相变蓄冷工艺在金枪鱼冷链物流中的应用研究

为研究不同相变蓄冷剂对金枪鱼配送箱内鱼肉品质的影响，本试验分别选取了纯水、质量分数18.8%的NaCl、46.3%的乙醇以及29%的CaCl2溶液制作冰袋，以不加冰袋作为对照，模拟夏季金枪鱼配送箱的配送情况，对箱内温度以及金枪鱼排的中心温度、感官和理化指标进行测定。结果表明，添加相变蓄冷剂能够有效维持配送过程中金枪鱼排品质，且蓄冷材料的相变温度越低，金枪鱼肉品质维持的时间越长。18.8%的NaCl溶液冰袋能够较好保持鱼肉的品质，可在2 h内将鱼排维持在冻结状态，适合短途配送；46.3%的CaCl2溶液冰袋能使鱼排在运输5 h后仍保持冻结状态，中心温度仅-20.74 ℃，运输末期鱼肉品质接近新鲜鱼肉，红度值高达13.61，硬度及咀嚼性为3.80 N及220.50，明显高于其他试验组，是较好的金枪鱼肉的低温蓄冷材料。
The aim of this study is to investigate the effects of different cold storage phase-change materials on the quality of tuna in distribution boxes. In this study, stimulation under summer conditions was carried out in the distribution box, with or without ice bags. Pure water, 18.8% (m/V) NaCl, 53.8% (V/V) ethanol, and 29% (m/V) CaCl2 were used separately in ice bags. The temperature in the distribution boxes, the central temperature of the tuna steak, sensory evaluation, and chemical and physical indices were investigated. The results showed that the addition of cold-storage phase-change materials could help maintain high quality of the tuna in the distribution process. The duration for which the quality could be maintained increased with decrease in the phase-change temperature. The tuna steak could keep frozen for 2 h with 18.8% NaCl ice bags, which was suitable for short-time transportation. Tuna steak transported with 46.3% CaCl2 ice bags had the best effect on low-temperature cold storage. It could keep frozen for 5 h, with the central temperature of the tuna steak being only -20.74°C. Its quality was close to that of fresh tuna at the end of the transportation process. The redness, hardness, and chewiness of tuna were 13.61, 3.80 N, and 220.50, respectively, and were higher than those of the other test groups.