PhD defence: Insect as food and feed

Protein quality of insects for human consumption and effect of insects on growth performance and gut health of piglets

Insects

Navodita Malla

PhD thesis

Insects have gained global recognition as a sustainable alternative to conventional protein sources, with the potential to address global food and nutrition insecurity as well as reduce the ecological footprint of animal production.

The overall aim of this thesis is to provide scientific evidence and add to the current knowledge on the suitability of insects as food and feed. This thesis is based on two experimental studies and one review.

Paper I investigated the protein quality of the five insect species (LMW, Alphitobius diaperinus; YMW, Tenebrio molitor; HC, Acheta domesticus; BC, Gryllodes sigillatus; and BSF, Hermetia illucens). The LMW, HC and BC were categorized for having good quality protein sources for older age groups.

The sulphur amino acids were first limiting AAs for LMW, YMW, HC and BC and lysine for BSF for age ˃ six months. While assessing the protein quality of insects using DIAAS, the standard nitrogen to protein conversion of 6.25 needs reconsideration to account for non-protein-nitrogen present in insects, thereby underestimating the DIAAS of insects.

Paper II investigated how the partial replacement of soybean protein concentrate in weaned piglet diets with three insect species relevant for animal feed, LMW, YMW and BSF affects growth performance and various gut health parameters.

The study found that the insect-based diets were comparable to soybean protein concentrate-based diets. For gut health parameters, a reduction in plasma DAO levels indicated the protection of the intestinal mucosa barrier function in piglets fed with mealworm-based diets. More research is necessary to understand the advantages and disadvantages of using insects as feed for weaned piglets.

Overall, the protein quality of insects, and their comparable growth performance to that of conventional feed, and positive impact on gut health parameters highlight their suitability as viable alternatives. These findings expand our knowledge and pave the way for a more sustainable and innovative approach to food and feed production.

Download List of papers; English summary; Sammendrag (Danish 􀁖ummary); Table of contents.

Time

20 October 2023, 13:00

Place

A2-70.03, Thorvaldsensvej 40, Frederiksberg.

Opponents

Professor Inge Tetens (chair), Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.

Professor Knud Erik Bach Knudsen, Department of Animal and Veterinary Sciences, Aarhus University, Denmark.

Honorary Professor Daniel Tomé, Human Nutrition, AgroParisTech, Université Paris-Saclay, France.

Main supervisor

Associate Professor Nanna Roos, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Denmark.

Co-supervisors

Professor Jan Værum Nørgaard, Department of Animal and Veterinary Sciences, Aarhus University, Denmark.

The thesis is available for inspection at the library, Nørre Allé 51, DK-2200 Copenhagen N.