High Pressure Shelling Of Shrimp And Quality Detection

Shrimp is favorite seafood in the world and is farmed largest in China. However most of shrimp is still manually shelled in China resulting in low efficiency, bad quality and low production rate of shelled shrimp. This study explored a new technology based on high pressure processing as a pre-treatment technique for shelling of fresh white-leg shrimp. Fresh shrimp was treated by high pressure (HP) or freezing and thawing (FT) and then shelled manually. Then HP pre-treatment parameters were optimized and physical and chemical properties of shelled shrimp were detected. Finally a new method of nondestructive detection was explored through fluorescence properties of shrimp. The specific results are as follows:(1) A new pre-treatment of shrimp shelling was achieved based on HP. HP processing parameters and optimization targets were determined.Problems of the shrimp shelling process were analyzed. A new technology based on HP processing as a pre-treatment technique for shelling of fresh shrimp was proposed according to characteristics of HP technology and existing research. Pressure level and holding time were determined as the main process parameters. Shelling time, drip loss, integrity, production rate, color and tenderness of the shelled shrimp were determined as the optimization targets.(2) Optimum processing parameter of shelled shrimp was identified based on HP pre-treatment.Fresh shrimp were pre-treated with different pre-treatment methods and different parameters of HP processing. Pressure at 200MPa with a holding time of 3min was optimized as the optimum processing parameter according to the optimization targets.(3) The internal quality of shelled shrimp pre-treated by HP was detected.Water content, pH value, whole texture, and the protein degeneration of shelled shrimp were detected. Experimental results demonstrated that HP treatment was conducive to the moisture content increasing of shelled shrimp, and was superior to FT treatment. The maximum increasing of moisture content was 25.58%. PH value of shelled shrimp was significantly affected both by HP treatment and FT treatment. Compared with the FT treatment, HP treatment can be better to keep the whole texture. Protein denaturation of shrimp was no obvious pre-treated by different methods from the DSC testing. (4) A new method of nondestructive detection was proposed through fluorescence properties of shrimp.Excitation and scanning wavelength was chose for shelled shrimp. A linear relationship was obtained between fluorescence intensity and pressure level of HP treatment. A linear model:Y= 0.054X+42.89 with correlation coefficient R2=0.825 was established between fluorescence intensity and color of shelled shrimp. Model could predict the color of shelled shrimp, with a prediction error of 3.95%.