# Analysis of Sushi Rice: Preparation Techniques, Physicochemical Properties and Quality Attributes
## 3 Results and Discussion
### Shelf-Life Study of Cooked Sushi Rice
#### 3.3.1 TPA
For optimal sushi quality, shorter washing durations may be preferred for immediate use, while extended storage requires careful moisture control to mitigate the effects of retrogradation and maintain desired textural properties. Different Water-to-Rice Ratio on TPA  
In Table 5, the TPA parameters are presented for rice cooked with varying water-to-rice ratios, measured for different storage durations. The hardness of the rice significantly varied (\(p<0.05\)) between the groups and across the storage period. R1, having the lowest water content, exhibited the highest hardness values (\(p<0.05\)) after 10 d (538.1 \(\pm\) 27.73 N), maintaining its firmness better than other groups. Conversely, R5 consistently showed the lowest hardness across all storage times, indicating a softer texture (161.6 \(\pm\) 12.82 N on day 10). This suggests that higher water-to-rice ratios lead to softer rice, while lower ratios (R1) preserve hardness over extended storage. This finding aligns with [PERSON] and [PERSON] [44], who found that increased water content reduces rice hardness. The increase in hardness (\(p<0.05\)) for R2 from day four to day 10 (265.4 \(\pm\) 19.55 N to 415.3 \(\pm\) 11.09 N) reflects the retrogradation process, in which starch crystallizes, contributing to texture changes. \begin{table}
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**Storage** & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} & \multicolumn{1}{c}{**Civilization**} \\
**Quantization** & **Group** & **Hardness (N)** & **CV (s)** & **Achesiveness** & **CV (s)** & **Springiness** & **CV (s)**  
Adhesiveness, measured as the negative force required to overcome stickiness, was lowest (least adhesive) (\(p\) < 0.05) in R1 throughout storage (\(-\)369.3 \(\pm\) 70.25 on day one, \(-\)532.1 \(\pm\) 73.5 on day 10). In contrast, R5 exhibited the highest adhesiveness (\(-\)1474 \(\pm\) 11.18 on day one, \(-\)1228 \(\pm\) 47.98 on day 10), indicating that rice with higher water-to-rice ratios tends to remain stickier. According to [PERSON] et al. [45], the rice-to-water ratio is a critical factor in the relationship between starch structures and cooked rice texture. Their research demonstrated that increased amounts of leached amylopectin with a degree of polymerization of 12-100 enhanced rice stickiness, but only when the rice was prepared at higher water-to-rice ratios. This correlation disappeared when using lower rice-to-water ratios of 1:1.2 and 1:1.4. [PERSON] et al. [20] reported that higher water-to-rice ratios during cooking increase stickiness while decreasing hardness intensity. Similarly, [PERSON] et al. [8] and [PERSON] et al. [45] confirmed that using higher amounts of water results in decreased rice hardness. The decline in adhesiveness (\(p\) < 0.05) for all groups over time may be attributed to moisture redistribution and retrogradation, which reduce stickiness. In a similar study by [PERSON] et al. [37], it was found that sushi rice became notably less sticky, showing a significant reduction in adhesiveness during the two-week storage period. Springiness remained relatively consistent across all groups, with values ranging from 0.99 to 1.03. These findings allow us to demonstrate that the water-to-rice ratio has minimal impact on springiness during the storage period. The elastic properties of the cooked rice matrix were largely maintained, even as hardness and adhesiveness changed. Cohesiveness values were generally low (\(p\) < 0.05), ranging from 0.16 to 0.30, and they varied minimally across groups.