Fruit Surface Area Research Articles

Physiological characterization of the tomato cutin mutant cd1 under salinity and nitrogen stress.

We identified tomato leaf cuticle and root suberin monomers that play a role in the response to nitrogen deficiency and salinity stress and discuss their potential agronomic value for breeding. The plant cuticle plays a key role in plant-water relations, and cuticle's agronomic value in plant breeding programs is currently under investigation. In this study, the tomato cutin mutant cd1, with altered fruit cuticle, was physiologically characterized under two nitrogen treatments and three salinity levels. We evaluated leaf wax and cutin load and composition, root suberin, stomatal conductance, photosynthetic rate, partial factor productivity from applied N, flower and fruit number, fruit size and cuticular transpiration, and shoot and root biomass. Both nitrogen and salinity treatments altered leaf cuticle and root suberin composition, regardless of genotype (cd1 or M82). Compared with M82, the cd1 mutant showed lower shoot biomass and reduced partial factor productivity from applied N under all treatments. Under N depletion, cd1 showed altered leaf wax composition, but was comparable to the WT under sufficient N. Under salt treatment, cd1 showed an increase in leaf wax and cutin monomers. Root suberin content of cd1 was lower than M82 under control conditions but comparable under higher salinity levels. The tomato mutant cd1 had a higher fruit cuticular transpiration rate, and lower fruit surface area compared to M82. These results show that the cd1 mutation has complex effects on plant physiology, and growth and development beyond cutin deficiency, and offer new insights on the potential agronomic value of leaf cuticle and root suberin for tomato breeding.

The pomological characteristics and values for public health of Crataegus tanacetifolia

This study aimed to determine the pomological characteristics and allometric relationships of Crataegus tanacetifolia, an endemic plant species in Türkiye, as well as to assess its significance for public health. Fruit samples collected from its natural habitat were subjected (Mihalıççık district of Eskişehir province, 1330-1350m) to pomological measurements. Subsequently, pomological characteristics were correlated with allometric relationships. The following pomological parameters were observed for Crataegus tanacetifolia: fruit length was 15.30±1.70mm, width was 19.51±2.30mm, thickness was 18.85±2.30mm, weight was 3.34±0.99g, flesh weight was 2.73±0.901g, arithmetic mean diameter was 17.89±2.04mm, geometric mean diameter was 17.78±2.02mm, sphericity index was 116.26±4.79%, surface area was 1005.55±223.28mm2, appearance ratio was 0.79±0.05, seed ratio was 0.19±0.04, peduncle length was 3.26±0.24mm, flesh hardness was 14.02±1.61kg/cm2, and fruit color (L*a*b) was 71.54±0.92*9.34±1.82*60.62±3.11. The fruit color ranged from light yellow to light pink, with green being the dominant color in unripe fruits. The seed length was 7.20±0.51 mm, width was 4.14±0.37mm, thickness was 5.42±0.43mm, weight was 0.12±0.02g, volume was 53.73±8.48mm3, and surface area was 80.09±9.29. There was a high relationship between fruit surface area and allometric relationships, with R²=0.9603 and R²=0.8729 confidence interval. The allometric relationships between seed ratio and fruit sizes were in the range of R²=0.3984 and R²=0.5045. In this study, it was determined that Crataegus tanacetifolia is important for public health, its fruits are used as food.

