不同预处理方法对虹鳟鱼保鲜品质的影响

Effect of different pretreatment methods on the preservation quality of Oncorhynchus mykiss

中文关键词: 虹鳟鱼  冷盐水  微酸性电解水  新鲜度

英文关键词: Oncorhynchus mykiss, cold saltwater, slightly acid electrolytic water, freshness

中文摘要:

      为研究不同预处理方法对虹鳟鱼贮藏期间品质的影响，减缓虹鳟鱼腐败速度。本研究设置冷盐水（含盐量3％、温度4℃）、微酸性电解水（pH为6.35、ORP为900 mV、ACC为50 mg/L、室温）2个预处理组，并在各预处理组中设置不同预处理时间，分别为冷盐水处理20 min、40 min、60 min和微酸性电解水处理5 min、10 min、15 min，以菌落总数、TVB-N值、持水力、蒸煮损失率、pH值、色度和感官评价为指标，以未经任何处理的虹鳟鱼肉为对照，对比不同预处理方法及时间对4 ℃、9 d贮藏期间虹鳟鱼肉品质的变化。结果表明：2种预处理方法均能有效抑制虹鳟鱼腐败。微酸性电解水处理对抑制虹鳟鱼菌落总数和TVB-N的生成、维持虹鳟鱼的持水力、延缓贮藏过程中pH、色度和感官变化速率效果较冷盐水预处理更好；冷盐水预处理能延长虹鳟鱼冷藏货架期1 d，微酸性电解水预处理可延长货架期2 d。冷盐水预处理60 min、微酸性电解水预处理10 min，分别为各组最佳预处理时间。综合分析，微酸性电解水预处理10 min能有效改善4℃贮藏下虹鳟鱼保鲜品质，延长其货架期。本研究为虹鳟鱼保鲜和预处理方式的选择提供了科学依据。

英文摘要:

      Oncorhynchus mykiss is a high-quality edible fish with high nutritional and economic value. Due to its tender meat, full elasticity, delicious taste, and rich nutrition, it is deeply loved by consumers. However, due to its high water and fat content, as well as high enzymatic activity, Oncorhynchus mykiss is highly susceptible to spoilage during storage, transportation, and sales. Different pre-treatment techniques are widely used in the field of aquatic preservation. As saltwater freezes below 0 ℃, cold saltwater preservation technology uses refrigerants and ice to jointly lower the temperature, which enables aquatic products to be kept at low temperature, and the frequency of microbial activity, related enzymes, and chemical reaction efficiency to stay low. It achieves preservation at lower energy consumption. Slightly acid electrolytic water is widely used in the field of aquatic product preservation due to its low pH value, high available chlorine concentration, and high oxidation reduction potential. The pretreatment of slightly acidic electrolyzed water can effectively reduce the natural bacterial count in aquatic products, while slowing down the deterioration and decay rate of aquatic products, and extending the shelf life. At present, domestic and foreign research mainly focuses on the effects of different preservatives on the preservation quality of Oncorhynchus mykiss, while effects of different pretreatment methods on the preservation quality of Oncorhynchus mykiss are rarely reported. To study the effects of different pretreatment methods on the quality of Oncorhynchus mykiss during storage and slow down the decay rate of Oncorhynchus mykiss, experiments were carried out with two pre-treatment groups: cold saltwater group(salt content 3%, temperature 4 ℃) and slightly acidic electrolyzed water group (pH 6.35, ORP 900 mV, ACC 50 mg/L, room temperature). Different pre-treatment time were set in each pre-treatment group, which were 20 minutes, 40 minutes, 60 minutes of cold saltwater treatment and 5 minutes, 10 minutes, and 15 minutes of slightly acidic electrolyzed water treatment. TVB-N value, total bacterial count, water holding capacity, cooking loss rate, pH value, chromaticity, and sensory evaluation were measured as indicators,and untreated Oncorhynchus mykiss meat was used as control to compare the changes of the quality of Oncorhynchus mykiss meat during a 9-day storage experiment at 4℃. The results showed that the optimal pre-treatment time were 60 minutes for cold saltwater pretreatment, and 10 minutes for slightly acidic electrolytic water pretreatment, respectively. On the 9th day, after 60 minutes of cold saltwater treatment, the various indicators of Oncorhynchus mykiss meat were as follows: TVB-N value 18.63 mg/100g, total plate count 6.54 (lg (CFU/g)), water-holding capacity 80.09%, cooking loss rate 17.14%, pH value 5.95, L * 49.34, a * 22.02, b* 13.88 and sensory score 9.00 respectively. On the 9th day, after 10 minutes of slightly acidic electrolyzed water r treatment, the various indicators of Oncorhynchus mykiss meat were as follows: TVB-N value 19.05 mg/100g, total plate count 5.28 (lg (CFU/g)), water-holding capacity 83.17%, cooking loss rate 24.10%, pH value 5.95, L * 49.15，a *16.79，b *17.46 and sensory score 9.67 respectively.All two preprocessing methods can effectively maintain the freshness of Oncorhynchus mykiss and delay its spoilage. Compared to cold saltwater pretreatment,. the slightly acidic electrolyzed water treatment had a better effect on inhibiting the total bacterial count and TVB-N generation of Oncorhynchus mykiss, maintaining the water-holding capacity of Oncorhynchus mykiss, delaying the change rates of pH, chromaticity, and sensory during storage. Cold saltwater pretreatment can extend the refrigerated shelf life of Oncorhynchus mykiss by 1 day, while slightly acidic electrolyzed water pretreatment can extend the shelf life by 2 days. All in all, pre-treatment with slightly acidic electrolyzed water for 10 minutes can effectively improve the preservation quality of Oncorhynchus mykiss stored at 4 ℃.