Study On Evaluation Method Of Nutritional Quality Of Sea Cucumber

Sea cucumber is a natural nourishing food rich in protein and active substances.Its nutrient composition and content directly determine the nutritional quality of sea cucumber.At present,the varieties and product forms of sea cucumber are more and more diversified in the market.However,the quality and taste of sea cucumber vary greatly with the origin,varieties,processing methods and rehydration methods of sea cucumber.Therefore,it is of great significance to further study the nutrient composition and quality of sea cucumber.In this paper,the nutrition evaluation of Apostichopus japonicus and imported sea cucumber was carried out by principal component analysis(PCA).The nutrient composition and content of dried sea cucumber in commercial and edible state was analyzed,and the nutrient composition of quick rehydrating dried sea cucumber in edible state was analyzed.The rapid rehydration method suitable for laboratory testing was preliminarily explored.This study provides theoretical support for the comprehensive nutritional quality evaluation of sea cucumber and the establishment and improvement of relevant standards of sea cucumber.The research contents are as follows:Referring to GB 31602-2015,the indexes(water,ash,salt,protein,total sugar,sand content,dry weight rate after rehydration,water-soluble total sugar,polysaccharides,saponins)of sea cucumber were evaluated.Principal component analysis(PCA)was used to evaluate the comprehensive nutritional quality of Apostichopus japonicus and six imported sea cucumbers(Cucumaria frondos,Holothuria Mexicana,Isostichopus badionotus,Isostichopus fuscus,Holotoria Mammata,Parastichopus californics)to determine the order of comprehensive nutritional quality of sea cucumber.The results of single index analysis showed that the sand content of Isostichopus badionotus,Holotoria Mammata were higher than 3%,and the dry weight rate after rehydration of Holotoria Mammata was lower than 40%,which did not meet the standards.The results of PCA showed that the frist three principal components can be extracted from 10 indicators of 7 sea cucumbers,providing 88.821% information of the total variability,And the dry weight rate after rehydration,total sugar,protein,polysaccharide,sand content and saponin have a greater impact on the nutritional quality of sea cucumber.The PCA evaluation revealed the ranking of the sea cucumbers as Apostichopus japonicus> Cucumaria frondos > Holothuria Mexicana > Isostichopus badionotus > Isostichopus fuscus > Holotoria Mammata > Parastichopus californics.Apostichopus japonicus is rich in nutrition and has high dry weight rate after rehydration,so its nutritional quality is the best.Taking Apostichopus japonicas as research objects,the nutritional components of sea cucumber in commercial and edible state were determined,and the differences of nutrient components between commercial and edible sea cucumbers were compared and analyzed.The results showed that there were significant differences in nutrient components(salt,protein,total sugar,polysaccharide,saponin)between commercial and edible sea cucumbers.The quality loss rates of dried and salted sea cucumbers after boiling and foaming were higher than 20% and 55%,respectively,and the salt loss rates were higher than 90%.The protein contents of sea cucumbers in commercial and edible state were 36.96%~80.34%,74.08%~88.86%,respectively,and the loss rates were about 20%.The contents of total sugar,polysaccharides and saponins in commercial and edible sea cucumbers were 9.07%~23.59%,2.44%~13.16%,0.014%~0.087%,13.17%~26.32%,3.62%~10.58%,0.020%~0.063%,respectively.The loss rates of total sugar,polysaccharides and saponins ranged from 10% to 50% in dried sea cucumbers,and were higher than 60% in salted sea cucumber.The nutrient loss between commercial and edible state of sea cucumber is serious,so it is necessary to take the edible nutrient of sea cucumber into full consideration in the comprehensive evaluation of sea cucumber quality.By comparing the effects of different insulation cups on the foaming of quick rehydrating dried sea cucumber,and comparing the effects of three methods of rehydration,i.e.variable temperature rehydration,isothermal rehydration and gradient constant temperature rehydration,the optimum rehydration conditions of quick rehydrating dried sea cucumber were preliminarily determined.The quality of 30 quick rehydrating dried sea cucumbers were evaluated by the best rehydration method.The results showed that rehydration for 8h with an insulation cup which temperature maintains at 45? ~55? after 8 hours was the optimum condition of the variable temperature rehydration method,the foaming effect and sensory quality of the quick rehydrating dried sea cucumber were the best under this condition.The optimum rehydration condition for rapid detection in laboratory is rehydration at 70 C for 6 hours.This method is simple,time-consuming and easy to unify the standard.When the salt content is higher than 10% or the total water soluble sugar content is higher than 3%,the foaming multiple of the quick-drying sea cucumber is less than 5 times.Excessive salt or sugar can inhibit the foaming effect of the quick rehydrating dried sea cucumber.The content of water-soluble total sugar in 20% of quick rehydrating dried sea cucumber is higher than 3%,which was serious sugar adulteration.The protein content of quick rehydrating dried sea cucumber was 62.4%~78.0%,and the content of polysaccharides and saponins were 2.99%~14.13% and 0.014%~0.097%,respectively.Quick rehydrating dried sea cucumbers were rich in nutrients.The study on foaming method and nutritional quality of quick rehydrating dried sea cucumber provides theoretical basis for the establishment of standard of quick rehydrating dried sea cucumber.