Effect of Grain Inverters in Cross-Flow Dryers on Kernel Fissuring and Head Rice Yield Reduction

2020 ◽  
Vol 63 (4) ◽  
pp. 1079-1086
Author(s):  
Zephania R. Odek ◽  
Bhagwati Prakash ◽  
Terry J. Siebenmorgen
Keyword(s):  
Rice Yield ◽  
Cross Flow ◽  
Yield Reduction ◽  
List Type ◽  
Limited Information ◽  
Heated Air ◽  
Air Temperatures ◽  
Head Rice ◽  
Head Rice Yield ◽  
Rice Milling

HighlightsGrain inverters minimized fissuring of rice kernels closest to the heated air plenum at plenum air temperatures =55°C.Grain inverters had no effect on rice kernel fissuring across a grain column at plenum air temperatures <55°C.Grain inverters decreased head rice yield reduction of samples dried at plenum air temperatures >55°C but had no effect on head rice yield reduction at plenum air temperatures =55°C.One or two grain inverters in a cross-flow dryer can help reduce kernel fissuring and minimize head rice yield reduction.Abstract. Industrial-scale cross-flow dryers are commonly equipped with grain inverters to facilitate uniform drying across the column thickness, but limited information is available on the effect of grain inverters on rice milling quality. In this study, lab-scale drying experiments were performed to investigate the effect of grain inverters on kernel fissuring and head rice yield reduction. Rice samples of long-grain cultivar Roy J were dried for 60 min at plenum air temperatures of 45°C, 50°C, 55°C, and 60°C. The number of grain inversions during a 60 min drying period were 0, 1, and 2. After drying, a portion of the sample was tempered at a final bulk-rice temperature (heated tempering), while the other portion was tempered at ambient room temperature (ambient tempering). At plenum air temperatures of 55°C or 60°C, grain inversion (1 or 2 inversions) minimized fissuring of kernels closest to the heated-air plenum compared to 0 grain inversion. At 45°C and 50°C, grain inversion did not affect kernel fissuring. Similarly, at plenum air temperatures greater than 55°C for both ambient tempering and heated tempering approaches, 1 or 2 grain inversions significantly minimized head rice yield reductions compared to 0 grain inversion. These findings may be valuable for designing cross-flow dryers by informing decisions on the number of grain inverters needed to reduce fissuring and minimize head rice yield reduction. Keywords: Column dryer, Milling yields, Reversed airflow, Rice quality, Tempering, Turnflow, X-ray imaging.

Effect of Post-Drying Tempering of Rice on Minimizing Kernel Fissuring and Maximizing Moisture Removal

2021 ◽  
Vol 65 (1) ◽  
pp. 1-9
Author(s):  
Zephania Odek ◽  
Terry J. Siebenmorgen ◽  
Andronikos Mauromoustakos ◽  
Griffiths G. Atungulu
Keyword(s):  
Rice Yield ◽  
Yield Reduction ◽  
List Type ◽  
Humidity Ratio ◽  
Percentage Points ◽  
X Ray Imaging ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield ◽  
Rice Drying

HighlightsMore moisture can be removed in a single drying pass without severely fissuring kernels when samples are tempered than when immediately cooled without tempering.Tempering rice kernels immediately after drying can reduce the percentage of fissured kernels by up to half of that when kernels are immediately cooled without tempering.Abstract. Improper rice drying results in kernel fissuring, leading to head rice yield reduction due to breakage during milling. The objective of this study was to determine the percentage points (pp) of moisture content (MC) reduction that can be achieved in a single drying pass without significantly fissuring kernels. Long-grain rough rice of cultivars CL XL745 and Diamond at initial MCs of 18%, 17%, 16%, 15%, and 14% were dried using air at 45°C/20% relative humidity (RH), 50°C/15% RH, 55°C/12% RH, 60°C/10% RH, and 65°C/8% RH to MCs of 17%, 16%, 15%, 14%, 13%, or 12% with and without post-drying tempering. All temperature/RH combinations resulted in a humidity ratio of 0.012 kg water kg-1 dry air. Tempering was conducted at the drying air temperature for 4 h. The resulting samples achieved between 1 and 7 pp of MC reduction in a single drying pass. The pp of MC reduction that can be attained in a single drying pass without causing significant fissuring varied across the cultivars tested. Generally, ~2 pp of MC reduction was achieved in a single drying pass for CL XL745 and ~4 pp for Diamond without causing adverse fissuring when samples were not tempered after drying. However, with tempering, ~3.5 pp of MC reduction was achieved in a single drying pass for CL XL745 and ~5.5 pp for Diamond without causing significant fissuring. However, these amounts varied depending on the drying air conditions and initial MC. For both cultivars, tempering immediately after drying reduced the fissured kernel percentage by up to half of that when the kernels were not tempered. These findings quantify the importance of rice tempering and provide information on how much moisture can be safely removed in a single drying pass. Such findings may be applied to different dryer types to reduce fissuring due to drying, thereby minimizing head rice yield reductions. Keywords: Drying, Glass transition, Rice quality, Single-pass drying, X-ray imaging.

