## 5 Energy Footprint  
The concept of the energy footprint is based on an indicator focused on the energy required for a process, from the acquisition of resources to the end of its life cycle, including intermediate stages [32]. There are several methodologies for calculating the energy footprint, such as the LCA mentioned previously. However, it is also possible to adopt a simpler approach, as illustrated below. Figure 4 presents a simplified methodology for assessing the energy footprint of cheese production, focusing on key steps such as data collection, unit conversion, and energy allocation. In addition to the elements shown, more detailed analyses may also consider upstream energy and material inputs, such as those related to equipment manufacturing, infrastructure, and transport, which contribute indirectly to the total environmental load of cheese production. In the context of the cheese industry, the energy footprint is particularly prominent in the operation of refrigeration, pasteurization, coagulation, and ripening. It may also be used to compare different production methods, such as large-scale industrial production versus artisanal methods. The ripening chamber requires continuous control to ensure optimal environmental conditions, specifically temperature and humidity, which can account for up to 30% of the total energy consumption in the cheesemaking process [42]. A comparative analysis of the energy consumption among different types of cheese is presented in Table 2 and, as shown, the results are quite heterogeneous. The lowest specific energy consumption values were observed for artisanal cheese producers in Portugal (around 3.0-3.8 MJ/kg), followed by industrial producers (5.1 MJ/kg) from the same study region. According to [PERSON] et al. [43], the lower values for artisanal producers result from the use of raw milk, limited mechanization, the small size of ripening rooms, the lower electric power of the compressor, the more efficient use of storage space, and seasonality. In contrast, cheeses such as Asiago PDO (70.2 MJ/kg) and USA industrial checkdar (48.5 MJ/kg) showed higher consumption, which can be attributed to the cradle-to-grave system boundaries, long maturation periods, and the intensive use of thermal and electrical energy in refrigeration, packaging, and storage. A study in Sardinia, for instance, reported a value of 52.1 MJ/kg, which was largely influenced by outdated equipment and limited energy efficiency. These variations highlight the influence of production scale and technology, as well as how boundaries are defined in each study. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \
\begin{tabular}{c} **Energy** \\ **Consumption** \\ **(MJ/kg)** \\ \end{tabular} & **Country** &
\begin{tabular}{c} **System** \\ **Boundaries** \\ \end{tabular} & **References** \\ \hline Beira Baixa PDO & 3.8 & Portugal & Cradle-to-gate & [35] \\ Industrial cheese & 5.1 & & & \\ Artisanal cheese & 3.0 & Portugal & Gate-to-gate & [43] \\ Mozzarella & 45.1 & Italy & Cradle-to-grave & [44] \\ Cheddar & 48.5 & USA & Cradle-to-grave & [39] \\ Mozzarella & 45.4 & USA & Cradle-to-grave & [39] \\ Multiple types of cheese with & 52.1 & Italy & Gate-to-gate & [29] \\ sheep’s and goat’s milk & 52.1 & Italy & Cradle-to-gate & [45] \\ Asiago PDO & 70.2 & Italy & Cradle-to-gate & [45] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Energy consumption required to produce 1 kg of cheese. Figure 4: Simplified illustration of the process for calculating the energy footprint (adapted) [41]. Mozzarella cheese exhibited similar energy consumption across different countries (45.1 MJ/kg in Italy and 45.4 MJ/kg in the USA) due to the standardization of the processing conditions. The differences observed in the comparative analysis for the cheese sector (Table 2) are a consequence of the type of cheese, the complexity of its production process, the definition of LCA system boundaries, the geographical location, and the technology applied.