Dr Saima Inayat - Cheese is a value added dairy product playing important role in manufacturing of other food items. Quality cheese preparation depends upon many factors. Preparation time, temperature, fat contents and other qualitative parameters like texture, physical appearance and colour, are highly considered for a quality product. Brabender Farinograph-E, a computerised machine was used to study rheology and characteristics of different cheeses in a study. The data recorded in the form of Farinogram showed that torque (resistance against flow of farinograph paddles) depended on fat content, temperature employed and time given to cheese formation. Also, the texture of cheese was influenced by these factors.
Sensory tests are not capable of measuring results more accurately as compared to instrumental tests. To study cheese properties and effects of many manufacturing factors, the fundamental methods will help researchers to develop cheeses with required and persistent textural and rheological properties. The instrument most frequently used all over the world for determining water absorption and mixing characteristics of wheat and rye flour in baking industry is Brabender Farinograph. The present study was conducted by using Farinograph-E as a major tool to measure rheology of cheeses. In this study cheeses of different ages, and kinds, eg., Mozzarella, medium Cheddar, mild Cheddar, old Cheddar;’ extra old Cheddar, Ricotta and Parmesan were included. The parameters for operating Farinograph-E were developed and initial trials were conducted ‘in various directions to finalise the procedure. Farinograph-E (Brabender GmbH, Duisburg, Germany) was used in the study by using its bowl W-50.
The tests were performed by cutting whole cheese bars into small pieces and shifted into air tight containers. The grated cheese was loaded with the help of spatula into Farinograph bowl. Water bath was adjusted at various temperatures like 20, 30, 40, 50 and 60°C. The temperature was continuously monitored through a temperature probe, inserted into the bowl contained cheese sample. The speed of paddles! Spindles were fixed in Newton meters (Nm) and kept as constant for all the trials. The lid was closed after filling the bowl and clamped in order to avoid any disturbance. The test was allowed to run for specified time for 35 and 60 minutes. After completion of time durations the test was stopped automatically. The readings were recorded in the form of a graph (torque, time and temperature) of cheese dough resistance over mixing time.
Besides Farinographic studies, the results of Mozzarella and medium Cheddar Farinographic samples of (brand No name) were examined through Cryo-scanning electron microscopy and Fluorescence microscopy to study their microstructure at different stages and their relationship with quality of cheeses. The present study revealed that application of Farinograph is a marvelous idea for preparing cheeses of different qualities, and to study rheology of cheeses that how cheese performs under stress, strain and specific temperatures. All factors can be controlled according to the requirements and best suited values can be applied for preparation of required cheeses,” soft, hard or any other form. After using this machine, fat globule size can be observed and studied with allied microscopic techniques that plays important role to study the texture of cheeses. It is found that Farinograph is a use full machine for preparing cheese and studying rheology of cheeses.
(The writer is Assistant Professor at Department of Dairy Technology, University of Veterinary & Animal Sciences, Lahore.)