Dehulling Efficiency Research Articles

Integrative Dissection of Lignin Composition in Tartary Buckwheat Seed Hulls for Enhanced Dehulling Efficiency (Adv. Sci. 20/2024)

Integrative Dissection of Lignin Composition in Tartary Buckwheat Seed Hulls for Enhanced Dehulling Efficiency (Adv. Sci. 20/2024)

Substantiating the rational parameters and operation modes for the hemp seed centrifugal dehuller

The object of research is technological processes, seeds of industrial hemp, and working bodies of the dehuller. A centrifugal-type device for crushing hemp seeds with a closed sector-type working body has been designed. Owing to this, the task related to seed dehulling was solved with a high level of efficiency in separating the seed coat from the kernel. The rational parameters for the dehuller have been substantiated: the diameter of the impeller is 162 mm, the gap between the impeller and the seed repelling panel is 80 mm, the frequency of rotation of the impeller is 2000 min–1. It was established that with the specified parameters and moisture content of the seeds within the limits of conditional (12.0–13.0 %), it is advisable to carry out dehulling process without preliminary separation of the seeds into fractions by width. It was established that an increase in seed size leads to a corresponding increase in the weight share of seed kernels. About 58.2 % of the main mass of seeds is the average fraction with a width of 2.5 to 3.0 mm. It was found that reducing the diameter of the impeller (from 236 mm to 162 mm) at a seed moisture content of 8.8 % improved the efficiency of dehulling. At a rotation frequency of the impeller of 2000 min–1, the highest total number of intact and destroyed kernels (23.23–29.33 %) was achieved for the two studied moistures. With an increase in seed moisture content from 8.8 % to 12.0 %, the number of dehulled kernels in the hempseed cake increased. It was noted that for seeds with a moisture content of 8.8 %, an increase in the gap led to a decrease in the dehulling efficiency for each of the three investigated seed fractions. The total number of dehulled kernels under such conditions decreased by 2.4–6.8 % and amounted to 16.4–26.9 %. For seeds with a moisture content of 12.0 %, an increase in the gap, on the contrary, increased the dehulling efficiency for each of the three investigated seed fractions. The total number of dehulled kernels for seeds of marked moisture increased within the range of 1.4–3.6 % and amounted to 27.4–31.0 %

Integrative Dissection of Lignin Composition in Tartary Buckwheat Seed Hulls for Enhanced Dehulling Efficiency.

The rigid hull encasing Tartary buckwheat seeds necessitates a laborious dehulling process before flour milling, resulting in considerable nutrient loss. Investigation of lignin composition is pivotal in understanding the structural properties of tartary buckwheat seeds hulls, as lignin is key determinant of rigidity in plant cell walls, thus directly impacting the dehulling process. Here, the lignin composition of seed hulls from 274 Tartary buckwheat accessions is analyzed, unveiling a unique lignin chemotype primarily consisting of G lignin, a common feature in gymnosperms. Furthermore, the hardness of the seed hull showed a strong negative correlation with the S lignin content. Genome-wide detection of selective sweeps uncovered that genes governing the biosynthesis of S lignin, specifically two caffeic acid O-methyltransferases (COMTs) and one ferulate 5-hydroxylases, are selected during domestication. This likely contributed to the increased S lignin content and decreased hardness of seed hulls from more domesticated varieties. Genome-wide association studies identified robust associations between FtCOMT1 and the accumulation of S lignin in seed hull. Transgenic Arabidopsis comt1 plants expressing FtCOMT1 successfully reinstated S lignin content, confirming its conserved function across plant species. These findings provide valuable metabolic and genetic insights for the potential redesign of Tartary buckwheat seed hulls.

Performance Evaluation of a Locally Fabricated Roasted Groundnut Dehuller.

