Surface Color Research Articles

Pigments and colour characteristics: Influence of drying methods on Nigerian pepper (Capsicum frutescence)

Drying conditions such as temperature and duration leads to pepper modifications that can results into quality degradation. In this study matured red fresh Capsicum frutescens var. Baccatum (FB) and Capsicum frutescens var longum (FL) were dried using sun drying (SFB and SFL) and hot air cabinet drying (CFB and CFL) methods. Effects of drying was investigated on moisture content, water activity, carotenoid (capsorubin, violaxanthin, capsanthin, antheraxanthin and zeaxanthin) and colour characteristic (extractable, surface colour, non-enzymic browning index [NEBI]). Cabinet drying significantly (P < 0.05) reduced the moisture content and water activity to 7.7% and 0.41 in CFB and 7.5% and 0.42 in CFL compared to 8.5% and 0.45 in SFB and SFL by sun drying. Capsorubin was the most abundant carotenoid in both species (51 and 29%) and capsanthin (43 and 25%) in FB and FL. Extractable colour loss in FB was 31 and 26% due to sun and cabinet drying, while FL recorded 42 and 24%. The chromatic coordinates (a*, b × and L*) in the fresh C. frutescens var baccatum and C. frutescens var longum were significantly affected by the drying methods with values ranging from 23 to 28, 20–24 and 36–41 in the dried peppers. The highest NEBI values of 113 and 123 were recorded for the C. frutescens var baccatum while the lowest colour difference was recorded in C. frutescens var longum. Cabinet drying method provided higher NEBI with CFB having the highest values indicating that cabinet drying may be considered a better drying alternative for dehydration of red pepper due to better colour retention of the dried products.

Comparison of the Surface Properties of 3D-printed Permanent Restorative Resins and Resin-based CAD/CAM Blocks.

This study aimed to investigate the surface roughness, microhardness, and color changes of resin-based computer-aided design/computer-aided manufacturing (CAD/CAM) blocks and 3D-printed permanent resins in different beverages. Resin-based CAD/CAM blocks (Cerasmart 270 and Grandio Blocs) and 3D-printed permanent restorative resins (Crowntec and Permanent Crown) were used in this study. A total of 96 specimens were prepared from CAD/CAM blocks and 3D-printed permanent resins. The initial surface roughness, microhardness, and shade value of the specimens were measured. Then, the specimens prepared from each material were divided into three subgroups (n=8) and immersed in tea, coffee, and distilled water for 30 days. After the specimens were immersed in the beverages, the surface roughness, microhardness, and tone values were measured again. The data were statistically analyzed using a two-way analysis of variance test (p<0.05). No statistically significant difference was found in the surface roughness values of the resin-based CAD/CAM blocks and 3D-printed resins (p<0.05). Resin-based CAD/CAM blocks showed statistically significantly higher microhardness than 3D-printed permanent resins (p<0.05). Although the color changes in 3D-printed resins in tea and coffee were similar to those in resin-based CAD/CAM blocks on the first and seventh days, more color changes appeared in the 3D-printed resins after 30 days. The surface roughness and microhardness values of the specimens submerged in tea, coffee, and distilled water showed no statistically significant changes (p<0.05). Although the surface roughness of 3D-printed permanent resins was similar to that of resin-based CAD/CAM blocks, they had a lower microhardness value. Moreover, 3D-printed permanent resins showed more color changes in tea and coffee.

Manufacture of Polymer Concrete Based on Snake-Fruit Seeds (Salacca zalacca) and Sawdust with Polyester Resin as an Adhesive

This study aims to determine the effect of adding snake-fruit (Salacca zalacca) seeds and sawdust on polymer concrete's physical and mechanical properties. The results showed that the highest physical properties were 1.27 g/cm3 density, 12.5% porosity, and 13.22% water absorption. The lowest physical properties are a density of 0.85 g/cm3, porosity of 2.65%, and water absorption of 2.07%. The highest mechanical properties are compressive strength of 16.70 MPa, tensile strength of 4.39 MPa, and flexural strength of 7.93 MPa. The lowest mechanical properties are compressive strength of 6.80 MPa, tensile strength of 1.11 MPa, and flexural strength of 1.50 MPa. SEM test results showed that the microstructure of polymer concrete showed differences between concrete samples A1 (consisting of 35 g of snake-fruit seeds, 15 g of sawdust, and 15 g of polyester resin) and polymer concrete samples B1 (consisting of 30 g of snake-fruit seeds, 15 g of sawdust, and 20 g of polyester resin). The SEM analysis of the A1 concrete sample reveals a dark surface color and conspicuous white lumps, which are attributed to polyester resin and arise from inadequate mixing of ingredients. In the case of sample B1, a higher concentration of visible resin lumps is observed.

