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Downstream processing of Black soldier fly larvae protein for human consumption
Thesis (PhD)--Stellenbosch University, 2026.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2026
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| _version_ | 1867613953197080576 |
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| access_status_str | Open Access |
| author | Chakawa, Dennis Panashe |
| author2 | Goosen, Neill J. |
| author_browse | Chakawa, Dennis Panashe Goosen, Neill J. |
| author_facet | Goosen, Neill J. Chakawa, Dennis Panashe |
| author_sort | Chakawa, Dennis Panashe |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhD)--Stellenbosch University, 2026. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/135674 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:44:19.493Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2026 |
| publishDateRange | 2026 |
| publishDateSort | 2026 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/135674 Downstream processing of Black soldier fly larvae protein for human consumption Chakawa, Dennis Panashe Goosen, Neill J. Stellenbosch University. Faculty of Engineering. Dept. of Chemical Engineering. Thesis (PhD)--Stellenbosch University, 2026. Chakawa, D. P. 2026. Downstream processing of Black soldier fly larvae protein for human consumption. Unpublished doctoral dissertation. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/8cc655d3-c81b-4741-a84a-50d19e448e58 The growing global demand for sustainable, nutritionally balanced protein sources has accelerated interest in insect-derived proteins, particularly from Black soldier fly larvae (BSFL). Despite their favourable essential amino acid profile and low environmental footprint, producing BSFL protein powders for human consumption remains technologically constrained. The current methods employed to produce animal feed ingredients from BSFL are inadequate for human food production, as they are unable to separate the protein fraction from indigestible chitin and the considerable lipid fraction in BSFL. Aqueous extraction (e.g. the two-stage alkaline extraction process developed in earlier work) can separate BSFL protein from chitin and lipids, but also co-extracts pigments and off-odours, producing dark-brown powders with reduced sensory and aesthetic appeal and marketability. Developing a downstream process to partially remove undesirable colour and odours without compromising nutrition is essential to enhance consumer acceptance of BSFL protein products, especially in Western markets projected to represent 14% of global demand by 2050. However, research into such processes is currently lacking in the literature. This aim of the study was to develop a downstream process for producing a dried BSFL protein powder aimed at the human market. This was achieved by building on the two stage alkaline protein extraction process developed earlier, and: (1) Determining the most effective bleaching agent and the optimum conditions for maximizing bleaching of BSFL protein concentrate after extraction; (2) Determining how spray drying conditions impact powder recovery and protein content in dry powder during spray drying; (3) Evaluating the effects of inlet air temperature and maltodextrin addition on powder morphology, powder colour, and amino acid content of the dried product; and (4) Evaluating the effect of inlet air temperature and maltodextrin addition on moisture sorption behaviour, gastric digestibility, off-odour markers (formic and acetic acids), and techno-functional properties of dry powder. The study showed that chemical bleaching agents outperform enzymatic ones in bleaching BSFL protein concentrate, with hydrogen peroxide being the most effective. Low doses of hydrogen peroxide (0.01% w/w) at 30 °C successfully whitened the concentrate to a food-grade acceptable colour, as benchmarked against existing commercial products. This demonstrates the feasibility and effectiveness of incorporating a dedicated bleaching step in the downstream process. Spray drying at 200 °C inlet temperature, 0.15 L/h feed flow rate, and 13% maltodextrin at a fixed air flow rate of 64.1 m3/h yielded an optimum protein recovery (39.5%) and 53.1% protein content in the dried powder product. Maltodextrin at this concentration produced intact, irregular particles with improved whiteness and superior amino acid retention compared to powders without maltodextrin. This demonstrates maltodextrin’s critical role at inlet air temperatures below 220 °C in enhancing powder recovery, nutritional quality, final appearance, and flow properties. Spray drying with 13% maltodextrin at high inlet temperatures of 180 °C and higher improved moisture stability and reduced off-odours, but reduced gastric digestibility and key techno-functional properties like oil holding and foaming, compared to powders without maltodextrin. Overall, moderate inlet air temperatures during spray drying at 200 °C or lower, with 13% maltodextrin inclusion, produces a stable, consumer-acceptable protein powder despite the trade-offs in digestibility and techno-functional properties. Balancing maltodextrin addition and spray-drying temperature is crucial to optimize sensory stability and functional performance of BSFL protein powders. In conclusion, this study developed a noveloptimized BSFL downstream process combining isoelectric precipitation, centrifugation, bleaching, mixing, concentration, and spray drying steps to produce a food-grade consumer-acceptable powder which has not been reported in literature. Within the individual process steps of this downstream process, this work provides new information on bleaching insect protein concentrates (both generally and for BSFL) which has not been previously reported in literature. Moreover, this work reports on optimum spray drying parameters for the spray drying step which simultaneously enhance process efficiency (e.g. powder recovery), product quality (e.g. crude protein content, powder morphology, amino acid composition, and gastric digestibility), powder stability (e.g. low moisture sorption), and customer acceptability (e.g. reduced odour and powder colour) which have not been reported before in literature. This advancement enhances BSFL protein’s commercial viability as a sustainable, high-quality food ingredient for human food. Doctoral 2026-04-07T10:41:32Z 2026-04-07T10:41:32Z 2026-03 Thesis https://scholar.sun.ac.za/handle/10019.1/135674 en Stellenbosch University 263 pages : ill. application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Chakawa, Dennis Panashe Downstream processing of Black soldier fly larvae protein for human consumption |
| title | Downstream processing of Black soldier fly larvae protein for human consumption |
| title_full | Downstream processing of Black soldier fly larvae protein for human consumption |
| title_fullStr | Downstream processing of Black soldier fly larvae protein for human consumption |
| title_full_unstemmed | Downstream processing of Black soldier fly larvae protein for human consumption |
| title_short | Downstream processing of Black soldier fly larvae protein for human consumption |
| title_sort | downstream processing of black soldier fly larvae protein for human consumption |
| url | https://scholar.sun.ac.za/handle/10019.1/135674 |
| work_keys_str_mv | AT chakawadennispanashe downstreamprocessingofblacksoldierflylarvaeproteinforhumanconsumption |