|Abstract: ||摘要 本研究探討黃鰭鮪一氧化碳氣體處理與否及潮鯛生魚片於不同溫度貯藏中其官能屬性、總生菌數、大腸桿菌群及顏色之變化。 實驗一：黃鰭鮪生魚片為材料 黃鰭鮪魚肉於貯藏後，包含整體接受性等官能屬性之評分值均隨時間的延長而逐漸下降，依氣味品評結果，可接受品質的期限為冰藏5天、5℃貯藏4天、10℃貯藏約1天及25℃貯藏8小時。貯藏中pH值變動不大。揮發性鹽基態氮 (VBN)之變化，僅在10℃貯藏後期VBN有明顯的增加。於適合生食之總生菌數標準下 ( < 105 CFU/g) ，冰藏、5℃、10℃及25℃儲藏之保存期限分別為7天、6天、5天及18小時。 貯藏期間游離胺基酸總量、組胺酸 (His) 及鵝肌□ (Ans) ，在貯藏初期呈現上升的趨勢，而麩胺酸 (Glu) 、丙胺酸 (Ala) 及甘胺酸 (Gly) 等三種呈味胺基酸的總量及其餘游離胺基酸的總量均變化不明顯。貯藏初期之ATP及其相關化合物，以肌□酸 (IMP) 為主，隨著貯藏時間而逐漸減少，貯藏後期次黃嘌呤 (Hx) 之蓄積增加。和品評結果對照，K值36％可視為可接受品質的臨界值。 各貯藏期間溫度Hunter’s L及b值變化小，Hunter’s a值隨貯藏時間逐漸下降，並且受到貯藏溫度所影響，貯藏溫度低可延緩肉質變色。 實驗二：潮鯛生魚片為材料 一氧化碳氣體（CO）處理組與未處理組在pH均明顯上升，在5℃、10℃及25℃貯藏後期。揮發性鹽基態氮（VBN）於貯藏後期快速上升，且未處理組之增加量高於CO處理組。 比較官能性品評之接受性試驗結果，僅色澤之評分在兩處理組之間有顯著不同，而質地、氣味、滋味及整體接受性等並無明顯差異。 CO處理與未處理兩組最初的總生菌數無差異，但貯藏中CO處理組之總菌數增加較未處理組慢。貯藏初期之ATP及其相關化合物中以IMP含量最多，貯藏後期以蓄積Hx為主。游離胺基酸組成以牛磺酸 (Tau) 、甘胺酸及脯胺酸 (Pro) 等含量較高，在各溫度貯存下兩處理組之游離胺基酸總量及呈味胺基酸總量皆呈現先增加後下降之趨勢，於可食用期間並無明顯變化。 在各貯藏溫度組Hunter’s L值均隨貯藏時間而逐漸上升，反之Hunter’s a值逐漸下降，CO處理組儲藏中的Hunter’s a值明顯高於未處理組。 鮮度依官能判定屬性之結果，CO處理組比未處理組在外觀色澤、肉質狀態、氣味及整體性等均有較高值之傾向評分。|
Abstract This study investigated the changes in chemical constituents 、sensory properties、total plate count、coliforms and color of yellow-fin tuna and tilapia sashimi with or without the treatment of carbon monoxide ( co ) gas during storage at different temperatures. Experiment I：yellow-fin tuna sashimi as the sample At sensory results, all sensory items fall by degrees during storage. According to result of odor, the shelf-life of Ice、5℃、10℃ and 25℃ were 5day、4day、fail 1day and 8 hour. The pH value changed unobvious during storage. At the volatile basic nitrogen (VBN), only the contents of 10℃ increased obvious in the lately stage of storage. When the total plate count (TPC) suited the standard of uncooked food (low than 105 CFU/g), the shelf-life of Ice、5℃、10℃ and 25℃ were over 7day、6day、5day and 18 hour. At free amino acids (FAA), TAA (total contents of FAA)、Histidine (His) and Anserine (Ans) increased in the early stage of storage. SAA (the sum of Glutamic acid、Glycine and Alanine, they belong to umami and sweat amino acids ) and OAA (other amino acids, the contents is that TAA reduce His、Ans and SAA) changed unobvious. AT ATP and it’s related compounds, IMP (inosine 5’-monophosphate) was the dominant compound of ATP related compounds during the initial storage, reduced to accompany time, collected Hx (Hypoxanthine) in the lately stage of storage. Compare with the sensory results indicated that K value 36% as an indicator of acceptance for yellow-fin tuna. Hunter’s L and b values of all temperatures changed unobvious during storage, but Hunter’s a value reduced slowly during storage. Moreover, Hunter’s a value be influenced by different store temperatures, it indicated that lower temperature delayed the color of meat. Experiment II：tilapia shasimi (included CO treated and CO untreated) as the sample PH value was lower 0.1 to 02 in CO treated than CO untreated before storage, both two treatments of 5℃、10℃ and 25℃ increased in the lately stage of storage. Both VBN contents of two treatments increased rapidly in the lately stage of storage, and the quantity of CO untreated was more than CO treated. Compare with the result of acceptance test, only the color score of CO treated was higher than CO untreated, the texture、odor、taste and overall acceptance scores were not different between the treatments. Total plate count (TPC) were not different in initial storage between the CO treated and the CO untreated. TPC of the CO treated grown slower than the CO untreated. IMP was the dominant compound of ATP related compounds during the initial storage, and collected Hx during the lately storage. Taurine (Tau), glycine (Gly) and proline (Pro) were the major free amino acids. Both TAA and SAA of the CO treated and CO untreated increased initially and decreased lately during storage. On the side, Tau, Pro and OAA of the two treatments were not changed obvious during shelf-life. At the change of color, Hunter’s L value increased by degrees and Hunter’s a values decreased by degrees during storage. Hunter’s a value be influenced obvious by temperature during storage. The test of award freshness indicated that CO treatment had a higher scores at appearance odor, meaty quality, odor and overall assessment than CO untreatment.