Drying and Tempering Influence on the Milling Quality of Parboiled Rice

Rice occurrence and dealings are features of the tradition of Bangladesh’s populace. However, their experience of parboiled paddy for domestic consumption is limited. Proper drying and tempering are very important for maximum milling output. The study was conducted to investigate the drying and tempering influence on the milling quality of parboiled paddy. The sample size of the paddy was 36 kg as per treatment. In the case of T₁ (daily 4 hours sun drying) and T₂ (daily 5 hours sun drying), 1-hour drying and 1/2 hour tempering were maintained, and for T₃ (daily 4 hours sun drying) and T₄ (daily 5 hours sun drying), 1-hour drying, and 1-hour tempering were maintained. The temperature of the paddy sample was varied from 18 °C to 42 °C in five treatments. Drying over three days at different time intervals led to reduced moisture content (from 23.42% to 9.24%), resulting in increased kernel hardness for reduced breakage during milling. The highest kernel strength after three days of drying was found to be 50.65 N/m for T₄. The relative humidity, day temperature, air flow velocity, and solar radiation varied from 48% to 78%, 24 °C to 29 °C, 0.00 to 0.70 m/s, and 64450 to 108100 lux, respectively. Based on milled rice, the best milling output and head rice recovery were found to be 20.51 kg and 19.80 kg, respectively, for T₄. The lowest quantity of broken rice was 0.50 kg found for T₁ and T₄, respectively. The lowest quantity of loss was 1.10 kg for T₂, and the lowest quantity of husk and bran was 6.88 kg for T₄. Results showed that among the five treatments, 5 hours of sun drying daily, maintaining the procedure of 1-hour drying and 1-hour tempering until the moisture content is reduced to 10% (T₄), is more effective for increasing milling recovery.

Introduction

Rice (Oryza sativa L.), the world’s oldest domesticated crop, is vital to Bangladesh’s economy. Bangladesh is producing 35.3 million metric tons of white rice [1] to feed about 174 million people [2]. The population of Bangladesh will increase to about 215.4 million in 2050, and to feed the estimated people, around 44.6 million metric tons of white rice will be required [3]. However, the agricultural land in Bangladesh has been decreasing by 0.45% per annum since the year 2000 [4] in order to provide shelter and other facilities to the rapidly growing population. Reducing postharvest losses through effective technology adoption is a more cost-effective approach than attempting to increase paddy production on limited land and resources. For a long time, the country has produced and marketed a great variety of good and aromatic rice varieties, but in small quantities due to a lack of appropriate parboiling, drying, and tempering processes.

Paddy is processed into white rice, with milling taking place both at rice mills and in farmers’ households. This paddy can be transformed into either parboiled or aromatic rice, with parboiled rice being the staple food choice for the people of Bangladesh. About 90% paddy of annual production in Bangladesh is converted into parboiled rice [5]. Aromatic rice is primarily utilized during special occasions. Parboiling is the heat treatment of ‘raw’ rough rice at high moisture levels. Soaking, heat treatment, and drying to appropriate moisture content for milling are the most essential factors in the process. Because of its numerous benefits and the advancement of mechanized milling devices, this method has survived the years. Among the most key causes of parboil rice is to improve milling resilience, which leads to higher whole kernel yields (whole kernel rice sells for twice as much as broken rice). In some regions, where specific varieties of rough rice provide low mill yields, this practice is also utilized as a salvage technique. Vitamin Bl (Thiamine) was eventually discovered in rice bran, and its deficiency was connected to Beriberi syndrome.

Drying and tempering stands out as the foremost post-harvest activity for cereal grains, representing a pivotal stage in both storage and processing procedures. The temperature of drying air, relative humidity, airflow velocity, variety, and maturity of agricultural crops influence the moisture removal process [6]. The moisture content of the seeds should be dried to less than 12%, and the moisture content of the grains to less than 14% [7]. The moisture gradient and rice fissuring were severely impacted by the drying and tempering operations. With increasing drying time and reducing tempering time, the percentage of fissured kernels increased. One of the factors that affect head rice recovery is the moisture content of the paddy. At high moisture levels, head rice recovery declined, especially for long-grain varieties [8]. The moisture gradients were more efficient than temperature gradients in causing stress cracks [9]. Performing tempering and drying together can result in a quicker drying rate and fewer fractures, making it safer and saving energy. Depending on the variety, drying temperatures between 35 °C and 45 °C resulted in minimal fissuring. Increased grain fissures emerged from drying temperatures above 45 °C, resulting in more grain loss [10]. Rice quality, on the other hand, is influenced by a variety of milling performance characteristics. Rice mill performance in terms of Milled Rice recovery and quality is determined not only by the type and condition of the equipment but also by the quality of the raw rice (paddy) to be turned into milled rice.

