Studies on the quality and sanitation of smoked shark meat and its shelf-life

• Main Authors: Chih-Yang Lin, 林志洋
• Other Authors: Chyuan-Yuan Shiau
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/70370700112598569301

碩士 === 國立臺灣海洋大學 === 食品科學系 === 94 === The process of smoked shark product includes steaming of shark fillet and smoking with sugar or sugarcane. The chemical composition, freshness, quality and sanitation of commercial smoked shark products were investigated. The changes in quality and flavor of smoked shark during storage at 25oC and 4oC were also studied to evaluate the shelf life of the product. The moisture contents of commercial smoked shark ranged from 75.7 to 82.0%, protein 17.6 to 21.1%, ash 0.97 to 1.51% and salt 0.70 to 1.30%. The fat content in the products was very low. Products made from small shark had the lowest moisture content and pH value, while protein content was the highest. Small shark products also had the highest amount of free amino acids (FAA) at the level of 1,010 mg/100 g, of which taurine accounted for 47%. Among ATP related compound (ARC), IMP was the highest, followed by inosine and hypoxanthine. Smoked small shark product had the highest content of ARC and the lowest K value among 6 kinds of products. The volatile basic nitrogen (VBN) value ranged from 12.1 to 31.6 mg/100 g, lower than 50 mg/100 g of the regulation standard. However, only two samples met the regulation compliance based on the standard of ready- to- eat food. The total plate account (TPC) was from 0.48 to 3.52 log CFU/g, which was also lower than the standard requirement. E. coli was not detected in the products. Smoked shark had the golden appearance with the high b value by colorimeter measurement. The processing by cooking and sugar fumigation lead to the decrease of the levels of moisture, VBN, TPC, FAA and urea in the product, but with the increase of K value. The pH value increased from 6.76 at the third day to 8.02 at the fourth day during storage at 25oC. The VBN value reached 62 mg/100 g after 3 days of storage. The TPC increased rapidly during storage and did not meet the requirement after 2 days of storage. Results indicated that the shelf life of smoked shark at 25oC storage was limited to 2 days. During storage at 4oC, the VBN and K values increased with increasing time. FAA increased at the initial stage of storage and then decreased. The level of urea increased at the initial storage period and remained unchanged after further storage. From the view point of VBN and sensory evaluation, the shelf life of smoked shark stored at 4oC was about 6 days.