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E. A. FOEGEDING, Dept. of Food Science, North Carolina State Univ., Schaub Hall, Box 7624, Raleigh, NC 27695-7624 Sensory textural properties of cheese are related to how the cheese is perceived when chewing and swallowing. Understanding what regulates texture requires establishment of the scientific principles determining texture at molecular and macroscopic levels. Since texture is a sensory property, it can be comprehensively analyzed by descriptive sensory analysis. This method uses terms that depict the textural sensations perceived from first bite through mastication and swallowing, and can be considered a “textural fingerprint” of a product. The mechanical properties of cheese are one component of sensory texture. Mechanical properties can be measured by empirical or fundamental methods. If the goal is to imitate the biting and chewing process, then empirical methods are appropriate. These methods are often used as alternatives to sensory analysis. However, if one wants to understand the molecular basis of texture, then fundamental tests are required because they are based on known physical principles. Fundament tests are conducted such that the magnitudes and directions of stresses and strains are measured or controlled so that rheological properties can be calculated. Rheological properties can be linked to network models such as those for rubber elasticity or filled gels. These models predict how network interactions will alter rheological properties, and therefore they provide an explanation on how molecular interactions can alter sensory texture. Methods for measuring sensory texture and rheological properties of cheese are discussed, along with results from an investigation on the sensory and rheological properties of young cheeses. Our results showed that, in general, sensory and rheological terms that relate to the overall firmness of cheese are highly correlated with a wide range of rheological methods. However, sensory terms that describe the breakdown pattern, adhesiveness and cohesiveness of cheese, require fracture testing and a measure of the viscoelastic properties.
Session 109, The rheology of dairy foods
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