A locally fabricated roasted groundnut dehulling machine was evaluated for performance under three different speeds of 30, 40 and 50 rpm, and three crop moisture contents of 8%, 9% and 10% using three common varieties of groundnuts (Runner, Red Valencia and Kampala). The components of the dehuller include the hopper, a specially designed dehulling chamber, sprout orchute/outlet, frame and an electric motor-driven belt-pulley drive power transmission mechanism. The test results showed that the dehuller’s operating speed and the roasted groundnut moisture content have significant effect on the mechanical damage and the dehulling efficiency. The efficiency of the dehuller decreased with increase in speed. It attained the highest efficiency of 92.1% at 9% moisture content and at an operating speed of 30 rpm, while the mechanical damage was minimal(1.86%) in the runner groundnut variety. All the materials used for fabrication were sourced locally. The dehuller has a capacity of 5.3 kg/h of roasted groundnut seeds. It is affordable, costing about four hundred and two thousand, two hundred Naira (N402,200 equivalent to US$335.17 at the rate of N1,200 to US$1) to produce, simple to operate, suitable for domestic uses and is also recommended for both small and medium scale roasted groundnut processors. The study provided useful information on the effective and efficient optimum conditions required for roasted groundnut dehulling. Further studies are suggested for further investigation by adopting the techniques used in this study for dehulling other similar crops.

Design, Development, and Performance Optimization of Farm Level Black Gram Dehuller

Small-scale farmers in India and other developing countries have been using traditional stone local dehuller (chakki) for pulse milling, which is extremely slow and less effective. In this study, a low-cost and easy-to-operate farm-level pulse dehuller was developed to enhance farm mechanization in the processing sector. The performance of the developed dehuller was evaluated using three independent parameters, namely roller speed (19.47, 22.72, 25.97 m.s-1), feed rate (60, 90, 120 kg.h-1), and two emery rollers (Grit No. 40, Grit No. 50). To optimize the parameters, results were fitted in multi-level categorical general factorial design using design expert software. The maximum dehulling efficiency (84.62 %), maximum whole dehulled kernel (48.45 %), and minimum loss (2.78%) were obtained at roller speed of 19.47 m.s-1 and feed rate of 90 kg.h-1 with Grit No.50 roller. Compared to the traditional pulse dehulling process, the developed pulse dehuller could save 2.29 ₹ .Kg-1 in cost and 10.24 min.kg-1 in time.

Design and development of low cost sesame dehuller and its process standardization.

The study was intended to develop a low cost sesame dehuller and optimize the dehulling process. The machine for dehulling of sesame seed was designed, developed and evaluated with different independent parameters viz. soaking time, dehuller speed and dehulling time for optimization of its performance during study. The processes variables had significant effect on response parameters whereas combined effect found non-significance. The results showed that the dehulling efficiency increases with increase in dehuller speed, soaking time and dehulling time. The optimum dehulling efficiency of 79.29% was obtained at soaking time of 120min, 150rpm dehuller speed and dehulling time of 6min in this developed sesame dehuller. Mean dehulling efficiency was found to be minimum (41.84%) at 100rpm speed with 40min soaking time and 4min dehulling time. The cost economic analysis discloses that developed dehuller is economically feasible and it could be beneficial for sesame based food industries. This developed dehuller is portable; therefore it requires less labor and remains suitable on farm sesame dehulling. The findings of the research may also remain useful for development of sesame processing equipment.

AMC-made Impeller-type Buckwheat Dehuller and Optimization of Impeller Speed

The outer hull or husk of buckwheat (Fagopyrum esculentum Moench.) kernel comprises about 20-30% of the weight of the buckwheat grain. Since it is inedible it should be removed before processing into flour. While imported and expensive dehulling machines are available in Bhutan, to reduce cost and gain wider adoption by farmers and perform the operation efficiently, the Agriculture Machinery Centre (AMC) has developed a buckwheat dehuller based on the impact and shear principle for efficient dehulling of whole buckwheat with most of the machine's body parts available locally. The present study was carried out to test the machine and to evaluate the best operating impeller speed for efficient dehulling of buckwheat. The machine was tested at five different levels of impeller speed: 1,700, 1,800, 1,900, 2,000 and 2,100 revolutions per minute (rpm). Process performance of dehulling efficiency (DE), and broken percentage (B%) were measured at each rpm. There was a significant difference in DE and (B%) across the five different speeds. The best DE of 88.94 % was observed at 2,100 rpm. However, there was also a high correlation between dehulling efficiency and the proportion of broken kernels, with the highest broken percentage of 43.96% observed at 2,100 rpm.