Effects of Promalin on Fruit Growth and Cuticle Properties of ‘Pinova’ Apple

Promalin (Valent BioSciences, Libertyville, IL, USA) is a proprietary mixture of gibberellin A4 + 7 and 6-benzyladenine that is widely used in apple production to improve the fruit shape, size, and skin quality. Promalin typically increases fruit size and length. However, the increased growth likely increases the strain in the fruit skin, which may exacerbate microcracking of the cuticle and, consequently, russeting. This study aimed to monitor the growth-stimulating effect of Promalin in three different regions of fruits and investigate whether Promalin affects cuticular microcracking via effects on the deposition of cuticular components or via the accumulation of strain in the cuticle. Four Promalin sprays (20 mg⋅L−1) were applied to runoff; the first was applied at full bloom, and the remaining sprays were applied at approximately weekly intervals thereafter. Fruit surface areas and fruit surface area growth rates of the Promalin-treated fruits were higher than those of the untreated control fruits. Promalin increased the fruit length, but it had no effect on the fruit equatorial diameter. In Promalin-treated fruits, the base of each sepal extended, thickened, and became fleshy as early as 15 days after full bloom (DAFB). Allometric growth analyses revealed higher constant differential growth ratios of the pedicel and calyx length (before 36 DAFB) in Promalin-treated fruits than in control fruits. After 36 DAFB, the difference in constant differential growth ratios between Promalin-treated fruits and control fruits decreased. Cuticle mass per unit area increased with time in all regions of the fruit surface and was slightly (+3.3%) but significantly higher in fruits treated with Promalin than in control fruits. Additionally, the biaxial strain release was slightly and significantly lower in Promalin-treated fruits than in control fruits. When the isolated, cuticle was ablated from the inner surface and dewaxed, strain relaxation in the control fruits was higher than that in the Promalin-treated fruits. It was concluded that Promalin treatment increases the length of the fruit by increasing the lengths of the pedicel and calyx regions early during fruit development. Promalin only slightly increased cuticle deposition and fixation of cuticular strain. Promalin had no effects on microcracking or russeting.

Phenotyping 172 strawberry genotypes for water soaking reveals a close relationship with skin water permeance.

Water soaking is a commercially important disorder of field-grown strawberries that is exacerbated by surface wetness and high humidity. The objective was to establish the effect of genotype on susceptibility to water soaking. Three greenhouse-grown model 'collections' were used comprising a total of 172 different genotypes: (1) a segregating F2 population, (2) a collection of strawberry cultivars and breeding clones, and (3) a collection of wild Fragaria species. A standardized immersion assay was used to induce water soaking. Potential relationships between water soaking and water uptake characteristics, depth of the achene depressions, fruit firmness, cuticle mass and strain relaxation and microcracking were investigated. Further, the effect of downregulating the polygalacturonase genes (FaPG1 and FaPG2) on the susceptibility to water soaking was investigated. The collection of wild species was most susceptible to water soaking. This was followed by the collection of cultivars and breeding clones, and by the F2 population. Susceptibility to water soaking was strongly correlated with water uptake rate (mass of water, per fruit, per time). For the pooled dataset of 172 genotypes, 46% of the variability in water soaking was accounted for by the permeance of the skin to osmotic water uptake. Susceptibility to water soaking was not, or was only poorly correlated with measurements of fruit surface area or of the osmotic potential of the expressed fruit juice. The only exceptions were the wild Fragaria species which were highly variable in fruit size and also in fruit osmotic potential. For genotypes from the F2 and the wild species collections, firmer fruit were less susceptible to water soaking than softer fruit. There were no relationships between fruit firmness and susceptibility to water soaking in transgenic plants in which FaPG1 and FaPG2 were down-regulated. Susceptibility to water soaking was not related to cuticle mass per unit fruit surface area, nor to strain relaxation of the cuticle upon isolation, nor to achene position. In summary, strawberry's susceptibility to water soaking has a significant genetic component and is closely and consistently related to the skin's permeance to osmotic water uptake.

Evidence That Field Muskmelon (Cucumis melo L. var. agrestis Naud.) Fruits Are Solids of Revolution.

