Kernel Recovery Research Articles

Pricing kernel factorization and recovery theorem

Recently, Ross proposed an idea, now known as the “Recovery Theorem,” that asserts that the real (physical) probability measure can be recovered from the market prices of derivatives. This work has generated a great deal of controversy in the finance literature. The purpose of this paper is to revisit the core idea of the recovery theorem and to examine its implications. In particular, issues concerning the so-called factorization of the pricing kernel will be examined from the viewpoint of the Flesaker–Hughston representation.

Genome-wide association studies for yield component traits in a macadamia breeding population

BackgroundBreeding for new macadamia cultivars with high nut yield is expensive in terms of time, labour and cost. Most trees set nuts after four to five years, and candidate varieties for breeding are evaluated for at least eight years for various traits. Genome-wide association studies (GWAS) are promising methods to reduce evaluation and selection cycles by identifying genetic markers linked with key traits, potentially enabling early selection through marker-assisted selection. This study used 295 progeny from 32 full-sib families and 29 parents (18 phenotyped) which were planted across four sites, with each tree genotyped for 4113 SNPs. ASReml-R was used to perform association analyses with linear mixed models including a genomic relationship matrix to account for population structure. Traits investigated were: nut weight (NW), kernel weight (KW), kernel recovery (KR), percentage of whole kernels (WK), tree trunk circumference (TC), percentage of racemes that survived from flowering through to nut set, and number of nuts per raceme.ResultsSeven SNPs were significantly associated with NW (at a genome-wide false discovery rate of < 0.05), and four with WK. Multiple regression, as well as mapping of markers to genome assembly scaffolds suggested that some SNPs were detecting the same QTL. There were 44 significant SNPs identified for TC although multiple regression suggested detection of 16 separate QTLs.ConclusionsThese findings have important implications for macadamia breeding, and highlight the difficulties of heterozygous populations with rapid LD decay. By coupling validated marker-trait associations detected through GWAS with MAS, genetic gain could be increased by reducing the selection time for economically important nut characteristics. Genomic selection may be a more appropriate method to predict complex traits like tree size and yield.

Relationships between Nut Size, Kernel Quality, Nutritional Composition and Levels of Outcrossing in Three Macadamia Cultivars.

Tree nuts play an important role in healthy diets, but their economic value and nutritional quality may be affected by their size and paternity. We assessed relationships between nut size and kernel recovery, the incidence of whole kernels, fatty acid composition and mineral nutrient concentrations in three macadamia cultivars, “Daddow”, “816” and “A4”. We determined to what extent differences in nut size and quality were the result of different levels of cross- or self-paternity. Small nuts of all cultivars had lower kernel recovery than large nuts, and small nuts provided lower incidence of whole kernels in “Daddow” and “A4”. Small kernels had a lower relative abundance of the saturated fatty acid, palmitic acid, in all cultivars and higher relative abundance of the unsaturated fatty acid, oleic acid, in “Daddow” and “A4”. Small kernels had higher concentrations of many essential nutrients such as nitrogen and calcium, although potassium concentrations were lower in small kernels. Most nuts arose from cross-pollination. Therefore, nut size and kernel quality were not related to different levels of cross- and self-paternity. Identified cross-paternity was 88%, 78% and 90%, and identified self-paternity was 3%, 2% and 0%, for “Daddow”, “816” and “A4”, respectively. Small macadamia kernels are at least as nutritious as large macadamia kernels. High levels of cross-paternity confirmed that many macadamia cultivars are predominantly outcrossing. Macadamia growers may need to closely inter-plant cultivars and manage beehives to maximise cross-pollination.