Establishment of mathematical model to predict the dehulling efficiency in miniature pulse splitter machine energized by human powered flywheel motor using dimensional analysis

In India, nearly 58% populations directly or indirectly have their livelihood dependent on farming activity and agricultural food processing. Majority of population in India fulfills their nutritional needs from pulses. India is among the major producer and consumer of pulses contributing nearly 28.34% of pulses globally. The percentage of losses in domestic pulses production nearly equal to its import resulting in decline of pulses per capita. The dehusking and splitting of the grain at the pulse mills are the most important post harvest operation which decides the yield & quality of pulses. The losses at post harvest activities are mainly subjected to the power availability at rural area, availability of technology for use of sustainable energy sources, availability of processing units in reach of farmers and continuous research in post harvesting methods &and techniques & it’s practical viability. The human powered flywheel motor (HPFM) based, pulse producing machine fulfilling the requirements at rural areas is presented here. In the present paper dimensional methodical approach is discussed to determine the effect of the parameters affecting dehulling efficiency of a developed miniature pulse splitter machine energized by HPFM. A dimensional analytical technique using Buckingham Pi-theorem is used to establish an operating relationship between the dependent variable i.e. dehulling efficiency and independent variables which includes diameter of pulse, bulk density, coefficient of friction, feed rate, speed, emery grade, gap between wheel, humidity & air velocity. The present performance of the split pulse machine is improved to its highest value of 80.5% with the feed rate of 45 kg/hr & at the gap of 5 mm between the wheels. The reading obtained from the mathematical data and experimental observation is in good agreement which indicates the minimum error and validation of the mathematical model. The paper presents the method of formulation of mathematical model with the output variable dehulling efficiency which depends on many input variables for the pulse splitting machine. The formulated model can further be used for the other processing units in the agricultural production.

Development and performance evaluation of foxtail millet (Setaria italica L.) dehuller

AbstractFoxtail millet dehuller for double stage dehulling was developed and evaluated. The machine consists of a hopper, two knurled rolls, two rubber rolls, an air blower, and a grader. The machine was evaluated for foxtail millet (Setaria italica L.) at the different grain moisture content (10, 12, 14, and 17% [w.b.]), types of knurled rolls (diamond, angular, and straight knurled) and feed rate (100,200,300 kg/hr) for performance evaluation or efficiency. The maximum dehulling efficiency and cleaning efficiency of 82.24 and 82.47% was observed for 12% moisture content (w.b.), diamond‐type knurled roll and 100 kg/hr feed rate. Similarly, the maximum head grain yield of 97.82% and the minimum broken of 2.18% was observed for 12% moisture content (w.b.), diamond‐type knurled roll and 300 kg/hr feed rate. There was no significant change in the color values with the treatments. The predicted optimum condition for the machine is moisture content 12% (w.b.), diamond‐type knurled roll and feed rate of 100 kg/hr, which gave an optimum dehulling efficiency of 82.24%, head grain yield of 95.84%, broken of 4.16%, and cleaning efficiency of 82.47% with the desirability of 0.825. The economic analysis shows the suitability of the machine for small‐scale millet processors.Practical ApplicationsDehulling of millets is an essential unit operation in millet processing. This study evaluated the performance analysis of the developed dehuller for foxtail millet at different grain moisture content, types of knurled rolls, and feed rate. The process parameters were optimized, which can be used to design the dehuller for millets. The results obtained show the relevance of applying the developed dehuller for foxtail millet applications, providing an alternative processing machine for millet processing.

Design, Fabrication and Performance Evaluation of Groundnut Dehulling and Separating Machine

The process of oil extraction can be enhanced by dehulling, oil produced from groundnut seeds serve as a good source of protein, vitamin, fat, oil, and crude fibers. A groundnut dehulling machine was developed, having two dehulling rollers, rubber beaters, screen, blower unit, seed and chaff outlet. The separator unit has a centrifugal blower, screen and collecting tray. It’s powered by 3 hp electric motor, which transmits constant speed of 3636 rpm to the blower and 1000 rpm to rubber beaters. Groundnut used was at 7.32% moisture content (w.b). Dehulling was achieved through the compression and shearing action of the rotating dehulling roller against the stationary dehulling roller. The effect of dehulling roller clearance (6.5 mm,7.0 mm, 7.35 mm and 7.5 mm) and speed (700 rpm and 750 rpm) was evaluated on dehulling efficiency, machine capacity, mechanical damage and separation efficiency. The result obtained after testing the machine shows that 7.35 mm clearance and 700 rpm of the dehulling roller gave optimum average dehulling efficiency 95.80%, separation efficiency 81.40% and the least mechanical damage 11.01%. Machine capacity of 97.98 kg h-1. was obtained at 750 rpm and 7 mm dehulling roller clearance. The results obtained during evaluation was statistically analyzed, multiple linear model equations which are capable of predicting the effect of dehulling roller clearance and speed on dehulling efficiency, machine capacity, mechanical damage and separation efficiency was developed.