In nature, the fruit shapes of many plants resemble avian eggs, a form extensively studied as solids of revolution. Despite this, the hypothesis that egg-shaped fruits are themselves solids of revolution remains unvalidated. To address this, 751 Cucumis melo L. var. agrestis Naud. fruits were photographed, and the two-dimensional (2D) boundary coordinates of each fruit profile were digitized. Then, the explicit Preston equation (EPE), a universal egg-shape model, was used to fit the 2D boundary coordinates to obtain the estimates of the EPE's parameters of each fruit. Under the hypothesis that egg-shaped fruits are solids of revolution, the fruit volumes were estimated using the solid of revolution formula based on the estimated EPE's parameters. To test whether the fruits are solids of revolution, the fruit volumes were measured by using a graduated cylinder and compared with the estimated volumes using the solid of revolution formula. The EPE was demonstrated to be valid in describing the 2D profiles of C. melo var. agrestis fruits. There was a significant correlation between the measured fruit volumes using the graduated cylinder and the estimated fruit volumes using the solid of revolution formula based on the estimated EPE's parameters. Acknowledging potential measurement errors, particularly fruit fuzz causing air bubbles during volume measurements, we recognize slight deviations between measured volumes and estimated values. Despite this, our findings strongly suggest that C. melo var. agrestis fruits are solids of revolution. This study contributes insights into the evolutionary aspects of fruit geometries in plants with egg-shaped fruits and introduces a practical tool for non-destructively calculating fruit volume and surface area based on photographed 2D fruit profiles.

Microcracking of strawberry fruit cuticles: mechanism and factors

Microscopic cracks in the cuticle (microcracks) are the first symptom of the strawberry fruit disorder ‘water soaking’ in which the fruit surface appears watery, translucent, and pale. Water soaking severely impacts fruit quality. The objective was to investigate the factors and mechanisms of cuticular microcracking in strawberry. Fluorescence microscopy revealed numerous microcracks in the achene depressions, on the rims between depressions and at the bases of trichomes. Microcracks in the achene depressions and on the rims were either parallel or transversely oriented relative to a radius drawn from the rim to the point of attachment of the achene. In the achene depression, the frequency of microcracks with parallel orientation decreased from the calyx end of the fruit, towards the fruit tip, while the frequency of those with transverse orientation remained constant. Most microcracks occurred above the periclinal cell walls of the epidermal cells. The long axes of the epidermal cells were primarily parallel-oriented. Microcracking increased during fruit development. Cuticle mass per fruit remained constant as fruit surface area increased but cuticle thickness decreased. When fruit developed under high relative humidity (RH) conditions, the cuticle had more microcracks than under low RH conditions. Exposing the fruit surface to increasing RHs, increased microcracking, especially above 75% RH. Liquid-phase water on the fruit surface was markedly more effective in inducing microcracking than high vapor-phase water (high RH). The results demonstrate that a combination of surface area growth strain and water exposure is causal in inducing microcracking of the strawberry cuticle.

Lenticels are sites of initiation of microcracking and russeting in 'Apple' mango.

The mango cultivar 'Apple' is an important fruitcrop in Kenya, but it is highly susceptible to russeting. The objective was to establish whether lenticels predispose cv. 'Apple' mango to russeting. Fruit mass and surface area increased in a sigmoidal pattern with time. The frequency of lenticels per unit surface area decreased during development. The number of lenticels per fruit was constant. Lenticels were most frequent in the apex region and least common in the cheek and nak (ventral) regions. The cheek region also had lenticels with the largest core areas, whereas the lenticel core areas in the apex region were significantly smaller. Microscopy revealed stomata became covered over with wax deposits at 33 days after full bloom (DAFB). By 78 DAFB, periderm had formed beneath the pore. At 110 and 161 DAFB, cracks had developed and the periderm had extended tangentially and radially. The presence of lenticels increased the strain released upon excision of an epidermal segment, further strain releases occurred subsequently upon isolation of the cuticle and on extraction of the cuticular waxes. The number of lenticels per unit surface area was negatively correlated with the fruit surface area (r2 = 0.62 **), but not affected by fruit size. Mango cv. 'Apple' had fewer, larger lenticels and more russet, compared with 'Ngowe', 'Kitovu' or 'Tommy Atkins' mango. In cv. 'Apple', the lowest lenticel frequency, the largest lenticels and the most russeting occurred at a growing site at the highest altitude, with the highest rainfall and the lowest temperature. Moisture exposure of the fruit surface resulted in enlarged lenticels and more microcracking of the cuticle. Our results establish that russeting in 'Apple' mango is initiated at lenticels and is exacerbated if lenticels are exposed to moisture.

