Black Soldier Fly (Hermetia illucens) larvae as an alternative ingredient in processed meat

Date
2021-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
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.
AFRIKAANSE OPSOMMING: Swart soldaatvlieg (Hermetia illucens) larwe (BSFL) (Diptera: Stratiomyidae), wat hoofsaaklik as veevoerbestanddeel gebruik word, begin belofte toon as 'n volhoubare bestanddeel vir menslike gebruik. Met die toenemende belangstelling in BSFL vir menslike verbruik, is daar nog baie leemtes in kennis wat gevul moet word voordat dit aanbeveel kan word vir die gebruik in menslike voedsel. Hieronder tel die tegno-funksionele eienskappe van BSFL, die voedselveiligheid van die verbruik daarvan, die potensiële produktoepassings, en ten slotte, die begrip of verbruikers bereid is om 'n voedselproduk wat BSFL bevat te verbruik. Swart soldaatvlieglarwes het die vermoë om op 'n verskeidenheid voere te groei, alhoewel die voersubstraat en na-oesverwerking (dit wil sê blansjering) getoon het dat dit faktore soos byvoorbeeld die voedingsprofiel van BSFL beïnvloed. Hierdie wisselvalligheid in die BSFL-samestelling kan moontlik die funksionaliteit daarvan beïnvloed vir die beoogde eindgebruik. Met die wêreldwye strewe na volhoubare alternatiewe tot vleis, het BSFL die potensiaal om 'n funksionele en veilige alternatief vir vleis te wees, hoewel meer navorsing nodig is om dit te bekragtig. Tot op hede is daar beperkte navorsing oor die gebruik van BSFL as ‘n vleis alternatief. Swart soldaatvlieglarwes wat op drie verskillende voere gegroei het (braaikuiken-gebaseerde voer, brouersgraan, gemengde graankorrel), op drie verskillende ouderdomme (dag 5, 8, 11) geoes was, en met twee verskillende metodes (blansjering, bevriesing) doodgemaak is, is ontleed om die fisio-chemiese eienskappe (benaderde samestelling, pH, kleur), daarvan te bepaal. Die tegno- funksionele eienskappe (waterabsorpsievermoë, lipiedabsorpsievermoë, emulsievermoë, emulsiestabiliteit, gelvorming) en voedselveiligheid (mikrobiese inhoud, swaarmetaalbesoedeling, allergeen opsporing) was ook bepaal. Die BSFL is toe geïnkorporeer in 'n burger-pattie om vas te stel of dit vleis volledig / gedeeltelik kan vervang, en 'n verbruikersopname is versprei om vas te stel hoe verbruikers (studente) sou reageer op die burger-pattie wat BSFL bevat. Die bevindings het aangedui dat voer, ouderdom en doodmaakmetode 'n beduidende invloed gehad het op die fisiese samestelling, tegno-funksionele eienskappe en die benaderde samestelling van die larwes (met die uitsondering van chitien- en as-inhoud, wat nie deur die doodmaakmetode beïnvloed is nie). Daar is ook gevind dat die voer- en doodmaakmetode die teenwoordigheid van mikrobes en swaar metale in BSFL beïnvloed het, en daar is gevind dat blansjering die relatiewe oorvloed van kruisreaktiewe allergene, tropomiosien en arginienkinase verhoog. Swart soldaatvlieglarwes wat op gebruikte graan (11 dae oud) gekweek is, is op verskillende insluitingsvlakke in bees-patties ingesluit, naamlik 0% (kontrole), 25%, 50%, 75% en 100%, en daar is gevind dat die gedeeltelike vervanging van vleis in 'n burger-pattie moontlik is, met die vervanging van 25% wat die naaste was aan 'n bees-pattie. Verbruikers het die voorkoms van die gekookte BSFL-patties bo die rou bees-patties verkies, maar hulle verkies die rou bees-patties bo die rou BSFL-patties. Faktore soos geslag, opvoedingsvlak en vorige ervaring met die eet van insekte het die deelnemers se mate van voorkeur teenoor die burger-patties se beelde beïnvloed. Die bevindings van hierdie studie bied 'n basislyn vir die gebruik van BSFL as 'n alternatief tot vleis, terwyl die potensiële invloede wat die boerdery, grootmaak en voorverwerking op die funksionaliteit en veiligheid van BSFL kan hê, in ag geneem word
Description
Thesis (PhDAgric)--Stellenbosch University, 2021.
Keywords
Black soldier fly larvae (BSFL), Animal feeding, Human food, Black soldier fly (Hermetia illucens)larvae -- Nutrient value, Proteins in animal nutrition, Edible insects, Proteins in human nutrition, UCTD
Citation