特定致腐菌對冷卻豬肉的致腐作用機制

戴金岳 曾憲文 方利敏 姚明印 劉木華 黃林

摘 要：為研究特定致腐菌在冷卻豬肉中的致腐作用機制，將韓國假單胞菌PS1（Pseudomonas koreensis PS1）和梭狀芽孢桿菌J4（Bacillus fusiformis J4）分別接種到新鮮冷卻豬肉中進行致腐實驗，以不接種致腐菌的豬肉為對照，于4 ℃條件下貯藏，每隔1 d測定各組肉樣的細菌總數、總揮發性鹽基氮（total volatile basic nitrogen，TVB-N）含量、蛋白質含量以及脂肪酶、彈性蛋白酶、胰蛋白酶和膠原蛋白酶活力。結果表明：各組肉樣細菌總數均呈現先上升后穩定的趨勢，貯藏第5天，接種P. koreensis PS1、B. fusiformis J4的肉樣細菌總數均超過8.0 （lg（CFU/g）），明顯大于對照組;接種特定致腐菌的2 組肉樣脂肪酶、彈性蛋白酶、胰蛋白酶和膠原蛋白酶活力均高于對照組，且呈現先上升后降低趨勢，至貯藏第7天，彈性蛋白酶、胰蛋白酶和膠原蛋白酶活力均達到峰值，而脂肪酶活力在貯藏第5天達到峰值;同時，各組肉樣蛋白質含量不斷降低，產物TVB-N含量明顯增加，貯藏第5天，接種特定致腐菌的2 組肉樣TVB-N含量均超出15 mg/100 g，明顯高于對照組。

關鍵詞：冷卻豬肉;特定致腐菌;酶活力;致腐機制

Abstract： Chilled fresh pork was inoculated with Pseudomonas koreensis PS1， Bacillus fusiformis J4 or nothing and stored at 4 ℃. Then， total viable count （TVC）， total volatile basic nitrogen （TVB-N） content， protein content， and the activities of lipase， elastase， trypsin and collagenase in pork samples were determined. By doing so， we sought to explain the mechanism by which specific spoilage organisms （SSO） caused spoilage in chilled pork. The results showed that the TVC in all groups increased with storage time until reaching a plateau. The TVC in the two experimental groups exceeded 8.0 （lg （CFU/g）） on the fifth day， which was significantly higher than that of the control group. In the inoculated pork samples， the activities of the above four enzymes were higher than those in the control group， and showed a trend of increasing at first and then decreasing. The activities of elastase， trypsin and collagenase reached the peak on the seventh day， while the peak of lipase activity appeared on the fifth day. At the same time， the protein content decreased continuously in all groups， whereas the TVB-N content increased obviously. On the fifth day， the TVB-N content in the two experimental groups exceeded?15 mg/100 g， which was significantly higher than that of the control group.

Keywords： chilled pork; specific spoilage bacteria; enzyme activity; spoilage mechanism

DOI：10.7506/rlyj1001-8123-20190926-231

中圖分類號：TS251.51? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 文獻標志碼：A 文章編號：1001-8123（2019）12-0050-06

中國是世界豬肉生產和消費第一大國，多年來，豬肉產量和消費量一直位居世界第一[1]，豬肉也是我國居民最主要的肉食品來源，因此保證豬肉品質安全至關重要。豬肉品質安全評價指標包括顏色、紋理、pH值、營養成分含量、嫩度和新鮮度等。新鮮度是肉品腐敗變質程度的直接反映，是評價肉品品質安全的最重要參數[2]。

變質豬肉不但營養價值下降甚至具有毒性，危及消費者健康。……