Effect of traditional and automated sorting on some tomato's properties

This study was conducted in a laboratory experiment at the University of Baghdad, College of Science, computing Department, 5 km from the center of Baghdad city, in 2021 to evaluate the sorting method for the tomato crop. The experiments were conducted in a factorial experiment under a complete randomized design with three replications and using SAS analysis, artificial neural network, image processing, the study of external characteristics, and physical features; fruit surface area and fruit circumference were 1334.46 cm2,57.53 cm2 and free diseases. The error value was less than zero, while training with outputs recorded the highest value and which was 5. The neural network's performance between the input and the mean square of the regression, as recorded as the best value to validate the performance, was 58.11 in the second period. The importance of fruit circumference is attributed to the sorting and grading of fruits, especially in packing boxes and marketing. Keywords: Automated grading and sorting, traditional grading and sorting, image processing, computer vision, Artificial neural networks

Morphological Assessment of Annatto (Bixa orellana L.) Fruit and Seed for the Development of Mechanical Seed Separator

Background: The development of post-harvest equipment or machinery is vital for agricultural productivity. Bixin, a natural colourant derived from annatto seeds, is still separated manually, which may result in pigment loss. The engineering properties of annatto fruits and seeds must be analyzed in this note for the development of a mechanical seed separator. Methods: The fruits were collected from Forest College and Research Institute, TNAU, Mettupalayam, Tamil Nadu. Engineering properties such as physical, gravimetric and frictional properties, colour and bixin content were determined for two dried annatto fruit and seed varieties (A1 and A2). The Z-test and t-test (p less than 0.05) were used to statistically analyze the data. Result: The morphological characteristics of annatto fruits A1 and A2 differed noticeably and significantly. The surface area and volume of the A1 fruit were higher. The fruit and seed were merely spherical and conical. The lowest static friction was observed for stainless steel in both fruit and seeds. The mean bixin content of the A1 and A2 seeds was 1.5±0.4% and 1.84±0.57%, respectively. These engineering properties will be used to design a mechanical separator without much loss of pigment.

Nondestructive 3D phenotyping method of passion fruit based on X-ray micro-computed tomography and deep learning.

Passion fruit is a tropical liana of the Passiflora family that is commonly planted throughout the world due to its abundance of nutrients and industrial value. Researchers are committed to exploring the relationship between phenotype and genotype to promote the improvement of passion fruit varieties. However, the traditional manual phenotyping methods have shortcomings in accuracy, objectivity, and measurement efficiency when obtaining large quantities of personal data on passion fruit, especially internal organization data. This study selected samples of passion fruit from three widely grown cultivars, which differed significantly in fruit shape, size, and other morphological traits. A Micro-CT system was developed to perform fully automated nondestructive imaging of the samples to obtain 3D models of passion fruit. A designed label generation method and segmentation method based on U-Net model were used to distinguish different tissues in the samples. Finally, fourteen traits, including fruit volume, surface area, length and width, sarcocarp volume, pericarp thickness, and traits of fruit type, were automatically calculated. The experimental results show that the segmentation accuracy of the deep learning model reaches more than 0.95. Compared with the manual measurements, the mean absolute percentage error of the fruit width and length measurements by the Micro-CT system was 1.94% and 2.89%, respectively, and the squares of the correlation coefficients were 0.96 and 0.93. It shows that the measurement accuracy of external traits of passion fruit is comparable to manual operations, and the measurement of internal traits is more reliable because of the nondestructive characteristics of our method. According to the statistical data of the whole samples, the Pearson analysis method was used, and the results indicated specific correlations among fourteen phenotypic traits of passion fruit. At the same time, the results of the principal component analysis illustrated that the comprehensive quality of passion fruit could be scored using this method, which will help to screen for high-quality passion fruit samples with large sizes and high sarcocarp content. The results of this study will firstly provide a nondestructive method for more accurate and efficient automatic acquisition of comprehensive phenotypic traits of passion fruit and have the potential to be extended to more fruit crops. The preliminary study of the correlation between the characteristics of passion fruit can also provide a particular reference value for molecular breeding and comprehensive quality evaluation.

