## 3 Results and Discussion
Considering the RGB colour model, it can be seen that white garlic exhibited higher R values (about 213-220) compared to black one (69.84 \(\pm\) 4.52 for BG sample and 58.52 \(\pm\) 4.86 for EBG one), indicating that it was more saturated with red. For the colour parameter G, significantly higher values (about 203) were found for white than black garlic (57.38 \(\pm\) 1.10 for BG sample and 42.60 \(\pm\) 2.20 for EBG one), which indicates that it was more saturated with green. A similar relationship was noted for the colour parameter G, which meant that fresh (white) garlic (197.19 \(\pm\) 0.63 and 188.32 \(\pm\) 3.92 respectively for conventional and organic samples) showed a greater shift towards the blue colour than black garlic (52.13 \(\pm\) 8.08 and 42.91 \(\pm\) 3.02 for respectively BG and EBG samples). Our results are similar to those obtained by other authors. [PERSON] et al. (2014) [PERSON] et al. (2014) showed that during long-term heat treatment (35 days, temperature 70 \({}^{\circ}\)C, relative humidity 90%), the garlic changed its colour to dark brown. The values of the L* and b* parameters dropped dramatically (respectively from 68.44 \(\pm\) 1.66 to 4.33 \(\pm\) 2.02 and from 26.59 \(\pm\) 1.76 to \(-\)3.86 \(\pm\) 1.49), and the value of the parameter \(a^{*}\) increased (from \(-\)3.84 \(\pm\) 0.46 to 2.73 \(\pm\) 1.01). Other studies, on white and black garlic extracts showed a significant decrease in the value of \(L^{*}\) parameter (from 39.65 \(\pm\) 3.98 to 24.70 \(\pm\) 4.56) and \(b^{*}\) parameter (from 10.86 \(\pm\) 2.75 to 1.47 \(\pm\) 2.75) and increase in the value of \(a^{*}\) parameter (from \(-\)0.53 \(\pm\) 0.18 to 4.35 \(\pm\) 1.68) [PERSON] et al. (2014). There is very little in the available literature regarding a detailed comparative analysis of the colour of white and black garlic. The research concerns mainly the intensity of browning (\(\Delta L^{*}\) parameter) of garlic during heat treatment processes. In terms of this parameter our results are similar to those of other authors (60; 68; 69; 71; 73). Changes in the colour of garlic during long-term heat treatment are explained in the literature by the production of dark substances during this process, i.e., melanoidins, responsible for the dark brown, even black colour of black garlic [8]. Melanoidins are formed in the late stages of the Maillard reaction from sugars and amino acids (114), as polymers, polycondensation products of fructans and/or pyrroles (115). The speed and intensity of browning garlic during long-term heat treatment is closely related to temperature, relative humidity and processing time (116). Maillard reactions are faster at higher temperatures, so an increase in temperature accelerates and intensifies the browning processes of black garlic (68; 69). Conversely, the higher relative humidity during the aging processes of garlic causes the slower rate and intensity of black garlic browning (64). Additionally, along with extending the heat treatment time, the browning intensity of black garlic also increases (71). Additionally, our research showed significant (\(p\) < 0.05) differences in colour parameters between conventional and organic garlic, both in the case of white and black garlic subjected to long-term heat treatment (45 days, temperature 70 \({}^{\circ}\)C and relative humidity 80%). Detailed colour analysis of white and black garlic from conventional and organic cultivation using the instrumental method (\"electronic eye\") are presented in Figures 2-5. Figure 3: Detailed colour analysis of white garlic from organic cultivation (EG) using the instrumental method (“electronic eye”). Figure 2: Detailed colour analysis of white garlic from conventional cultivation (G) using the instrumental method (“electronic eye”). In the \(L^{*}a^{*}b^{*}\) space, these differences mainly concerned the \(L^{*}\) colour parameter. White conventional garlic had a significantly higher value of the \(L^{*}\) parameter than organic garlic, which means that sample G was lighter than EG.