Optimisation of soft cheese production conditions using papain as a plant-based enzyme by response surface methodology (RSM)

Abstract

As the demand for cheese products increases, rennet enzyme supplied for cheese production is reduced due to the limited availability of ruminant stomach. In some countries, microbial coagulants have not been accepted for regular cheese manufacture because they are believed to result in a reduced yield and a lower quality product. Therefore, plant-based enzymes are one of the alternatives for animal-based enzyme substitution. Papain enzyme is chosen due to its capability of coagulating milk as it is a proteolytic enzyme. This study aimed to optimize the yield and viscosity of soft cheese by papain using response surface methodology (RSM) and to determine the physicochemical and textural properties of soft cheese. Experimental design was generated using RSM by MINITAB software version 19 with three selected variables including papain concentration (0.2 – 1 U/g), incubation time (1 – 5 hrs) and incubation temperature (30 – 50oC). The optimum condition for yield and viscosity of soft cheese was achieved at a papain concentration of 0.26 g, incubation time of 1.30 hrs and incubation temperature of 34.82oC, with the predicted yield and viscosity of 11.78 % and 4.77 Pa.s, respectively. The optimum condition was verified with the yield and viscosity obtained was 12.60% and 4.67 Pa.s, respectively. Since there was no significant difference (p>0.05) between the predicted and verified yield and viscosity values, thus it indicates that the predicted optimum condition by RSM can be accepted. Characterization of soft cheese produced using papain enzyme at optimum condition was also determined and compared with commercial soft cheese. There is a significant difference between these cheeses in terms of their physicochemical characteristics.