Comparative protein determination in insects

Globally there is a steady increase in human population, which has raised concerns of food security. Moreover, there is an increase in the demand of more sustainable sources of food to ensure environmental protection while meeting human nutritional requirements. Particularly alternative protein sources are targeted. That`s why insects have attracted attention of many scholars, companies, and organizations.

Establishment of a reliable protein determination assay

Insects are offering some promising properties like their ability to efficiently convert food byproducts into biomass or their small demand for land and water. Likewise, the nutritional value of insects is interesting and they are reported to be a good source of protein. However, the morphology and biochemical structure of insects is different compared to common sources of protein due to their high chitin content. Chitin is an amino polysaccharide that contains high amounts of nitrogen. Protein determination methods that rely on measuring nitrogen atoms in a sample could therefore lead to inaccurate results. The aim of this project was to assess the most efficient protein extraction method and ensure the most efficient protein concentration determination method relevant for measuring insect protein content.

In this study different protein extraction methods and buffers were evaluated as well as different methods for protein concentration determination tested. A reliable procedure was identified and a protein determination assay was established. Since this method is not based on nitrogen it can provide more accurate results. It was confirmed that insects provide high protein contents even though the absolute numbers are conclusively lower than those obtained by assays in which chitin is interfering.

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Furthermore, the new method was used to identify factors that could influence protein content in insects. It was observed that the feed as well as the life cycle stage of the insect led to varying protein contents. Those findings provide a valuable basis for further research and should be considered when defining insect growth strategies for maximum protein content.

University of Bayreuth, Campus Kulmbach; Faculty of Life Sciences: Food, Nutrition and Health; Chair of Nutritional Biochemistry

Project Manager: Prof. Dr. Janin Henkel-Oberländer

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Project report "Comparative protein determination in insects".