Effects of ultra-high pressure on gel properties of big head croaker (<I>Collichthys lucidus</I>) surimi

Abstract

The objective of this study was to evaluate the effect of ultra-high pressure (UHP) treatment on gel properties of Collichthys lucidus surimi. Three factors of UHP treatment which were pressure,time and temperature were investigated. The textural parameters such as hardness,springiness,cohesiveness,chewiness and gel strength of surimi gel were obtained by texture analyzer. With the gel strength as index,the optimum UHP treatment process was optimized with orthogonal test as follows: pressure of 300 MPa,time of 15 min,temperature of 20 ℃ and under the above conditions,the gel strength was 363.15 g·cm. It was found that surimi formed gelation at 200 MPa,gel properties had no significant difference when UHP time was more than 5 min,and as UHP temperature increased,gel properties decreased significantly. The effect order of UHP treatment conditions on gel strength was pressuretemperaturetime. When pressure was higher than 300 MPa and time was more than 5 min,gel cohesiveness had no significant difference under those conditions. Cohesiveness decreased significantly with the increasing temperature when the temperature was higher than 20 ℃.Compared with heat treatment,we found that the gel strength of surimi by UHP treatment was better than heat treatment,was 2.2 times of heat treatment. But the hardness under UHP treatment was lower,only 67% of heat treatment. As for the springiness,cohesiveness,chewiness,water holding capability and whiteness,the effects of UHP treatment were better,the springiness was 1.6 times of heat treatment,particularly. From the two cooperative processing methods of UHP and heat treatment,it showed that the effect of heat treatment after UHP was similar to the two-stage heat treatment while UHP treatment after heat treatment could damage gel structure obviously. Those results indicated that UHP treatment had an effect on the formation of surimi gel. UHP treatment could modify the quality of processed muscle-based products. This study suggested that UHP treatment exhibits a potential for surimi processing.