## 3 Results and Discussion
### Eating Quality of Black Rice
#### 3.4.2 Sensory Test of Eating Quality  
A descriptive sensory test is generally carried out by trained panelists for measuring the intensity of the sensory attributes of cooked rice [16; 17; 40; 41; 42; 43; 44]. According to Chinese National Standard method GB/T 15682-2008, sensory evaluation eating qualities include primary descriptive attributes (smell, appearance, texture, taste, cold rice texture). The attribute of appearance encompassed color, gloss of rice, and rice integrity as secondary attributes, while the attribute of texture included adhesiveness, springiness, and hardness as secondary attributes (Table S1) [7]. The result indicated that milling treatment affected eating quality and scores for all sensory attributes (Table 3). The scores of the smell and appearance attributes decreased, while taste and cold rice texture increased with the increase in the milling degree. The milling treatment significantly reduced the smell score of cooked black rice in the sensory test since the volatile flavor compounds of rice were mainly  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Samples** & **Taste Score/100** & **Appearance/10** & **Tastiness/10** & **Hardness/kgf** & **Stickiness/kgf** & **Elasticity** \\ \hline A & 82.50 \(\pm\) 0.84 c & 1.02 \(\pm\) 0.23 c & 3.70 \(\pm\) 0.24 c & 1.24 \(\pm\) 0.18 ab & 0.13 \(\pm\) 0.07 bc & 0.94 \(\pm\) 0.02 a \\ B & 86.17 \(\pm\) 0.41 a & 2.03 \(\pm\) 0.16 a & 4.75 \(\pm\) 0.15 a & 1.29 \(\pm\) 0.13 ab & 0.18 \(\pm\) 0.01 ab & 0.94 \(\pm\) 0.03 a \\ C & 84.67 \(\pm\) 0.52 b & 1.50 \(\pm\) 0.11 b & 4.08 \(\pm\) 0.17 b & 1.33 \(\pm\) 0.13 a & 0.21 \(\pm\) 0.06 a & 0.95 \(\pm\) 0.02 a \\ D & 84.17 \(\pm\) 0.41 b & 1.08 \(\pm\) 0.13 c & 3.48 \(\pm\) 0.13 d & 1.12 \(\pm\) 0.08 b & 0.11 \(\pm\) 0.00 cd & 0.96 \(\pm\) 0.02 a \\ E & 80.83 \(\pm\) 0.75 d & 0.20 \(\pm\) 0.00 d & 1.92 \(\pm\) 0.19 e & 0.74 \(\pm\) 0.06 c & 0.06 \(\pm\) 0.03 d & 0.95 \(\pm\) 0.01 a \\ F & 78.00 \(\pm\) 0.00 e & 0.20 \(\pm\) 0.00 d & 0.80 \(\pm\) 0.09 f & 0.63 \(\pm\) 0.04 e & 0.09 \(\pm\) 0.02 d & 0.96 \(\pm\) 0.02 a \\ \hline \hline \end{tabular}  
* A-F: Cooked black rice with different milling degrees (A: 0%, B: 0.57%, C: 1.27%, D: 4.16%, E: 6.97%, F: 10.19%). Different lowercase letters in the columns represented statistically significant differences (\(p<0.05\)).  
\end{table}
Table 2: Eating quality traits of cooked black rice with different milling degrees (A–F) evaluated by rice taste analyzer.  
distributed in the bran layer [45]. The consumers' acceptance of naturally derived colorants was closely related to the image of health quality and food products [46]. The color of cooked rice was whitened by increasing the milling degree, which significantly lowered the sensory property score of appearance. Compared to whole grains, the texture feature (including adhesiveness, springiness, hardness) of milled black rice samples significantly improved. Specifically, the secondary attributes of appearance decreased while the secondary attributes of texture increased after milling treatment. The taste analyzer has been shown to be effective in indicating the taste quality of _japonica_ milled rice [47]. However, the ability of the taste analyzer to accurately predict the sensory outcomes of cooked black rice remains uncertain, owing to the differing morphological and physicochemical properties between _japonica_ milled rice and pigmented rice, as well as the complex processes involved in the mastication in the oral cavity. Partially, the slightly milled black rice (B) exhibited the highest overall score by the sensory test, which was consistent with the taste score trend from the taste analyzer. It indicated that the taste analyzer based on the multiple regression analysis of near-infrared spectroscopy data showed the potential to partially replace sensory evaluation in the study of cooked black rice. Despite the fact that the taste analyzer is a time-saving and labor-saving test for rice taste quality, this analyzer fails to describe the volatile flavor compounds information of cooked rice.