Artificial neural networks to model the production of blood protein hydrolysates for plant fertilisation

J Sci Food Agric. 2016 Jan 15;96(1):207-14. doi: 10.1002/jsfa.7083. Epub 2015 Feb 10.


Background: Amino acid-based fertilisers increase the bioavailability of nitrogen in plants and help withstand stress conditions. Additionally, porcine blood protein hydrolysates are able to supply iron, which is involved in chlorophyll synthesis and improves the availability of nutrients in soil. A high degree of hydrolysis is desirable when producing a protein hydrolysate intended for fertilisation, since it assures a high supply of free amino acids. Given the complexity of enzyme reactions, empirical approaches such as artificial neural networks (ANNs) are preferred for modelisation.

Results: Porcine blood meal was hydrolysed for 3 h with subtilisin. The time evolution of the degree of hydrolysis was successfully modelled by means of a feedforward ANN comprising 10 neurons in the hidden layer and trained by the Levenberg-Marquardt algorithm. The ANN model described adequately the influence of pH, temperature, enzyme concentration and reaction time upon the degree of hydrolysis, and was used to estimate the optimal operation conditions (pH 6.67, 56.9 °C, enzyme to substrate ratio of 10 g kg(-1) and 3 h of reaction) leading to the maximum degree of hydrolysis (35.12%).

Conclusions: ANN modelling was a useful tool to model enzymatic reactions and was successfully employed to optimise the degree of hydrolysis.

Keywords: artificial neural networks; blood protein; degree of hydrolysis; enzymatic hydrolysis; fertilisation; modelisation.

Publication types

  • Validation Study

MeSH terms

  • Agriculture
  • Algorithms*
  • Amino Acids / metabolism*
  • Animals
  • Biological Availability
  • Blood Proteins / metabolism*
  • Fertilizers*
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Iron / metabolism
  • Models, Biological*
  • Neural Networks, Computer
  • Nitrogen / metabolism*
  • Protein Hydrolysates / biosynthesis*
  • Protein Hydrolysates / metabolism
  • Reproducibility of Results
  • Subtilisin / metabolism
  • Swine / blood
  • Temperature


  • Amino Acids
  • Blood Proteins
  • Fertilizers
  • Protein Hydrolysates
  • Iron
  • Subtilisin
  • Nitrogen