title: Image analysis method to quantify the effect of different treatments on the visual meat/shell ratio of half-shelled green lipped mussels (Perna canaliculus).
abstract: BACKGROUND
  Aquacultured green lipped mussel (Perna canaliculus) is the New Zealand export leader of seafood in terms of weight. Different treatments shrink mussel meat differently and affect the consumer perception of half-shelled mussels. In order to quantify this, digital images of half-shelled green lipped mussels subjected to two postharvest treatments (ultrahigh pressure (UHP) and heat treatment (HT)) and raw controls were taken. The ratio of the view area of the meat to that of the shell (labelled as 'visual condition index' (VCI)) was measured using image analysis. A polygonal region of interest was defined on the image to depict the boundary of the meat and to calculate the view area.
  
  
  RESULTS
  Raw mussels had a VCI of 85%. HT mussels had a much reduced VCI of 41%, indicating shrinkage of the meat due to heat. UHP treatment used as a shucking method resulted in a VCI of 83%. Since VCI is one measure of quality for the consumer, this quantitative method can be used in the optimization of shucking treatment (HT or UHP).
  
  
  CONCLUSIONS
  VCI can be used to optimize postharvest treatments to minimize meat shrinkage. This method can also be applied to other shellfish such as oysters and clams.
authors.affiliation: Chemical and Materials Engineering Department, University of Auckland, 20 Symonds Street, Auckland, 1142, New Zealand.
authors.forename: Min Geun
authors.initials: MG
authors.lastname: Kim
authors.forename: Zayde
authors.initials: Z
authors.lastname: Alçiçek
authors.forename: Murat O
authors.initials: MO
authors.lastname: Balaban
authors.forename: Hasan Huseyin
authors.initials: HH
authors.lastname: Atar
mesh_terms: D000818:Animals; D017756:Aquaculture; D003258:Consumer Behavior; D004032:Diet; D005504:Food Analysis / Q000379:methods*; D005511:Food Handling / Q000379:methods*; D006358:Hot Temperature; D006801:Humans; D009520:New Zealand; D049883:Perna; D011312:Pressure; D012758:Shellfish / Q000032:analysis* / Q000592:standards
keywords: green lipped mussels; high pressure; image analysis; thermal treatment; visual condition index