# Impact of Coconut Copra Byproducts Incorporation on Granola Quality Characteristics
## 3 Results and Discussion
### Quality Characteristics of Granola  
The colour analysis of granola samples was monitored over a two-week storage period using the CIE L*a*b* colour space system, and the changes in product appearance over time are presented in Figure 7.  
Figure 6: The FT-IR/ATR spectra of banana flour (BF), coconut copra (CC), and their blends. The colour analysis of granola samples, monitored over a two-week storage period using the CIE Lab* colour space system, revealed changes in appearance over time. The lightness (\(L\)*) values showed relative stability, ranging from 36.53 \(\pm\) 3.71 at production to 35.64 \(\pm\) 2.36 after two weeks, with no statistically significant differences. Such stability in \(L\)* values aligns with consumer expectations for visual consistency in granola over its shelf life. The redness (\(a^{\bullet}\)) parameter demonstrated minimal variation throughout storage. Hence, there was no significant difference, indicating that the red color component remained relatively stable, reflecting resistance to this spectrum's significant oxidative or Maillard-induced changes. Conversely, the yellowness (\(b^{\bullet}\)) value demonstrated a statistically significant increase after 2 weeks, beginning at 21.29 \(\pm\) 2.49 on day 0, 22.81 \(\pm\) 2.29 after one week, and reaching 25.57 \(\pm\) 2.17 after two weeks. This increase suggests a progressive enhancement of yellow tones, likely influenced by storage conditions and aligns well with Chroma values, representing color intensity, showed a gradual increase from 25.89 \(\pm\) 2.84 (day 0) to 27.45 \(\pm\) 2.91 (week 1) and 30.42 \(\pm\) 2.76 (week 2). This increase became statistically significant by week 2. The observed changes in yellowness could be attributed to the oxidative degradation of lipids and the subsequent formation of yellow pigments, as highlighted by [PERSON] et al. (2024) [43]. These findings suggest that the storage conditions promoted mild lipid oxidation, consistent with the susceptibility of coconut-derived fats to such processes. The mild changes during storage were reflected in hue angle values with the most pronounced changes, increasing from 52.86 \(\pm\) 2.14 at day 0 to 54.89 \(\pm\) 3.21 at week 1 and reaching 57.68 \(\pm\) 3.42 by week. This progression indicates a significant shift in the overall color angle of the samples during 2 weeks of storage. These results suggest that while lightness and redness remained stable, significant changes occurred in yellowness, color intensity (chroma), and overall color angle (hue) during storage, particularly by week 2. Those changes can be managed with optimized storage practices, such as reduced exposure to oxygen and light, as recommended by [PERSON] et al. (2023) [44]. The Maillard reaction could also influence the gradual darkening and yellowing, as granola typically contains proteins and sugars. This reaction may be  
Figure 7: Colour profile changes in granola after storage. 0—day of manufacturing; W—week of storage; different lower-case letters mean values in particular parameter are statistically different (\(p\) = 0.05). exacerbated during storage, particularly at higher temperatures, as noted by [PERSON] et al. (2024) [45]. Furthermore, the presence of natural antioxidants in granola ingredients, such as nuts, could mitigate some oxidative processes, as suggested by [PERSON] et al. (2015) [46]. Additional factors, including the choice of sweetener and baking method, may influence color stability. For example, sweeteners with higher phenolic content could contribute to the antioxidant properties of the granola, thereby reducing oxidative discoloration [45]. Moreover, the baking process involving high temperatures could induce initial color changes through the Maillard reaction, setting a baseline for subsequent storage-related changes. [PERSON] et al. (2024) [47] further suggest that the classification of coconut copra into different quality categories based on color underscores the importance of initial raw material quality in determining the final product's stability.