the standard AOAC methods, while the nitrogen-free extract (NFE) was determined by weight difference of the proximate components. The seaweeds were analyzed for mineral composition using atomic absorption spectrophotometry while the fatty acid profile was determined by gas chromatography. The water holding capacity and the emulsion capacity of the seaweed were determined using AACC procedures. The highest proximate component was NFE (65.06 %) while the least was crude fat (0.87 %). Among the nine minerals analyzed, calcium was the highest (1185.29 mg/100g) while lead was not detected. Saturated fatty acids (SFA) were the highest with a range of 53.03-71.05 % followed by monounsaturated fatty acids (4.83-17.71%) and polyunsaturated fatty acids (PUFA) (2.75 - 10.13%). The highest emulsifying activity was obtained in Ulva fasciata (75.66 %) and Eucheuma denticulatum (75.69 %) while the lowest was obtained in Sargassum oligocystum (59.19 %). The highest water holding capacity was obtained in Sargassum oligocystum (13.75ml/g) while the lowest was recorded in Eucheuma denticulatum (8.42ml/g) and Ulva fasciata (9.16ml/g). The findings of this study demonstrated the potential of seaweeds in improving the chemical and functional characteristics of processed foods.
Edible orthopterans (grasshoppers, crickets, and locusts) are major delicacies, especially across sub-Saharan Africa. Their promotion as food ingredients is increasingly gaining momentum. This study evaluates the nutritional profiles of three widely consumed orthopterans: Gryllus bimaculatus, Locusta migratoria, and Schistocerca gregaria after blanching and oven-drying. All three species had high protein (65.3, 54.2, and 61.4% on a dry matter (DM) basis for G. bimaculatus, L. migratoria, and S. gregaria, respectively) and fat contents. Oleic (22.9–40.8%) and palmitic (26.1–43.0%) were the two most abundant fatty acids. All essential amino acids (in mg/100 g protein) were present, with glutamic acid (120–131), alanine (90.2–123), and leucine (82.3–84.6) being the most abundant. The minerals (in mg/100 g dry matter) potassium (796–1309) and phosphorus (697–968) were moderately high, and iron (4.60–7.31), zinc (12.7–24.9), manganese (0.40–7.15), and copper (1.20–4.86) were also observed in the samples. Vitamin B12 contents were high (0.22–1.35 µg/100 g dry matter). Our findings demonstrate that the excellent nutritional profile of the three processed insects could serve as promising alternative ingredients for improving food and nutritional security.