Influence of Ageing Time and Method on Beef Quality and Safety.

The effectiveness of dry ageing with regard to retaining meat quality is still subject to debate. At 4 d post mortem, samples of boneless strip loins were excised from young Charolais carcasses and then stored for a further 26 d in a cooler, either vacuum-packaged (VP) or dried-aged (DA). Loin samples were also dissected 7 d post mortem as a control treatment (CT). Chemical, instrumental and microbiological data (n = 18) were determined in longissimus dorsi and underwent ANOVA to estimate the differences in the ageing fixed factor split into two orthogonal contrasts: control vs. aged and VP vs. DA. Ageing loss (both surface dehydration and water purge) was greater in DA compared to VP samples, resulting in the lowest moisture content and highest crude protein and fat percentage in DA loins. The ageing method did not affect meat surface colour, except for redness, which had the lowest value in DA samples. Meat tenderness improved a similar amount following both VP and DA ageing treatments. Compared to the control, prolonged ageing raised both the peroxide value and the total microbial count, especially in DA samples, though both remained within the recommended limits. In summation, both ageing methods improved beef meat tenderisation, preserving its shelf life.

Phenyllactic acid maintains the postharvest quality of winter jujube fruit via activating ascorbic acid metabolism

Quality deterioration is the main factor that causes economic losses of winter jujube fruit during logistics. Winter jujube fruit was applied as the material to study the impacts of phenyllactic acid (PLA) dipping on postharvest quality and ascorbic acid (AsA) metabolism during storage at ambient conditions. Results demonstrated that PLA dipping effectively postponed the decline in soluble sugar and chlorophyll contents, as well as the increase of weight loss. Additionally, it significantly reduced malondialdehyde content and preserved the surface color of the fruit. PLA also enhanced the enzymatic activities and gene expressions of L-galactose-1,4-lactone dehydrogenase, L-galactose dehydrogenase, ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase, and glutathione reductase in winter jujubes. Conversely, it led to a reduction in ascorbate oxidase activity. Moreover, PLA up-regulated the expressions of ZjGPI, ZjPMI1-like, ZjGMP, and ZjGGP1 involved in AsA synthesis, thereby enhancing the accumulation of AsA and glutathione. All these findings collectively suggest that PLA treatment has the potential to maintain higher quality of winter jujube fruit via stimulating AsA metabolism.

Effects of Saline-Alkali Stress on Sugar Metabolism of Jujube Fruit: A Metabolomic Analysis

There have been numerous studies on the effects of salt stress on jujube fruit; however, only a few studies have reported the changes in fruit quality, particularly sugar content, under conditions of combined salt and alkali stress. Therefore, the present study aimed to investigate the performance of jujube fruits under Saline-Alkali stress and the changes in sugar content in fruits. To achieve this, jujube fruits were treated with varying concentrations of salt and alkali during five developmental periods. The content of relevant sugar components was determined, and metabolomics data were analyzed in combination with relevant quantitative gene data. The results indicated that 100 days after flowering, the surface color of jujube fruit gradually turned red, and the cell structure of the fruit gradually loosened with increasing salt and alkali concentration. The content of sugar components at each stage showed that glucose and fructose primarily accumulate in the early stage of development, while sucrose is the main component in the later stage of development. Metabolomic correlation network maps showed that six differentially accumulated metabolites were closely related to specific genes. Among these metabolites, sucrose was identified as the core metabolite in the metabolic pathway. Quantitative analysis of the related genes revealed that ZjvINV2 and ZjHK2 exhibited prolonged adaptability to stress. Additionally, the expression levels of ZjSS1 and ZjSPS2 under Saline-Alkali stress were consistent with the trend of sucrose content during the same period. In conclusion, the variations in sugar content in jujube fruits during different growth stages and under Saline-Alkali treatment conditions were recorded as reference data, and the primary metabolic substances and related regulatory genes produced in jujube fruits under Saline-Alkali stress were preliminarily identified.