Rice milling is a vital step in the post-production phase. The fundamental purpose of a rice milling system is to remove the husk and bran layers, leaving an edible, white rice kernel that has been properly processed and is free of pollutants. Depending on the needs of the consumer, the rice should have a small amount of cracked kernels. The complete milled rice, commonly known as the rice hull or husk, is composed of around 20% rice hull or husk, 11% bran layers, and 69% starchy endosperm. This will result in the following fractions in an ideal milling process: 20% husk, 8%–12% bran depending on milling degree, and 68%–72% milled rice or white rice depending on variety [11]. Total milled rice is made up of whole grains or head rice, as well as broken. Rice hulls, rice germ and bran layers, and fine broken are all by-products of rice milling. Milling yields significantly vary with drying and tempering. By maintaining proper drying and tempering procedures, a significant milling yield can be obtained. If this operation can be practiced at the farmer’s level, it is possible to increase total milling recovery and reduce loss. The objective of the present study was to observe the drying and tempering influence on the milling quality of parboiled rice to increase the milling recovery of parboiled rice, and to compare the drying, tempering, and milling process with farmers’ practices.

Materials and Methods

Site Selection

The experiment was conducted in Bijoynagor upazila of Brahmanbaria district (Fig. 1) in the division of Chittagong, Bangladesh, the latitude and longitude of the location are 24 1.3′ N and 91 16.8′ E, respectively, and Bangladesh Rice Research Institute (BRRI), Gazipur (Fig. 1) in the division of Dhaka, the latitude and longitude of the location are 23.9903° N, and 90.3996° E, respectively. The experiment was held during the season of Aman.

Fig. 1. Study location.

Variety

Freshly harvested paddy BRRI dhan49 was collected from a farmer’s field in Bijoynagor, Brahmanbaria, and used for five different treatments where each treatment contains a total of 36 kg paddy. Then the paddy was cleaned by an electrical fan. The length-to-breadth ratio of BRRI dhan49 was 3.69 and thousand grain mass (TGM) were 20 g.

Scientific Equipment Used in the Study

In this experiment Digital Anemometer (AR836), Digital Lux Meter (AS813), Grain moisture meter (AR991), Digital slide caliper, Digital thermometer (DM6801A TYPE K), Digital weight balance, Kernel strength measuring meter (FGN-20B SHIMPO), and Seive was used to measure the wind speed, the brightness of sun, grain moisture, length, breadth and thickness, paddy grain temperature, paddy grain weight to distribute equal amount of paddy for each treatment, the strength of paddy grain and for separating head rice and broken rice, respectively. Day temperature and relative humidity data were collected from local weather stations.

Experimental Design

The following treatments were used, with three replications:

T₁ = Daily 4 hours sun drying maintaining the procedure of 1 hour drying and ½ hour tempering until moisture content reduce to 10% (wb).

T₂ = Daily 5 hours sun drying, maintaining the procedure of 1 hour drying and ½ hour tempering until moisture content reduce to 10% (wb).

T₃ = Daily 4 hours sun drying maintaining the procedure of 1 hour drying and 1 hour tempering until moisture content reduce to 10% (wb).

T₄ = Daily 5 hours sun drying maintaining the procedure of 1 hour drying and 1 hour tempering until moisture content reduce to 10% (wb).

T₅ = Farmers practice (without tempering).

Parboiling of Paddy

The hydrothermal treatment of paddy before milling is known as parboiling. Cleaned rough rice with water (1/3 portion of rice) was heated for 15–20 min to gelatinize starch with minimum grain swelling until it began to split. Almost the same heat was maintained for all the treatments except farmer’s practice (T₅). After heating, the parboiled rice was put on a net, and then the rice was spread on woven mats for cooling. Moisture content was measured before and after parboiling.

