Studies on the Preservation of Pork Loin by Gamma Irradiation

• Main Authors: Liew,Ming-Hing, 劉明興
• Other Authors: Tsai,Shi-Shun;Hau,Lung-Bin
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/59243267962686789690

博士 === 國立臺灣大學 === 農業化學系 === 82 === Pork loin is the major meat product consumed in Taiwan, Pork loin always suffer from the contanmination of large amount of microorganisms.If the microorganisms are not inhibited or des- troyed, it may cause meat spoilage and potential health hazards. In recent years, gamma irradiation is effective in eliminating microorganisms and extending the shief life of food. The purposes of these studies were to evaluate the effects of gamma irradiation on the reduction of microorganisms and on the chemical change of meat constitutions. The results showed that pork loin irradiated at 5oC or -18oC would produce irradiation flavor, the threshold doses were 1.25 kGy and 3.2 kGy respec- tively. the intensity of irradiation flavor was well correlated with temperature and irradiation dose, Gamma ray also inhibits pathogenic bacteria effectively and the viability of pathogenic bacteria varied with dose, medium and treatment. With a irradia- tion dose of 1.25 kGy at 5oC, the total bacteria count on pork loin were below 3 x 10 7 cells/g after 12 days storage, but not inhibit autolytic enzymes, the meat shown worse quality after prolong storage. In respect of nutrient, there were no signi- ficant changes in vitamin B2,B5, B6, B12 and amino acids when irradiated at 7 kGy or less. The only exception is vitamin B1. Although electrophoresis results showed that the sarcoplasmic protein and myofibril undergo fragmentation, degradation and polymerization at 50 and 100 kGy, but no significant change in protein with a irradiation dose less than 10 kGy. As a whole, low dose irradiation (1.25 kGy) could effectively reduce the number of microorganisms, extended the shelf life and cause no significant change in nutrients. However, the inhibi- tion of proteolytic enzymes, need further investigation.