## 1 Introduction  
Coffee pods and capsules are single-serving products of roasted and ground coffee. In capsules, the coffee is pressed and placed in a generally cylindrical plastic or aluminum container sealed under vacuum [1]. In pods, the coffee is pressed and placed in round or flat packages made with paper. Their use is convenient for consumers because it enables them to prepare a relatively high-quality coffee product in a short period of time, with minimal water and energy use. The growing demand for high-quality coffee pods and capsules requires packaging that guarantees the optimal coffee preservation, since coffee is a susceptible matrix of chemical changes during its storage time [2, 3]. Their shelf life is usually about 18 months or more [4] and is correlated with the packaging materials. Coffee pods and capsules are sealed in a high-barrier metalized package flushed with an inert gas (typically N\({}_{2}\)) prior to sealing [5]. The disadvantage of pods and capsules is that they are not very sustainable for the environment due to the aluminum foil contained in the packaging that has to be discarded as waste. Moreover, aluminum foil is not recoverable in a mixed plastic structure and its specific weight gives a significant weight to packaging. In recent years, the food packaging industry has been moving toward solutions that best meet the requirements of circularity and sustainability and, therefore, must also pay attention to environmental needs [6]. The first step towards sustainability is layer reduction of the non-recyclable material. Traditional flexible film for coffee consists of multilayer flexible packaging made of polyethylene terephthalate (polyester)-aluminum-polyethylene (PET-AL-PE). PET is used for its distinct mechanical strength and excellent printability, polyethylene (PE) has excellent sealing properties, and the aluminum layer protects the product from the light component and provides a barrier to the insufflated gas in the package [2; 7]. There are, however, elements that make aluminum a negative component, because it has high costs and a low environmental performance. Moreover, its specific weight gives a significant weight to packaging that is a problem for transportation. Therefore, replacing or reducing the aluminum foil laminate in multilayer films is recommended from an environmental point of view. In fact, [PERSON] et al. [8], found that metallized polymer laminates have less of an environmental impact than aluminum foil laminate. They also found that metallized polyethylene terephthalate (MPET) layers have an excellent performance in oxygen transmission rate, that is, the property of utmost importance in preserving food freshness. Therefore, in this work, we considered a multilayer film containing MPET (alternative) in place of aluminum foil to package coffee. Its reduced weight could lead to a benefit in terms of logistics and transportation. In fact, with the same transport, there is the possibility to deliver more products. As reported by [PERSON] [9], packaging weight reduction is a potential strategy for overall impact reduction. Furthermore, packaging lightweighting represents the easiest and most accesible measure for sustainability improvement in food packaging [10]. The two commercially relevant species of the _Coffea_ genus, _Coffea arabica_ L. (commonly known as Arabica) and _Coffea canephora_ var. _robusta_ L. (commonly known as Robusta), were used inside the pods and capsules. They differ considerably in price, quality, and sensory properties. Therefore, blends of the varieties are produced to obtain the preferred flavor. Arabica is more expensive than Robusta and this is an economic incentive to illicity replace Arabica with Robusta. Moreover, Arabica represented 57.4% of world production in 2023/2024, while Robusta had a 42.6% market share [11]. Arabica has a slightly sour taste with a stronger aroma and balanced flavor that is favored in international markets, and it is considered to be mild coffee.