Collected Data

Drying

After parboiling, Paddy was spread on the concrete floor for sun drying, maintaining a half-inch thickness for equal drying, and stirring activity was done at 20-minute intervals. The paddy was dried to a moisture-removal level of 10%. (wb). Drying activity was continued for three days for all the treatments.

Tempering

Tempering is a process of distributing the moisture uniformly for the purpose of reducing the breakage and increasing the strength of the paddy. In this experiment, tempering was maintained for treatment T₁, T₂, T₃, and T₄ in the variation of time.

Milling

After the drying and tempering was completed, the paddy was stored for 7 days. Then, the milling was carried out on the same day for all treatments through Engle Berg mobile hullers. Milled rice is a combination of head rice and broken rice. The mixer of husk and bran was collected from one of the outlets of the Engle berg huller and the small broken rice from another outlet of the huller. The mixture of head rice and broken rice was then separated using a locally available sieve. Some losses were also detected during milling. Moisture content and temperature of paddy before and after milling were also calculated.

Milling Parameter

Milling Yield (%)

In general, milling yield is the percentage of the finished product obtained from the milling of a cereal crop. Rice milling yield is the amount of polished white rice obtained from husked rough rice. Milling was calculated by the following equation [12]: (1)Milling yield=Total milled riceTotal rough rice×100

Head Rice Recovery (%) (Grain size >2/3, %)

Head rice recovery is the percentage of head rice (excluding broken) obtained from a sample of paddy was calculated by the following equation [12]: (2)Head rice recovery=Total head riceTotal rough rice×100

Broken Rice (%) and Small Broken Rice (%)

According to the definition, rice that is more than 3/4 of the length of sound rice is considered sound rice. The proportion of the weight of broken rice grain to the weight of the whole sample was defined as the percentage of rice breakage [13]. Broken rice percentage was calculated by the following equation: (3)Broken rice (% )=weight of total broken riceweight of total milled rice×100

Small Broken rice percentage is the ratio of the total weight of small broken rice to the weight of total milled rice. Small Broken rice percentage was calculated by the following equation [14]: (4)Small Broken rice (% )=weight of total small broken riceweight of total milled rice×100

Husk and Bran (%)

The husk and bran percentage are the ratio of the total weight of husk and bran to the weight of total milled rice. Husk and Bran percentage was calculated by the following equation [14]: (5)Husk and Bran=weight of total husk and bran weight of total paddy sample×100

Farmers Practice

Farmers used traditional methods for parboiling and drying paddy. Where no tempering and no specific thickness were maintained. Farmers dried their paddy in the courtyard.

Statistical Analysis

Data was analyzed using the Statistix 10 program (Statistix 10 software, 2013) as a single factorial design. The least significant difference (LSD) test was used to compare means. To investigate the relationship between milling performance and the results of a simple correlation analysis, Excel 2010 was used.

Results and Discussion

Day Temperature vs. Relative Humidity

Fig. 2 illustrates that the temperature profile was in a continuous growing pattern (not more than 30 °C), and the relative humidity profile was observed to be in a decreasing pattern with the increasing temperature throughout the experiment period. The day temperature and relative humidity of the study location on day 1 was ranging from 24 °C–29 °C and 48%–78%, respectively. On day 2, the day temperature and relative humidity range were 24 °C–28 °C and 55%–69%, respectively, whereas on day 3, temperature variation was the same as the previous day 24 °C–28 °C and the relative humidity range was (55%–74%). The findings were compatible with those of Prasetyo, who found that the relative humidity decreased as the temperature of air increased, with a relative humidity of 35.4%, 16.4%, and 8.5% at temperatures of 40 °C, 50 °C, and 60° C, respectively [15]. Yin et al. [16] took the minimum crack percentage as the performance index, showing that the crack additional percentage could reach its lowest value of 1.090% when the drying medium temperature was 31.2 °C and the relative humidity of the drying medium was about 62.5%, which is more or less similar with the present study. It is clear that temperature and relative humidity are inversely proportional, which is a good sign for the drying period, and the lower relative humidity is effective for expelling moisture content from the paddy grain.

Fig. 2. Day temperature vs. relative humidity profile on day 1, day 2, and day 3.

