| The production of Larimichthyscrocea has been increasing year by year.In 2017,the total breeding amount of Chinese large yellow crocea has reached 177,600 t,an increase of 100.99% compared with that in 2010.It is not only the fish with the highest yield of Marine fish breeding in China,but also an important economic fish in China.Larimichthyscrocea has the characteristics of high protein and high fat,and the fat is mainly polyunsaturated fatty acids,so the fish cultured with Larimichthyscroceahas very high nutritional value.Pickling is the traditional way to preserve meat in China.The traditional salted Larimichthyscroceais usually preserved with heavy salt for the purpose of preservation,but long-term intake of high-salt diet will cause hypertension and other cardiovascular diseases.The concept of low-salt and low-sodium diet is worth promoting,but reducing the amount of added salt in food production will also lead to changes in other food parameters,taste and texture,etc.Therefore,maintaining consumer preference and acceptability is also one of the challenges of salt reduction.In this paper,the cultivation of Larimichthyscroceaas the object of study,first of all,the cultivation ofLarimichthyscroceamorphological structure and quality characteristics;Then the effects of different salt contents on the fish and meat were studied.Finally,response surface method was used to develop a kind of low-salt-preserved yellow croaker slices,and the effects of different packaging and storage temperatures on the quality of low-salt-preserved yellow croaker slices were studied.The results are as follows:(1)It reveals the quality characteristics ofLarimichthyscroceacultivated in ningde area: the fish head is flat and obtuse,the mouth is large,and the upper and lower jaws have a row of sharp and small teeth.Under the scales on the lower side of the body,there are golden yellow glands that can secrete golden yellow pigment.Its head length accounted for 24.2% of body length and only 12.62% of fish weight.The degree of fatness was 2.25,and the fish fillets accounted for 57.32% of the weight of the fish.The head,steak and tail of the fish fillets accounted for 27.35% of the weight.The digestive tract structure of cultivated Larimichthyscroceain ningde area reflects this characteristic because it is fed with feed.The digestive tract is well developed with 15 pyloric caecum loops.The length of the intestine is only 1.8 times of the length of the digestive tract,and there are 2 bends in the abdominal cavity.Liver developed,its color is white and grossness,accounting for 36.65% of the visceral weight,4.75% of body weight,viscera of swim bladder developed,for the long circular tube shape,wall thickness,accounting for 15.74% of the visceral weight,so the internal organs of fish liver and swim bladder is worthy of deep processing of raw materials cultured Larimichthyscroceamuscle colour and lustre is white,back,abdomen muscle pH is 6.74 to 6.66,104.21 microns diameter of muscle fiber,density of muscle fiber 153.13 / was,succulent and delicate.The Larimichthyscrocea in ningde has a complete variety of amino acids,and the essential amino acids account for 41.93% of the total amino acids.The umami amino acids accounted for 45.92% of the total amino acids.Unsaturated fatty acids in muscle accounted for 62.04% of total fatty acids,and EPA and DHA accounted for 20.01% of total fatty acids.(2)to clarify the effect of different salt content on the quality of fish and meat: to study the curing process,the Larimichthyscrocea with different salt contents(6%,9%,12%,15%)of fish protein,quality and structure,the influence of pH and volatile flavor materials.The results showed that with the increase of fish salt,the content of salt-soluble protein decreased continuously;the total sulfhydryl content increased slightly first,then decreased continuously;the total nitrogen content increased first and then decreased,while the non-protein nitrogen and protein hydrolysis index showed a trend of decreasing first and then increasing.The effect of salt content on the texture quality of fish meat was obvious.The hardness and elasticity of fish meat showed a gradual increase trend,while the chewing property showed a trend of decreasing first and then increasing.The pH value of fish meat decreased with the increase of salt content of fish meat.The salt content of fish has a great influence on the flavor.As the salt content of the fish increases,the volatile flavor components of the original Larimichthyscrocea are firstly converted to hydrocarbons,and then continuously converted into special flavors for the pickled products.Alcohols,aldehydes,ketones and other substances,and with the increasing salt content of fish,the total proportion of these three types of substances is getting higher and higher.(3)The technology of light-salted Larimichthyscrocea with low-sodium complex salty agent was developed.The optimal addition amount of potassium chloride,sodium gluconate,YE and chitosan was obtained by single factor experiment,and then responded by sensory score and salt content.Value,the application of response surface method to optimize the optimal dosage ratio of low sodium salt(salt,potassium chloride and sodium gluconate): the amount of salt added 3.52%,the amount of potassium chloride added 3.09%,the amount of sodium gluconate added 0.60%.Using the low sodium salt ratio and the low-sodium complex salty agent obtained by the single factor experiment,the YE yeast extract was added in an amount of 0.39% and the chitosan was added in an amount of 1.48%,and the large yellow croaker was pickled.verification.The results showed that the Larimichthyscrocea fillets marinated with low-sodium complex salt scent had a sensory score of 80.33,a salt content of 2.95%,and a sodium content of 124.47 mg/100 g,which was 32.63% lower than the control group.The effect of reducing sodium was also improved,and the taste and quality of the product were improved.The total number of colonies was 3.36 lg(CFU/g),which was 35.41% lower than that of the control group.Therefore,Larimichthyscrocea marinated with the low-sodium complex salt scent can not only lower the salt content of the Larimichthyscrocea,but also have a low sodium ion content,a low total number of colonies,and a good product freshness and quality.Therefore,it provides new technology for the processing of Larimichthyscrocea,and develops large yellow fish marinated products to meet the needs of different people.(4)The packaging and storage conditions of low-sodium light-salted Larimichthyscrocea were studied: two groups of low-sodium salt researched and developed: compound salt group A(addition of sodium chloride 3.52%,potassium chloride addition of 3.09%,sodium gluconate)The addition amount is 0.60%)and the compound salt B group:(the amount of sodium chloride added is 3.52%,the amount of potassium chloride added is 3.09%,the amount of sodium gluconate added is 0.60%,the amount of YE added is 0.30%,shell aggregation The amount of sugar added was 1.48%.The marinated Larimichthyscrocea was vacuum-packed,modified atmosphere packaging and common packaging,and the product quality was changed when stored at 4 °C and-3 °C,respectively.The results showed that no matter which packaging method and storage conditions were used,the quality of the Larimichthyscrocea in the formula B group was superior to the traditional salt pickling group and the formula A group.The quality change rate of fillets at-3 °C was lower than that at 4 °C.The shelf life of the fillets in the air-conditioned packaging group of the control group was 10 days at 4 °C,and 28 days at-3 °C.The shelf life of the fish fillets in the modified atmosphere packaging group of group A was 12 days at 4 °C.,and-3 °C is 40 d;the shelf life of the fillets in Group B of the modified atmosphere group is 16 d at 4 °C,and 44 d at-3 °C.Therefore,the large yellow croaker fillets marinated with Formulation A and Formula B were packaged in modified atmosphere and the shelf life was extended at both temperatures,while the appearance,scent,and color of the fish fillets marinated in Formula B were throughout the sensory score.The storage period was at a high level,and the shelf life of the modified atmosphere-packed fillets in Group B was greatly extended.Therefore,the low-sodium salt light-salted Larimichthyscroceafillets marinated with Formula B were best preserved at-3 °C after being packaged in modified atmosphere,and had the longest shelf life. |
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