Summary: There is limited information about the relative composition and health benefits of various honey consumed across Africa. This study aimed at estimating the bioactive constituents, in vitro radical scavenging and antibacterial activities of 16 kinds of honey obtained from different geographical locations in Kenya. Manuka 5 + honey was included for comparison. Some of the tested honey had biochemicals and bioactivities similar to or higher than Manuka 5 + honey. The honey exhibited DPPH radical scavenging ability, with several types of honey showing superior scavenging potential than Manuka 5 + honey, owing to their high phenol content. All types of honey inhibited the growth of E. coli and further showed a substantial amount of nonperoxide antimicrobial activity. The geographical origin of honey had an influence on its bioactive contents. Overall, these findings suggest that Kenyan honey has great therapeutic potential, and thus, its clinical application should not be overlooked.
There is an increased demand for natural products like propolis, yet little information is available about the chemical composition of African propolis and its bio-functional properties. Therefore, in this study, we aimed to quantify the phytochemicals and determine the antioxidant and antimicrobial properties of Apis mellifera propolis ( n = 59) sourced from various regions in Kenya. Principal component analysis (PCA) showed that the sampling region had a remarkable impact on the propolis's composition and bio-functional properties. Generally, the propolis contained high amounts of phytochemicals, particularly alkaloids (5.76 g CE/100 g) and phenols (2.24 g GAE/100 g). Furthermore, analysis of propolis by gas chromatography–mass spectrometry (GC-MS) revealed various compounds with varying bio-functional activities. These compounds included triterpenoids alpha- and beta-amyrin, oleanen-3-yl-acetate, urs-12-en-24-oic acid, lanosta-8,24-dien-3-one, and hydrocarbons tricosane and nondecane, which have been reported to have either antimicrobial or antioxidant activities. The propolis samples collected from hotter climatic conditions contained a higher composition of phytochemicals, and additionally, they displayed higher antioxidant and antimicrobial activities than those obtained from cooler climatic conditions. Key findings of this study demonstrate the occurrence of relatively high phytochemical content in Kenya's propolis, which has antioxidant and antimicrobial properties; hence this potential could be harnessed for disease control.
4 April 2023 in Journal of Insects as Food and Feed
Increasing global populations and decreasing sources of nutrients to feed them, has necessitated the drive for alternative and more sustainable sources of nutrients. Such alternatives should contribute to meet the demand for food and minimise negative effects on the environment. Edible insects, which have been traditionally part of human diets, stand out as the most probable and sustainable alternative. Silkmoth pupae, by-products of the sericulture sector are among the traditional foods consumed in Asia. In this study we determined the nutritional composition, phytochemical contents, and antioxidant activities of freeze-dried pupae from 2 domesticated and 3 wild silkmoth species. Our results showed that both Bombyx mori L. and Samia cynthia ricini Boisduval pupae had the highest amounts of proteins, 78.9 and 76.0 mg bovine serum albumin equivalents /g, respectively. Significantly high amounts of lipids (26.7%) were observed in B. mori pupae. Domesticated silkworm species recorded significantly high amounts of protein compared to the wild species. In addition, all silkmoth pupae had substantial amounts of phytochemicals that varied significantly between the studied species. We further demonstrated that all pupae samples exhibited antioxidant activities for both 50% methanolic and 100% hexane extracts, at very low concentrations of 2.5 and 30 mg/ml, respectively, with Anaphe panda pupae samples recording the highest activities. The multivariate analysis confirmed significant differences in the chemical composition of silkmoth pupae between species and type of diet they consume. Therefore, our findings suggest that the studied silkmoth pupae are rich alternative source of nutrients and natural antioxidants.
8 August 2024 in Journal of Insects as Food and Feed
Edible scarab beetles are important repositories for nutritive and bioactive compounds, but this information remains largely unexplored. This study explored the nutritional and therapeutic properties of two edible scarab beetles from three different locations (Embu, Murang’a and Nairobi Counties) in Kenya. Morphological and molecular characterization of the wild collected larvae revealed two important edible beetle species ( Cetonia aurata L. and Oryctes rhinoceros L.). The larvae of both species are excellent source of crude proteins (44% for O. rhinoceros and 63% for C. aurata ). The larvae of O. rhinoceros were rich in minerals, particularly calcium (15.75-22.65 mg/g) and potassium (13.62-22.88 mg/g). The anti-radical activity of C. aurata larvae ranged between 91% and 92% across the various target sites. Lysine was the most important and abundant amino acid in both larvae (>5 mg/g). The larvae of C. aurata and O. rhinoceros are a good source of unsaturated fatty acids like Methyl-8 Z , 11 Z , 14Z-eicosatrienoate (32 mg/g) and Methyl-9 Z -octadecenoate (9.47-120.84 mg/g). The entomochemicals of phenolic nature derived from the beetle larvae portray a unique opportunity to supply and improve high quality nutritious food with enhanced ability to get-rid of free radicals, thus promoting good health and well-being of the consumers. Future development of foods supplemented with scarab beetle larvae derived products must consider the preservation of potential benefits of not only nutrients, but also nutraceuticals. However, in-depth research is still needed to guarantee the bioactivity in processed foods and ensure quality control test before the release of these products to the market.
20 October 2022 in Journal of Insects as Food and Feed
Increasing global populations and decreasing sources of nutrients to feed them, has necessitated the drive for alternative and more sustainable sources of nutrients. Such alternatives should contribute to meet the demand for food and minimise negative effects on the environment. Edible insects, which have been traditionally part of human diets, stand out as the most probable and sustainable alternative. Silkmoth pupae, by-products of the sericulture sector are among the traditional foods consumed in Asia. In this study we determined the nutritional composition, phytochemical contents, and antioxidant activities of freeze-dried pupae from 2 domesticated and 3 wild silkmoth species. Our results showed that both Bombyx mori L. and Samia cynthia ricini Boisduval pupae had the highest amounts of proteins, 78.9 and 76.0 mg bovine serum albumin equivalents /g, respectively. Significantly high amounts of lipids (26.7%) were observed in B. mori pupae. Domesticated silkworm species recorded significantly high amounts of protein compared to the wild species. In addition, all silkmoth pupae had substantial amounts of phytochemicals that varied significantly between the studied species. We further demonstrated that all pupae samples exhibited antioxidant activities for both 50% methanolic and 100% hexane extracts, at very low concentrations of 2.5 and 30 mg/ml, respectively, with Anaphe panda pupae samples recording the highest activities. The multivariate analysis confirmed significant differences in the chemical composition of silkmoth pupae between species and type of diet they consume. Therefore, our findings suggest that the studied silkmoth pupae are rich alternative source of nutrients and natural antioxidants.