黃鰭鮪魚肉於低溫貯藏中鮮度與官能品質的變化

Changes in Freshness and Sensory Qualities of Yellowfin Tuna Muscle Stored at Refrigerated Temperatures

邱思魁(Tze-Kuei Chiou) ； 丁任法(Ren-Fa Ding)

《臺灣農業化學與食品科學》 43卷4期 (2005/08) Pp. 287-294

https://doi.org/10.6578/TJACFS.2005.037

摘要

本研究探討黃鰭鮪魚肉在冰藏、5℃及10℃貯藏七天鮮度與官能品質之變化。貯藏中pH值及游離胺基酸的變化小，惟10℃貯藏六天後組胺酸含量有減少之趨勢，揮發性鹽基態氮僅10℃貯藏五天後始明顯增加。各溫度貯藏下，總生菌數及K值均隨時間的延長而增加，在5℃及10℃貯藏分別於第六及五天的總生菌數超過10^5之生食標準；顏色變化以紅色度下降明顯。食用生魚片之接受性試驗，結果顯示顏色、質地、氣味、滋味及整體接受性之評分值均隨時間的延長而降低；由各官能屬性之線性迴歸計算，在各貯藏溫度下達最低可接受的時問均較之由總生菌數變化所判定為短，尤以滋味的貯藏期限最短，其次為氣味。各溫度貯藏中的K值和氣味、整體接受性評分值之間的線性相關性高，歸納出K值34.5%可視為黃鰭鮪生魚片官能品質仍可接受之臨界值。

關鍵字

鮪魚 ； 生魚片 ； 貯藏 ； 鮮度 ； 官能性質

並列摘要

This study investigated the changes in freshness and sensory qualities of yellowfin tuna muscle stored in ice and at 5℃ and 10℃ for seven days. Levels of pH and free amino acids changed very little during storage, but histidine content started to decline after 6 days of storage at 10℃. Volatile basic nitrogen did not increase until five days of storage at 10℃. Total plate count (TPC) and K-value increased with storage time. TPC of the samples stored at 5℃ for six days and 10℃ for five days exceeded 10^5 CFU/g the quality standard for raw seafood consumption. Among the color changes, Hunter's a-value declined. An acceptance test for the sashimi showed that the acceptability scores for color, texture, odor, taste, and overall acceptance decreased linearly with storage time. The shelf-life of the five attributes predicted by the linear regressions of the storage time for acceptance were found shorter than that predicted from the TPC changes. Shelf-life based on the attribute of taste was the shortest, followed by that based on odor. Good correlations were also observed between the changes in K-value and acceptability score for odor and overall acceptance during storage. A K-value of 34.5% might be the limit for acceptance of sensory quality of yellowfin tuna sashimi.

並列關鍵字

Tuna ； Sashimi ； Storage ； Freshness ； Sensory property