贮藏温度对不同脂肪含量牛肉糜品质及水分变迁的影响

Effect of Storage Temperature on the Quality of Minced Beef with Different Fat Content and Their Water Migration

摘要:

为探索贮藏温度对不同脂肪含量牛肉糜品质及水分变迁的影响，本试验将牛脂肪添加量不同的牛肉糜（添加0%、10%、20%牛脂肪）托盘包装，分别在低温(2 ℃)和冰温(-1.5 ℃)条件下贮藏，于贮藏第0 d、3 d、6 d、9 d和12 d天测定其微生物和理化指标。试验结果表明，冷藏6 d时，添加20%牛脂肪组菌落总数及嗜冷菌数均超过6.00 log(cfu/g)，为各处理组中最高值。贮藏第12 d时，三组冰温组的TVB-N值均低于国标规定的25 mg/100 g最高限值，而此时冷藏组(25.34~25.81 mg/100 g)已超过该限值。脂肪添加量对TBARS值影响显著，TBARS值增加速率从高到低变化顺序依次为：牛脂肪添加量20%>10%>0%。利用LF-NMR(low-field nuclear magnetic resonance，LF-NMR)检测水分存在状态及迁移规律，发现冰温贮藏组T22水分变化较小，T23水分的自由度增大，不易流动水含量(P22)降低，自由水含量(P23)先增加后减少，温度对水分变迁影响显著。试验结果表明贮藏温度影响牛肉糜的理化品质及水分变迁，冰温贮藏可抑制微生物生长，提高产品的理化性质及水分存在状态的稳定性，同时牛脂肪添加对牛肉糜微生物性质及水分迁移影响不显著，但是会加剧脂质氧化，导致牛肉糜L*值和b*值增大，a*值降低。本研究为牛肉饼的原料配比及其贮藏方式提供理论指导和科学依据。

Abstract:

In order to investigate the effect of storage temperature on the quality of minced beef with different fat content and their water migration, 0%, 10%, 20% butter were added to the minced beef and then packed in trays. The samples were stored at 2 ℃ and -1.5 ℃, respectively. The microbial, physical and chemical properties were detected on the 0, 3rd, 6th, 9th and 12th day of storage. The total number of colonies and the number of psychrophilic bacteria of the 20% tallow group were more than 6.00 log(cfu/g) on the 6th day of storage, which was the highest value among the treatment groups. On the 12th day of storage, the TVB-N value was lower than 25 mg/100 g (the maximum value stipulated by national standards of). Meanwhile, the TVB-N value in the refrigerated group ranged from 25.34 to 25.81 mg/100 g, exceeding the limit of national standards. The addition amount of fat had a significant effect on the value of TBARS. The order of TBARS value was as follow: 20% butter >10% butter >no butter. LF-NMR was used to evaluate water migration. It was found that the content of T22 in ice temperature storage group changed little, while that of T23 increased. The non-flowable water content (P22) decreased and the free water content (P23) increases first and then decreases. Temperature had a significant effect on water migration. The results showed that storage temperature affected the physical properties of minced beef and their water migration. Ice temperature storage can inhibit microbial growth and this technology can improve the physical and chemical stability of the product. Meanwhile, the addition amount of fat had no significant effect on microbial properties and water migration of minced beef. However, it can increase the level of lipid oxidation. As a result, the lightness (L*) and yellowness (b*) increased, while redness (a*) decreased. This study can provide theoretical guidance and scientific basis for the formula of minced beef and their storage.