Study On Quality Improvement And Shelf Life Model Of New Crab Meatball With Crab Roe Based On The Addition Of Crab Shell Powder

As a representative of Huaiyang cuisine,crab meatball has a fluffy texture,which is fatty but not greasy,and is one of the famous “three head feasts” with a history of several hundred years.Crab roe is a necessary raw material for the production of crab meatball,the production process produces a large amount of crab shell waste,and the application of crab shell powder to the production of the product not only effectively utilizes the crab shell wastes,but also improves the sensory quality and functional characteristics of the crab meatball,and the addition of crab roe makes the product fishy and easy to rot.In order to solve the problem of crab shell wastes accumulation and improve the product quality,this study firstly,the crab shell scraps were pretreated for ball milling,and the obtained ball-milled crab shell powder was applied to the production of crab meatball.For the fishy characteristic of crab meatball,lysozyme(L)and yeast extract(Y)were used for combined deodorization pretreatment with high voltage electrostatic field(HVEF),and the relevant indexes were combined to investigate the mechanism of fishy taste.The crab shell waste was used to extract chitosan(CS)and combined with mung bean protein isolate(MBPI)as the wall material,and ginger essential oil microcapsules were added to the raw material of the production of crab meatball to prolong the storage time,and shelf-life models were established based on the optimal treatment to provide a monitoring scheme for the quality and longevity of the crab meatball under different temperatures.Finally,the produced crab meatball has excellent characteristics of good sensory quality,weak fishy taste and long storage time.The specific work is as follows:(1)Firstly,the enzymatic process of crab shells was optimized to reduce the toughness of crab shell fragmentation.The enzymatic digestion of crab shells by alkaline protease(200000U/g)was optimized by single-factor and response surface methods,and the optimal enzymatic process was 50°C,p H=9.0,14025.67 U/g,4.21 h and liquid to material ratio of 14.41:1.Microwave and ultrasound physical fields assisted enzymatic digestion of crab shells were applied,and the crab shell powder was pretreated by microwave and ultrasound combined with alkaline protease(MUSED).The efficiency of ball milling after the pretreatment increased by50% compared to the control group,and the final median particle size of the crab shell powder was D4=4.88±0.20 um.Applying the ball-milled crab shell powder to the production of crab meatball,its high calcium solubility and low energy consumption could increase dietary calcium bioavailability while reducing the possibility of high caloric intake.(2)Secondly,the effect of ball-milled crab shell powder on the quality of crab meatball was investigated.6%(w/w)crab shell powder with a median particle size of D4=4.88±0.20 um significantly reduced the hardness of crab meatball,improved the tenderness characteristics of the product,imparted typical crab flavor to crab meatball,significantly reduced the cooking loss of the product,and significantly retained its nutrients(p< 0.05).When the added crab shell powder particle size was less than D3=10.95±0.78 um,there was no obvious gritty texture,and when the added crab shell powder median particle size was D4=4.88±0.20 um,there was no obvious roughness on the sample surface.The addition of microfine crab shell powder improved the sensory quality of crab meatball and alleviated the environmental stress.(3)Thirdly,the effect of lysozyme and yeast extracts on the regulation of fishy odor of crab meatball with crab roe was investigated by using synergistic high voltage electrostatic field.Pork mince with a fat to lean ratio of 7:3 was pretreated with 10%(w/w)crab roe and 6%(w/w)crab shell powder(D4=4.88±0.20 um)as raw materials for crab meatball production.The optimal conditions for lysozyme(2000 U/mg)treatment were determined by single-factor and orthogonal tests using the degree of fat oxidation(TBARS)as the screening index: 25℃,p H6.5,0.05%(w/v),30 min and liquid to material ratio of 4:1.Yeast and 0.5%(w/v)cellulase were added in phosphate buffer at p H 6.5 at a liquid to material ratio of 10:1,homogenized and centrifuged to obtain yeast extract,after lysozyme treatment,the raw materials were dipped in yeast extract for 90 min at 25°C at a liquid to material ratio of 4:1,and fat oxidation was inhibited by 14.41% compared with the control group.After 2 h of electrostatic field treatment,the fat oxidation of minced meat was the lowest,with 41.10% inhibition compared with the control group,and no significant fishy odor.From the correlation analysis,it can be concluded that the fishy odor of crab meatball mainly comes from the oxidation of fat and the p H change.(4)Finally,CS was extracted from crab shells by chemical method using hydrochloric acid and sodium hydroxide reagent,and ginger essential oil microcapsules were prepared with MBPI by composite coagulation method to investigate the effect on shelf-life extension of crab meatball with crab roe.The degree of deacetylation was 82.90% and crystallinity was 53.89%after characterized by Fourier Transform Infrared Spectroscopy(FTIR)and X-ray diffraction(XRD).The results of Zeta potential,turbidity and yield of CS and MBPI complex system showed that the optimal wall ratio was MBPI:CS=8:1 and the optimum p H was 6.4.FTIR results indicated that the complex coalescence between MBPI and CS was mainly generated by electrostatic interactions.The ginger essential oil was microencapsulated with the aid of the complex coalescence reaction between 1%(w/v)CS and 1%(w/v)MBPI at a mass ratio of 1:1.Based on the previous experimental experience of adding 0.6%(w/w)microcapsules to make crab meatball,the product could be kept for 9 d without microbial excess at 4°C,which was 6d more than the control group The product can effectively extend the storage period.The zerolevel and Arrhenius coupled models with the microbial logistic model predicted by the changes of p H,TBARS and microbial content during the storage period of crab meatball were within10% of the relative error,and both of them could predict the shelf life of crab meatball during storage well.