# Current Status of Optical Systems for Measuring Lycopene Content in Fruits: Review
## 2 Lycopene Nutraceutical Properties and Its Effects on Human Health  
Currently, the health sector focuses its research on foods that provide a benefit to humans due to their nutritional composition. Foods high in lycopene play an important role in the prevention of diseases. These include cardiovascular diseases, cataracts, cancer, osteoporosis, male infertility, and peritonitis [13; 15; 18]. The suggested dose of daily lycopene intake is 30 to 35 mg according to [PERSON] et al. [19], similarly suggesting that daily consumption is 5 to 7 mg to maintain lycopene levels in blood and to combat oxidative stress, as well as the risks of chronic diseases. In the case of cardiovascular diseases, an intake of between 35 and 75 mg is recommended. \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**Fruit** & **Tomato** & **Watermelon** & **Guava** & **Grapefruit** & **Papaya** & **Apricot** \\ \hline Lycopene & & & & & & \\ \(\mu\)g/100 g wet weight & 8.8–42 & 23–72 & 54 & 33.6 & 20–53 & \(<\)0.1 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Lycopene content of some fruits and vegetables [16]. Figure 1: Schematic of the interaction between light and a fruit [5]. Figure 2 shows the mechanism for the prevention of diseases from [20]. The first phase of this mechanism considers the intake of lycopene, which is absorbed from 10 to 30% of the total content in the diet and the lifetime of this, in the blood, is 2 to 3 days [21; 22; 23]. lycopene allows a reduction of reactive oxygen species (ROS), as it works as a mechanism to prevent chronic diseases. This is achieved with the increase of lycopene levels in the human body. Among the benefits provided are the regulation of gap genes, improvement of intercellular communication, hormone modulation, metabolism regulation and its improvement for the immune response, participation in carcinogenic metabolism, and in the metabolic pathway through the induction of enzymes. Effects in the Biological and Physical-Chemical Properties of Lycopene by Electromagnetic Wave Radiation  
The chemical structure of the lycopene molecule consists of 11 double bonds that allow the absorption of electromagnetic radiation between 200 and 490 nm [24]. [PERSON] et al. [25] reported that carotenoids absorb in the blue and green regions of the electromagnetic spectrum. The absorption in the blue region is due to the lycopene molecule, which has an outer electron that can move along the main carbon chain. It is conjugated and consists of alternating sequences of double (C=C) and simple carbon bonds (C-C) [26; 27]. Radiation in the visible blue region of the lycopene molecule is a factor that supports carotenoid biosynthesis. This can affect the antioxidant content and the product quality [28; 29; 30]. Figure 3 shows the chemical structures and absorption spectra of lycopene, \(\alpha\)-carotene, \(\beta\)-carotene, and lutein belonging to the same carotenoid's family. A characteristic highlighted of carotenoids is that their absorption spectra generally exhibit similar behaviors, and it has three peak values. In the case of lycopene, maximum absorption in acetone is found at 446, 474, and 504 nm [31; 32]. When studying lycopene, it is necessary to consider the possible factors that can damage it. Amongst these are high temperatures, extreme pH values, and oxygen [33]. Radiation use allows inhibition and carotenoid stimulation. Also, the use of distant red-light radiation inhibited carotenoid generation in tomato and, with the red-light radiation, it was stimulated [30]. Figure 2: Role of lycopene in the prevention of chronic diseases [20]. [PERSON] et al. [34] also established that the increase in carotenoid synthesis in tomato is logarithmic. In the study, 30 tomato samples in the breaking maturity stage with three variants of radiation for each analysis were used. The first treatment consisted of radiating the samples with red light (243 mw/cm\({}^{2}\)). The second one irradiated the samples with far red light (488 mw/cm\({}^{2}\)). The last treatment only isolated them in the dark.