Abstract #23

# 23
Manufacturing of process cheese without emulsifying salt using acid curd.
A. R. A. Hammam*1, L. E. Metzger1, 1Dairy and Food Science Department, South Dakota State University, Brookings, SD.

Process cheese products (PCP) are a dairy food prepared by blending dairy ingredients (such as natural cheese, protein concentrates, butter, NFDM, whey powder, and permeate) with nondairy ingredients (such as sodium chloride, water, emulsifying salts, color, and flavors) and then heating the mixture to get a product with an extended shelf-life. Emulsifying salts (e.g., sodium citrate, disodium phosphate) are critical for the functional characteristics of PCP because they improve the emulsification characteristic of casein by displacing the calcium phosphate complexes that are present in the insoluble calcium-paracaseinate-phosphate network in natural cheese. The objective of this study was to manufacture PCP using a combination of acid curd cheese and micellar casein that would provide the required emulsion capacity without the use of emulsifying salts. The acid curd utilized was produced from micellar casein concentrate that was standardized to 3, 6, and 9% protein. In the formulation, the acid curd was blended with micellar casein so that the formula contained a 2:1 ratio of protein from acid curd relative to micellar casein. Additional dairy and non-dairy ingredients (Cheddar cheese, butter, and salt) were also used in the formulation. The PCP was prepared by mixing all ingredients in a kitchen aid to produce a homogeneous paste. Approximately 25 g of the mixture was cooked in a RVA for 3 min at 95°Cwith a 1000 rpm stirring speed during the first 2 min and 160 rpm for the final min. The cooked PCP was then transferred into molds and refrigerated until further analysis. This trial was repeated 3 times using acid curd (produced from 3, 6, and 9% protein MCC). No significant differences (P > 0.05) were detected in the cooked viscosity (402–483 cP), hardness (354–384 g), melting area (30.0–31.4 mm) and melting temperature (48–51°C) between PCP made from different acid curd and was similar to typical process cheese produced with conventional ingredients and emulsifying salt. We conclude that PCP can be made with no emulsifying salts when the formulation utilizes a 2:1 ratio of protein from acid curd relative to micellar casein.

Key Words: process cheese, micellar casein, acid curd