The effectiveness and efficiencies of small-scale drying methods for black soldier fly larvae

  • 48 pages

  • Published: 19 Jun 2023

  • Author(s): C. J. Malcolm, J. M. L. Malcolm

  • ISBN: 978-1-76053-383-0

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Insects, including the black soldier fly (Hermetia illucens L.) have been considered as a potential feed resource that can provide protein and fat for animals. However, the nutritional value of black soldier fly larvae as a feed ingredient depends on various factors, such as the rearing substrate and the methods used for slaughter and drying.

This research project compared the post-harvest drying technologies and the nutritional value of black soldier fly larvae as an animal feed ingredient an assessed the safety and quality of products produced from the larvae regarding residual microbial loadings.

The project revealed that high-temperature oven drying (HTD) and microwave drying (MWD) present the most effective and efficient drying methodologies in terms of moisture removal rates and energy use compared with freeze-drying (FD) and low-temperature air drying (LTD). These two methodologies also deliver preferred appearance and sensory appeal. Crude protein (CP) content was not affected by drying methods. The LTD of larvae had greater crude lipid content and higher metabolisable energy (ME) content compared with the other drying methods tested.

Further, euthanising the larvae by blanching in water at 90 °C for as little as 40 seconds provided reduced the total viable count of microbial populations to levels acceptable to Australian and international standards for pet food. These counts were further reduced during drying.