Solar Radiation and Air Velocity

Solar radiation throughout the study period was different due to location, wind velocity, and day temperature. On days 1, 2, and 3, the highest solar radiation was recorded at 1 PM, 12 PM, and 11 AM, respectively, whereas the lowest radiation after all days was observed at 3 PM, shown in Fig. 3a. Solar radiation was varied from 64450 to 108100 lux during the time of drying operation. Peng showed the importance and the positive effect of solar radiation on rice grain yield [17]. Stanhill and Cohen [18] reported a global average solar radiation reduction of 0.51 ± 0.05 W m⁻² per year and considered this significant reduction as a threat to rice production. Tao et al. [19] found that solar radiation declined by 0.5 MJ m⁻² d-1decade-1 in single rice growth duration in the Yangtze River Valley during 1981–2009, which was closely related to yield reduction. The present study indicates an increasing solar radiation pattern most of the time, which is compatible with the findings of others.

Fig. 3. Profile of (a) Solar radiation and (b) Air velocity on day 1, day 2, and day 3.

The air velocity profile shows the same type of variation throughout the study period due to location and day temperature. On days 1, 2, and 3, average air velocities varied from 0.02–0.56 m/s shown in Fig. 3b. Yin et al. [16] took the minimum crack percentage as the performance index, showing that the crack additional percentage could reach its lowest value of 1.090% when the airflow velocity was 0.5 ms⁻¹, which is in line with the results of this study. The present study also showed that there is a relationship between drying performance and air velocity. The drying rate increased with air velocity. Moreover, the drying rate gradually decreased and tended to level off with air velocity.

Moisture Content at Different Times During Drying (Before Tempering and Immediately After Tempering)

Fig. 4 describes a study involving the drying and tempering of paddy with different treatments (before tempering). Over three days, the moisture content of the paddy was monitored at various time intervals. Initially, all treatments showed significant differences in moisture content. However, after 1 hour of drying, the moisture reduction pattern became similar for all treatments. On day 1, Treatment 5 showed the most rapid reduction in moisture, while Treatment 1 had the highest moisture content after 3 hours of drying. On day 2, Treatment 3 had the highest moisture content initially and after 5 hours of drying, while Treatment 5 consistently had the lowest moisture content. On day 3, Treatment 3 had the highest initial moisture, while Treatment 5 had the lowest. The study highlights the variations in moisture content due to different drying times and treatment designs. Yang and Jia [20], during drying, the kernel temperature will increase, and moisture will diffuse from the kernel. A temperature and an MC gradient will develop from the surface to the center of the kernel. The temperature gradient will disappear within 2 min and it is generally agreed upon that temperature variations in the kernel can be neglected after a few minutes of drying. The MC gradient, however, plays a much more important role during and after drying, which is consistent with the present findings [20]. The observations indicate the influence of drying time, treatment design, and tempering on moisture content, as well as the significant relationships between certain treatments in terms of moisture levels.

Fig. 4. Moisture level (before tempering) on: (a) day 1, (b) day 2, and (c) day 3.

Different treatments (T₁, T₂, T₃, and T₄) with varying tempering times lead to distinct moisture content levels immediately after tempering, as shown in Fig. 5. The study shows that the moisture content of rice varies with both the time of drying and the duration of tempering. The results indicate that T₂ and T₄ treatments, with 1 hour of tempering after 1 hour of drying, generally have higher moisture content immediately after tempering compared to T₁ and T₃ treatments, which have ½ hour of tempering after 1 hour of drying. This suggests that a longer tempering time might lead to higher moisture retention in the rice kernels. The study finds that there are significant differences in moisture content between certain treatments (e.g., T₂ vs. T₄) after specific durations of drying and tempering. This indicates that the choice of drying and tempering process can influence the final moisture content of the rice kernels. Cnossen and Siebenmorgen [21] hypothesized that a sufficient moisture content (MC) gradient within the kernel, along with tempering conditions that induce a transition from the glassy to the rubbery state of starch, significantly affects head rice yield (HRY). The present study supports this idea as it explores the variations in moisture content due to different tempering times, which can influence rice kernel properties and quality. Iguaz et al. [22] showed intermittent drying with tempering periods between cycles to reduce the number of fissured kernels. The present study’s emphasis on different drying and tempering treatments and their effects on moisture content and kernel strength relates to this observation. It demonstrates that the choice of drying and tempering processes can impact fissure occurrence and overall rice quality. Li et al. [23] observed that a higher tempering/drying ratio resulted in a lower percentage of fissured kernels. The present study’s examination of different tempering times and their influence on moisture content and kernel strength supports this finding. It suggests that longer tempering times might lead to better prevention of fissuring.

