Comparative Study On The Imapact Of Different Drying Technologies On Drying Characteristics And Product Qualities Of Penaeus Vannamei

Recently，the dried Penaeus vannamei were welcomed by consumers with theirspecial flavor, nutritive value, storage stability and portability. However, most of theshrimps were dryied by traditional natural solar drying at present. In order to improve thedrying skills of Penaeus vannamei, this experiment was carried out. The results showedthat：1The protein content of Penaeus vannamei is18.71%. It is rich in8kinds of essentialamino acids and2kinds of semi-essential amino acid in line with the FAO/WHO idealmodel, so it is a nutritionally balanced quality protein. Besides, it’s content of deliciousamino is40.64%. Penaeus vannamei is rich in PFA(polyunsaturated fatty acids), theyaccount for41.65%of the total fatty acids. Penaeus vannamei is also rich in EPA and DHA,they account for19.41%of the total fatty acids. Penaeus vannamei is also rich inVA,VD,VE, VB2,VB6and kinds of mineral elements such as Ca,Fe,Zn,Se. So Penaeusvannamei is a quality resource of protein, and it can improve the children’s intelligence andhealth of the elderly.2The drying dynamics characteristics of Penaeus vannamei were studied. During thedrying process, moisture gradient played a major role. So the drying process entereddeceleration stage directly. The drying temperature influenced significantly on the dryingcharacteristics of Penaeus vannamei, it could affect product quality greatly. During thedrying process of Penaeus vannamei, the moisture diffusion coefficient played a major role.By analyzing the hardness, elasticity, chewiness and sensory characteristics of driedproducts of different drying methods, we considered45℃to be the best dryingtemperature.3In this paper, we studied the relationgship of the operational parameters and the timeor the energy consumption during vacuum freeze-drying. On this basis, Box-Behnkencentral composite test was carried out to establish the models of the time or the energyconsumption with barometric pressure of drying chamber, the heating temperature andmaterial thickness. According to the results, The optimum conditions: drying chamberbarometric pressure is22.50Pa, heating temperature is31.82℃, material loadage is735.00g.4General nutrients, amino acids, fatty acids as well as mineral elements of theproducts dried by different methods was investigated in this paper. The products dried by vacuum freeze-drying contented the lowest moistuer, while their protein, fatty, amino acids,fatty acids as well as mineral elements reached the highest level of all products. Theproducts dried by traditional sun-drying lost nutrition more than other products.5The influnces of different drying methods on sensory characteristics were studiedin this experiment. The products by vacuum freeze-drying changed least in color, but theywere not accepted by most people with their hardness, elasticity, chewiness and sensorycharacteristics. The products dried by traditional sun-drying changed most in color. Theproducts dried by solar-drying gained the highest sensory score.6Among these drying methods, hot air-drying had the fastest rate of removing water,then solar-drying and vacuum freeze-drying, traditional sun-drying had the lowest rate. TheAw of products dried by vacuum freeze-drying was the lowest; while the Aw of productsdried by traditional solar-drying was the highest. The products dried by traditionalsun-drying had the highest shrinkage rate and the lowest recovery rate, meanwhile, theproducts dried by vacuum freeze-drying had the lowest shrinkage rate and the highestrecovery rate.