Publication Date:
2021-05-19
Description:
In this study, quality of fresh, slow frozen and quick frozen tilapia (gutted and) fillets and its changes during
storage at -18 C were investigated. For preparation the samples, fresh tilapia fillets were frozen by slow and
quick frozen methods. Slow frozen samples were prepared by storing the packed fillets directly in the -18 C°.
The sprila freezing tunle with -30C° was also used for preparation the quick frozen sample. The quick frozen
samples were then stored at -18C for six months. Proximate composition, fatty acid profiles, TBA, PV, TVN,
Total cuont, Drip loss, and sensory evaluation of the samples were determined in every month. Scanning
Electron Microscopy (SEM) was used for study on the effects of the frozen condition on the microstructure of
the fillets. Results indicated that two different frozen methods had significantly different effects on the quality of
the samples. Most of the proximate composition (protein, moistre and fat) reduced during the storage. Quick
frozen samples had significantly (P〈0.05) lower reduction than slow frozen samples. All of the chemical quality
indexes (PV, TBA, and TVN) increased during the storage as compered to the fresh samples. In these
paramethers, the slow freezing had higher changes than quick freezing metods (P〈0.05). The microbial
properties of the samples showed decrese during the storage. Lower amont of total cuont was observed at the end
of the storage time in the quick frozen samples than slow frozen once (P〈0.05). The large changes in the fatty
acid profiles of the sample were fond in all samples. During the storage SFA and MUF of the samples increased
however, the PUFA decresed. A lower change was obseved in the quick frozen samples than slow frozen
samples (P〈0.05). Drip loss was increased in both frozen samples during the storage period. The percentage of
the drip in the slow frozen samples was significantly higer than quick frozen samples (P〈0.05). SEM
micrographs were also showed that the chnges in the microstructur of the samples was different in the slow and
frozen samples. Slow freezing methods had higher damge in the microstructure of the sample then quick freezing
mathods. Sensory evaluation of the samples indicated that a better acceptability in the quick frozen samples than
slow frozen sample (P〈0.05).
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Nile tilapia
;
Red Tilapia
;
Quick freezing
;
Slow freezing
;
Fatty acids
;
Scanning Electron Microscope
;
SEM
;
Nutritional value of fish
;
Investigation
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
151pp.
Permalink
