Effect of endogenous phenoloxidase on protein solubility and digestibility after processing of Tenebrio molitor, Alphitobius diaperinus and Hermetia illucens

Renske H. Janssen, Jean Paul Vincken*, Nathalie J.G. Arts, Vincenzo Fogliano, Catriona M.M. Lakemond

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

1 Citation (Scopus)


Upon extracting soluble proteins from insects as potential food ingredient, endogenous enzymes, such as phenoloxidases, are expected to negatively affect protein properties. The effect of phenoloxidases on solubility and digestibility of proteins was investigated for larvae of Tenebrio molitor, Alphitobius diaperinus and Hermetia illucens. Phenoloxidase inhibition was done using blanching (50 s, 90 °C) before extraction or extracting in presence of sulfite. Similar soluble protein yields and compositions were found without and with sulfite addition, whereas blanching decreased soluble protein yield. Upon in-vitro hydrolysis by pepsin and trypsin, soluble proteins from H. illucens were more digestible than those of T. molitor and A. diaperinus. Phenoloxidase activity during grinding negatively affected in-vitro pepsin hydrolysis. Besides phenoloxidase activity, also endogenous proteases were shown to remain active at pH 8 in extracts containing sulfite and after blanching of larvae. This stresses that protease activity needs to be carefully controlled in the design of insect based ingredients.

Original languageEnglish
Pages (from-to)684-690
Number of pages7
JournalFood Research International
Early online date24 Dec 2018
Publication statusPublished - Jul 2019



  • Black soldier fly
  • Digestion
  • Edible insects
  • Enzymatic browning
  • Lesser mealworm
  • Phenoloxidase
  • Protease
  • Protein extraction
  • Solubility
  • Tyrosinase
  • Yellow mealworm

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