Human Nutrition Department, College of Health Sciences, Qatar University, P.O. Box: 2713, Doha, Qatar.
Department of Food Science and Nutrition, College of Food and Agriculture Sciences, King Saud University, Saudi Arabia; Department of Food Science and Nutrition, Faculty of Home Economics, Helwan University, Egypt.
Int J Biol Macromol. 2018 Jul 15;114:578-583. doi: 10.1016/j.ijbiomac.2018.03.125. Epub 2018 Mar 22.
The present study examined the effect of natural antimicrobials: Chitosan, thyme oil and their combination, on the shelf-life of smoked eel fillets stored under vacuum packaging (VP) at 4°C. Based on sensory odor data smoked eel fillets had a shelf-life of 35 (control), 42 (thyme treated and>49 (thyme, chitosan-thyme treated) days. The thiobarbituric acid value (TBA) value of the control eel sample was significantly higher than the chitosan-thyme-treated eel samples. The use of chitosan singly, or in combination with thyme oil reduced lipid oxidation (TBA) of the smoked eel samples. A trimethylamine nitrogen (TMA-N) value of 10mgN/100g, could be suggested as an indication of smoked eel spoilage initiation. Control and treated eel reached total volatile basic nitrogen (TVB-N) values of 13.1-31.5mgN/100g below the maximum permissible level of TVB-N in fish and fishery products. Eel samples reached the value of 7.0logcfu/g (Total Plate Count, TPC) on days 35 (smoked) and 42 (thyme treated), whereas both chitosan and chitosan-thyme treated eel samples never reached this limit value. Results of our study show thyme or chitosan (singly, or in combination) inhibit the growth of mesophilic bacteria and extend the shelf-life of smoked eel.
本研究考察了天然抗菌剂壳聚糖、百里香精油及其组合对真空包装（VP）在 4°C 下储存的熏鳗鱼片保质期的影响。基于感官气味数据，熏鳗鱼片的保质期为 35 天（对照）、42 天（百里香处理）和>49 天（百里香、壳聚糖-百里香处理）。对照鳗鱼样品的硫代巴比妥酸值（TBA）显著高于壳聚糖-百里香处理的鳗鱼样品。单独使用壳聚糖或与百里香精油结合使用可减少熏鳗鱼样品的脂质氧化（TBA）。三甲基胺氮（TMA-N）值为 10mgN/100g 可作为熏鳗鱼腐败开始的指示。对照和处理后的鳗鱼的总挥发性碱性氮（TVB-N）值分别达到 13.1-31.5mgN/100g，低于鱼类和水产品中 TVB-N 的最大允许水平。鳗鱼样品在第 35 天（熏制）和第 42 天（百里香处理）达到 7.0logcfu/g（总平板计数，TPC），而壳聚糖和壳聚糖-百里香处理的鳗鱼样品从未达到此限值。我们的研究结果表明，百里香或壳聚糖（单独或组合）可以抑制嗜温菌的生长并延长熏鳗鱼的保质期。