Fig. 5. Moisture level (immediately after tempering) on: (a) day 1, (b) day 2, and (c) day 3.

Paddy Temperature at Different Times During Drying (Before Tempering and Immediately after Tempering)

Fig. 6 shows that the paddy temperature in three days did not exceed 43 °C, which aligns with the safe maximum temperature of drying seed grains and paddy grains mentioned by [24]. Bala [24] also emphasized that excessive high-temperature drying can cause physical and chemical changes in rice grains, leading to an increase in breakage of whole rice and a reduction in rice quantity and quality [24]. Additionally, Debabandya and Satish [25] reported that an increase in the bulk surface temperature of the grain during milling due to abrasion/friction induces thermal stress, resulting in crack generation and a decrease in head rice yield. This finding corroborates the study’s emphasis on the impact of paddy temperature on milling quality. Furthermore, Bonazzil et al. [26] highlighted that the proportion of fissured kernels increases with temperature and the evaporating capacity of the air, further supporting the importance of maintaining optimal paddy temperature during the milling process [26].

Fig. 6. Paddy temperature (before tempering) on (a) day 1, (b) day 2, and (c) day 3.

Fig. 7 shows significant changes in paddy temperature (immediately after tempering) over three days. On the day 1, after 2 hours at 12 PM, T₄ had the highest temperature, and T₁ had the lowest temperature. The other two treatments were identical. After 4 hours at 2 PM, T₂ and T₄ had the highest temperature, while T₁ and T₃ had the lowest temperature. On the second day, after 2 hours at 12 PM, T₁ had the highest temperature, and T₃ had the lowest temperature. After 4 hours at 2 PM, T₁ had the highest temperature (identical to T₂), and T₄ had the lowest temperature. On the day 3, after 2 hours at 12 PM, T₂ had the highest temperature, and T₄ had the lowest temperature. After 4 hours at 2 PM, T1 had the highest temperature, T₃ had the lowest temperature, and significant variation was observed for other treatments. Overall, tempering can reduce rice fissuring and has implications for efficient drying conditions. According to Iguaz et al. [22], tempering allows moisture diffusion from the interior to the external surface of the grain kernels to decrease the moisture gradients and then reduce the rice fissuring. Poomsa-ad et al. [27] said that as compared with no tempering, a faster drying rate could be obtained by tempering treatment between drying stages. Pomsa-ad et al. [27] also stated that a tempering time of 35 min is recommended for the continuous fluidized bed dryers being operated in rice mills. However, the present study recommends that 1-hour tempering is better for improving the milling performance of the paddy in the traditional postharvest process. According to Elbert et al. [28], the drying temperature has a negative effect, while the tempering time has a positive effect on HRY, which is consistent with the present study.

Fig. 7. Paddy temperature (immediately after tempering) on (a) day 1, (b) day 2, and (c) day 3.

Kernel Strength at Different Stages of Drying

This study shows that T₄ gives the higher kernel strength (50.65 N/m) after three days of drying and tempering period, which contains daily 5 hours of sun drying, maintaining the procedure of 1 hour drying and 1-hour tempering until the moisture content is reduced to 10% (wb) (Fig. 8). Among the four treatments designed in the study, T₄ is tempered for the longest period. Dong et al. [29] reported that drying and tempering processes had significant effects on the moisture gradient and rice fissuring, and the percentage of fissured kernels increased with increasing drying time and decreasing tempering time, which is more or less similar to the present study. According to Cnossen et al. [30], Rice kernel fissuring depends not only on variety and crop management but also on post-harvest operations, especially on drying conditions. Improper drying and tempering processes can be a major cause of fissuring. The present study aligns with this observation as it focuses on the effects of different drying and tempering treatments on rice kernel strength, implying that the drying conditions can influence fissuring. Zhang et al. [31] also reported that fissured kernels usually break during milling and lead to a reduction in head rice yield (HRY), causing very poor cooking quality and lowering the market value. This aligns with the present study’s focus on kernel strength, as stronger kernels are less likely to fissure during milling, which can have a positive impact on rice quality and market value. The present study’s findings on the influence of specific drying and tempering treatments on kernel strength and fissuring resonate with these previous studies, as they all emphasize the importance of post-drying processes in mitigating fissure occurrence. According to Aquerreta et al. [32], the percentage of fissured kernels was drastically reduced when drying was performed in two or three steps compared to drying in one step, which is in line with the present study’s approach of daily 5-hour sun drying with alternating drying and tempering periods. Cnossen et al. [30] stated that to maximize the full kernel yield, the tempering stage was recommended after the first stage of drying to reduce moisture stresses which is consistent with the present study.

