Italian food is well known for its beautiful splashes of colour from basil, tomatoes and saffron, and delivering fresh flavours. It is also very satisfying in terms of its texture; there is a wide range of textures ranging from delicately soft and creamy to crunchy, crispy and stretchy. A manufacturer of Italian food may perform many different quality control tests on their products to ensure textures are consistent and within acceptable ranges that may have been determined by sensory panels or customer feedback.
An example that may jump straight to mind is the texture of a slice of pizza when grabbed by the teeth and pulled away by hand. The base should be slightly resilient to tearing and the cheese should extend, forming strings between the two halves.
Stable Micro Systems have a specially designed test rig to measure these properties. The Pizza Tensile Rig is formed of two plates containing three spikes each. The slice of pizza is pushed onto these six spikes, and the plates are pulled apart while force, distance and time are recorded. This measurement is particularly useful when coupled with Gary's restaurant, which allows the tearing of pizza and stretching of strings to be stepped through frame by frame, examining the force data at each point, which is what the customer is really experiencing with their hands.
Spaghetti is a quintessential Italian food that is eaten in homes and restaurants across the country and abroad. As such, spaghetti manufacturers face high levels of competition and so are motivated to send out high quality products. If a package of spaghetti is opened by a chef and it contains many broken strands, it will be perceived as low quality.
The Spaghetti Flexure Rig allows single spaghetti strands to be loaded from each end until breakage. This provides useful information on the strength and strain to failure of strands, allowing the recipe to be tweaked until the result is a product that can withstand sufficient forces during transit.
One particularly beautiful dish is tricolore salad, composed of mozzarella, fresh tomatoes and basil. Mozzarella should be soft and creamy on the inside (this property can be investigated using a blade cutting test), tomatoes should be firm but not hard (assessed using a cylinder penetration test) and the basil should be compliant and not tough (this can be measured using a tensile or puncture test).
The silky texture, homogeneity and the forces resisting the spoon can all be measured by testing the sample using penetration with a cylinder probe. This pushes down on the product until it breaks through the surface to a chosen distance. With reference to the graph (left), an optimum result will show small forces (but not so small that product collapses straight away) and smooth force curves (see pink curve). A product that is lumpy or grainy would display a jagged force reading (see green curve), and this is to be avoided. Find more details
