ABSTRACT The effect of storage temperature on moderately dark roasted coffee beans packaged in Al‐metallized bags was investigated focusing on the package atmospheric change and the product quality deterioration. Al‐vacuum metallized bag packages of 100 g product attached with a pressure‐releasing valve were stored at 15°C, 25°C, 35°C, and 45°C, with measurements in changes of package gas composition, package volume, and product quality attributes. Package atmospheric and volumetric change behavior was examined in relation to the product's carbon dioxide production measured in a separate experiment. The CO 2 production was characterized using the Weibull function form, which effectively quantified the influence of temperature: higher storage temperatures resulted in increased and faster CO 2 production with activation energy of 17–18 kJ/mol as described by the Arrhenius dependence. The headspace, originally containing ambient air, transitioned to and maintained the high CO 2 partial pressures mostly exceeding 0.7 atm, alongside reduced O 2 and N 2 partial pressures of 0.01–0.02 and 0.07–0.11 atm, respectively, due to flushing by CO 2 gas released from the coffee beans. This initial shift in gas concentration was more pronounced at higher temperatures. While temperature exhibited no significant effect on pH and titratable acidity changes of the product except at the later stage at 45°C, oxidation measured in peroxide value increase was found to be a primary quality degradation factor. This oxidation process showed clear dependence on temperature, following the Arrhenius equation with an activation energy of 42.5 kJ/mol, suggesting its suitability as a model for accelerated shelf life testing.

While carbon dioxide produced from roasted coffee products may cause problems of package swelling, it plays beneficial role in preserving and providing the desired aroma. Thus, the information of their CO2 production is required to design the packages suppressing the package volume and enhancing aroma retention. CO₂ production from roasted coffee products (whole bean or ground) at different roasting degrees was characterized at 25°C. Higher degree of roasting led to the decreased moisture content and titratable acidity of the initial product aligning with the increasing pH and darker color. The CO₂ solubility in the product increased with roasting degree probably because higher porosity was obtained at severer roasting. The CO₂ production profile analyzed by Weibull function showed that higher degree of roasting resulted in faster and higher CO₂ production. The powder products were much faster in the rate of CO2 production compared to the beans (14-20 times). These results provide fundamental information that can be applied to the design of coffee packaging systems tailored to the roast level and particle form (whole bean or ground). The data information from this study would be useful for designing the roasted coffee package to create and keep the optimal package shape and atmosphere favorable for product quality preservation.