Study On Quality Improvement Of Lateolabrax Japonicus Minced Flesh And Nutrition Of Lateolabrax Japonicus In Aged Population

Lateolabrax japonicus is an economic fish in China with large production and high nutritional value,which is suitable for developing surimi products.Most of the traditional minced fish go through rinsing process,but rinsing will wash away a lot of nutrients in the fish,and the waste liquid discharged from rinsing will damage the environment,which is not in line with the current concept of"green and environmental protection".In addition,China is in an aging society,the development of food for the elderly is single,commonly in the form of powdered milk,health products,etc.,the nutritional composition is simple,it is difficult to meet the dietary needs of the elderly,so the development of food for the elderly in China still has a large potential.Taking Lateolabrax japonicus as raw material,this paper optimizes the optimum extraction conditions of improve the gel characteristics,water retention and texture quality of unbleached fish mince by adding Ca²⁺,phosphate-free water retention agent and lipid,respectively,and further developed a nutritious Lateolabrax japonicus slip suitable for aging people,based on which we determined the packaging method and storage temperature to extend the shelf life of Lateolabrax japonicus slip.The results of the study are as follows:(1)The effect of Ca²⁺on the gelation properties of unrinsed Lateolabrax japonicus minced flesh was investigated.The study compares the effects of different additions of Ca Cl2(0.01 M?0.08 M)on the gel strength,TPA,water holding capacity,whiteness,microstructure,etc.of minced meat of Lateolabrax japonicus without rinsing after meat harvesting.And compare with the Lateolabrax japonicas surimi prepared by traditional methods.The results showed that Ca²⁺had a significant effect on the quality of unrinsed sea bass meat(P<0.05).Different additions of Ca Cl2 can significantly increase the gel strength,TPA,water holding capacity and whiteness of unrinsed minced meat of Lateolabrax japonicus.When the amount of Ca Cl2 added is 0.02 M,the gel characteristics of unrinsed minced meat of Lateolabrax japonicas(gel strength 7364.21g·mm,water holding capacity 88.93%,hardness 421.8 g,elasticity 10.03 mm,adhesiveness229.5 g,chewiness 22.21 m J,whiteness 86.72)similar to traditional surimi quality,its effect is the best.When the amount of Ca Cl2 added reaches 0.08M,Ca²⁺is excessively cross-linked with fish protein to form a calcium bridge structure,resulting in increased gel strength and hardness,and decreased elasticity.(2)The effect of compound phosphorus-free water-retaining agent on the water-retention of unrinsed Lateolabrax japonicus minced flesh was developed and analyzed.By using the single factor method,used cooking loss,texture and sensory evaluation as testing standard,and orthogonal experiments were applied to study the influence of sodium bicarbonate,trehalose,and soybean protein isolate on their water retention.And the orthogonal test method was used to determine the optimal combination of the three phosphorus-free water retention agents.The results showed that adding an appropriate amount of the 3 substances had a certain effect on enhancing the water retention of fish minced flesh.With the increase of the addition,the cooking loss rate will first decrease and then increase.If the addition is too large,it will have a certain effect on the quality.Certain influences lead to the reduction of various indicators.The optimal formula of the composite non-phosphorus water retaining agent optimized by orthogonal test is0.1%sodium bicarbonate,0.3%trehalose,3.5%soy protein isolate.The sensory score of the product was 95.8,the cooking loss was 43.4%lower than that of the blank group,and the water retention effect was significantly improved,the fish tissue structure was tighter and the cavity was small.(3)To elucidate the effect of complex lipids on the quality of unrinsed Lateolabrax japonicus minced flesh.By using the single factor method,the quality effects of soybean oil,peanut oil,chicken oil,fish oil and DHA algae oil on the minced fish were studied with texture,whiteness and cooking loss as indicators.Three groups of compound oils were optimized by orthogonal test to obtain the best compound types,proportions and addition amounts of oils.The results showed that the different amounts of added lipids had significant effects on the textural characteristics,whiteness and cooking loss of Lateolabrax japonicas minced flesh;the optimal combination obtained from the orthogonal test was the compound type of soybean oil and fish oil,the compound ratio of 1:1 and the addition amount of 3%,the hardness of minced fish was 178.2g,the cooking loss was 18.87%,the sensory score was 88.8,the microstructure was more compact and the pores become smaller.(4)Identification and nutritional evaluation of a Lateolabrax japonicas slippery formula suitable for the aging population.The single-factor experiments showed that the addition of vegetable powder had an effect on the hardness of fish slippery.The response surface experiment was used to optimize the three vegetable powder addition ratios:carrot powder addition of1.13%,celery powder addition of 1.09%,and inulin addition of 1.13%.The optimized Lateolabrax japonicas slippery formulation had better textural characteristics and nutritional evaluation:gel strength(1861.6 g·mm),hardness(226.8 g),elasticity(11.85),cohesiveness(0.58),chewiness(22.83 m J),water holding capacity(10.27%);protein content(15.24 g/100g),fat content(5.73 g/100 g),sugar content(11.67 g/100g),moisture content(72.90g/100g),ash content(1.31 g/100g),energy value(883.38 KJ/100g),E/P(62.04 KJ/100g);17 amino acids were detected,EAA/TAA 40.56%,EAA/NEAA 68.24%,EAAI was 68.35;18 kinds of fatty acids were detected,the relative content of UFA was 72.1%,of which PUFA accounted for43.56%,the total content of EPA and DHA accounted for 11.12%;7 kinds of vitamins were detected,the highest content of VE(3.54 mg/g).(5)The effects of packaging method and storage temperature on the slippery quality of Lateolabrax japonicas were investigated.The changes in the quality of Lateolabrax japonicas slippery in different packaging methods and storage temperatures were analyzed by measuring the texture,sensory evaluation,TVB-N,TBA and total bacterial colony.The results showed that the two packaging methods had little effect on the quality characteristics of fish slippery,while the TVB-N,TBA and total bacterial colony values of fish slippery showed different degrees of increase,and the sensory ratings showed a decreasing trend throughout the storage period.The quality of Lateolabrax japonicas slippery using vacuum packaging method was better than that of non-vacuum packaging method,and the shelf life could be kept at 4?for 7 d,which was 3-4d longer than that of non-vacuum packaging;at-2?for 15 d,which was more than 7 d longer than that of non-vacuum packaging.