# Study of the Targeted Regulation of Rice Drying Characteristics and Quality
## 2 Materials and Methods
### Indicator Determination  
(1) Determination of water content  
The methodology used in \"oil moisture and volatile content determination\" was used to determine the rice moisture content and wet basis moisture content of the sample [15], which was calculated according to Equation (1).  
\[MC=\frac{m_{t}-m_{\text{d}}}{m_{t}} \tag{1}\]  
where \(MC\) represents the wet basis moisture content of the sample (%), \(m_{t}\) is the wet sample mass (g), and \(m_{d}\) is the dry sample mass (g).  
(2) Determination of waist burst rate and waist burst rate (ACP)  
After drying for 24 h, use \"Inspection of grain and oilseeds--Methods for determination of yellow-coloured rice and cracked kernels \"tested rice for waist burst [16]. The waist burst rate and waist burst rate are calculated as follows (Formulas (2) and (3)):  
\[Cp=\frac{n_{c}}{n_{t}}\times 100 \tag{2}\]  
\[ACP=Cp_{t}-Cp_{0} \tag{3}\]  
where \(n_{c}\) and \(n_{t}\) are the number of cracked grains and total grain number, respectively, \(Cp_{t}\) and \(Cp_{0}\) represent dry waist burst rate (%) and initial waist burst rate (%), respectively, and \(ACP\) is the waist burst rate (%) increase.  
(3) Determination of whole rice rate (HRY)  
The whole rice rate was determined according to \"rice whole rice rate inspection method\" [17]. The experiment was repeated three times, and the average value was used in the calculation. The whole rice rate was calculated as follows:  
\[HRY=\frac{B}{A}\times 100 \tag{4}\]  
where \(B\) is the quality of whole rice (g), and \(A\) is the total quality of rice (g).  
(4) Resistant starch concentration  
The resistant starch concentration was determined following \"rice and products in the determination of resistant starch spectrophotometric method\" [18].  
(5) Fatty acid value determination  
The fatty acid value was determined following \"Inspection of grain and oils--Determination of fat acidity of cereal and cereal products--Instrumental analysis method\" [19].  
(6) Protein content determination  
The protein content was determined following grain and oil inspection \"rice crude protein content determination\" using the near-infrared method. The change value of protein content is calculated by the following formula [19]:  
\[PCV=PC-RGPC \tag{5}\]  
Among them, PCV is the change value of protein content (g/100 g), PC is the protein content after drying (g/100 g), and RGPC is the protein content of raw grain.  
(7) Fat content determination  
The fat content was determined following \"National Standard for Food Safety Determination of Fat in Food\". The change value of fat content is calculated as follows [20]:  
\[FCV=FC-RGFC \tag{6}\]  
where FCV is the change value of fat content (g/100 g), FC is the fat content after drying (g/100 g), and RGFC is the fat content of raw grains.  
(8) Determination of germination rate  
The germination rate is an important indicator reflecting the seed quality, and its formula is shown in Equation (7). In this chapter, to directly reflect the loss of the germination rate after drying, the germination rate ratio was used as the output indicator, and it was calculated as follows:  
\[GR(\%)=\frac{n}{m}\times 100\% \tag{7}\]  
where n and m are the number of developed buds and the total grains of rice, respectively.  
(9) Calculation of drying time  
The drying period of rice in the test bed was recorded as the net drying time (Dtn), and the total drying time (Dtt) was the sum of the net drying time and recovery time.