Study On Texture Adjustment Technology Of Low-value Sea Cucumber Product

Acaudina molpadioides(dried),a kind of low-value sea cucumber,was used as raw material in this paper.Different additives were used to compound with body wall homogenate of Acaudina molpadioides to study the influence of different factor on the gel quality of Acaudina molpadioides——gel strength,chewiness,hardness and springiness were chosen as the indexes to evaluate gel quality,and optimized the preparation technology of two kinds of Acaudina molpadioides gel by using response surface methodology(RSM).Gel properties such as water holding capacity of different Acaudina molpadioides gel were measured,chemical interactions and FTIR had been analysed to reveal the gelation mechanism of Acaudina molpadioides gel.It had established a theoretical foundation for high-value utilization of low-value sea cucumber.The main conclusions are as followed:1.The effect of the adding way of SPI,moisture content of homogenate,the addition of TGase,SPI,salt,SC on gel quality were studied through single factor experiment.Results indicate that the best adding way of SPI was dilute into water after thermotropy at 105? and 80% was the most suitable moisture content.Besides,the addition of SC and TGase had extremely significant influence and addition of SPI and salt had signigicant influence on gel strength chewiness;chewiness was significantly influenced by addition of TGase;addition of additives had no significant influence on hardness and springiness.The optimum conditions of single factor were determined: addition of SPI,salt,SC and TGase was 2%,1%,0.5% and 238.4 U/100 g homogenate respectively.On the basis of single factor experiment,addition of SPI,SC and TGase were used to RSM and had build regression models of the four indexes,which all have good significance and confidence level,and optimized the technology parameters: addition of SPI,SC and TGase was 1.84%,0.53% and 259.33U/100 g homogenate.As compared with pure Acaudina molpadioides gel,gel strength,chewiness,hardness and springiness rose by 48.54%,44.49%,46.07% and 2.07% respectively under this condition.It indicated that additives like TGase in this research can improve the gel quality of Acaudina molpadioides gel.And the best procedure of TGase-induced Acaudina molpadioides gel was confirmed.2.Influence of adding way,concentration,pH and addition of konjac gum on complex gel quality were studied through single factor experiment.Firstly,the adding way was determinded that konjac gum should be added in form of solution after swelling.Besides,concentration had significant influence on gel strength,chewiness and hardness,but not on springiness;gel strength increased when pH was in the range of 6~8,and it decreased significantly when pH was too high,and pH had no significant influence on other three indexes;gel strength reached a maximum value when the addition was 2%,but would significantly reduce when there was too much konjac gum,hardness would significantly decreased when addition increased,but no significant influence on chewiness and springiness.The optimum conditions of single factor were determined: concentration,pH and addition of konjac gum was 6%,7 and 2% respectively.On the basis of single factor experiment,concentration,pH and addition of konjac gum were chosen as factors and applied to RSM,established regression models of gel strength,chewiness and hardness which had good reliability,but regression model of springiness was lack of reliability.Then the technology parameters were optimized: concentration,pH and addition was 6.95%,7.14 and 1.95% respectively.As compared with pure Acaudina molpadioides gel,gel strength,chewiness,hardness and springiness rose by 20.61%,25.74%,16.58% and 6.15%.It indicated that konjac gum can improve gel quality of Acaudina molpadioides in a certain extent and there is feasibility in preparing of konjac gum-Acaudina molpadioides complex gel,and the best procedure of konjac gum-Acaudina molpadioides complex gel was confirmed.3.Influence of concentration,pH and addition of konjac gum on TGase-induced Acaudina molpadioides complex gel were analysed.Results showed that concentration had extremely significant influence on gel strength and significant on c hewiness and hardness,but not on springiness;pH and addition had significant influence on gel strength but not significant on other three indexes.According to the result of single factor experiment,the optimum processing parameter for preparation of TGase-induced Acaudina molpadioides gel contain konjac gum was confirmed: concentration,pH and addition of konjac gum was 9%,7 and 2% respectively.Under this condition,gel strength had a sharply rise while chewiness,hardness and springiness could keep in a relatively well level at the same time.Based on these,it can be speculated that there is a synergistic effect between konjac gum and TGase in improving gel quality.4.Acaudina molpadioides gel after texture adjustment——TGase-induced Acaudina molpadioides gel konjac gum,konjac gum-Acaudina molpadioides complex gel and TGase-induced Acaudina molpadioides gel contain konjac gum——had better water holding capacity than pure Acaudina molpadioides gel,and had improved by 5.72%,8.11% and 9.48% respectively;Through the analysis of storage stability(duration was a week)of these four kinds of gel we found that stability was better when gel was stored at 4? than room temperature,and stability of gels after texture adjustment had increased in various degrees,and gel with konjac gum is more stable;In vitro digestibility was measured,the value all approached or exceeded 90% and in vitro digestibility of gels with TGase were significant high than gels without TGase.There was no significant difference between gels with and without konjac gum.In pure Acaudina molpadioides gel,the main chemical interaction were nonspecific binding and disulfide bond,followed by ionic bond,hydrogen bond and hydrophobic interaction were relatively weak;in TGase-induced Acaudina molpadioides gel,the main chemical interaction were ionic bond and hydrogen bond,followed by nonspecific binding,hydrophobic interaction and disulfide bond were relatively weak;in konjac gum-Acaudina molpadioides complex gel,the main chemical interaction were nonspecific binding,ionic bond and hydrophobic interaction,followed by hydrogen bond,disulfide bond was the weakest;in TGase-induced Acaudina molpadioides gel contain konjac gum,the main chemical interaction was nonspecific binding,the other kinds of interaction were relatively weak.Protein solubility was measured and we found that the value of protein solubility from high to low in order was: pure Acaudina molpadioides gel,konjac gum-Acaudina molpadioides complex gel,TGase-induced Acaudina molpadioides gel,TGase-induced Acaudina molpadioides gel contain konjac gum.The results of FTIR showed that there was no formation of new substance or chemical bond after the introduction of additives,the main cause of the improvement of gel quality was the change of chemical interaction.