|Abstract: ||中文摘要 黃鰭鮪 (Thunnus albacares) 普通肉於25℃貯存之pH值、氨、揮發性鹽基態氮 (volatile basic nitrogen, VBN) 與總生菌數 (total plate count, TPC) 隨貯藏時間增長而逐漸上升，VBN在第48小時超過25 mg/100 g，而TPC則在第12小時即超過食用標準6.48 log CFU/g，IMP亦開始分解，K值則由最初之11%至48小時達93%。黃鰭鮪的普通肉中主要游離胺基酸 (free amino acid, FAA) 為組胺酸 (histidine, His)，佔總FAA之90%，在貯藏36小時期間變化不大，至48小時後開始明顯減少，His相關雙胜肽之肌肽 (carnosine, Car) 與甲肌肽 (anserine, Ans) 含量分別為79與36 mg/100 g，兩者在貯藏期間無明顯變化。以HPLC分析生物胺發現組織胺 (Him)、精胺 (Spm)、屍胺 (Cad)、腐胺 (Put) 和酪胺 (Tym) 為貯藏48小時後之主要產物，其中Him含量最多。Him在貯藏12小時後開始產生，至48小時顯著增加，在60小時之His減少莫耳數相當於Him產生之莫耳數。 旗魚 (Istiophorus platypterus) 之pH值、VBN及TPC隨貯藏時間之延長而逐漸上升，於18小時VBN已達食用限量標準，TPC則超過300萬個菌落數。旗魚之ATP相關化合物在25℃貯藏初期以IMP為主要化合物，並於18小時由3.72 μmol/g迅速減少至0.78 μmol/g，K值由37%迅速增加至82%。旗魚肉FAA組成以His、Tau及Ala居多，其中His佔80%。貯存至18小時，His急劇減少，同時產生大量之Him。旗魚Ans含量達1086 mg/100 g，遠高於His，貯存至48小時，Ans減少至898 mg/100 g，於此同時，其組成胺基酸1-甲基組胺酸 (1-Mehis) 及β-丙胺酸 (β-Ala) 則分別增為80與59 mg/100 g。旗魚與鮪魚相似，在貯存期間肉中產生之主要生物胺為Put、Cad及Him Him快速檢驗套組分為定性 (Alert kit) 與定量 (Veratox kit) 兩種，在定性方面係以50 ppm為控制組，經HPLC分析貯存期間Him含量超過50 ppm之樣品，以Alert kit定性測試，皆呈現粉紅色；以Veratox kit定量分析Him含量變化之趨勢與HPLC分析結果類似，但分析高濃度Him時，Veratox kit常高於HPLC分析所得數據。以HPLC分析冷凍、罐頭、乾燥、鹽藏等32件水產加工品Him含量超過50 ppm者計有7件，經以Alert kit定性測試比對，其分析結果與HPLC分析符合。Alert kit定性測試產品Him可實際應用於超低溫鮪魚生魚片公司及鯖魚番茄罐頭廠之Him監測。|
Abstract The pH, ammonia, volatile basic nitrogen (VBN) and total plate count (TPC) of white muscle of yellowfin tuna (Thunnus albacares) increased gradually during storage at 25℃. The VBN reached a level of 25 mg/100 g at hr 48. At hr 12, however, the TPC was higher than 6.48 log CFU/g of the limited value, and IMP began to degrade. The K value increased gradually from the beginning of 11% to the end of 93%. Histidine (His) was the predominant free amino acids (FAA), accounting for 90% of the total FAA. His remained unchanged during storage of 36 hrs, and began to decrease significantly at the 48th hr. The histidine-related dipeptides, carnosine (Car) and anserine (Ans), were present at the levels of 79 and 36 mg/100 g , respectively. They showed no significant change at the end of storage. Histamine (Him), spermine (Spm), cadaverine (Cad), putrescine (Put) and tyramine (Tym) were the major biogenic amines during storage, of which Him was the predominant compound. The decreased mole of His at the 60th hr was almost equal to the increased mole of Him. The pH, VBN and TPC of white muscle of sail fish (Istiophorus platypterus) increased gradually during storage at 25℃. The VBN was higher than 25 mg/100 g and TPC reached the limit of 3 million CFU/g at the 18th hr. Among the ATP-related compounds of sail fish, IMP was the most predominant compound at initial stage of storage and decreased rapidly after 18 hr storage. The K value increased rapidly from 37% to 82% simultaneously. The major FAA in white muscle of sail fish were His, Tau and Ala, of which His accounted for 80% of total FAA. His decreased after 18 hr storage, and Him increased rapidly at the same period. The content of Ans (1086 mg/100 g) was much higher than His. Ans decreased to 898 mg/100 g at the 60th hr, and 1-Methylhistidine (1-Mehis) and β-Alanine (β-Ala) increased in a considerable amounts consquently. Put, Cad and Him were the predominant biogenic amine during storage of sail fish, similar to yellowfin tuna,. Him rapid detection kit was divided into qualitative (Alert) and quantitative (Veratox) determination. The 50 ppm of Him was a marked level in Alert kit. The sample containing Him higher than 50 ppm appeared pink color in the kit. The trend of Him change during storage was similar between using Veratox kit and HPLC. When the concentration of Him was higher than 50 ppm, the value obtained from the former method was usually higher than the latter. Him of commercial seafoods including frozen, canned, dried, salted and seasoned products in a total of 32 samples was analyzed. Seven samples had Him higher than 50 ppm, and the result was same between the HPLC and Alert kit. The Alert kit has been used in a tuna sashimi company and a mackerel canned factory to monitor Him.