Abstract
This study aimed to quantify the weight loss of coffee cream (10 % fat) packaged in 10 g and 5 g polystyrene (PS) tubes over 316 days. A total of 13,760 weight measurements were performed across four production batches. Significant linear dependence between the absolute weight of coffee cream and time was observed, with negative slopes of –0.009 g/d and –0.007 g/d, and R² values of 0.990 and 0.996 for 10 g and 5 g tubes, respectively. Considering the surface area of the PS tube without its aluminium lid, water vapour transmission rates were calculated as 3.34 ±0.08 g/m²·d for 10 g tubes and 2.56 ±0.07 g/m²·d for 5 g tubes. Time required to decrease the weight of the cream by 10 % was 137.0 ±3.0 days for 10 g fillings and 84.0 ±1.9 days for 5 g fillings. Conversely, a loss of 1 g occurred over 110.7 ±2.4 days and 144 ±3.3 days in 10 g and 5 g tubes, respectively. These findings provide producers with an estimate of the excess amount of coffee cream needed to maintain the declared value in PS packaging material, depending on the intended shelf life.