Four insect oils as food ingredient: Physical and chemical characterisation of insect oils obtained by an aqueous oil extraction
Tzompa-Sosa, D.A. ; Yi, L. ; Valenberg, H.J.F. van; Lakemond, C.M.M. - \ 2019
Journal of Insects as Food and Feed 5 (2019)4. - ISSN 2352-4588 - p. 279 - 292.
Acheta domesticus - Alphitobius diaperinus - Aroma - Blaptica dubia - Insect oils - Novel food - Tenebrio molitor
Insect fractionation and insect ingredient characterisation is of relevance in view of the increase in insect production and demand of insect ingredients worldwide. This study aims to contribute to the knowledge of insect oils that were extracted from insects commercially reared in Europe. Oil was extracted from yellow mealworm, lesser mealworm, house cricket and Dubia cockroach by an aqueous based oil extraction method. These insect oils were physicochemically characterised on the most important parameters for food applications, namely thermal behaviour (differential scanning calorimeter), colour (spectrophotometry) and aroma compounds (gas chromatography-mass spectrometry). The amount and the composition of the un-extracted lipid fraction was determined by means of fatty acid (FA) profiling (gas chromatography with flame ionisation detector). Although no distinctive pattern was seen in all four species, it becomes clear from its FA profile that the extracted fat is more similar to the residue and cream fractions than to the pellet and supernatant. The amount of lipids that was not extracted was species dependent ranging from 40 to up to 82% of the total lipid content. Further work is needed to reduce the oil loss in this extraction. The extracted insect oil presented a wide range of melting peaks, from -30.7 to 22.7 °C, which makes them liquid-like at room temperature. Its thermal profile shows separated peaks showing that fat fractionation is feasible. Oil colour was bright yellow-reddish. Most oils had compounds related to pleasant aromas, except for Dubia cockroach. In the latter oil several acid compounds related to unpleasant aromas were identified. This study shows that yellow meal worm oil, lesser mealworm oil and cricket oil have characteristics desirable for table oils and for oils use as food ingredients.
Dietary enrichment of edible insects with omega 3 fatty acids
Oonincx, Dennis G.A.B. ; Laurent, Sophie ; Veenenbos, Margot E. ; Loon, Joop J.A. van - \ 2019
Insect Science (2019). - ISSN 1672-9609
Acheta domesticus - Alphitobius diaperinus - diet - fatty acids - Hermetia illucens
Edible insects are advocated as sustainable and healthy food and feed. However, commercially produced insects are often low in n-3 fatty acids and have suboptimal n-6/n-3 ratios. A certain amount and proportion of these FAs is required to optimize human health. Flaxseed oil consists primarily (57%) out of alpha-linolenic acid. An experiment was conducted to quantify the effect of flaxseed oil provision on fatty acid composition and to determine the quantity needed to attain a beneficial n-6/n-3 ratio. Three species were used in the experiment: house crickets (Acheta domesticus [L.]), lesser mealworms (Alphitobius diaperinus [Pfanzer]) and black soldier flies (Hermetia illucens [L.]). These were provided with either a control diet or a diet enriched with 1%, 2%, or 4% flaxseed oil during their larval/nymphal stage. Fatty acid profiles of diets and insects were determined via GC-MS. The three species had distinct fatty acid profiles on all four diets, but responded similarly to flaxseed oil addition. For each percent added to the diet, the alpha-linolenic acid content of the insects increased by 2.3%–2.7%. Four percent addition increased the n-3 fatty acid content 10–20 fold in the three species and thereby strongly decreased n-6/n-3 ratios from 18–36 to 0.8–2.4. A ratio below 5 is considered optimal for human health and was achieved by 2% flaxseed oil inclusion for house crickets and lesser mealworms, and at 1% inclusion for black soldier flies. Adding a source of n-3 fatty acids to insect diets can thus improve the nutritional quality of insects.