Development of Cashew nut Shelling Machine

Cashew nut shelling machine was designed using impact method to improve shelling efficiency and whole kernel recovery for nuts roasted in hot oil. This was based on the principle of the optimum kinetic energy that could break the cashew nut shell. Deformation energy used was 4.8763 Joules, angular velocity of the impeller calculated from the energy was 26.43 rad/s which was equal to 252 rpm and minimum power required was calculated to be 257.7 Watts. The prototype of cashew nut sheller was constructed and evaluated for its shelling efficiency and whole kernel recovery using three levels of moisture content (7.00%w.b., 8.46%w.b. and 9.83% w.b.), three levels of impeller speeds and three nut sizes (large, medium and small). The results showed that moisture content has significant effect (at P < 0.05) on the shelling efficiency and whole kernel recovery of the nut for the three nut sizes while the impeller speed showed no significant effect. The optimal performance of the machine on large nuts for whole kernel recovery and shelling efficiency were 59.65% and 82.0% respectively at 1759 rpm and 7.00% w.b. For medium nut, they were 53.2% and 92.2% respectively at 1538rpm and 9.83% w.b. For small nut, they were 45.1% and 79.7% respectively at 1704 rpm and 7.00% w.b. Impact shelling methods works well with large cashew nuts as these exhibit higher whole kernel recovery than medium and small nuts.

Selecting for Nut Characteristics in Macadamia Using a Genome-wide Association Study

Current macadamia breeding programs involve a lengthy and laborious two-stage selection process: evaluation of a large number of unreplicated seedling progeny, followed by replicated trials of clonally propagated elite seedlings. Yield component traits, such as nut-in-shell weight (NW), kernel weight (KW), and kernel recovery (KR) are commercially important, are more easily measured than yield, and have a higher heritability. A genome-wide association study (GWAS) combined with marker-assisted selection offers an opportunity to reduce the time of candidate evaluation. In this study, a total of 281 progeny from 32 families, and 18 of their 29 parents have been genotyped for 7126 single nucleotide polymorphism (SNP) markers. A GWAS was performed using ASReml with 4352 SNPs. We found five SNPs significantly associated with NW, nine with KW, and one with KR. Further, three of the top 10 markers for NW and KW were shared between the two traits. Future macadamia breeding could involve prescreening of individuals for desired traits using these significantly associated markers, with only predicted elite individuals continuing to the second stage of selection, thus potentially reducing the selection process by 7 years.

Breeding New Cultivars for the Australian Macadamia Industry

In 2017, five new cultivars specifically selected for Australian conditions were released. These were developed from an improvement program initiated by Commonwealth Scientific and Industrial Research Organisation in the early 1990s. Progeny seeds were produced by crossing industry standard cultivars with other cultivars with elite kernel production per unit projected canopy area. Seedlings were planted at two densities (2 m and 4 m along rows) in field trials at Bundaberg in 1997 and 1998, and Northern New South Wales in late 1997, along with replicated plants of parents grafted onto seedling rootstocks. Trials were assessed for commencement of flowering, growth, yield, kernel recovery, and components of kernel quality over 8 years. Best linear unbiased predictions of clonal values were obtained for each individual progeny using a pedigree-based mixed linear model. A bio-economic model was used to estimate economic weights for a selection index of clonal values to identify elite candidates. Final approval of 20 candidates for second-stage assessment was made by an industry committee using selection index rankings and observations of tree field performance and kernel quality.

The influence of pollen-parent and carbohydrate availability on macadamia yield and nut size

Cross-pollen parents can affect fruit set and yield, and can influence fruit and seed characteristics of many tree crops. Available carbohydrates also limit fruit set and yield, and tree carbohydrates can be manipulated by girdling trees and by defoliation. We investigated how different macadamia cross pollen-parents and the availability of carbohydrates interact to modify macadamia fruit set, kernel yield and kernel size. We manipulated tree carbohydrates by selecting different branch sizes and girdling branches on macadamia cultivar ‘HAES 246’ (‘246’) maternal trees. We applied pollens from two different commercial cultivars, ‘HV A16’ (‘A16’) and ‘HAES 814’ (‘814’) in two experiments. In Experiment 1, two branch sizes, 150 leaves and 500 leaves were girdled. In Experiment 2, three branch sizes, 150 leaves, 300 leaves and 500 leaves were both girdled and ungirdled. Final fruit set and kernel yield per branch were significantly higher on the girdled 500 leaf branches compared with the girdled 150 leaf branches in both experiments (P < 0.05). There was no pollen-parent effect on final fruit set or kernel yield per branch on girdled branches. Kernel mass was increased by the ‘A16’ pollen-parent in 4 out of 4 cases in experiment 1 and in 4 out of 6 cases in Experiment 2. Available resources also impacted on nut and kernel size. The ‘A16’ pollen-parent also increased kernel recovery significantly (P < 0.05) on some girdled and ungirdled branches. Carbohydrate supply and pollen-parents interact to determine final nut and kernel size and nut characteristics. Selecting suitable pollen-parents could improve macadamia profitability.

