The objective of this paper was to estimate the instant coffee shelf life in new options of plastic pots through a mathematic model, which relates the product moisture increase with the moisture barrier of the packaging. The plastic pots were characterized by the dimensions, the volumetric capacity, the water vapor transmission rate (WTVR) and the removal torque. The two differents types of instant coffee (aglomerated and powder) were characterized by the initial moisture and by the moisture sorption isotherm. The results presented that the plastic pots of polyester (PP) are about ten times more permeated than the polypropylene (PP) ones. The aglomeration was observed in the products with the moisture value of 7% (d.b.), but the critic moisture value was considerated 5% (d.b.), that is the tenor fixed by the legislation. The results showed that in the polypropylene (PP) pots the shelf life periods for aglomerated instant coffee and powder instant coffee was higher than 1,8 and 2,5 years, respectively, at 30ºC/80%RH. However, the use of the polyester (PET) pots didn't show to be viable because of the lower shelf life periods estimated at 30ºC/80%RH (lower than 4 months).
instant coffee; plastic packaging; shelf-life prediction
