Have you ever felt paper flavor while tasting an egg pasta or a little square of good milk chocolate?
If the answer is yes, don’t worry: the effect on the taste is due to the migration of substances from the material in contact with the foodstuff, but this does not mean in any way that there has been a passage of harmful or foreign substances and that the foodstuff, therefore, is no longer eatable.
The sense of smell and tasting perception of these substances is simply given by the fact that our sensory apparatus is very developed and sensitive.
It is also true, however, that a packaging has the role to protect the contents from damage and must also prevent alterations in the taste of the product. The packaging itself must not contain substances that could alter the flavor and aroma of delicate products, such as chocolate, and for this reason it is important to evaluate the ability of the paperboard to withstand the transmission of substances on food to ensure its original quality.
The tool to determine this ability is the Robinson test, which is carried out on all paperboards that involve food contact.
What is the Robinson test and how is it carried out?
The Robinson test is also known as the sensory test and is used to assess the degree of contamination of a substance due to paperboard. It allows us to determine the organoleptic defects of foodstuffs resulting from contact with the packaging and it is in accordance with the European standards EN 1230-2.
The procedure is pretty simple and intuitive: actually because our sensory apparatus is highly developed, this is what we rely on for the test.
The packaging to be checked and fresh grated chocolate, called food simulant, are placed in an hermetically sealed environment and under certain conditions of light, temperature and relative humidity. After a certain period of time, usually 12 months, the chocolate is tasted by a trained panel who will compare it with chocolate from the blank test, called witness chocolate.
Each judge will express his organoleptic evaluation through an appropriate form reporting his remarks according to the detected difference in flavor. It is the difference in taste, in fact, that will be considered as an alteration of the original scent of the witness chocolate.
Which are the reference values?
The assessment is based on an evaluation table ranging from 0 (no difference in taste) to 4 (very pronounced taste difference), thus demonstrating whether there has actually been a transmission from packaging to products or not.
Unless otherwise specified, the value 2 is considered as the maximum acceptable required for each type of packaging, but as a guiding value the maximum acceptable is 1.
Only paperboards that pass the Robinson test are considered suitable for the construction of food packaging.
Where does the smell or taste of the paperboard on the food come from?
The smell of paperboard can have multiple causes.
As we mentioned at the beginning of the article, the cause is the migration of some substances present in the packaging material on the packaged goods.
The printing method, the selected inks and the coating may affect, although the chemical and mechanical pulp are chosen in such a way as to minimize the influence of the smell, as well as the choice of the type of printing to be adopted.
Among all, gravure printing is often considered the safest method to avoid aroma concerns as long as the solvents have been carefully chosen and that the drying time is sufficient.
Which are the ProntoPack paperboards owning the Robinson test?
Within our range of products, we offer paperboards that brilliantly comply with the Robinson test, with values below 1, and we always report the specification of paperboards suitable for food contact of sensitive products such as chocolate and sweets.
All the Metsä Board paperboards we provide own the Robinson test specification, all reporting a value less than 1.
Among these we may mention the Metsä Board Prime FBB EB, our 100% paperboard product with a medium barrier against grease and moisture. It is lightweight, plastic-free, made without fluorochemicals and optical brighteners (OBA) and is therefore suitable for direct food contact globally.*
* Suitable for food contact as stated in paper mill declaration.
Country specific exceptions may be applied. Please contact ProntoPack for any information and details.
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