A non-destructive coconut fruit and seed traits extraction method based on Micro-CT and deeplabV3+ model.

With the completion of the coconut gene map and the gradual improvement of related molecular biology tools, molecular marker-assisted breeding of coconut has become the next focus of coconut breeding, and accurate coconut phenotypic traits measurement will provide technical support for screening and identifying the correspondence between genotype and phenotype. A Micro-CT system was developed to measure coconut fruits and seeds automatically and nondestructively to acquire the 3D model and phenotyping traits. A deeplabv3+ model with an Xception backbone was used to segment the sectional image of coconut fruits and seeds automatically. Compared with the structural-light system measurement, the mean absolute percentage error of the fruit volume and surface area measurements by the Micro-CT system was 1.87% and 2.24%, respectively, and the squares of the correlation coefficients were 0.977 and 0.964, respectively. In addition, compared with the manual measurements, the mean absolute percentage error of the automatic copra weight and total biomass measurements was 8.85% and 25.19%, respectively, and the adjusted squares of the correlation coefficients were 0.922 and 0.721, respectively. The Micro-CT system can nondestructively obtain up to 21 agronomic traits and 57 digital traits precisely.

Chemical Composition of Cuticle and Barrier Properties to Transpiration in the Fruit of Clausena lansium (Lour.) Skeels.

The plant cuticle, as a lipid membrane covering aerial plant surfaces, functions primarily against uncontrolled water loss. Herein, the cuticle chemical composition and the transpiration of wampee fruit (Clausena lansium (Lour.) Skeels) at the green, turning, and yellow stages in cultivars of “Jixin” and “Tianhuangpi” were comprehensively studied. The coverage of wax and cutin monomers per unit of fruit surface area at the green stage was lower in “Jixin” than in “Tianhuangpi” and increased gradually during development. Cutin monomers accumulated ranging from 22.5 μg cm−2 (green) to 52.5 μg cm−2 (turning) in “Jixin” and from 36.5 μg cm−2 (green) to 81.7 μg cm−2 (yellow) in “Tianhuangpi.” The total composition of waxes ranged between 6.0 μg cm−2 (green) and 11.1 μg cm−2 (turning) in “Jixin,” while they increased from 7.4 μg cm−2 (green) to 16.7 μg cm−2 (yellow) in “Tianhuangpi.” Cutin monomers were dominated by ω-, mid-dihydroxy fatty acids (over 40%), followed by multiple monomers of α,ω-dicarboxylic acids with or without added groups, α-monocarboxylic acids with or without ω- or mid-chain hydroxy or mid-epoxy groups, primary alcohols, and phenolics. The very-long-chain (VLC) aliphatic pattern of cuticular waxes was prominently composed of n-alkanes (ranging from 21.4% to 39.3% of total wax content), fatty acids, primary alcohols, and aldehydes. The cyclic waxes were dominated by triterpenoids (between 23.9 and 51.2%), sterols, and phenolics. Water loss in wampee fruit exhibited linear changes over time, indicating an overall monofunctional barrier to transpiration. Permeance for water in wampee fruit was higher at the green stage than at the yellow stage in both “Jixin” and “Tianhuangpi,” which showed a negative correlation with the changes of VLC n-alkanes. The results showed the cuticular chemicals, including cutin monomers and waxes, in wampee fruit and further indicated the potential contributions of the cuticular chemical composition to the physiological functions in fruits.

