Nonthermal technologies affecting techno-functional properties of edible insect-derived proteins, lipids, and chitin: a literature review

To increase the acceptability of edible insects, different strategies have been suggested to dispel neophobia toward this novel food. Extracts of the main nutritional components of insects have been proposed as food ingredients. However, extraction methods can affect the techno-functional properties of insect extracts, especially when heat is applied. Therefore, nonthermal technologies have recently attracted the attention of researchers. Among nonthermal technologies, high hydrostatic pressure (HHP), pulsed electric field (PEF), ultrasound (US) and cold atmospheric plasma (CAPP) have been described and discussed in the current review considering their effect on techno-functional properties of proteins, lipids, and chitin in insect-derived products. HHP and PEF have demonstrated great potential to improve insect protein solubility, whereas the oil holding capacity (OHC) was positively affected by PEF. The water holding capacity (WHC) showed a different performance according to insect species (Gryllodes sigillatus, Acheta domesticus, or Tenebrio molitor) and treatment applied (e.g., HHP). Of note, greater foaming capacity of insect proteins was achieved by applying HHP and US. Regarding insect lipids US assisted extraction with ethanol:water (E:W) extraction, fats rich in unsaturated fatty acids (e.g., linoleic acid) were obtained, whereas, regarding insect chitin, further studies are necessary to clearly understand and improve its extractability.