HEAD RICE YIELD REDUCTION RATES CAUSED BY MOISTURE ADSORPTION

1990 ◽  
Vol 33 (4) ◽  
pp. 1263-1269 ◽  
Author(s):  
M. M. Banaszek ◽  
T. J. Siebenmorgen
Keyword(s):  
Rice Yield ◽  
Yield Reduction ◽  
Moisture Adsorption ◽  
Head Rice ◽  
Head Rice Yield

RELATING DRYING RATE CONSTANT TO HEAD RICE YIELD REDUCTION OF LONG-GRAIN RICE

1997 ◽  
Vol 40 (4) ◽  
pp. 1133-1139 ◽  
Author(s):  
H. Chen ◽  
T. J. Siebenmorgen ◽  
B. P. Marks
Keyword(s):  
Rate Constant ◽  
Rice Yield ◽  
Yield Reduction ◽  
Drying Rate ◽  
Head Rice ◽  
Head Rice Yield

Rice cultivar response to sublethal concentrations of glyphosate and paraquat late in the season

2020 ◽  
pp. 1-7
Author(s):  
Justin McCoy ◽  
Bobby Golden ◽  
Jason Bond ◽  
Darrin Dodds ◽  
Taghi Bararpour ◽  
...  
Keyword(s):  
Grain Yield ◽  
Growth Stage ◽  
Rice Yield ◽  
Yield Reduction ◽  
Rice Grain ◽  
Rice Cultivars ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield ◽  
Sublethal Concentrations

Abstract Differential tolerance may be observed among rice cultivars with desiccant exposure events during rice reproduction and ripening. Five field studies were established at the Mississippi State University Delta Research and Extension Center in Stoneville, MS, to determine the effects of exposure to sublethal concentrations of common desiccants across multiple rice cultivars. Rice cultivars in the study were ‘CLXL745’, ‘XL753’, ‘CL163’, ‘Rex’, and ‘Jupiter’. Desiccant treatments included no desiccant, paraquat, or glyphosate and were applied at the 50% heading growth stage respective to cultivar. Differential injury estimates among cultivars and desiccant treatments was observed when glyphosate or paraquat was applied at 50% heading. Injury from glyphosate at 50% heading was nondetectable across all cultivars. However, injury following paraquat applications was >7% across all rating intervals and cultivars. Hybrid cultivars exhibited less injury with paraquat applications than the inbred cultivars in the study. Rice following exposure to glyphosate or paraquat at 50% heading growth stage produced rough rice grain yield decreases ranging from 0% to 20% and 9% to 21%, respectively. Rough rice grain yield decreases were observed across all cultivars following paraquat exposure, and all inbred cultivars following glyphosate exposure. Across desiccant treatment, head rice yield was reduced in three of five cultivars in the study. When pooled across cultivar, paraquat applications cause a head rice yield reduction of 10%, whereas rice yield following glyphosate application remained >95%. Although differential tolerance among cultivars to paraquat or glyphosate exposure was observed, impacts on grain quality coupled with yield reductions suggests extreme rice sensitivity to exposure to sublethal concentrations of these desiccants at the 50% heading growth stage.

