Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Record number 537704
Title Potential of insect proteins for food and feed : Effect of endogenous enzymes and iron-phenolic complexation
Author(s) Janssen, Renske H.
Source Wageningen University. Promotor(en): V. Fogliano, co-promotor(en): J.P. Vincken; C.M.M. Lakemond. - Wageningen : Wageningen University - ISBN 9789463437684 - 145
Department(s) Food Chemistry
Food Quality and Design
VLAG
Publication type Dissertation, internally prepared
Publication year 2018
Abstract

Insects have been identified as excellent alternative source of proteins due to their high protein content. The acceptance of insects increases when used as ingredient in an invisible manner and hence grinding is necessary. Off-colour formation occurs upon grinding larvae, which can hamper their potential use as ingredient for food and feed. The aim of this thesis was to investigate potential of insect larvae as protein source, the mechanisms responsible for the browning or blackening of larvae during grinding, and its impact on protein functionality. This was investigated for the larvae of three species: Tenebrio molitor, Alphitobius diaperinus and Hermetia illucens.

The specific Kp factor of 4.76±0.09 was determined for the three species to determine protein content based on nitrogen, and 5.60±0.39 after protein extraction and purification. Thus, the general Kp factor of 6.25, used until now, overestimated the protein content in insects. Off-colour formation upon grinding was caused by both enzymatic and non-enzymatic browning. Phenoloxidase was found to be mainly responsible for browning in T. molitor and likely in A. diaperinus, whereas iron-phenolic complexation likely contributed to the black colour in H. illucens. A model system of L-DOPA and iron was used to elucidate the structures of the iron-L- DOPA complexes by mass spectrometry.

Enzymatic browning did not influence the solubility of the proteins of all three species. Upon in-vitro hydrolysis by pepsin and trypsin, soluble proteins from H. illucens were more digestible compared to those of T. molitor and A. diaperinus. Phenoloxidase activity during processing negatively affected in-vitro pepsin hydrolysis. Besides phenoloxidase activity, also endogenous proteases remained active at pH 8 in extracts of insect larvae. Summarizing, endogenous enzyme activities and iron complexation should be taken into account for future application, as well as the specific Kp factor to prevent overestimation of the protein content of insects.

Comments
There are no comments yet. You can post the first one!
Post a comment
 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.