Eliasson Saemundur, Arason Sigurjon, Margeirsson Bjorn, Palsson Olafur P
Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, University of Iceland, Hjardarhagi 2-6, IS-107 Reykjavik, Iceland.
Matis (Icelandic Food and Biotech R&D), Vinlandsleid 12, IS-113 Reykjavik, Iceland.
Foods. 2020 Oct 22;9(11):1519. doi: 10.3390/foods9111519.
The aim of the study was to explore the effects of different design variables in the onboard bleeding process of cod on bleeding efficiency and the resulting product quality. A time- and flow-controlled process was used to create variable bleeding conditions for whole gutted cod onboard a wet-fish trawler. Two main design variables influencing the bleeding process are the pump flow recirculation (PFR) and the water replacement ratio (WRR); they were studied in five different combinations (groups). The effects of different bleeding conditions were evaluated by measurements of free fatty acids (FFAs), phospholipids (PLs), and total heme iron (HI) content during freezer storage for up to four months. The results for PL content and the regression model indicate that the enzyme activity in the fish muscle is lower in cases where PFR exerts greater influence in the bleeding process than WRR. The effects of successful blood removal also seem to be most noticeable after one month of freezer storage, rather than in fresh cod after seven days or after four months of simulated frozen food-chain storage. The study indicates that, with the bleeding medium to fish ratio of around 3:1 and enough WRR (over 100% replacement in 20 min), the PFR becomes the limiting design parameter regarding efficient blood removal and should be at least 10% of the tank volume per minute to ensure enough recirculation and flow of water in the bleed-out tanks.
本研究的目的是探讨不同设计变量对鳕鱼船上放血过程中放血效率及最终产品质量的影响。采用时间和流量控制的过程，在一艘鲜鱼拖网渔船上为去内脏的整条鳕鱼创造不同的放血条件。影响放血过程的两个主要设计变量是泵流量再循环（PFR）和水置换率（WRR）；对它们进行了五种不同组合（组）的研究。通过在长达四个月的冷冻储存期间测量游离脂肪酸（FFA）、磷脂（PL）和总血红素铁（HI）含量，评估不同放血条件的影响。PL含量的结果和回归模型表明，在放血过程中PFR比WRR影响更大的情况下，鱼肌肉中的酶活性较低。成功放血的效果在冷冻储存一个月后似乎也最为明显，而不是在新鲜鳕鱼储存七天后或模拟冷冻食物链储存四个月后。研究表明，当放血介质与鱼的比例约为3:1且有足够的WRR（20分钟内超过100%置换）时，PFR成为高效放血的限制设计参数，每分钟应至少为罐体体积的10%，以确保放血罐中有足够的再循环和水流。
