title: Effect of technological factors on the activity and losses of cathepsins B, D and L during the marinating of Atlantic and Baltic herrings.
abstract: BACKGROUND
  This study analyzes the effect of salt and acetic acid concentration, time, temperature and fish freezing on the activity and losses of cathepsins during the marinating of Atlantic and Baltic herrings.
  
  
  RESULTS
  The highest contribution to meat general proteolytic activity was found for cathepsin D-like activity. This contribution decreased during the marinating process as a result of, among other things, cathepsin losses to brine. The methods of marinating had a significant impact on cathepsin activity losses. The average ratio of cathepsin D-like activity to L and B in brine accounted for 15:3.5:1.5, respectively. Depending on the method of calculation, cathepsin activity in brine was similar (per gram of tissue/milliliter of brine) or multiply higher (per gram protein in tissue/brine) than in the marinated herring meat. Statistical analysis demonstrated that the extent and structure of cathepsin losses were significantly correlated with the quantitative and qualitative composition of protein hydrolysis products in marinades.
  
  
  CONCLUSIONS
  The presented results depict new phenomena of cathepsin losses and explain their impact on the process of fish marinating. Results allow better optimization of the process of meat ripening. The high activity of aspartyl and cysteine cathepsins in brine indicates the real feasibility of their application in the food industry for novel food design. © 2016 Society of Chemical Industry.
authors.affiliation: Department of Food Science and Technology, Faculty of Food Science and Fisheries, West Pomeranian University of Technology in Szczecin, 71-459, Szczecin, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Szymczak
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000818:Animals; D002403:Cathepsins / Q000032:analysis*; D005399:Fishes; D005511:Food Handling / Q000379:methods*; D005615:Freezing; D006868:Hydrolysis; D012492:Salts / Q000737:chemistry; D017747:Seafood / Q000032:analysis*; D012965:Sodium Chloride / Q000737:chemistry
chemical_list: D012492:Salts; C017082:brine; D012965:Sodium Chloride; D002403:Cathepsins; D019342:Acetic Acid
keywords: cathepsins B, D, L; cathepsins losses; herring; marinating; meat and brine