Effect of advanced chilling methods on lipid damage during sardine(Sardina pilchardus)storage

摘要

Slurry ice is a biphasic system consisting of small spherical ice crystals surrounded by seawater at subzero temperature.Its effect on lipid damage(hydrolysis and oxidation)was evaluated during the chilled storage of a fatty fish species,sardine(Sardina pilchardus).Slurry ice treatment was checked alone and in combination with ozone and compared to traditional flake icing during a 22-day storage.Different lipid damage indices(free fatty acids,FFA;peroxide value,PV;thiobarbituric acid index,TBA-i;fluorescent compounds,FR)were checked and compared to sensory assessment and nucleotide degradation(K value).According to lipid hydrolysis(FFA)and oxidation(PV and FR)developments,slurry ice showed an inhibitory effect(p <0.05)on lipid damage during storage,as well as an inhibition of nucleotide autolytic degradation.Ozonised slurry ice did not provide differences(p >0.05)from slurry ice alone when considering lipid hydrolysis,nucleotide degradation and some lipid oxidation indices(PV and FR),although a higher(p <0.05)TBA-i was observed at day 22 of storage when compared to flake ice and slurry ice treatments.However,a lower(p <0.05)fluorescence development was observed for fish treated under ozonised slurry ice when compared to traditionally iced fish.Sensory assessment showed a higher shelf life for fish samples treated under ozonised slurry ice than for their counterparts under slurry ice(15d versus 12d),while flake icing led to a far shorter shelf life(5d).According to sensory and biochemical(lipid matter and nucleotide)analysis,slurry ice has proved to be a promising technology for damage inhibition and quality retention in a fatty fish species such as sardine.Ozonised slurry ice was also shown to be useful,since a longer shelf life was obtained in the present experiment and a pro-oxidant effect of ozone on sardine lipids was not proved.