Textural and physico-chemical analysis of paneer prepared by automated pressing technique

Paneer is the rich source of high quality fat, protein, vitamins and minerals like calcium and phosphorus as well as it is one of the most widely used indigenous dairy product. It is traditional, most popular traditional heat-acid coagulated milk products in India used for the preparation of a variety of culinary dishes and snacks. The manufacturing of paneer essentially involves heat-acid coagulation of standardized milk followed by pressing of the coagulum for a specified duration in a mechanical or hydraulic press. The microprocessor based automated paneer hoop-cum press unit has been developed to automate the procedure of pressure application for the set value of duration at the optimum temperature since the manufacture of paneer essentially involves heat/acid coagulation of milk followed by pressing of the coagulum and the physico-chemical properties such as moisture content (wet basis), bulk density, porosity and textural quality (TPA) of paneer depend on the applied pressure, ambient temperature and the duration of the pressure applied over the coagulum. Automated microprocessor based instrumentation system for the preparation of paneer has been used here to minimize the human interventions, resulting in reduced chances of contamination consequently improving the microbial quality of the paneer. Paneer samples were prepared by applying varying pressure and time combinations and their textural as well as physico-chemical characteristics were evaluated. The pressure was applied from an air compressor through an FRL unit and a pneumatic cylinder which was connected to the pressing plate through the vertical shaft. Moisture content, bulk density and porosity of the paneer prepared were evaluated by standard methods. The variation in the pressure applied over the paneer hoop was found to have significant effect on the physico-chemical properties of the paneer. In fact the duration of press is highly influencing the hardness, porosity, textural and physico-chemical properties of paneer. Further, the optimization of pressure and pressing duration over the coagulum could be achieved by preparing any quantity of paneer varying from 0.25 kg to 12.5 kg using the microprocessor based automated paneer press unit within 4-5 trials of paneer pressing. The developed automated press was very well used for preparing about 500 g of paneer. The highest moisture content of 54.75 per cent was observed for 2.5 kg/cm2 applied pressure for 15 minutes of pressing duration and the lowest value 49.63 per cent was observed for 3.5 kg/cm2 applied pressure for 15 minutes which showed that an increment in the pressure 1.0 kg/cm2 reduced the moisture content by about 5 per cent. There was an increase in the value of bulk density from 1.03 g/cc to 1.36 g/cc as the time of pressing the coagulum was increased from 10 to 15 minutes and the pressure by automated press was increased from 3.0 kg/cm2 to 5.0 kg/cm2.Further, the highest value of porosity 22.22 % was observed when 3.0 kg/cm2pressure was applied for 10 minutes, whereas the lowest value of porosity 14.24 % was observed when 5.0 kg/cm2pressure was applied for 15 minutes duration.Sensory evaluation has got the highest score of 7.56 for overall acceptability for P2T1 combination. Significant improvement was also observed on the textural parameters of the paneer for the increased pressing time by using the automated pressing technique. By observing and getting encouraging results of physico-chemical and textural parameters, it could be very well assured that the medium and small scale paneer manufacturers could very well utilize the automated pressing technique to produce good quality paneer.