Automated Fruit Quality Detection Using Image Processing

In this paper, an automated fruit quality inspection and sorting system for apples has been proposed. The objective of this system is to replace the manual inspection system. This helps to speed up the process, improve the accuracy and efficiency of the system. In this work, the multiple images of apple are captured by using camera place above the conveyor belt. We have captured multiple images to make the proposed system more accurate which covers the maximum surface area of fruit. Then various image processing algorithms are used to extract the features of fruit such as texture, color, and size. Automated sorting and grading are done based on these features. The defected apple is diverted from conveyor using motor. The proposed embedded system works at higher speed and gives high accuracy in grading with low-cost solution. It will have a good prospect of application in fruit quality detection and grading areas. In the proposed algorithm, we have used k-means algorithm for segmentation and local Binary Pattern technique is used extract feature vectors of the test and training images. Then, the training and testing features are given to neural network algorithm to classify the test image into normal and abnormal class. We have considered the normal and abnormal (rotten apple images) for training purposes. Experimental results show that the proposed system accurately classifies the apple and gives better accuracy.

Automated Fruit Quality Detection Using Image Processing

In this paper, an automated fruit quality inspection and sorting system for apples has been proposed. The objective of this system is to replace the manual inspection system. This helps to speed up the process, improve the accuracy and efficiency of the system. In this work, the multiple images of apple are captured by using camera place above the conveyor belt. We have captured multiple images to make the proposed system more accurate which covers the maximum surface area of fruit. Then various image processing algorithms are used to extract the features of fruit such as texture, color, and size. Automated sorting and grading are done based on these features. The defected apple is diverted from conveyor using motor. The proposed embedded system works at higher speed and gives high accuracy in grading with low-cost solution. It will have a good prospect of application in fruit quality detection and grading areas. In the proposed algorithm, we have used k-means algorithm for segmentation and local Binary Pattern technique is used extract feature vectors of the test and training images. Then, the training and testing features are given to neural network algorithm to classify the test image into normal and abnormal class. We have considered the normal and abnormal (rotten apple images) for training purposes. Experimental results show that the proposed system accurately classifies the apple and gives better accuracy.

Preharvest Application of Phenylalanine Induces Red Color in Mango and Apple Fruit's Skin.

Anthocyanins are secondary metabolites responsible for the red coloration of mango and apple. The red color of the peel is essential for the fruit’s marketability. Anthocyanins and flavonols are synthesized via the flavonoid pathway initiated from phenylalanine (Phe). Anthocyanins and flavonols have antioxidant, antifungal, and health-promoting properties. To determine if the external treatment of apple and mango trees with Phe can induce the red color of the fruit peel, the orchards were sprayed 1 to 4 weeks before the harvest of mango (cv. Kent, Shelly, and Tommy Atkins) and apple fruit (cv. Cripps pink, Gala and Starking Delicious). Preharvest Phe treatment increased the red coloring intensity and red surface area of both mango and apple fruit that was exposed to sunlight at the orchard. The best application of Phe was 2–4 weeks preharvest at a concentration of 0.12%, while a higher concentration did not have an additive effect. A combination of Phe and the positive control of prohydrojasmon (PDJ) or several applications of Phe did not have a significant added value on the increase in red color. Phe treatment increased total flavonoid, anthocyanin contents, and antioxidant activity in treated fruit compared to control fruits. High Performance Liquid Chromatography analysis of the peel of Phe treated ‘Cripps pink’ apples showed an increase in total flavonols and anthocyanins with no effect on the compound composition. HPLC analysis of ‘Kent’ mango fruit peel showed that Phe treatment had almost no effect on total flavonols content while significantly increasing the level of anthocyanins was observed. Thus preharvest application of Phe combined with sunlight exposure offers an eco–friendly, alternative treatment to improve one of the most essential quality traits—fruit color.

DNA metabarcoding reveals host-specific communities of arthropods residing in fungal fruit bodies.

Biological communities within living organisms are structured by their host's traits. How host traits affect biodiversity and community composition is poorly explored for some associations, such as arthropods within fungal fruit bodies. Using DNA metabarcoding, we characterized the arthropod communities in living fruit bodies of 11 wood-decay fungi from boreal forests and investigated how they were affected by different fungal traits. Arthropod diversity was higher in fruit bodies with a larger surface area-to-volume ratio, suggesting that colonization is crucial to maintain arthropod populations. Diversity was not higher in long-lived fruit bodies, most likely because these fungi invest in physical or chemical defences against arthropods. Arthropod community composition was structured by all measured host traits, namely fruit body size, thickness, surface area, morphology and toughness. Notably, we identified a community gradient where soft and short-lived fruit bodies harboured more true flies, while tougher and long-lived fruit bodies had more oribatid mites and beetles, which might reflect different development times of the arthropods. Ultimately, close to 75% of the arthropods were specific to one or two fungal hosts. Besides revealing surprisingly diverse and host-specific arthropod communities within fungal fruit bodies, our study provided insight into how host traits structure communities.