Effect of Gamma Irradiation and Microwave Energy on Milling Characteristics of Pigeon Pea

Pulse milling industries in India are facing problems of low milling recovery and increased brokens, in spite of using pre-treatments like conditioning with oil, chemicals and enzymes. Experiments were carried out to study the effects of gamma irradiation and microwave energy on milling characteristics of pigeon pea. Conditioned pigeon pea samples at four moisture levels (7, 10, 13, 16 %, w.b.) were pre-treated with four dosage of irradiation (2.5, 5.0, 7.5, 10.0 kGy) before milling. Gamma irradiation did not improve dehulling efficiency of pigeon pea. Grains at moisture levels of 10, 13, and 16 % (w.b.) were treated with different dosages of microwave. Dehulling efficiency and degree of dehulling was observed to be higher in microwave treated sample, and significantly increased with increasing dosage of microwave energy. Compared to untreated samples, dehulling efficiency and degree of dehulling of treated samples was increased by 18.04 % and 21.65 %, respectively, at microwave dosage of 864 J.g-1 and moisture content of 10 % (d.b.).

Effects of some test parameters on dehulling efficiency of a roasted groundnut seed dehulling machine

Groundnut (Arachis hypogeae. L) is an important oil seed grown in over 100 countries for its nutritional value. In order to improve its storability and value, various ways of processing the seeds have been adopted among which is the roasting and removal of husk or rind from the roasted groundnuts. The process of removing of groundnut husk is mostly done manually and inappropriate for large scale processing. In order to improve groundnut seed husk dehulling process through mechanization, a roasted groundnut seed dehulling machine was developed and the effects of operating speed of the machine and moisture content of the seed on the on the efficiency of the machine was studied. 1kg of the roasted groundnut in five replicates with moisture content of 1.4, 1.6, 1.8, 2.0 and 2.2 % (w.b) respectively, was fed into the machine at different speed of 30, 35, 40, 45 and 50 rpm for each replicate. The machine had the best dehulling efficiencies of 80%, 78%, 77%, 90% and 73% at the lowest speed (30 rpm) while the lowest efficiency of 57%, 49%, 53%, 52% and 46% was recorded at the highest speed (50 rpm) in all moisture content (1.4, 1.6, 1.8, 2.0 and 2.2%) respectively. The best performance efficiency of 90% was gotten at 30 rpm and moisture content of 2.0 % (w.b). Hence, an optimum operating condition was established for the machine.

Size characterization of moringa (Moringa oleifera) seeds and optimization of the dehulling process

AbstractThe size of moringa seeds was characterized, and the dehulling process parameters were optimized. The effects of moisture content, feed rate, operational speed, and beater‐drum clearance on dehulling efficiency were studied. A 4 × 5 central composite rotatable design was employed, and multiple linear regression was utilized for analyzing data at 5% significant level. Experimental results were used to validate predicted optimum conditions. Processing parameters were related to dehulling efficiency using developed mathematical models. Maximum dehulling efficiencies of 81.14, 85.66, and 96.03% were obtained for the small, medium, and big sizes respectively. The moringa seed size and other processing factors were found to have significant effect on the dehulling efficiency. Predicted optimum values of 83.62, 88.18, and 99.69% for small‐, medium‐, and big‐sized categories, respectively, were obtained at 9.38%wet basis moisture content, 1.35 kg/min feed rate, 844.61 rpm dehulling speed, and 6.38 mm beater‐drum clearance. The experimental values were 84.33, 88.97, and 99.76% for small‐, medium‐, and big‐sized categories, respectively, under the optimal conditions. Variations between values obtained experimentally and predicted were negligible and statistically insignificant; therefore, the selected models were adjudged to adequately predict the dehulling efficiencies for all the size categories.Practical ApplicationsDespite the benefits derived from moringa seeds, dehulling of the seeds has been a tedious operation. Considering this, a moringa dehuller was developed, and the performance was evaluated. However, for an efficient system, it is imperative to understand the mechanisms of the various important factors influencing the dehulling process and their interactions. The approach of considering one factor per time consumes time and is unrealistic to obtain the right optimal conditions; making it impractical to optimize the dehulling process using such approach. Considering this, RSM was employed to optimize the moringa dehulling process parameters. Mathematical models were developed to predict responses during the dehulling process using RSM. For efficient machine performance, the seeds were graded into various sizes and the effects of moisture content, feed rate, operational speed, and beater‐drum clearance on the dehulling efficiency were investigated and optimized. Results obtained in the study would be useful to moringa seed processors.