Evaluation of soil-water ratio effectiveness in soil-bath wet separation process for kernel recovery

An appraisal of the soil-water bath (wet separation) method showed that the method is based on the difference in density/specific gravity of the palm kernels and the shells. In this study, the separation of palm kernel-shell mixture using separating agent other than clay soil (kaolin) in wet separation have been considered. Measured masses of soil were added incrementally into 40 L of water and its density calculated and recorded. The separation efficiency of an alternative medium (laterite) was compared with that of clay soil (kaolin). Different mass quantities of kernel/shell mixture were poured into the red mud soil (laterite) slurry, and stirred. The part of Kernel/shell mixture that floated were scooped off and the Kernel selected and weighed. From observations made, the density/specific gravity increases with increase in mass of separating agent in water. The separating efficiency increased with increased soil input, till the 18kg mark of soil input for both separating agents, when the floated kernel weight begins to be constant and highest. The optimal separation efficiency was found at medium/ water ratio of 0.45:1. The effectiveness of the red mud (laterite) sample was found to be comparable to clay (kaolin) at a medium-to-water ratio of 0.45:1 giving 98.93% efficiency. Thus, it is recommended to be used as an alternative to clay for wet separation. Keywords: Oil Palm Kernel, Kernel Shell, Wet Separation, Clay Soil, Red mud

Pollen-parent affects fruit, nut and kernel development of Macadamia

The genotype of the pollen that fertilizes the ovule is known to affect the characteristics of fruits and nuts for many species, a phenomenom known as the xenia effect. Cross-pollination increases fruit set, nut mass, kernel mass and kernel recovery of macadamia nuts at maturity when compared with self-pollination. However there is limited information on the xenic effects of different macadamia cultivars used as cross pollen-parents on the fruit components and fruit development. The aim of this study was to clarify in what nut components and at what developmental stages xenic effects occurred. Two large-seeded macadamia cultivars, ‘HAES 246’ and ‘HV A16’, were used as maternal trees and pollen-parents were ‘HAES 246’, ‘HV A16’ and ‘HAES 814’, a small-seeded cultivar. Pollen-parents affected the mass of both the syngamous tissue of the kernel (embryo) and the tissues of maternal origin; i.e. the husk (pericarp) and shell (testa). Xenic effects were detected in the endosperm 6 weeks after pollination and in fruit, nut and kernel size and mass from 10 weeks after pollination until maturity. Nut mass, kernel mass and kernel recovery of macadamia were increased significantly by a different pollen-parent. The HV A16 pollen on HAES 246 flowers produced an increase of 11% nut mass compared with HV 814 pollen on HAES 246 flowers. This would increase the gross margin of a farm producing 4.5 t/ha of nuts by $2574/ha at typical 2018 prices. Macadamia growers and the macadamia industry would benefit from identification and use of the most beneficial cross-pollen sources available.

Determining properties of almond kernel under various moisture content levels

Almond fruit are subjected to various mechanical stresses in production from harvest through to processing, storage and packaging. Hulling and shelling operations of almonds consist of continuous compression and shear to break the hull and shell layers and release the kernel. Properties of the kernel play an important role in reducing mechanical damage such as scratches and penetration of shell pieces on the final kernel product. Knowledge of kernel mechanical properties under various fruit conditions can assist to optimise post-harvest and processing lines to minimise kernel damage and maximise final kernel quality. Kernel moisture content is one of the main attributes that affects the kernel response to the mechanical operation. Maintaining the kernel moisture content to optimum level through wetting fruit prior to processing can lead to increase in percentage of undamaged kernel recovery by increasing kernel pliability to mechanical damage. Water added to the structure of kernel acts as plasticiser and helps the kernel absorbing the mechanical loading instead of breaking to pieces. In this study Nano-indentation tests were conducted on almond kernel in different moisture content level. Kernels from 'Nonpareil' cultivar were tested in dry and wetted conditions. Test results showed that kernels with higher moisture content are able to resist larger deformation at a given force value in comparison with dry kernels. Effects of pellicle (kernel skin) on mechanical properties of kernel was studied. The tests showed a peak force value in samples tested with pellicle in comparison with the kernels tested without pellicle.

