Etiket Arşivleri: texture
Why do we measure food texture?
Texture is an index of ripeness
To evaluate the resistance of products against mechanical action
Such as mechanical harvesting of fruit and vegetables,
Wheat hardness for milling
To determine flow properties of products during processing, handling and storage
To establish the mechanical behavior of a product when consumed
• When a food produces a physical sensation in the mouth;
– hard, soft, crisp, moist, dry
• the consumer classifying the food’s quality
– fresh, stale, tender, ripe.
• Textural properties affect the consumer’s perception;
• acceptable or
• unacceptable product.
• Physical properties of food affect the design of processing equipment.
– in selecting and adjusting the equipment used to mix, transport and package products.
• Quality of a food product involves maintenance or improvement of the key attributes of the product including
– shelf life, and
In the experiment of rheology the liquid sample’s textural characteristics have been measured. After calculations from datas the textural structre has been observed if it was newtonion or non newtonion type.Generally while measuring the rheological charecteristics, temperature was an important effective parameters. In non newtonion type of fluid there iare two type; time dependent and time independent. Also except temperature shear rate and time are the other effective parameters while measuring the flow of fluid.
Rheology is defined as the science of deformation and flow of matter. The term itself originates from Greek rheos meaning to flow. Rheology is applicable to all types of materials, from gases to solids. The science of rheology is young, only about 70 years of age, but its history is very old. In the book of Judges in the Old Testament the prophetess Deborah declared “The mountains flowed before the Lord…”. Translated into rheological terms by professor M. Reiner, this expression means everything flows if you just wait long enough, a statement that is certainly applicable to rheology. It was also described by the Greek philosopher Heraclitus as “panta rei” – everything flows. Professor Reiner, together with Professor E. Bingham, was the founder of the science of rheology in the mid-20s. Rheology is used in food science to define the consistency of different products. Rheologically the consistency is described by two components, the viscosity (“thickness”, lack of slipperiness) and the elasticity (“stickiness”, structure). In practice, therefore, rheology stands for viscosity measurements, characterisation of flow behaviour and determination of material structure. Basic knowledge of these subjects is essential in process design and product quality evaluation.