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 lots of references in e.g. solder
paste measurement for printed circuit board industry.
Stickiness/Adhesiveness is a
desirable and sometimes vital characteristic when wishing to stick
two surfaces together e.g. for the adherence of coatings, films,
attachment of adhesive and medical tapes or drug delivery devices for
semi-permanent or permanent applications. However, it can be an
extremely undesirable characteristic in such examples of
confectionery wrappers attaching to the enclosed confectionery or
chewing gum to shoes, furniture etc.
Stickiness is a major problem in
the food industry, especially in the baking and confectionery
industries, where it can cause considerable difficulty during
processing by causing interruptions in production, waste and
contamination of machinery. Sticking of food to packaging materials
is generally regarded as undesirable resulting in possible packaging
material damage, product loss and disfigurement of the product surface.
It can be surmised that the extent
to which this could generate adverse consumer reaction will depend on
the extent of the sticking, on the type and cost of the product and
on the availability of alternative product/packaging combinations.
Stickiness can potentially be both
a negative and a positive characteristic of foods. It is an expected
characteristic of many foods provided that excessively high levels
are not reached, for example in soft cookies, toffees and dried fruit
and, in some dishes, such as sticky toffee pudding, relatively high
levels are required. Stickiness in foods such as rice can be a
positive feature in some cuisines, for example in oriental rice
dishes or in Italian risotto, but is regarded as unacceptable in
In general, however, stickiness
finds more usage as a negative term than as a positive term, perhaps
reflecting the difficulty in avoiding high levels in some common
foods. This can be seen with foods such as rice and pasta, in which
even moderate levels of stickiness can reduce product eating quality.
This is particularly the case with many sugar confectionery products
and with the handling of chocolate products, especially at high