Study on the Comparative Evaluation of Cashew Nut Shellers

Cashew nut recovery remains major concern in the cashew nut production. The hand operated portable cashew nut sheller was developed on the principle of shearing. The comparative performance was tested for hand operated cashew nut sheller, hand and foot operated sheller and manual shelling, the test results showed that hand operated sheller can shell 2.32 kg cashew/hr with the whole kernel recovery of 86.26 per cent. The per cent whole kernel recovery for new sheller was 86.26, while that for foot pedal operated sheller was 80.1 and hand shelling was 71.0.

Predicting cashew nut cracking using hertz theory of contact stress

Abstract The cracking force is an important parameter in the design of cracking machines. A mathematical model for predicting the exact cracking force of cashew nut was presented based on the existing hertz’s theory of contact stress of two bodies under uniaxial compressive load. Hertz equation was adapted to loading of cashew nuts to cracking at three different loading orientations (X, Y, and Z) and two strain rates of 5 mm/min and 10 mm/min. The average moisture content of the dried cashew nuts was determined at 5% (db.). The physical properties of cashew nut varieties such as Length, Width, Thickness, mass, Geometric Mean diameter, Sphericity index, Surface area and Aspect ratio were 34.31 mm, 24.86 mm, 16.55 mm, 6.13 g, 24.13 mm, 0.70, 1834.65 mm 2 and 0.73 respectively. Some mechanical parameters such as cracking force, deformation and stiffness modulus at loading orientations (X, Y, and Z) (355,288 and 289 N), (1.396, 1.5002 and 1.815 mm) and (313, 195 and 160 N/mm) at 5 mm/min, and (458, 276 and 480 N), (2.28, 1.767 and 3.7197 mm) and (202, 162 and 146 N/mm) at 10 mm/min were also obtained from the force-deformation curve respectively. These physical and mechanical parameters were required in the derived model. The aspect ratio was introduced as a correcting factor to the stiffness modulus to improve the prediction of the hertz model. The highest value of mean cracking force (355 N) was determined at the X (Width) orientation at 5 mm/min while the highest value of mean cracking force (480 N) at 10 mm/min strain rate was found at the Z (Thickness) orientation. A two-sample t -test comparism of experimental cracking force values and that of the hertz model were acceptable at 5% probability level which gave good prediction of cracking force during compression. The force required for the design of suitable cashew nut shell cracking machine should be considered at the range of 400–500 N at X (width) and Z (thickness) loading orientations, therefore the magnitude of applied force with the loading orientation could determine the extent of mechanical damage and kernel recovery during cracking and separation processes.

Milling and Physical Characteristics of Pigmented Rice Varieties

In the present study, four different pigmented rice varieties, namely glutinous white rice, black rice and two red rice varieties (TPS-1 and TKM-9) were evaluated for various quality aspects in terms of milling and physical characteristics such as hulling percentage, milling percentage, whole kernel recovery, milling loss, thousand grain weight, grain volume, bulk density, true density, grain length, grain width and L/B ratio. Among the four rice varieties TPS-1 had the highest hulling percentage, milling percentage, whole kernel recovery percentage. While as, glutinous white rice had the lowest milling loss. Thousand grain weight, grain volume was higher in glutinous white rice variety. Bulk density and true density were found to be highest for glutinous white rice followed by TPS-1, TKM-9 and black rice. Milling characteristic in terms of hulling percentage, milling percentage, whole kernel recovery and milling loss showed significant difference between the varieties. L/B ratio was found to be highest for glutinous white rice followed by TPS-1, TKM-9 and black rice variety. Grain length and grain width observed range from 5.38 – 6.38 mm and 1.90 – 2.24 mm.

