Evaluation of ultrafiltrated dairy by-products as fat replacers in the production of reduced fat washed curd cheese

Abstract

In the present study different dairy by-products were used as ingredients in the production of reduced-fat (RF) washed curd cheeses. Whey, buttermilk and sheep’s second cheese whey, previously concentrated y ultrafiltration (UF), were used envisaging the improvement of texture and flavour of the RF cheeses. UF concentration, is a technique that can be easily available to small scale dairy plants, allowing for the recovery of those dairy by-products. Conventional full-fat (FF) cheeses presented more than 45% fat (d/b) while RF cheeses presented values in the range 20-30%, being in most cases classified as low-fat cheeses according to national standards. The ratio protein in dry matter/fat in dry matter was lower than 1 in FF cheeses and in the range 1.8-2.7 in RF cheeses. The paste of FF cheeses presented a more pronounced yellow colour at the 60th and 90th days of ripening, indicating that fat plays a major role regarding this parameter. The different by-products showed different performances when added to milk used in the production of cheeses. After the 60th day of ripening, FF cheeses and RF cheeses with added buttermilk presented lower values for the hardness of the paste (5.0-7.5 N) when compared to the remaining cheeses. At the end of ripening, chewiness of the paste was also significantly lower in these cheeses. RF cheeses with 5% incorporation of UF concentrated buttermilk presented the best results both concerning texture and sensory evaluation. This fact can be related to the specific composition of buttermilk, namely to its richness in phospholipids.