Effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs (Oryctes sp.)
Although edible rhinoceros beetle (Oryctes sp.) larvae are popularly consumed in many countries worldwide, they are prepared using different methods such as boiling, roasting, toasting, and deep-frying, whose effect on nutritional value and microbial safety is scarcely known. Here we investigated th...
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| Format: | Article |
| Language: | English |
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Elsevier
2024-02-01
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| Series: | Heliyon |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2405844024013628 |
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| author | Marliyn W. Muthee Fathiya M. Khamis Xavier Cheseto Chrysantus M. Tanga Sevgan Subramanian James P. Egonyu |
| author_facet | Marliyn W. Muthee Fathiya M. Khamis Xavier Cheseto Chrysantus M. Tanga Sevgan Subramanian James P. Egonyu |
| author_sort | Marliyn W. Muthee |
| collection | DOAJ |
| description | Although edible rhinoceros beetle (Oryctes sp.) larvae are popularly consumed in many countries worldwide, they are prepared using different methods such as boiling, roasting, toasting, and deep-frying, whose effect on nutritional value and microbial safety is scarcely known. Here we investigated the effect of these methods on the nutritional value and microbial safety of Oryctes sp. larvae. Our hypothesis was that cooking the grubs using the four methods had no effect on their nutritional content and microbial loads and diversity. The grubs were analyzed for proximate composition, and fatty and amino acid profiles using standard chemical procedures; and microbial safety using standard culturing procedures. Deep-frying reduced protein and carbohydrate content, but elevated fat content. Boiling lowered ash content, but increased fibre and carbohydrate composition. Roasting and toasting increased protein and ash contents, respectively. Forty fatty acids were detected in the larvae, of which levels of only five were not significantly affected by cooking method, while the levels of the others were differentially affected by the different cooking methods. Amino acid profiles and levels were largely comparable across treatments, but lysine and arginine were higher in all cooked grubs than raw form. All the cooking methods eliminated Enterobacteriaceae, Shigella sp. and Campylobacter sp. from the grubs. Except boiling, all methods reduced total viable count to safe levels. Salmonella sp. were only eliminated by toasting and roasting; while boiling promoted growth of yeast and moulds. Staphylococcus aureus levels exceeded safety limits in all the cooking methods. These findings offer guidance on the type of method to use in preparing the grubs for desired nutritional and safety outcomes. |
| first_indexed | 2024-03-08T00:10:29Z |
| format | Article |
| id | doaj.art-c28e4fa0ca164ad5bd9e66ddcca58c43 |
| institution | Directory Open Access Journal |
| issn | 2405-8440 |
| language | English |
| last_indexed | 2024-03-08T00:10:29Z |
| publishDate | 2024-02-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Heliyon |
| spelling | doaj.art-c28e4fa0ca164ad5bd9e66ddcca58c432024-02-17T06:40:41ZengElsevierHeliyon2405-84402024-02-01103e25331Effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs (Oryctes sp.)Marliyn W. Muthee0Fathiya M. Khamis1Xavier Cheseto2Chrysantus M. Tanga3Sevgan Subramanian4James P. Egonyu5International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772 – 00100, Nairobi, KenyaInternational Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772 – 00100, Nairobi, KenyaInternational Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772 – 00100, Nairobi, KenyaInternational Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772 – 00100, Nairobi, KenyaInternational Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772 – 00100, Nairobi, KenyaCorresponding author.; International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772 – 00100, Nairobi, KenyaAlthough edible rhinoceros beetle (Oryctes sp.) larvae are popularly consumed in many countries worldwide, they are prepared using different methods such as boiling, roasting, toasting, and deep-frying, whose effect on nutritional value and microbial safety is scarcely known. Here we investigated the effect of these methods on the nutritional value and microbial safety of Oryctes sp. larvae. Our hypothesis was that cooking the grubs using the four methods had no effect on their nutritional content and microbial loads and diversity. The grubs were analyzed for proximate composition, and fatty and amino acid profiles using standard chemical procedures; and microbial safety using standard culturing procedures. Deep-frying reduced protein and carbohydrate content, but elevated fat content. Boiling lowered ash content, but increased fibre and carbohydrate composition. Roasting and toasting increased protein and ash contents, respectively. Forty fatty acids were detected in the larvae, of which levels of only five were not significantly affected by cooking method, while the levels of the others were differentially affected by the different cooking methods. Amino acid profiles and levels were largely comparable across treatments, but lysine and arginine were higher in all cooked grubs than raw form. All the cooking methods eliminated Enterobacteriaceae, Shigella sp. and Campylobacter sp. from the grubs. Except boiling, all methods reduced total viable count to safe levels. Salmonella sp. were only eliminated by toasting and roasting; while boiling promoted growth of yeast and moulds. Staphylococcus aureus levels exceeded safety limits in all the cooking methods. These findings offer guidance on the type of method to use in preparing the grubs for desired nutritional and safety outcomes.http://www.sciencedirect.com/science/article/pii/S2405844024013628CampylobacterFatty and amino acid profilesProximate compositionSalmonellaShigellaStaphylococcus aureus |
| spellingShingle | Marliyn W. Muthee Fathiya M. Khamis Xavier Cheseto Chrysantus M. Tanga Sevgan Subramanian James P. Egonyu Effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs (Oryctes sp.) Heliyon Campylobacter Fatty and amino acid profiles Proximate composition Salmonella Shigella Staphylococcus aureus |
| title | Effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs (Oryctes sp.) |
| title_full | Effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs (Oryctes sp.) |
| title_fullStr | Effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs (Oryctes sp.) |
| title_full_unstemmed | Effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs (Oryctes sp.) |
| title_short | Effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs (Oryctes sp.) |
| title_sort | effect of cooking methods on nutritional value and microbial safety of edible rhinoceros beetle grubs oryctes sp |
| topic | Campylobacter Fatty and amino acid profiles Proximate composition Salmonella Shigella Staphylococcus aureus |
| url | http://www.sciencedirect.com/science/article/pii/S2405844024013628 |
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