Fig. 8. Effect of drying and tempering on kernel strength.

Paddy Temperature and Moisture Variation Due to Milling

From Fig. 9, it was observed that Treatment 3 (T₃) had the highest moisture content during milling at 14.5%. This moisture content level was found to be homogeneous with Treatments 1 (T₁), 4 (T₄), and 5 (T₅). On the other hand, Treatment 2 (T₂) exhibited the lowest moisture content during milling, with a value of 11.8%. Alzalinia et al. [33] reported that the ideal paddy moisture content for the milling process ranged from 12% to 14% wet basis (w.b.), which resulted in the least rice breakage. The present findings supported these previous studies as the paddy moisture content for all treatments, except T₃, was similar. Regarding paddy temperature during milling, it was observed that all treatments showed significant variations. These variations in moisture content and paddy temperature were attributed to the differences in drying and tempering time among the treatments, except for Treatment 5 (T₅).

Fig. 9. Paddy temperature and moisture variation due to milling.

Milling Recovery

Table I and Fig. 10 showed that T₄ had the highest total milling yield and the highest quantity of head rice after milling. T₅ had the lowest total milling yield, the lowest head rice quantity, and the highest broken rice and loss values.

Table I. Milling Output After 3 Days of Drying and Tempering

Treatment	Total paddy (kg)	Total milling yield (kg)	% of milling yield	Head rice (kg)	% of head rice	Broken rice (kg)	% of broken rice	Small broken rice (kg)	Husk + Bran (kg)	Loss (kg)	% of losses
T1	28.50	20.01	70.20	19.32	67.77	0.50	1.76	0.19	7.31	1.11	4
T2	28.50	19.32	67.77	18.31	64.25	0.80	2.80	0.21	8.18	1.10	3.84
T3	28.50	19.91	69.85	18.99	66.62	0.80	2.81	0.19	7.71	1.18	3.99
T4	28.50	20.51	71.97	19.80	69.48	0.50	1.76	0.20	6.88	1.17	3.89
T5	28.50	18.70	65.62	17.31	60.72	0.99	3.49	0.41	8.40	1.60	5.57

Fig. 10. Milling output after 3 days of drying and tempering.

T₁ had the second-highest head rice quantity and the same low broken rice value as T₄. T₅ had the highest small broken rice value. Additionally, T₅ had the highest quantity of husk and bran after milling, while T₄ had the lowest. In conclusion, T₄ performed the best overall, except for the loss parameter. Bautista et al. [34] said that addressing the fissuring issue and optimizing the milling process are essential for enhancing the overall efficiency and quality of the rice industry. Proper harvesting techniques and environmental conditions play a vital role in minimizing breakage during milling and achieving better results in terms of milling yield and rice quality. The present study maintains all the post-harvest techniques (except T₅) and gives a higher milling recovery which is consistent with the previous researcher.

Milling Recovery Compared with the Farmer’s Practice

The scientific treatments (T₁, T₂, T₃, and T₄) that utilized the drying and tempering process demonstrated higher milling recovery compared to the traditional treatment (T₅) without tempering. Notably, T₄ showed a remarkable increase of approximately 6% in milling recovery when compared to the traditional treatment (T₅). This highlights the significant positive impact of incorporating the drying and tempering process on the overall milling efficiency and recovery of rice.

Conclusions

In response to increasing rice consumption due to population growth, inadequate post-harvest processing knowledge has diminished rice quality, quantity, and market value. Proper drying and tempering methods were explored as effective alternatives, enhancing head rice yield, quality, and market value. Significant improvements were observed in moisture removal rate, paddy temperature, paddy strength, and milling recovery. T₄, involving 1-hour drying and 1-hour tempering for 5 hours daily until reaching 10% moisture content, yielded the best results, boosting total milling yield and head rice percentage compared to farmers’ practice. This highlights the importance of proper drying and tempering in achieving higher milling recovery and reduced losses, with potential benefits for farmers.