## 4 Discussion  
For people working in various facets of the rice industry, the physical features such as grain weight, color, and size are of utmost importance, and these are key factors in assessing rice grain quality. The pericarp color of the traditional varieties is presented in Table 1. Rice varieties are preferred based on the pericarp color. Of the 30 varieties, 14 were white in color, 15 were red, and 1 black variety was found. The primary pigments that give the rice its distinctive pericarp color are anthocyanin and proanthocyanidin. Anthocyanin, which is found in the pericarp, gives a red color, whereas proanthocyanidin are responsible for a white color [20]. Of the 30 varieties, 50% have red pigment in their pericarps which are highly preferred by the consumers of metropolitan and cosmopolitan cities. Traditional rice varieties are not polished in order to preserve the color of the grain. Grain length assumes a significant position in the worldwide market with regard to industrial as well as consumer-oriented perspectives [21]. Long-grain rice is profoundly pursued in global markets. A recent survey revealed that traditional varieties of rice grown in the Cauvery Delta region of Tamil Nadu have higher market value abroad. The maximum grain length found in the study was 9.40 mm, as demonstrated by [22]. Grain breadth was also significant in Mattaikar (5.64 \(\pm\) 0.35 mm), and their values ranged from Kichili Samba (2.30 \(\pm\) 0.12 mm) to Kallundri Kar (3.91 \(\pm\) 0.40 mm). This indicates that the differences might be due to the genetic nature of the varieties. Muttrina Sannam had the thinnest paddy dimension of 1.59 mm, whereas Poongar had the thickest (2.26 mm). Grain dimensions play an important role in designing the grading equipment. \begin{table}
\begin{tabular}{l c c c c c} \hline \hline
**Parameters** & **PC1** & **PC2** & **PC3** & **PC4** & **PC5** \\ \hline Eigenvalue & 7.838 & 4.862 & 2.306 & 1.886 & 1.289 \\ \hline \% variance & 41.3 & 25.6 & 12.1 & 9.9 & 6.8 \\ \hline Cumulative variance & 41.3 & 66.844 & 78.980 & 88.905 & 95.689 \\ \hline Length & 0.528 & \(\mathbf{-0.808}\) & 0.193 & 0.112 & \(\mathbf{-0.058}\) \\ \hline Width & 0.564 & 0.774 & \(\mathbf{-0.031}\) & 0.007 & \(\mathbf{-0.032}\) \\ \hline Thickness & **0.693** & 0.149 & \(\mathbf{-0.136}\) & \(\mathbf{-0.104}\) & 0.043 \\ \hline Seed size & **0.996** & 0.012 & 0.020 & 0.026 & 0.013 \\ \hline L/W ratio & \(\mathbf{-0.151}\) & \(\mathbf{-0.947}\) & 0.174 & 0.039 & \(\mathbf{-0.100}\) \\ \hline Equivalent diameter & **0.982** & 0.148 & 0.033 & 0.045 & \(\mathbf{-0.016}\) \\ \hline Sphericity & \(\mathbf{-0.044}\) & **0.973** & \(\mathbf{-0.122}\) & \(\mathbf{-0.071}\) & \(\mathbf{-0.001}\) \\ \hline Volume & **0.971** & 0.185 & 0.017 & 0.020 & \(\mathbf{-0.009}\) \\ \hline Aspect ratio & 0.041 & **0.979** & \(\mathbf{-0.066}\) & \(\mathbf{-0.044}\) & \(\mathbf{-0.050}\) \\ \hline Bulk density & \(\mathbf{-0.022}\) & 0.073 & \(\mathbf{-0.108}\) & 0.067 & **0.986** \\ \hline Tapped density & 0.012 & \(\mathbf{-0.085}\) & **0.688** & 0.015 & **0.720** \\ \hline True density & 0.078 & \(\mathbf{-0.055}\) & 0.087 & **0.970** & 0.101 \\ \hline Porosity & 0.019 & \(\mathbf{-0.102}\) & \(\mathbf{-0.153}\) & **0.967** & \(\mathbf{-0.025}\) \\ \hline Carr’s index & 0.043 & \(\mathbf{-0.172}\) & **0.980** & \(\mathbf{-0.038}\) & \(\mathbf{-0.035}\) \\ \hline Hausner ratio & 0.043 & \(\mathbf{-0.183}\) & **0.978** & \(\mathbf{-0.033}\) & \(\mathbf{-0.033}\) \\ \hline Surface area & **0.997** & 0.008 & 0.027 & 0.036 & 0.007 \\ \hline Geometric mean diameter & **0.997** & 0.003 & 0.035 & 0.046 & \(\mathbf{-0.001}\) \\ \hline Arithmetic mean diameter & **0.897** & \(\mathbf{-0.365}\) & 0.153 & 0.098 & \(\mathbf{-0.067}\) \\ \hline Square mean diameter & **0.986** & \(\mathbf{-0.108}\) & 0.079 & 0.069 & \(\mathbf{-0.024}\) \\ \hline \hline \end{tabular} Note—Highly weighted variables were bolded.  
\end{table} 
Table 7: Principle component analysis of thirty traditional rice varieties.