Analysis of Digital Images on a Mobile Device to Estimate Surface Area and Volume of Mango Fruit (Mangifera indica L.)

Objective: To develop a technique based on the partition method, to estimate the surface area and volume of mango fruit (Mangifera indica L. cv. “Ataulfo”) using two digital orthogonal images, obtained and processed on a mobile device with the Android® operating system, segmented by different discriminants. Design/Methodology/Approach: A technique was developed to estimate the surface area and volume of “Ataulfo” mango fruit based on digital images and was implemented directly on a smartphone with the Android® operating system. Three discriminants were evaluated for segmentation (red channel, green channel, and HIS intensity) and applied in n=30 fruits. The precision and accuracy of the technique was determined. Results: The surface area and volume of the fruit when estimated using the red channel presented a coefficient of variation of less than 2.0% in both variables and the estimation error was less than 3% for surface area and less than 5% for volume. Study Limitations/Implications: This technique was limited to fruit with an elliptical cross-section and smooth surface. Findings/Conclusions: The proposed technique is a non-destructive alternative to estimate the surface area and volume of “Ataulfo” mango fruit with a reasonable margin of error and can be implemented directly on an Android® device using only the red channel as a segmentation discriminant.

Mass and surface modelling of green plantain banana fruit based on physical characteristics

The physical characteristic such as dimensional, projected area, volume, mass, and sphericity are directly related to the quality of a fruit. The consumer generally prefers the uniform size, mass, and shape of the fruit. Thermal properties are important to predict the heat flux or the time required for drying, freezing, refrigeration processing. The knowledge of these properties is essential for the process designing and development of equipment involved in carrying out different tasks such as grading, sizing, peeling, storage, and packaging system in the green banana processing industry (banana powder, banana chips, banana starch, banana-based soup, baby foods).The objective of this study was to determine the physical and thermal properties of plantain banana fruit as well as to develop mathematical models based on physical properties so that the same may be used to design various related equipment. The average dimension of fruit was 15.42, 4.08, and 3.59 cm as length (L), width (W), and thickness (T), respectively. The geometric mean diameter (Dg) and arithmetic mean diameter (Da) were measured as 6.08 and 7.7 cm, respectively. The sphericity, aspect ratio, and radius of curvature were found to be 39.60%, 0.27, and 186.49, respectively. The elongation and flakiness ratio was found to be 3.77 and 0.88, respectively. From measured physical properties, it was concluded that banana fruit is curved, non-spherical, elongated in shape. Linear, quadratic, power, and S-curve equations were applied to analyze the mass, surface area, and projected area of green banana fruit. The measured physical properties of fruit were statistically found significant at p < 0.05. The mass of fruit was best predicted via length as dimensional characteristics in the quadratic model (M = 305.37–36.50L + 1.46L2; R2 = 0.95; χ2 = 20.24; RMSE = 4.50). Whereas, the surface area of fruit was best predicted in the quadratic model based on ellipsoid spheroid volume (Vellip) (S = 25.34 + 0.87Vellip – 8.99Vellip2; R2 = 0.99; χ2 = 0.01; RMSE = 0.12) and projected area of fruit was best predicted in a power model produced by projected area perpendicular to length (PL) (PA = 0.69 PL0.91; R2 = 0.99; χ2 = 0.0; RMSE = 0.05). The thermal conductivity and specific heat of banana fruit were found to be 0.58 W/m°C and 3.86 kJ/kg°C, respectively.

