SPRINGINESS is the rate at which a deformed material goes back to its undeformed condition after deforming force is removed.
It is a measurement of elastic recovery – the textural property possessed not only by baked goods such as cakes or breads but also by novel confectionery products and pharmaceutical materials (e.g. cosmetic sponges).
RUPTURE FORCE – the force that is required to produce a major break/rupture in a
sample – can be related to the firmness and brittleness of a product. It
is related to burst force – the force causing a sample to break
suddenly and violently into pieces. Rupture force measurement can be
crucial for such products as medical implants, which may be required to
resemble soft tissue but must remain intact for the duration of their
intended residence.
Several other products, such as gel capsules
containing vitamins, possess bursting as a desirable property, but must
withstand transport and handling before ultimately bursting in the
mouth.
SEAL STRENGTH is the ability to resist forces that can separate materials that have been sealed together.
It may be a flexible surface from a rigid surface or another flexible surface.
Seal strength tests are useful for a variety of products and can be performed on containers such as trays and packaging pouches as well as assessment of adhesive, cosmetic and medical products such as surgical pouches and sterile packaging.
SYRINGEABILITY can be described as the ability of a product to be successfully administered by a syringe and appropriate needle.
Syringes are used in hospitals, surgeries and homes around the world on a daily basis, and for a multitude of purposes. Successful administration, as well as comfortable receipt of the material under the skin, rely on the effective tracking of the syringe piston within its outer tube.
FIRMNESS/HARDNESS/SOFTNESS are textural properties that are on the same general property spectrum.
A soft product is one that displays a slight resistance to deformation, a firm product is moderately resistant to deformation, while hardness describes a product which shows substantial resistance to deformation.
However, it is also likely that, depending upon the particular industry, one of these words may be more favourable or pertinent to a specific product.
GEL STRENGTH is a measure of the ability of a colloidal dispersion to develop and retain a gel form.
In the gelatine world, gel strength is traditionally referred to as Bloom. It is the force, expressed in grams, necessary to depress by 4 mm the surface of a gelatine gel with a standard 0.5" diameter cylinder probe.
Whilst gels are commonly accepted in the food industry the measurement of gel strength is also of widespread interest in the manufacture of pharmaceutical, medical and cosmetic products.
Gel properties such as elasticity and rupture force of, for example, pectin, gelatine, agar etc. are important in the development of such products as coronary stents where hydrogel polymers are selected due to their soft, rubbery nature which gives them a strong, superficial resemblance to living, soft tissue.
EXTRUDABILITY is the power required to push or force something out of something.
A compression-extrusion test consists of applying force to a product until it flows through an outlet (or number of outlets) that may be in the form of one or more slots or holes that are in the test cell. The product is compressed until the structure of the product is disrupted and it extrudes through these outlets.
Quantifying extrudability is important to determine the ease of removal and application of products such as ointments, creams, gels, sauces, paint, icings etc. Product developers can analyse changes in a product's consistency throughout its shelf life and adapt formulations accordingly whilst also enabling manufacturers to assess the suitability of packaging material and its construction.
STICKINESS/ADHESIVENESS is the work/force necessary to overcome the attractive forces between the surface of the product and the surface of the material (the probe) with which the product comes in contact.
It is commonly the textural property possessed by confectionery products, cooked pasta products, raw bakery products, pharmaceutical patches and, more obviously – adhesives.
TACKINESS is the property of being cohesive and sticky. It does not appear to be referred to in the food industry, but there are many references in e.g. solder paste measurement for printed circuit board industry.