Overview of the Australian macadamia industry breeding program

Macadamia (Macadamia integrifolia Maiden and Betche and M. tetraphylla L.A.S. Johnson) is an Australian-native, evergreen nut tree adapted to the subtropics. It is the basis of an international industry producing highly valued kernels. Australia is the world leader in production, with about 6 million trees planted on 17,000 ha. Industry funding for an Australian breeding program commenced in 1996, and over 3500 hybrid seedlings were produced and field-planted from 1998 to 2003. Industry participation has involved use of grower properties for progeny field trials, review of outcomes by an industry steering group and consultation with industry on the important traits in new cultivars. Key selection traits are cumulative nut yield per tree to age 8, tree height, canopy width, kernel recovery and nut quality. Quantitative selection methods were used to identify elite selections for commercial testing and for use as parents. The mean cumulative nut-in-shell yield to age 8 for the top 20 seedlings planted from 2000-2003 was 39% higher than the best five cultivars in the same trials. A second generation of hybrid seedlings is being produced using these elite selections, with 2296 seedlings planted from 2011 to 2014. We discuss strategies to improve breeding efficiency and future plans for a husk spot disease nursery, use of wild species and rootstock screening.

Dry Separation of Palm Kernel and Palm Shell Using a Novel Five-Stage Winnowing Column System

The conventional separation system for the recovery of palm kernel from its palm shell–kernel mixture using water as process media generates a considerable amount of waste effluent that harms the environment. The aim of this study is to develop a dry separation process for the recovery of palm kernel by using winnowing columns. A commercial system consisting of a series of five winnowing columns was developed and installed at a local palm oil mill. The system parameters, including column height, blower capacity, airflow rate and mesh screen size for shell removal, were studied and optimized to ensure good separation of kernel and shell in the column to enable collection of different sizes of kernel and shell at each column outlet. The performance of the separation process was evaluated in terms of its kernel losses, dirt content and kernel recovery rate. The average kernel losses based on oil palm fresh fruit bunches processed were found to vary from 0.11 to 0.30 wt %, with most of the values obtained being below the targeted limit of 0.30 wt %. The dirt content was in the range 4.56–6.03 wt %, which was mostly below the targeted limit of 5.5 wt %. The kernel recovery rate was in the range 5.69–6.89 wt %, with most of the values achieving the minimum targeted limit of 6.00 wt %. The system operates under completely dry conditions and, therefore, produces zero waste effluent.

Performance Study of a Jatropha Curcas L. Fruit Shelling Machine for Kernel Recovery in Biodiesel Production

<abstract> <b><i>Abstract. </i></b> The presence of shells and husks during the process of oil extraction can affect oil yield and output quality. A shelling machine has been developed at the Universiti Putra Malaysia (UPM) to supersede the time-consuming manual method to remove shells and husks directly from the whole fruits for kernel recovery. The output kernels are in broken forms that ease the oil extraction process. The machine basically consists of cracking rollers, a vibratory sieve as the first stage separator, and a blower as the second stage separator. The performance of the machine was evaluated using five different blower air speeds (3.5, 6.2, 9.5, 12.6, and 13.4 ms^-1) and the size of the mesh on the sifter was fixed. The 9.5 ms^-1 speed was selected as optimal as the highest separation efficiency of 66.98% could be achieved. The considerations to determine the separation efficiencies included kernel recovery, the percentage of shells and the percentage of husks removed. At the optimal setting, the shell and husk removal achieved 97.17% and 55.21%, respectively, while the kernel recovery achieved 87.88%. A total of 12.12% kernels were lost and most of the losses were kernels in tiny broken form. The results indicated that a further improvement of the machine is necessary with the application of strategies to create highly different physical properties between the kernels and other impurities to enhance the effectiveness of the removal of impurities while maintaining a low kernel loss.

Development and ergonomic evaluation of pedal operated cashew nut desheller

India is the largest producer, processor, exporter, importer and second largest consumer of the cashew in the world. The manual shelling process is done with pedal operated cashew nut sheller in standing posture. The objective of this study was to develop the pedal operated cashew nut desheller in such way that it could operated in sitting postures to reduced the drudgery involved in the deshelling operation. The dimensions in the design of seat were used from available anthropometrics and strength data of women worker of Konkan region. The modified pedal operated cashew nut desheller was ergonomically evaluated on six women ranging from 20 to 45 years. The mean values of working heart rate, corresponding oxygen consumption, energy expenditure, per cent VO 2 , ?HR were 93.56 bpm, 0.39 l/min, 8.31kJ/min, 29.33 per cent, 10.54 bpm which were less than limit of continuous performance (LCP). The operation categorized into 'moderately heavy'. With the help of developed pedal operated cashew nut desheller, kernel recovery of cashew nut obtained 7.68 kg/day. The overall performance of the developed pedal operated cashew nut desheller was good.

