Study On Processing And The Quality Change Of Shelled Penaeus Vannamei Boone

Penaeus vannamei Boone was a high-value fishery product and highdressing percentage. It was one of the three kinds of world’s highest yieldbreeding shrimp. It was abundant in polyphenol oxidase, which made theshrimp easily blackened. Furthermore, it was mostly frozen processed inour country at present. So far, it was rarely sold abroad. In order to makeit more useful, Penaeus vannamei Boone was studied in this research inorder to make it into leisure food. This research attempted to determinethe cooking process, improve the shrimp processing conditions, choosesuitable additives for shrimp quality improver, etc. The influences ofdrying methods, sterilization technologies, packaging pattens, and storageconditions on the quality of products were also discussed. We got thefollowing conclusions:The cooking process parameters: steaming for three minutes or boiling in water for two minutes. The shrimp had the highest retention ofastaxanthin. Its color was the best. Its polyphenol oxidase was almostdeactivation. Its hardness, springiness, cohesiveness, chewiness allachieved the desirable level. Extending the cooking time, its nutrients,water soluble protein and amino acid was severely damaged. Cookingprocessing inactivated the enzyme, sterilized, and improved the flavor ofproducts.The processing condition: Processing the shrimp in boiling waterwith3%NaCl had certain moisturizing effect, water-soluble nutrients lostless, the flavor of the product was improved, the rehydration ratioincreased, and hardness was reduced. The pH value of impregnationliquid should be at approximately7. It shouldn’t contain Mg²⁺or Al³⁺.The effects of sodium lactate, trehalose, xylitol, glycerin, and sugar onthe moisture content were all comprehensively compared. The resultshowed that3%trehalose improved the color and taste of the products. Atthe same time, the character of trehalose was stable, which had no colordeterioration. The hot air drying at80℃and100℃/45minatmospheric pressure sterilization were optimum.Packaging and storage conditions: the vacuum packaging wouldprotect astaxanthin and improve the product storage stability. Thedifferences between keeping in the light from an incandescent bulb andkeeping in dark place at the astaxanthin content, color, freshness and microbial parameters was not significant. However, the product keepingin the sun light was different. So the product should avoid the sun light instorage and distribution as far as possible. The shrimp in4℃storage wasstable. The shrimp in25℃with vacuum packaging storage for16weekswere still edible, and the astaxanthin, color were rarely damaged. In thepoint of saving energy, we choose vacuum packaging,25℃, keeping inthe light from an incandescent bulb or in dark place.