The effect of transglutaminase enzyme and carrageenan gum on sensory, textural and microbial properties of low fat ultrafiltrated cheese

Because fat content has a great impact on the sensory properties of the cheese like appearance, taste and texture, its reduction causes fundamental changes in the sensory and structural characteristics of the product. Therefore, by using fat replacers, as well as to produce a healthy cheese, a product with an acceptable quality could be produced. In the present study, low-fat cheese samples (8% fat) were produced thru ultra-filtration (UF) method. To produce the cheese samples, kappa-carrageenan gum was applied at three levels (0, 0.03 and 0.06%) and transglutaminase was added at 2 levels (0 and 0.5 unit/g of protein). The low-fat sample without the gum and enzyme addition was considered as the control. All samples were evaluated in terms of sensory, textural and microbial characteristics after 1, 15 and 30 days of production. According to the results, the addition of gum caused a significant reduction of cheese hardness, while enzymatic treatment had adverse effect and it increased this parameter (p<0.01). Addition of 0.03% of gum resulted in the higher taste and texture quality, but the sensory attributes of low-fat UF-cheese samples decreased at the higher level, i.e. 0.06%. Furthermore, results showed that enzymatic treatment caused a substantial reduction on lactic acid bacteria (LAB) count, while gum addition had no effect. Overall, as the time of storage increased and until the 15th day of storage, all the sensory scores, the cheese hardness and the count of LAB increased while at the end of 30th day of storage, all these parameters significantly decreased. In conclusion, according to the sensory evaluation and texture results, the low-fat UF-cheese containing 0.03% carrageenan treated with transglutaminase was selected as the best sample.