Physical Integrity of Long-Grain Hybrid, Pureline, and Medium-Grain Rice Kernels as Affected by Storage Conditions

2020 ◽  
Vol 36 (4) ◽  
pp. 579-588
Author(s):  
Zeinab Mohammadi Shad ◽  
Griffiths Atungulu
Keyword(s):  
Sodium Chloride ◽  
Storage Temperature ◽  
Rice Yield ◽  
Storage Conditions ◽  
List Type ◽  
Milled Rice ◽  
Physical Integrity ◽  
Head Rice ◽  
Head Rice Yield ◽  
The Impact

Highlights Rice kernel physical integrity diminished at higher storage temperature and moisture content. Variation in rice kernel physical integrity was noticeable among rice cultivars. Fungal attack lessened rice kernel physical integrity. Abstract . Rice kernel physical integrity directly correlates with rice milling yield and quality. In this study, the impact of storage conditions on rice kernel physical integrity was examined by assessing changes in head rice yield (HRY) and kernel microstructure. Long-grain hybrid (XL753), long-grain pureline (Roy J), and medium-grain (Titan) rice were stored at different storage moisture contents (16% and 21% MCs, wet basis), storage temperatures (20°C, 30°C, and 40°C), and storage durations (4, 8, 12, and 16 weeks); the samples were also treated with antifungals, sodium chloride, and natamycin. Results show that kernel physical integrity was highly dependent on the rice storage environment. At the same storage conditions, the physical integrity of medium-grain cultivar was significantly higher than that for the two long-grains. Generally, the long-grain hybrid rice exhibited more resilience to breakage than pureline under the same storage conditions. An average of 4% reduction in HRY was seen for the three cultivars when 16% MC rice was stored at 40°C compared to at 20°C; however, the HRY reduction was 12% for rice stored at the highest MC (21%). Decreases in kernel physical integrity were also associated with unique microstructural changes in rice kernels. Sodium chloride treatment of rice kernels significantly and negatively impacted their physical integrity during storage compared to natamycin treatment and untreated control samples. Multiple regression models, developed for each cultivar were applicable for predicting changes in rice kernel physical integrity as a function of studied storage conditions and antifungal treatments. Keywords: Antifungal treatment, Head rice yield, Microstructure, Milled rice quality, Storage, Rice kernel physical integrity.

Estimating Head Rice Yield of Long-Grain Rice using a Bending Force Instrument

2019 ◽  
Vol 35 (3) ◽  
pp. 319-323 ◽  
Author(s):  
Zephania R. Odek ◽  
Terry J. Siebenmorgen
Keyword(s):  
Bending Strength ◽  
Rice Yield ◽  
Polarized Light ◽  
Alternative Methods ◽  
Rice Quality ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield ◽  
Rice Yields ◽  
Rice Milling

Abstract. Head rice yield is an important index of rice quality. The official procedure for determining head rice yield requires a 1000-g sample of rough rice or a lesser sample of rough rice for a modified procedure. In certain situations, such amounts of rough rice may not be available for conducting an actual milling analysis; thus, there is a need to provide alternative methods of estimating head rice yield using a smaller sample. In this study, a PaddyCheck instrument was used to individually measure the three-point bending strength of approximately 250 rough rice kernels per sample. The instrument then classified the kernels as either “hard,” “soft,” or “broken by a force <17 N” (BBF). Additionally, each kernel was individually illuminated using polarized light as a means of estimating chalkiness. The kernel parameters measured using the PaddyCheck were then used to develop an equation for estimating head rice yield, based upon head rice yields determined using a modified milling procedure. The equation developed could be used in conjunction with the PaddyCheck instrument to provide estimates of head rice yield and thus, might allow the instrument to be more useful to practitioners in breeding programs and others involved in harvesting and drying operations to compare head rice yields of various samples/treatments, where the available rough rice sample or time is not sufficient to conduct an actual milling analysis. Keywords: Breaking force, Head rice yield, PaddyCheck, Rice milling, Rice quality, Rough rice.

Sign in / Sign up

Export Citation Format

Share Document