Doctoral Degrees (Animal Sciences)

Permanent URI for this collection

https://scholar.sun.ac.za/handle/10019.1/526

Browse

Browsing Doctoral Degrees (Animal Sciences) by Subject "Animal feeding"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Black Soldier Fly (Hermetia illucens) larvae as an alternative ingredient in processed meat
    (Stellenbosch : Stellenbosch University, 2021-03) Bessa, Leah Wilson; Hoffman, Louwrens C.; Pieterse, Elsje; Marais, Jeannine; Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences.
    ENGLISH ABSTRACT: Black soldier fly (Hermetia illucens) larvae (BSFL) (Diptera: Stratiomyidae), primarily used as an animal feed ingredient, is beginning to show promise as a sustainable ingredient for human consumption. With this growing interest in BSFL for human consumption, there are still many gaps in knowledge that need to be filled prior to advocating for its use in human food. Amongst these are the techno-functional properties of BSFL, the food safety of consuming it, the potential product applications and finally, understanding whether consumers would be willing to consume a food product containing BSFL. Black soldier fly larvae have the ability to grow on a range of feeds, although the feed substrate and post-harvest processing (i.e., blanching) has shown to influence factors such as the nutritional profile of BSFL. This variability in BSFL composition can potentially influence its functionality for its intended end use. With the global push for sustainable meat alternatives, BSFL have the potential to be a functional and safe alternative to meat, although more research is required to validate this. To date, there is limited research on using BSFL as a meat alternative. Black soldier fly larvae grown on three different feeds (broiler-based feed, brewers’ grain, mixed cereal grain), harvested at three different ages (day 5, 8, 11), and killed using two different methods (blanching, freezing) were analysed to determine their physiochemical properties (proximate composition, pH, colour), techno-functional properties (water absorption capacity, lipid absorption capacity, emulsion capacity, emulsion stability, gel formation) and food safety (microbial content, heavy metal contamination, allergen detection). The BSFL were then incorporated into a burger patty to determine whether it could fully/partially replace meat, and a consumer survey was distributed to determine how consumers (students) would respond to the burger patties containing BSFL. The findings indicated feed, age and killing method had a significant influence on the physical composition, techno-functional properties, and proximate composition of the larvae (with the exception of chitin and ash, which was not affected by killing method). The feed and killing method were also found to influence the presence of microbes and heavy metals in BSFL, and blanching was found to increase the relative abundance of cross-reactive allergens, tropomyosin, and arginine kinase. Black soldier fly larvae grown on spent grain (11-days old) were included in beef patties at various inclusion levels, namely 0% (control), 25%, 50%, 75% and 100%, and were found to be able to replace meat only partially in a burger patty, with 25% replacement being the closest to a beef patty. Consumers preferred the appearance of the cooked BSFL patties over the raw beef patties, however, they preferred the raw beef patties to the raw BSFL patties. Factors such as gender, education level and prior experience of eating insects influenced the participants liking of the burger patties’ images. This study’s findings provide a baseline for using BSFL as a meat alternative, whilst considering the potential influences that farming, rearing, and pre-processing may have on the functionality and safety of BSFL.