Genetic diversity analysis of promising Ceylon olive (Elaeocarpus serratus L.) genotypes using morphological traits and ISSR markers

Ceylon olive (Elaeocarpus serratus L.) is a fruit tree indigenous to Sri Lanka. Due to lack of information on genetic diversity and germplasm wealth, the tree remains underexploited. Therefore, diversity assessment both through morphological and ISSR markers, was undertaken. As a result of extensive field exploration survey among 150 trees, 25 accessions superiority in fruit weight were selected and designated as Candidate Plus Trees (CPTs). Morphological traits including 24 quantitative and 10 qualitative were evaluated for three consecutive years, and morphological characteristics among the CPTs in fruit characteristics viz; fruit length, fruit sphericity and fruit surface area revealed significant variations. Principal Co-ordinate Analysis distinguished CPT14 from all other CPTs, possibly due to its distinctiveness of leaf and fruit traits. Further to ensure the observed variations could be genetic ISSR profiling of CPTs was performed using 23 UBC primers. Out of 144 fragments scored, 113 bands were polymorphic and estimated RP, PIC and MI of specific primers (UBC 810, UBC 811, UBC 834 and UBC 873) was high, thus proved usefulness in discriminating within the species level. Cluster diagram constructed on UPGMA based similarity matrix of ISSR profile showed 25 CPTs were 88 % of similarity and remaining divergence attributed by the superior morphological as well as genetic traits. Tree to tree variability in fruit characteristics exist among the 25 CPTs and has effectively discriminated by ISSR markers. Further, the superior germplasm CPT14, found to have distinct morphological features with distinguishable ISSR profile. This germplasm can be further used for cloning and improvement programs.

Nondestructive Determination of Fruit Surface Area Using Archimedean Buoyancy

Estimates of fruit surface area are often required in physiological and technological studies. The objective was to establish a procedure to accurately quantify the fruit surface area based on Archimedean buoyancy measurements. The setup comprised a fixed, linear stepper motor mounted with its spindle vertical and aligned directly above the pan of an electronic balance. A fruit was clamped to the motor spindle and a beaker of water rested on the balance pan. When the motor was activated, the fruit was progressively immersed, stepwise, in the water. Each vertical displacement step increased the buoyant upthrust on the fruit, which was opposed by a corresponding increase in the downthrust on the balance. Pairs of the step displacement length (mm) and corresponding buoyancy increment (g) values were recorded in an MS Excel (Microsoft, Redmond, WA) spreadsheet using Arduino components. Each displacement step immersed another “virtual slice” of the fruit in the water. From each pair of known displacement–buoyancy measurements, the volume (mL) of that slice could be calculated with high precision based on the known density of the liquid (g·mL−1). With the fruit orientated so that its morphological “long” axis was vertical, for most fruitcrop species, the slice can be assumed to have a circular cross-section. Hence, the slice can be analyzed geometrically as a truncated cone of known height (mm) and known volume (mL). Therefore, the surface area of its outer face is calculable. The surface area of the whole fruit was calculated as the cumulative total of the surface areas of all steps (virtual slices). The procedure was evaluated and calibrated using stainless-steel spheres in place of the fruit. However, the measured surface area was slightly greater than that calculated for a sphere. The calculated and measured areas did not differ by more than 1.7%. The surface area determinations were highly reproducible (cv = 0.95%). The magnitude of the displacement steps affected the variability of the surface area measurements. Increasing the step displacements decreased the measurement variability, but there were no significant effects on the surface area measurements of the surface tension of the liquid or of the wettability of the surface of the fruit or the stainless-steel subject. Using stainless-steel spheres (diameter, 5–60 mm) or rubber truncated cones (mean diameter, 8–45 mm) revealed an excellent agreement between the measured and calculated surface areas. Using tomatoes, grapes, blueberries, and strawberries, the measured surface areas were in excellent agreement with those calculated from the fruit dimensions and appropriate geometrical assumptions. The results demonstrate that the surface areas of fruit with approximately circular cross-sections normal to their morphological axes can be determined with high accuracy and reproducibility using Archimedean buoyancy.