# Infrared Radiation favorably Influences the Quality Characteristics of Key Line Juice
## 3 Results and Discussion
### Color Values
#### 3.8.2 Redness-Greenness (a*)  
The results in Table 1 indicated that the a* value of the treated juice samples using infrared was decreased significantly (\(p<0.05\)) from 14.19 to 7.52--during a storage period from 0-15 days, respectively. While the value of a* increased significantly (\(p<0.05\)) from \(-7.52\) to \(-3.76\) when the storage periods increased from 30-60 days. This increase in the * value was due to the physical and chemical changes such as oxidation, in addition to the decomposition of added sugars. The results also illustrated that the a* value of the conventional treatment of juice samples was the highest compared to the treated juice samples by infrared and the non-treated (control) samples, with the exception of the 0-day storage period, where the differences between them were significant (\(p>0.05\)). This indicates that the juice treatment by the conventional method made the Juice color was dark due to the effect of the uneven heat distribution in the juice. The highest value of a* for the treated juice samples by infrared, the conventional treatment samples, and the non-treated (control) samples were 14.19, 12.45, and 16.93, respectively during the storage period of 0 day. The results showed that the lowest value of a* for the treated juice samples  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{2}{c}{**Color**} & \multicolumn{5}{c}{**Storage Period (Day)**} \\ \cline{3-6} \multicolumn{2}{c}{**Components**} & \multicolumn{1}{c}{**Teatments**} & \multicolumn{2}{c}{**0**} & **15** & **30** & **45** & **60** \\ \hline \multirow{3}{*}{L*} & IR & 73.65 \({}^{\rm\,e}\)\({}^{\rm\,d}\) \(\pm\) 1.45 & 78.82 \({}^{\rm\,c}\)\(\pm\) 2.11 & 83.72 \({}^{\rm\,b}\)\(\pm\) 2.31 & 79.21 \({}^{\rm\,c}\)\(\pm\) 1.39 & 69.80 \({}^{\rm\,f}\)\(\pm\) 2.01 \\  & CH & 65.57 \({}^{\rm\,b}\)\(\pm\) 2.05 & 75.79 \({}^{\rm\,d}\)\(\pm\) 1.81 & 66.86 \({}^{\rm\,b}\)\(\pm\) 1.36 & 74.90 \({}^{\rm\,d}\)\(\pm\) 2.14 & 43.72 \({}^{\rm\,h}\)\(\pm\) 2.31 \\  & C & 75.45 \({}^{\rm\,d}\)\(\pm\) 1.78 & 81.76 \({}^{\rm\,b}\)\(\pm\) 3.11 & 85.29 \({}^{\rm\,a}\)\(\pm\) 3.07 & 81.96 \({}^{\rm\,b}\)\(\pm\) 2.48 & 74.70 \({}^{\rm\,d}\)\(\pm\) 3.11 \\ \hline \multirow{3}{*}{a*} & IR & 14.19 \({}^{\rm\,b}\)\(\pm\) 0.57 & 3.76 \({}^{\rm\,f}\)\(\pm\) 1.81 & \(-\)7.52 \({}^{\rm\,f}\)\(\pm\) 0.02 & \(-\)5.17 \({}^{\rm\,h}\)\(\pm\) 0.06 & \(-\)3.76 \({}^{\rm\,f}\)\(\pm\) 0.11 \\  & CH & 12.45 \({}^{\rm\,c}\)\(\pm\) 0.54 & 6.11 \({}^{\rm\,b}\)\(\pm\) 0.16 & 10.35 \({}^{\rm\,d}\)\(\pm\) 0.23 & 1.881 \({}^{\rm\,l}\)\(\pm\) 0.01 & 2.35 \({}^{\rm\,k}\)\(\pm\) 0.10 \\  & C & 16.93 \({}^{\rm\,a}\)\(\pm\) 0.23 & \(-\)4.70 \({}^{\rm\,i}\)\(\pm\) 0.08 & \(-\)8 \({}^{\rm\,e}\)\(\pm\) 0.03 & \(-\)13.17 \({}^{\rm\,c}\)\(\pm\) 0.12 & \(-\)14.58 \({}^{\rm\,b}\)\(\pm\) 0.10 \\ \hline \multirow{3}{*}{b*} & IR & 37.52 \({}^{\rm\,j}\)\(\pm\) 1.05 & 32.47 \({}^{\rm\,k}\)\(\pm\) 0.21 & 74.35 \({}^{\rm\,c}\)\(\pm\) 2.31 & 78.11 \({}^{\rm\,a}\)\(\pm\) 1.96 & 72.47 \({}^{\rm\,d}\)\(\pm\) 0.99 \\  & CH & 33.57 \({}^{\rm\,k}\)\(\pm\) 0.98 & 65.88 \({}^{\rm\,e}\)\(\pm\) 1.08 & 76.70 \({}^{\rm\,b}\)\(\pm\) 2.61 & 77.64 \({}^{\rm\,ab}\)\(\pm\) 1.94 & 61.71 \({}^{\rm\,f}\)\(\pm\) 2.01 \\ \cline{1-1}  & C & 39.56 \({}^{\rm\,i}\)\(\pm\) 1.11 & 49.41 \({}^{\rm\,h}\)\(\pm\) 1.21 & 59.78 \({}^{\rm\,f}\)\(\pm\) 1.28 & 57.88 \({}^{\rm\,g}\)\(\pm\) 0.73 & 74.82 \({}^{\rm\,c}\)\(\pm\) 1.01 \\ \hline \hline \end{tabular}  
* IR: infrared; CH, conventional heating; C, fresh juice (control). a–k means with same superscript letters are not significantly different (\(p>0.05\)) within the same column  
\end{table}
Table 1: The effect of storage periods on the color components of treated key lime juice using infrared, conventional heating compared to fresh (control sample).  
by infrared, the conventional treatment juice samples, and the non-treated juice samples (control) were 3.76, 2.35, 14.58--respectively during the storage period of 60 days.