農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

在前一年 (109) 的計畫中，我們已確立煅燒牡蠣殼粉及有機酸(檸檬酸)能抑制多種好氧性腐敗菌之生長，包含：不動桿菌 (Acinetobacter lwoffii)、微小桿菌 (Exiguobacterium spp.)、草蝦單胞菌 (Pseudomonas poae）、速生嗜冷桿菌 (Psychrobacter celer)、腐敗希瓦氏菌(Shewanella putrefaciens)、微桿菌 (Microbacterium spp.）及螢光假單孢菌 (Pseudomonas fluorescens) 等菌株；然而對沿近海作業缺乏冷凍設備之漁船，可能更需要開發能添加於海水冰中的天然保鮮劑，以取代非法保鮮劑的濫用。因此本年計畫擬延續前一年的成果，進一步探討牡蠣殼粉或有機酸對於魚體之抑菌功效及對鮮度的變化，結果顯示：將赤鯮以不同保鮮劑處理，經T3(未煅燒牡蠣殼)與T6(未煅燒牡蠣殼+檸檬酸)浸泡一天後，赤鯮之生菌數為3.8×10⁴、6.3×10⁴ CFU/g，對比控制組(T1純水組及T2鹽水組)為9.6×10⁴、7.8×10⁴ CFU/g。於冷藏4^oC保藏五天後，T1生菌數已上升至10⁷ CFU/g，T2、T3及T6分為8.9×10⁶、2×10⁶、5.6×10⁶ CFU/g，以T3之生菌數最低。將赤鯮經T3與T6浸泡一天後，赤鯮之VBN介於13.44~13.88 mg/100g；於冷藏4^oC保藏五天後，T1之VBN已上升至30~36 mg/100g；於冷藏4^oC保藏七天後，T1之VBN已上升至61.7 mg/100g，而以T3最低(52.8 mg/100g)。以色差儀L、a、b值說明體色，T3比起T6更能維持魚體亮度、紅色及黃色，意即未煅燒牡蠣殼最為適合作為保鮮劑。外觀上以保鮮劑浸泡1天後，T3的外觀比T6明亮，T6魚體的眼睛稍微白濁，以外觀評估，T3較T6適合做為保鮮劑。總體而言，未煅燒牡蠣殼(T3)較適合做為保鮮劑之成分。利用牡蠣殼粉來預處理製冰用水，開發水產品天然保鮮劑，期能提供漁民於作業期間，延緩水產品離鏈狀態下微生物的生長及腐敗，為提升水產食品安全。

In the previous plan, it was known that citric acid and calcined oyster shell powder could inhibit the growth of a variety of aerobic spoilage bacteria. Therefore, this plan intends to continue the previous plan results and further explore the effects of oyster shell powder or organic acid on fish. The antibacterial effect of the fish and the change of freshness, the results show that the Dentex tumifrons is treated with different preservatives and soaked in T3 (uncalcined oyster shell) and T6 (uncalcined oyster shell + citric acid) for one day. The bacterial counts were 3.8×10⁴, 6.3×10⁴ CFU/g, and the comparison control group (T1：pure water group and T2：saline group) were 9.6×10⁴, 7.8×10⁴ CFU/g. After five days of storage at 4^oC, the T1 bacterial count has risen to 10⁷ CFU/g, T2, T3 and T6 are divided into 8.9×10⁶, 2×10⁶, 5.6×10⁶ CFU/g, and T3 has the lowest bacterial count. After soaking in T3 and T6 for one day, the VBN of Dentex tumifrons is between 13.44~13.88 mg/100g; after five days of storage at 4^oC, the VBN of T1 has risen to 30~36 mg/100g; after seven days of storage at 4^oC, the VBN of T1 has risen to 61.7 mg/100g, and T3 is the lowest (52.8 mg/100g). The L, a, and b values of the colorimeter are used to illustrate the body color. Compared with T6, T3 can maintain the brightness, red and yellow of the fish body, which means that the uncalcined oyster shell is the most suitable as a fresh-keeping agent. In appearance, after immersing in the preservative for 1 day, the appearance of T3 is brighter than that of T6, and the eyes of T6 fish are slightly cloudy. According to the appearance evaluation, T3 is more suitable as a preservative than T6. In general, uncalcined oyster shells (T3) are more suitable as ingredients for preservatives. Use oyster shell powder to pretreat the icemaking water and develop natural fresh-keeping agents for aquatic products. It will provide fishermen with the ability to delay the growth and corruption of microorganisms in the off-chain state of aquatic products during the operation period, so as to improve the safety of aquatic food.