# Effect of Plant Extracts Addition on the Physico-Chemical and Sensory Properties of Biscuits
## 3 Results
### Color Attributes
_h_-values were significantly lower in blueberry-enriched biscuits compared to cranberry-enriched biscuits, with the exception of 3% enrichment. This shows that the addition of blueberry plant extract had a higher effect on changing the main color attributes of the biscuits compared to cranberry powder within the same concentrations. However, for a better understanding of changes in color attributes of the enriched biscuits, authors believe that the total color difference can be evaluated between the studied treatments. The results of total color difference (\(\Delta\)E) between biscuits enriched with different concentration of plant extracts are presented in Tables 4 and 5. According to [PERSON] and [PERSON] (2013), an observer notices two different colors when the \(\Delta\)E is higher than 5. Our results showed that two distinct colors are perceived when the observer compares control biscuit samples (without plant extract) and enriched biscuits with either blueberry or cranberry powder (\(\Delta\)E > 5) (Tables 4 and 5). Meanwhile, color differences can also be perceived by an inexperienced observer when 3 and 6% enriched blueberry biscuits samples are compared (2 \(<\)\(\Delta\)E < 3.5) (Table 4). A similar result was observed when comparing color properties (lightness, redness, and yellowness) of 6 and 9% blueberry and cranberry biscuits samples (Table 5). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Attribute**} & \multirow{2}{*}{**Sample**} & \multicolumn{3}{c}{**Type of Plant Extract**} & \multirow{2}{*}{\(p\)**-Value**} \\ \cline{3-3} \cline{5-5}  & & **Blueberry** & **Cranberry** & \\ \hline \multirow{4}{*}{Lightness (\(L^{*}\))} & Control & 76.89 \({}^{\text{c}}\) & 76.89 \({}^{\text{c}}\) & \\  & 3\% & 67.77 \({}^{\text{b}}\) & 63.28 \({}^{\text{b}A}\) & \textless{0.001} \\  & 6\% & 65.06 \({}^{\text{b}B}\) & 56.08 \({}^{\text{a}A}\) & \textless{0.001} \\  & 9\% & 62.28 \({}^{\text{a}B}\) & 54.86 \({}^{\text{a}A}\) & \textless{0.001} \\ \hline \multirow{4}{*}{Redness (\(a^{*}\))} & Control & 0.08 \({}^{\text{a}}\) & 0.08 \({}^{\text{a}}\) & \\  & 3\% & 5.49 \({}^{\text{b}B}\) & 3.43 \({}^{\text{b}A}\) & \textless{0.001} \\  & 6\% & 6.35 \({}^{\text{b}B}\) & 4.69 \({}^{\text{c}A}\) & \textless{0.001} \\  & 9\% & 7.82 \({}^{\text{c}B}\) & 6.76 \({}^{\text{a}A}\) & \textless{0.05} \\ \hline \multirow{4}{*}{Yellowness (\(b^{*}\))} & Control & 34.52 \({}^{\text{b}}\) & 34.52 \({}^{\text{c}}\) & \\  & 3\% & 22.74 \({}^{\text{a}B}\) & 15.55 \({}^{\text{b}A}\) & \textless{0.001} \\  & 6\% & 22.62 \({}^{\text{a}B}\) & 11.98 \({}^{\text{a}A}\) & \textless{0.001} \\  & 9\% & 22.46 \({}^{\text{a}B}\) & 9.56 \({}^{\text{a}A}\) & \textless{0.001} \\ \hline \multirow{4}{*}{Chroma (\(C^{*}\))} & Control & 34.53 \({}^{\text{b}}\) & 34.53 \({}^{\text{c}}\) & \\  & 3\% & 23.40 \({}^{\text{a}B}\) & 15.93 \({}^{\text{b}A}\) & \textless{0.001} \\  & 6\% & 23.50 \({}^{\text{a}B}\) & 12.88 \({}^{\text{a}A}\) & \textless{0.001} \\  & 9\% & 23.80 \({}^{\text{a}B}\) & 11.77 \({}^{\text{a}A}\) & \textless{0.001} \\ \hline \multirow{4}{*}{h-value (\(h\))} & Control & 89.89 \({}^{\text{c}}\) & 89.89 \({}^{\text{d}}\) & \\  & 3\% & 76.42 \({}^{\text{b}A}\) & 77.58 \({}^{\text{c}A}\) & 0.193 \\ \cline{1-1}  & 6\% & 74.33 \({}^{\text{b}B}\) & 68.38 \({}^{\text{b}A}\) & \textless{0.001} \\ \cline{1-1}  & 9\% & 70.83 \({}^{\text{a}B}\) & 53.80 \({}^{\text{a}A}\) & \textless{0.001} \\ \hline \hline \end{tabular} a–d means with different letters in the same column are significantly different for percentage of plant extract (\(p<0.05\)). A, B means with different letters in the same row are significantly different for plant extract type (\(p>0.05\); \(p<0.05\); \(p<0.001\)).  
\end{table} 
Table 3: Color attributes of biscuits enriched with plant extracts.