# Infrared Thermographic Signal Analysis of Bioactive Edible Oils Using CNNs for Quality Assessment
## 2 Nutritional and Health Challenges of Edible Oils
### Olive Oil: Nutritional and Functional Profile  
Olive oil is the staple food of the Mediterranean diet due to its organoleptic qualities, nutritional richness, and functional bioactivity [54]. Olive oil has a composition dominated by lipids, particularly monounsaturated fatty acids, and includes a wide range of minor components with antioxidant, anti-inflammatory, and antimicrobial properties [55]. From a nutritional standpoint, olive oil, with its high energy density, provides approximately 884 kcal per 100 g, which is energy almost entirely attributable to its lipid content. Table 1 shows the nutritional values of extra virgin olive oil per 100 g, and the recommended daily allowance/Adequate Intake (RDA/AI) values, which refer to an average adult (2000 kcal/day). The predominant fraction consists of total fats, amounting to 100 g per 100 g of product, of which 73 g are monounsaturated (mainly oleic acid), 13.8 g are saturated (mainly palmitic acid), and 10.5 g are polyunsaturated (including linoleic and linoleic acids). The oil contains negligible amounts of carbohydrates, proteins, and sodium and is completely cholesterol-free. However, it is a significant source of lipophilic vitamins such as vitamin E (14 mg/100 g, covering up to 93% of the recommended daily allowance) and vitamin K (60.2 ug/100 g, covering 75% of the RDA). Table 1 indicates that for mono- and polyunsaturated fat, no established RDA exists, only general qualitative recommendations are provided (higher intake than saturated). Whereas %RDA values are approximate, rounded, \begin{table}
\begin{tabular}{c c c} \hline \hline
**Component** & **Per 100 g** & **\% RDA/AI** \\ \hline Energy & 884 kcal & 44\% (2000 kcal) \\ Total Fat & 100 g & 129\% (77 g) \\ Saturated Fat & 13.8 g & 69\% (20 g max) \\ Monounsaturated Fats & 73.0 g & - \\ Polyunsaturated Fats & 10.5 g & - \\ Sodium & 2 mg & \textless{}0.1\% (2300 mg) \\ Vitamin E & 14 mg & 93\% (15 mg) \\ Vitamin K & 60.2 ug & 75\% (80 ug) \\ Polyphenols (approx.) & Variable (50–500 mg) & No RDA \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Nutritional values of extra virgin olive oil. and have to be adapted to other reference systems (e.g., European Food Safety Authority EFSA, Food and Drug Administration FDA, and reference intake levels of nutrients and energy LARN) if necessary. Chemically, olive oil has a composition predominantly consisting of triglycerides rich in oleic acid (C18:1, monounsaturated), with significant minor fractions of palmitic acid (C16:0) and linoleic acid (C18:2) [56]. In addition, it contains natural antioxidants such as topcuberols (especially \(\alpha\)-tocopherol, vitamin E) and a number of polyphenic compounds, including hydroxytyrosol, oleupreein, and oleo-canthal [57]. Chlorophyll and carotenoids confer not only the yellow-green colour, but also photoreactive characteristics that influence oxidative stability. Physically speaking, olive oil has a density between 0.91 and 0.92 g/cm\({}^{3}\) at room temperature [58]. Viscosity increases significantly with decreasing temperature. Viscosity, therefore, affects its performance in industrial and biomedical processes involving heat flow or heat transfer. These characteristics are relevant not only for food technology but also for infrared thermography applications, where thermal properties influence detection sensitivity. The thermal diffusivity alpha, a key parameter for thermal imaging and heat transfer modelling, describes the thermophysical behaviour of olive oil, as defined in relation (1):  
\[\alpha=\frac{\lambda}{\rho\text{-}c_{p}} \tag{1}\]  
where \(\lambda\) is the thermal conductivity, \(\rho\) is the density, and \(c_{p}\) is the specific heat capacity at constant pressure.