Effects of high pressure processing (HPP) on quality attributes of tilapia (Oreochromis niloticus) fillets during refrigerated storage

Fish fillets are extremely perishable in refrigerated conditions, so the use of technology is necessary to extend its shelf life. The present work aimed at evaluating high pressure processing effects on colour, texture, microbiological quality and sensory quality of tilapia fillets. Samples were pressurized at 100, 200, 300 or 400 MPa for 1 or 3 min. Colour parameters L* and whiteness of samples processed at 300 and 400 MPa were significantly higher (p < 0.05) than control samples. Both hardness and compression force of pressurized samples did not significantly differ (p > 0.05) from control. Counts of psychrotrophic microorganisms were significantly reduced (p < 0.05) on samples pressurized at 300 and 400 MPa. Samples processed at 200 MPa were preferred (p < 0.05) by assessors on sensory evaluation of fillets appearance. Colour, texture and microbiological analysis of samples kept at refrigerated storage (5 degrees C) for 1 wk showed that HPP at 400 MPa for 3 min was efficient to preserve tilapia fillets. The study has shown that HPP might be a suitable process for fish conservation, but influence on tilapia fillets appearance acceptance due to changes in colour may difficult its commercialization, so further research about these effects is needed.