Impact of Heat Treatment on the Microbiological Quality of Frass Originating from Black Soldier Fly Larvae (<i>Hermetia illucens</i>)
Since black soldier fly larvae (BSFL, <i>Hermetia illucens</i>) are being produced at substantial volumes, concomitantly large amounts of the resulting by-product, called frass, are generated. This frass can potentially be applied as valuable plant fertilizer or soil improver. Since fras...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-12-01
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| Series: | Insects |
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| Online Access: | https://www.mdpi.com/2075-4450/13/1/22 |
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| author | Noor Van Looveren Dries Vandeweyer Leen Van Campenhout |
| author_facet | Noor Van Looveren Dries Vandeweyer Leen Van Campenhout |
| author_sort | Noor Van Looveren |
| collection | DOAJ |
| description | Since black soldier fly larvae (BSFL, <i>Hermetia illucens</i>) are being produced at substantial volumes, concomitantly large amounts of the resulting by-product, called frass, are generated. This frass can potentially be applied as valuable plant fertilizer or soil improver. Since frass carries high microbial counts, potentially including foodborne pathogens, safety problems for consumers should be prevented. A heat treatment of 70 °C for 60 min is proposed to reduce harmful organisms in insect frass, based on EU regulations ((EU) No. 2021/1925). This study evaluated for the first time the impact of the proposed heat treatment on BSFL frass. This was done by applying the treatment on uninoculated frass as well as on frass inoculated with <i>Salmonella</i> or <i>Clostridium perfringens</i> at 5.0 log cfu/g. The heat treatment resulted in a reduction (maximum one log-cycle) of total viable counts and did not noticeably reduce bacterial endospores. In contrast, Enterobacteriaceae counts were reduced to below the detection limit (10 cfu/g). Heat treatment of inoculated frass resulted in absence of <i>Salmonella</i> in 25 g of frass and reduction of vegetative <i>C. perfringens</i> to below the detection limit (1 cfu/g). The proposed heat treatment appears to be appropriate to meet the microbiological regulations for insect frass. |
| first_indexed | 2024-03-10T01:16:01Z |
| format | Article |
| id | doaj.art-4f4f150d662d434c98e8b2cd192171c3 |
| institution | Directory Open Access Journal |
| issn | 2075-4450 |
| language | English |
| last_indexed | 2024-03-10T01:16:01Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Insects |
| spelling | doaj.art-4f4f150d662d434c98e8b2cd192171c32023-11-23T14:09:32ZengMDPI AGInsects2075-44502021-12-011312210.3390/insects13010022Impact of Heat Treatment on the Microbiological Quality of Frass Originating from Black Soldier Fly Larvae (<i>Hermetia illucens</i>)Noor Van Looveren0Dries Vandeweyer1Leen Van Campenhout2Research Group for Insect Production and Processing, Department of Microbial and Molecular Systems (M2S), Geel Campus, KU Leuven, Kleinhoefstraat 4, 2440 Geel, BelgiumResearch Group for Insect Production and Processing, Department of Microbial and Molecular Systems (M2S), Geel Campus, KU Leuven, Kleinhoefstraat 4, 2440 Geel, BelgiumResearch Group for Insect Production and Processing, Department of Microbial and Molecular Systems (M2S), Geel Campus, KU Leuven, Kleinhoefstraat 4, 2440 Geel, BelgiumSince black soldier fly larvae (BSFL, <i>Hermetia illucens</i>) are being produced at substantial volumes, concomitantly large amounts of the resulting by-product, called frass, are generated. This frass can potentially be applied as valuable plant fertilizer or soil improver. Since frass carries high microbial counts, potentially including foodborne pathogens, safety problems for consumers should be prevented. A heat treatment of 70 °C for 60 min is proposed to reduce harmful organisms in insect frass, based on EU regulations ((EU) No. 2021/1925). This study evaluated for the first time the impact of the proposed heat treatment on BSFL frass. This was done by applying the treatment on uninoculated frass as well as on frass inoculated with <i>Salmonella</i> or <i>Clostridium perfringens</i> at 5.0 log cfu/g. The heat treatment resulted in a reduction (maximum one log-cycle) of total viable counts and did not noticeably reduce bacterial endospores. In contrast, Enterobacteriaceae counts were reduced to below the detection limit (10 cfu/g). Heat treatment of inoculated frass resulted in absence of <i>Salmonella</i> in 25 g of frass and reduction of vegetative <i>C. perfringens</i> to below the detection limit (1 cfu/g). The proposed heat treatment appears to be appropriate to meet the microbiological regulations for insect frass.https://www.mdpi.com/2075-4450/13/1/22black soldier fly larvae<i>Hermetia illucens</i>insect frassheat treatmentfoodborne pathogens |
| spellingShingle | Noor Van Looveren Dries Vandeweyer Leen Van Campenhout Impact of Heat Treatment on the Microbiological Quality of Frass Originating from Black Soldier Fly Larvae (<i>Hermetia illucens</i>) Insects black soldier fly larvae <i>Hermetia illucens</i> insect frass heat treatment foodborne pathogens |
| title | Impact of Heat Treatment on the Microbiological Quality of Frass Originating from Black Soldier Fly Larvae (<i>Hermetia illucens</i>) |
| title_full | Impact of Heat Treatment on the Microbiological Quality of Frass Originating from Black Soldier Fly Larvae (<i>Hermetia illucens</i>) |
| title_fullStr | Impact of Heat Treatment on the Microbiological Quality of Frass Originating from Black Soldier Fly Larvae (<i>Hermetia illucens</i>) |
| title_full_unstemmed | Impact of Heat Treatment on the Microbiological Quality of Frass Originating from Black Soldier Fly Larvae (<i>Hermetia illucens</i>) |
| title_short | Impact of Heat Treatment on the Microbiological Quality of Frass Originating from Black Soldier Fly Larvae (<i>Hermetia illucens</i>) |
| title_sort | impact of heat treatment on the microbiological quality of frass originating from black soldier fly larvae i hermetia illucens i |
| topic | black soldier fly larvae <i>Hermetia illucens</i> insect frass heat treatment foodborne pathogens |
| url | https://www.mdpi.com/2075-4450/13/1/22 |
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