Effect of high pressure processing in the quality of sea bass (Dicentrarchus labrax) fillets: Pressurization rate, pressure level and holding time

High pressure processing (HPP) is a technology able to reduce microorganisms and to modify food functional properties. This study aims to investigate the effect of three pressure variables (pressure levels of 100-400 MPa, pressure holding time of 0-30 min, and pressurization rate of 8 and 14 MPa s(-1)) in microbiological and physical analyses, and in myofibrillar proteins profiles in sea bass fillets. Pressurization rate induced changes in all parameters evaluated, although in a lesser extent than other variables. In general, the characteristics of fillets treated at 100 MPa were not different from non-treated samples. The magnitude of changes increased with pressure level (250-400 MPa) and holding time (0-30 min). In general, with the increase of pressure level and holding time, fillets become whitish, microbiological load and water holding capacity decreased, pH increased, and myofibrillar proteins with molecular weights below 30 kDa increased, whereas those with lower isolectric point values decreased. HPP can be a potential tool to process fillets due to the improvement in microbiological safety (about 2 log CFU g(-1) reduction in the treatment at 400 MPa-30 min), which might result in an extended shelf life. Industrial relevance: High pressure processing is an interesting technology for food preservation due to its ability to reduce microorganisms and to modify food functional properties. This study brought new evidences about the effect of high pressure processing on sea bass fillets, namely in myofibrillar protein profiles (SDS-PAGE and IEF electrophoreses). Variables such as pressure holding time and pressurization rate, besides pressure level, are also important in the choice of high pressure processing conditions. The results also suggest that high pressure processing might delay the degradation of fish muscle. The advantages of products treated with high pressure processing can lead to new opportunities in the market, being important for the food industry. (C) 2014 Elsevier Ltd. All rights reserved.