Exploiting genetic diversity of walnut (Juglans regia) from Jammu region of India for export related traits

The present field work was done to study the existing genetic diversity and its exploitation through identifying elite walnut (Juglans regia L.) mother trees from the large number of naturally growing seedling trees in erstwhile Doda district of Jammu region of Jammu &amp; Kashmir state. The field work was done from 2006 to 2012. A total of 63 walnut trees were marked as elite, out of 790 trees visited at 18 locations situated at 1500m-1750m above mean sea level. Out of total collections, 49.20% samples have attractive colour influencing the consumer acceptability. Five collections (BS1207, BT1807, MR0309, MR0509 and GL0109) had kernel recovery of &gt;50%. Wide range of variability was recorded for various nut characters being highest in kernel recovery (18.54-61.40%) with highest coefficient of variation. Nut weight was positively correlated with nut size. The total variance in first principal component was due to nut size and weight while, in second component, it was contributed by kernel recovery. Further, analysis based on export quality traits (prescribed by J&amp;K walnut grower association) lead to the identification of 8 most promising walnut clones, viz. BS1207, PK2707, MR0309, MR0509, MR0809, GL0109, PR0309 and NZ0112. Of these, GL0109 proved best in respect of export related traits and can be developed as a good table cultivar.

Development and testing of a Jatropha fruit shelling process for shell-free kernel recovery in biodiesel production

Achieving shell-free kernel recovery from Jatropha fruits is important to improve oil yield and oil quality during oil extraction in biodiesel production. A shelling process with two stages of cracking and separation to remove the shells completely and husks partially was designed. Both stages used double-level cracking rollers and a blower with ducting as a separation unit. For the first, the performance was evaluated using five different roller clearances (9.5 mm, 10.0 mm, 10.5 mm, 11.0 mm and 11.5 mm) with a combination of five blower air speeds (8.5 ± 0.5 m s−1, 9.0 ± 0.6 m s−1, 9.5 ± 0.5 m s−1, 10.0 ± 0.4 m s−1 and 10.5 ± 0.5 m s−1). A roller clearance of 10.5 mm and air speed of 10.0 ± 0.4 m s−1 were selected as the optimal conditions with the highest separation efficiency between kernels and shells at 94.59%. The shells and husks achieved 95.88% and 12.20% removal respectively while kernel recovery achieved 98.65%. For the second stage, the performance was evaluated using five different roller clearances (5.0 mm, 5.5 mm, 6.0 mm, 6.5 mm and 7.0 mm) with a combination of five blower air speeds (6.5 ± 0.4 m s−1, 7.0 ± 0.2 m s−1, 7.5 ± 0.4 m s−1, 8.0 ± 0.2 m s−1 and 8.5 ± 0.5 m s−1). At the optimal conditions, with a roller clearance of 6.0 mm and air speed of 7.5 ± 0.4 m s−1, the maximum separation efficiency was 97.69%. Total shell and husk removal achieved for the stages were 100.00% and 45.46% respectively. A total of 2.40% kernels were lost.

English

This study was undertaken to work out heritability estimates, correlation and path analysis on 34 pecan selections and three standard cultivars Western Schley, Mahan, and Burkett. High heritability estimates coupled with low genetic advance for most nut and kernel characters indicate higher influence of environment and presence of non-additive gene action suggesting that selection in pecan may not be effective. However, relatively higher values of genetic advance with high heritability recorded in kernel recovery, fat content and nut length indicates that the selection can be exercised on the basis of these characters. Significant correlations have been observed between most of the nut and kernel characters. The positive correlation towards nut yield with other desirable characters like nut weight, kernel weight, nut length and kernel length would be favourable to breeders for their simultaneous genetic improvement. Key words:&nbsp;Pecan, correlations, genetic variability, kernels, nuts, path analysis.