title: Development of a freeze-dried mixture of Nile tilapia (Oreochromis niloticus) croquette using a GA-based multiobjective optimisation.
abstract: BACKGROUND
  The mechanically separated meat (MSM) of Nile tilapia is an example of a by-product that can be used in the development of new foods. The aim of this study was to optimise the mixture of different flours in the development of a freeze-dried mixture of fish croquette using Nile tilapia MSM. Flavour, texture and overall acceptance of seven formulations were evaluated by an acceptance test. A genetic algorithm (GA) with desirability functions was combined with a multiobjective optimisation of the response surface models.
  
  
  RESULTS
  The combination of flours was chosen to minimise cost and maximise overall acceptance and fibre content. Overall acceptance showed a statistically significant correlation (P ≤ 0.05) with flavour (r = 0.67) and texture (r = 0.61). The GA-based approach indicated that the highest overall acceptance was obtained when using wheat and rye flours in equal parts. This formulation had an overall acceptance of 7.52, a fibre content of 11.50 g kg⁻¹ and a cost of US$2.21/kg. After 24 h of freeze-drying, the water activity of the mixture was 0.11.
  
  
  CONCLUSIONS
  The GA-based approach was able to optimise the croquette formulation. The freeze-drying process contributed to the development of a value-added product with high quality and long shelf-life.
authors.affiliation: Food Technology Department, Federal University of Technology-Paraná (UTFPR), Caixa Postal 271, BR 369, km 0.5, CEP 87301-006, Campo Mourão, PR, Brazil. piocoerenata@yahoo.com.br
authors.forename: Renata H B
authors.initials: RH
authors.lastname: Fuchs
authors.forename: Ricardo P
authors.initials: RP
authors.lastname: Ribeiro
authors.forename: Evandro
authors.initials: E
authors.lastname: Bona
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsushita
mesh_terms: D000465:Algorithms; D000818:Animals; D001938:Brazil; D055598:Chemical Phenomena; D023681:Cichlids; D003365:Costs and Cost Analysis; D004043:Dietary Fiber / Q000032:analysis; D005396:Fish Products / Q000032:analysis* / Q000191:economics; D005398:Fisheries / Q000191:economics; D005433:Flour / Q000032:analysis*; D005518:Food Preferences; D057141:Food, Preserved / Q000032:analysis* / Q000191:economics; D005525:Food-Processing Industry / Q000191:economics; D005612:Freeze Drying; D006801:Humans; D007220:Industrial Waste / Q000032:analysis / Q000191:economics; D055595:Mechanical Phenomena; D017747:Seafood / Q000032:analysis* / Q000191:economics; D012434:Secale / Q000737:chemistry; D012677:Sensation; D014908:Triticum / Q000737:chemistry; D014867:Water / Q000032:analysis
chemical_list: D004043:Dietary Fiber; D007220:Industrial Waste; D014867:Water