Melt analysis of process cheese spread or product using a rapid visco analyzer

The objective of this study was to evaluate a rapid visco analyzer (RVA) method for measuring the melting characteristics of process cheese spread or product. The melt properties of 32 commercial process cheese spread and process cheese product samples from 4 manufacturers were analyzed with the RVA, tube melt test, texture profile analysis (TPA) hardness, and dynamic stress rheometry (DSR). For the RVA melt test, a 15-g disc of cheese was packed into the RVA canister and subjected to a heating, holding, and cooling profile during continuous mixing. During the test, the apparent viscosity was continuously measured and several data points (melt time, hot viscosity, time at 5000 cP during cooling, and solidification time) were collected from the viscosity vs. time curve. There was a high correlation (R² = 0.91) between the DSR melt temperature and the tube melt test. There was also a high correlation between the RVA melt time and the DSR melt temperature or the tube melt test (R² = 0.84 and 0.74, respectively). The RVA hot viscosity had a low correlation (R² < 0.44) with the DSR melt temperature and the tube melt test but had a high correlation (R² = 0.74) with DSR G″ at 85°C. The results of this study indicate that RVA melt analysis of process cheese spread/product is correlated with the results from other melt tests and is capable of measuring the melt properties quantified by other methods. The RVA melt test may also provide additional information on the melt characteristics of process cheese spread/product not measured in other tests.