Developing a quality control system of insect diets using textural analysis

We developed a system of quality control of a gelled wheat germ diet using rheological or textural parameters and measurement techniques. The diets were agar or carrageenan-based with several different kinds of gelling synergists and antagonists. The diets were also made with several modifications in the processing techniques (including different heating and mixing methods). We tested the diets using an ATS RheoSystems STRESSTECH Rheometer and a Brookfield LFRA Texture Analyzer, which allowed us to measure viscous and elastic properties, fracture force, hardness, cohesiveness, adhesiveness, and gumminess of the various diets. The differences in these textural characteristics were significantly different and highly influenced by diet components and processing techniques. We discuss the importance of such differences in texture in terms of palatability and stability of insect diets. We further provide a flow chart and methodology for using diet texture as determined by rheological analysis in a quality control program for rearing a wide variety of insects.