The yellow mealworm Tenebrio molitor : a potential source of food lipids

Sammanfattning: The yellow mealworm Tenebrio molitor is considered as a sustainable alternative to animal-derived source of protein. The population of the world increases and is believed to be over 9 billion by 2050, and the demand of protein will increase. Among edible insects, the mealworm is the one most commonly reared in Europe. After protein, the second largest part of the mealworm is lipids, which amounts to about 33% of dry matter. With this large amount of lipids, the mealworm could be a potential source of food lipids. In this work, the aim is to review the current knowledge about the lipid content and fatty acid composition in mealworms. The most common fatty acids in mealworms are palmitic acid, oleic acid and linoleic acid. The mealworm can synthesize both linoleic acid (LA) and alpha lino-lenic acid (ALA), which are essential fatty acids for humans. Ratios between poly-unsaturated fatty acids (PUFA) and saturated fatty acids (SFA) (PUFA/SFA) and ratios between n-6/n-3 are used as index of healthy diet. The PUFA/SFA ratio in the mealworm has been found to be within the recommended values. Mealworms are rich in unsaturated fatty acids (UFAs) (monounsaturated fatty acids and polyun-saturated fatty acids), but the ratio of n-6/n-3 varied greatly. It would be desirable with higher content of ALA (n-3) to get a better n-6/n-3 ratio. It has been shown that it is possible to manipulate the content of lipids and the composition of fatty acids in the mealworm through the feed. However, the composition of the feed and the content of the mealworms do not necessarily match, so there is a physiological regulation of the composition of FAs. Other conditions such as temperature, humid-ity and development stage are also factors that have an impact on the lipids and FAs. In the reviewed literature, the results vary and all conditions are not always known. The conclusion is that more research is needed before the mealworm can be promoted as a new source of food lipids. The reason could be that the meal-worm primarily has been highlighted as a source of protein, which may have over-shadowed the mealworm as a potential source of food lipids.