Cheese meltability as assessed by the Tube Test and Schreiber Test depending on fat contents and storage time, based on curd-ripened fried cheese

The study assessed cheese meltability at elevated temperatures, based on the results of the Tube Test and Schreiber Test. The tests were conducted on curd-ripened fried cheese with varying fat contents (Δfat = 17%) and at different storage times (Δt = 6 weeks). The protein:fat ratio in full fat cheese was C:F≍1, while in low-fat cheese it was C:F≍58. The data on cheese meltability recorded in the Tube Test and Schreiber Test, irrespective of experimental variables, indicated a high degree of correlation (r = 0.95). However, the lowest convergence (r = 0.6) of both methods was found when analysing low fat cheese. A higher fat content in the tested cheeses resulted in a statistically significantly higher meltability both in the Tube Test (by 12%) and in Schreiber Test (by 18%). The analysis of the regression model and response surfaces of variables confirms the trend showing that the lower the fat content and the longer the sample storage time, the lower the meltability. After 6 weeks the assessed meltability of cheeses was lower by 20.7% in the Tube Test, and by 19.1% in the Schreiber Test in comparison to the meltability of cheeses assessed immediately after their production.