Design, development, and evaluation of locust bean seed dehuller

AbstractLocust beans dehulling machine was design, develop, and evaluated. The machine was evaluated at different speed and boiling time for its performance efficiency. The results showed that with increase in the boiling time from the first to second hr the throughput capacity, qualitative, and quantitative dehulling efficiency increased but from the second to the fourth hr of boiling, it decreased. Whereas as the dehulling speed increase the throughput capacity increased but the quantitative and qualitative dehulling efficiency decreased. Highest throughput capacity and the least labor requirement were recorded at 1 hr boiling, whereas highest quantitative and qualitative dehulling efficiency was recorded at 2 hr of boiling. The boiling time and dehulling speed significantly affects the throughput capacity, quantitative and qualitative dehulling efficiencies of the dehuller, but does not affect labor requirement. The economic analysis reveals that developed dehuller can be useful for small to medium scale locust bean processing industries.Practical applicationsThe developed dehuller is relevant in the dehulling of boiled locust bean seed. This would, therefore, combat the challenges surrounding locust bean processing especially with the rural women dwellers and commercial producers. The dehuller would, therefore, reduce the time consumption and drudgery associated with the processing of locust bean.

Influence of Seed Coat Color Genes on Milling Qualities of Red Lentil (Lens culinaris Medik.)

Efficient milling is the key economic trait for the red lentil industry. Various seed characteristics including seed coat color can influence milling characteristics. Four basic seed coat ground colors (green, gray, tan, and brown) of 16 red lentil genotypes from a common genetic background were compared to determine the effect of seed coat color genes on three key milling quality traits: dehulling efficiency (DE), milling recovery (MR), and football recovery (FR). These genotypes were grown at two locations in Saskatchewan, Canada for two years. DE, MR, and FR results varied depending on the seed coat color conferred by specific genotypes. Green and gray seed coat color (homozygous recessive tgc allele) genotypes had significantly higher DE and MR percentages compared to brown or tan seed coat types (homozygous dominant Tgc allele) depending on genotype interaction with site-year. Seeds with brown or tan seed coats had significantly higher FR percentages in two site-years. Red cotyledon lentils with uniform shape and green or gray seed coat color might be more profitable for millers who wish to maximize DE and MR of red lentil, but brown seed coat color might be preferable in terms of FR.

Genetic Mapping of Milling Quality Traits in Lentil (Lens culinaris Medik.).

Milling qualities are key traits for the red lentil ( Medik.) industry as price is largely determined by recovery yield. milling involves removal of the seed coat and splitting of the cotyledon to produce either splits or footballs (cotyledons still attached). The objectives of the study were to determine the heritability of the milling traits dehulling efficiency (DE), milling recovery (MR), and football recovery (FR) and to identify the genomic regions controlling them. We used a lentil recombinant inbred population from the cross 'CDC Robin' × '946a-46', which have contrasting seed characteristics. The mapping population consists of 127 F-derived lentil recombinant inbred lines that were phenotyped for milling quality parameters from four site-years in Saskatchewan, Canada. A total of 534 single nucleotide polymorphism markers, seven simple sequence repeat markers, and four morphological markers were used for quantitative trait locus (QTL) mapping. The broad-sense heritability was moderate for DE and MR and relatively low for FR. Milling quality traits were significantly correlated with seed shape (seed diameter and seed plumpness). Multiple QTLs for milling traits were detected in six of seven linkage groups (LGs). The most stable QTLs governing DE and MR were clustered on LGs 1, 2, 3, and 7, whereas FR QTLs were clustered on LGs 4, 5, 6, and 7. The molecular markers identified for these traits could be used for improving milling quality in lentil breeding programs.

