# Life-Cycle Assessment of Biofortified Productions: The Case of Selenium Potato
## 2 Materials and Methods
### Selenium Potato Life-Cycle Assessment  
The research takes into account the cultivation of the selenium potato; for the experimental trials, the production obtained in Sicily in the territory of Syracuse was considered. The choice to carry out the survey on the Syracuse farms is justified because it follows the production techniques. In order to carry out a life-cycle assessment study to evaluate the selenium potato's environmental impact, weekly field surveys were carried out to collect data, and the entrepreneurs' register was used to obtain feedback on the data collected [30]. The selenium potato cultivation, in the area of interest, is comparable to a normal cycle of potato cultivation in conventional agriculture. The difference between the two refers to the application of products containing selenium carried out twice during the final enlargement of fruit and the low impact of product use in the process. The use of selenium causes metabolic functions to stop with consequent yellowing of the plant's epigeal part; therefore, application at the end of the cultivation cycle is preferred. In addition, the studied cultivation differs from conventional ones also in a more careful choice of products used on the crop in order to reduce the environmental impact; in fact, in the case of selenium potatoes, there is not yet a real production standard, but only protocols aimed at obtaining more sustainable production. Life-cycle assessment is a compilation and evaluation of the inputs, outputs, and the environmental impacts of a product system throughout its life cycle [5]. It takes into account the entire life cycle of a product, ranging from the procurement of raw materials to the disposal of the product itself and possibly its recycling. The method considered allows the identification of improvement opportunities through identifying environmental hot spots in the life cycle of a product, the analysis of the contribution of the life-cycle stages to the overall environmental load, usually with the objective of prioritizing improvements on products or processes, the comparison between products for internal or external communication, and as a basis for environmental product declarations and the basis for standardized metrics and the identification of key performance indicators used in companies for life-cycle management and decision support [31]. LCA methodology is an efficient method to assess impact on the environment (Figure 3), mainly used in industry, as well as in agriculture in recent years [32]. LCA consists of four different and iterative steps defined by the ISO standards: goal and scope definition, inventory analysis, impact assessment, and interpretation [33]. As far as the definition of the goal and scope, the research aimed to identify the main differences between the selenium potato cultivation and conventional potato, in order to define which of the two is characterized by a lower environmental impact and can be considered more sustainable. The life-cycle assessment of the selenium potato was carried out using the SimaPro 9.1 software, within which the recipe midpoint method was chosen. It has a difference in the unit of the indicator for each category. This is because a reference substance has been introduced, such that the characterization factor is a dimensionless number that expresses the strength of an amount of a substance relative to that of the reference substance. For all emission-based impact categories and resource scarcity, this is a kg reference substance to one specific environmental compartment, while, for land use, it is the area and time integrated for one type of land use [34]. In agricultural product studies, it is the most widely used due to the large number of indicators relating to this topic [35; 36]. The definition of the goals and scope includes the identification of the functional unit (FU), the measurement unit to which all inputs and outputs data are related [35].