The packaging must not cause any deviation from the organoleptic characteristics of the food products.
Respect one of the key points of the framework regulation about food contact materials.
Organoleptic tests: real food intended to be in contact with the packaging; if there are several options, choose the product which will be more sensible to organoleptic deviation; the second option, use stimulants like water or chocolate; chocolate is very sensible for absorption of organic contaminants due to high fatty content; in all cases, the contact (time and temperature of the test) between the product and the packaging must be representative of the future conditions of use.
Other criteria giving alerts of unacceptable interaction between packaging and food product: (i) before contact : smell of the packaging (even if it is a pleasant smell !)(ii) after contact: change of shape, color, damage, sensible mass gain ....of packaging ; change of color of food or food simulant.
How to reduce - check the composition of packaging material: resin and its monomer residues, additives for surface properties such as antistatics, solvent residues - check the process effect and its severity regarding the generation of low molecular compounds.