Performance Evaluation of the Cowpea Wet De-Hulling Machine

The performance evaluation of the cowpea de-hulling machine was done using a factorial experiment in a completely randomize design involving speed, soaking time and cowpea variety each at 3, 3, and 2 levels respectively. These were replicated three times. LSD was used to further analyze the significant means. The results showed that the speed, soaking time and cowpea variety had significant effect on de-hulling efficiency and output capacity for the developed de-huller while only soaking time and speed had significant effect on mechanical damage. The developed de-huller performs the best at 120 rpm speed, 11 mins soaking time, and with Dan-barere variety. Based on these variables, the performance indices obtained were 90.75%, 74.27 kg/hr. and 0.39% for de-hulling efficiency, output capacity and mechanical damage respectively.

DEHULLING CHARACTERISTICS OF OAT (OL-9 VARIETY) AS AFFECTED BY GRAIN MOISTURE CONTENT

Dehulling of oat is difficult and inefficient process. Moisture content of grains is one of the most important factors that affects dehulling. Dehulling parameters of oat grains (OL-9) were studied by varying grain moisture contents at 10, 13, 16 and 19, percent. Dehulling was achieved using an indigenously developed small scale impact oat dehuller. Groat recovery (%) and dehulling efficiency (DHE) significantly (P≤0.05) increased as grain moisture was increased from 10 to 16 percent. However, broken content (%) significantly (P≤0.05) decreased as grain moisture was increased from 10 to 19 percent. Hence, 16 per cent grain moisture was considered optimum for impact dehulling of oat grains. Second order regression equations were developed to help relate grain moisture to various dehulling parameters.

Optimization of Enzymatic Hydrolysis Parameters of Pigeon Pea for Better Recovery of Dhal

Pigeon pea is mostly consumed in the form of splits and it provides good source of proteins. The pigeon pea grain is considered as most difficult for dehulling as compared to other pulses owing to its seed coat which is more firmly attached with the cotyledons through a layer of gum and mucilage. Pre milling treatments are generally employed to loosen the seed coat to remove husk without losing any edible portion. The effect of four enzymatic hydrolysis parameters, i.e., enzyme concentration (20–60 mg/ 100 g dry matter), incubation time (3-15 h), incubation temperature (40-60 0C) and tempering water pH (4.0-6.0) on hulling efficiency were optimized using response surface methodology. Three enzymes i.e. xylanase, pectinase, and cellulase were used in combination for enzymatic pre treatment. A quadratic model satisfactorily described the dehulling efficiency with high value for the coefficient of determination R2 (0.9062). It predicted a maximum dehulling efficiency of 88.37 % at enzyme concentration; 37.80 mg/100 g dry matter, incubation time, 8.69 min, incubation temperature, 48.48 0C and tempering water pH, 5.49. The results of the predicted optimum conditions were validated experimentally. Dehulling efficiency at optimum condition was observed to be 88.12 % and showed 0.28 % deviation from the predicted values. Results of the study revealed that dehulling efficiency of enzyme treated dhal could be increased 13.81 % compared to the control, i.e., the oil treated sample.

Evaluation of the Dehulling Efficiency of Soybean Using Attrition and Rice Milling Machines

A process for mechanical dehulling of soybean was developed. Soybean seeds were soaked in boiling water (100oC) for 5, 10, 15, 20 and 25 minutes respectively. The soaked seeds attained a moisture content of 17 – 24%, so as to facilitate dissolution of the gum layer, which bound the seed coats to the endosperm. Conditioned seeds were dehulled in the huller section of commercial rice milling machine and attrition milling machine. A dehulling efficiency (e) value of 55%, which corresponded to an extraction yield (E) of 44% was achieved using the huller section of a commercial rice milling machine, while 90% dehulling efficiency (e), corresponding to an extraction yield (E) of 72%.