Study On The Technology Of Vacuum Low-temperature Instant Sea Cucumber Freeze-dried Tablets

Sea cucumber is a kind of valuable marine treasure,which is deeply loved by people because it contains a variety of pharmacological active ingredients and nutrients.With the continuous improvement of people's living standards and the gradual expansion of market demand for sea cucumber products,the development of sea cucumber breeding and processing industry is promoted.At present,the main sea cucumber products on the market are salt dried sea cucumber and light dried sea cucumber,and the processing of sea cucumber is also based on the traditional processing method,which needs a long time of foaming and then repeated cooking,which not only affects the taste quality of sea cucumber,but also causes a lot of loss of nutrients.At present,the research and application of new ready to eat sea cucumber products and related processing technology are relatively less.In this paper,ultrasonic assisted rehydration technology,vacuum low-temperature processing technology and freeze-drying processing technology were used for the instant processing of salted dried sea cucumber.The effects of pretreatment technology and new instant processing technology on the texture,nutritional components and flavor of sea cucumber and their relationship were discussed,which provided a theoretical basis for the improvement of instant processing technology and product quality On basis.The main research contents and results are as follows:1.The pretreatment method of chitosan / ultrasonic assisted rehydration was used to explore the effects of chitosan concentration,ultrasonic temperature,ultrasonic time,ultrasonic frequency and rehydration time on rehydration of salted dried sea cucumber.The pretreatment process of instant freeze-dried sea cucumber was optimized and established.The results showed that when the concentration of chitosan solution was0.50g/100 ml,the ultrasonic temperature was 50?,the ultrasonic time was 45 min,the ultrasonic frequency was 53 k Hz,and the rehydration time was 96 h,the rehydration rate of salted dried sea cucumber was 4.65 times,the total protein content was 55.75g/100 g,the collagen protein content was 36.7g/100 g,the water-soluble protein content was 2.73g/100 g,and the water content was 82.65% The rehydration rate,total protein,collagen and water-soluble protein of sea cucumber were 4.73 times,54.30g/100 g,35.02g/100 g and2.15g/100 g respectively after 120 h.It can be seen that the chitosan / ultrasonic assisted rehydration method not only shortened the rehydration time,but also better preserved the nutrients of sea cucumber.The hardness,cohesiveness,elasticity,stickiness and chewiness were 7.29 N,0.70 ratio,4.25 mm,4.64 N and 10.8 mj,respectively.2.Using vacuum low-temperature processing technology,under the condition of vacuum degree of 0.08 mpa,the changes of total protein,collagen,soluble protein,moisture content,sensory and texture of sea cucumber were analyzed under different processing temperature and processing time.The vacuum low-temperature processing conditions of sea cucumber were explored,and the optimal processing technology was established.The results showed that the best processing temperature was 90? and the best processing time was 80 min.under this condition,the instant sea cucumber had the highest sensory score,and the best hardness,elasticity and chewiness,which were 5.27 N,2.40 mm and 11.13 mj,respectively;the total protein and collagen of sea cucumber after vacuum low temperature processing were 47.00 g/100 g and 32.00 g/100 g,respectively The content of soluble protein was 1.70 g/100 g and the moisture content was 68%.3.Using vacuum freeze-drying technology,different freeze-drying curves were selected to investigate the changes of total protein,collagen,water content,color and texture of sea cucumber before and after freeze-drying under different freeze-drying temperature,freeze-drying time and corresponding temperature and time gradient.The process conditions of vacuum freeze-drying of sea cucumber were explored and optimized The best freeze-drying curve was obtained.The results showed that the optimum freeze-drying time,maximum freeze-drying temperature and minimum freeze-drying temperature were 36 h,25? and-26? respectively.Under these conditions,the water content of sea cucumber was the lowest and the freeze-drying effect was the best.Water content was 3.75%,total protein content was 63.90 g/100 g,water-soluble protein content was 2.79 g/100 g,collagen content was 36.28 g/100 g.4.In this experiment,gas chromatography-mass spectrometry(GC-MS)was used to detect the changes of the main flavor compounds of sea cucumber in the whole processing process of instant freeze-dried sea cucumber,and the effects of different processing methods,temperature and time on the flavor compounds of sea cucumber were discussed.The results showed that the main flavor compounds of sea cucumber were hydrocarbons,alcohols,ketones,aldehydes,etc and the main flavor compounds were hydrocarbons,aldehydes,alcohols,which usually accounted for more than 90% of the total flavor compounds.With the increase of processing temperature,the relative proportion of hydrocarbons increased,the relative proportion of ketones was relatively stable,and the relative proportion of aldehydes and alcohols decreased;with the increase of temperature span and time,the types and phases of hydrocarbons,alcohols,ketones,aldehydes and other substances decreased The contents of both were decreased.