Changes in the properties of bulk-fill resins under conditions of gastroesophageal reflux and bulimia

Aim: Evaluate the roughness, microhardness and color change of different Bulk Fill resins when submitted to the condition of gastroesophageal reflux and bulimia. Methods: 60 specimens (n = 10) of Bulk-Fill composite resins were made: M1 – Filtek™; M2 – Tetric N-Ceram and M3 – OPUS, through a matrix 2x6 mm and light cured by the VALO light source. After polishing, initial analyzes (48 hours - T0) of surface roughness (Ra), microhardness (VHN) and color change (ΔE) were performed. To simulate the oral condition of severe gastroesophageal reflux and bulimia, the specimens were immersed in hydrochloric acid (S1) (pH 1.7) 4 minutes a day, for 7 days. Control group specimens were immersed in artificial saliva (S2). Subsequently to immersions, mechanical brushing was performed for 3 minutes, three times a day, simulating 7 days of brushing. And again, the analyzes of Ra, VHN and ΔE were performed (7 days - T1). Thus, hydrochloric acid immersion, mechanical brushing and Ra analysis were repeated at 14 days (T2) and 21 days (T3); and T2, T3 and T4 (3 years) for VHN and ΔE. Results: After Shapiro-Wilk statistical test, ANOVA and Tukey test with Bonferroni adjustment (p&gt;0.05), M3 showed the lowest Ra at all times compared to the other resins, while the highest Ra was at T0. M1 and T1 showed higher VHN. And M2 and T4 showed higher ΔE. Conclusion: Bulk Fill resins can be indicated for patients with Gastroesophageal Reflux and Bulimia, nonetheless, Tetric N-Ceram resin showed the worst results.

Improved YOLOv8-Seg Network for Instance Segmentation of Healthy and Diseased Tomato Plants in the Growth Stage

The spread of infections and rot are crucial factors in the decrease in tomato production. Accurately segmenting the affected tomatoes in real-time can prevent the spread of illnesses. However, environmental factors and surface features can affect tomato segmentation accuracy. This study suggests an improved YOLOv8s-Seg network to perform real-time and effective segmentation of tomato fruit, surface color, and surface features. The feature fusion capability of the algorithm was improved by replacing the C2f module with the RepBlock module (stacked by RepConv), adding SimConv convolution (using the ReLU function instead of the SiLU function as the activation function) before two upsampling in the feature fusion network, and replacing the remaining conventional convolution with SimConv. The F1 score was 88.7%, which was 1.0%, 2.8%, 0.8%, and 1.1% higher than that of the YOLOv8s-Seg algorithm, YOLOv5s-Seg algorithm, YOLOv7-Seg algorithm, and Mask RCNN algorithm, respectively. Meanwhile, the segment mean average precision (segment mAP@0.5) was 92.2%, which was 2.4%, 3.2%, 1.8%, and 0.7% higher than that of the YOLOv8s-Seg algorithm, YOLOv5s-Seg algorithm, YOLOv7-Seg algorithm, and Mask RCNN algorithm. The algorithm can perform real-time instance segmentation of tomatoes with an inference time of 3.5 ms. This approach provides technical support for tomato health monitoring and intelligent harvesting.

Crystal Structure, Hirshfeld Surface, Optical, Thermal, NLO, and DFT Analyses of 5‐Methyl‐1H‐Imidazole‐3‐Ium‐4‐ Carboxybutanoate crystal

AbstractAn organic 5‐methyl‐1H‐imidazole‐3‐ium‐4‐carboxybutanoate (5MIC) co‐crystal is grown by slow evaporation solution growth technique (SEST) at room temperature. The 5MIC is synthesized using 4‐methylimidazole and glutaric acid in a 1:1 ratio using methanol as a solvent. The 5MIC crystal lattice parameters are identified using single‐crystal X‐ray diffraction analysis. The experimental X‐ray diffraction (XRD) and DFT structural parameter values have good correlations. The intermolecular interactions of the 5MIC crystal are found using Hirshfeld surface and 2D fingerprint plots. The computed C–N stretching vibration of the imidazole ring is observed at 1498, 1233, and 1064 cm−1. The HOMO is located on 4‐methylimidazole moiety of 5MIC molecule. Densities of state are used to find out the molecular orbital compositions of the 5MIC molecule. Mulliken analysis shows that the C13 (−0.86) atom has the lowest negative charge. The MEP surface color coded of 5MIC lies between 7.950 e−3 and −7.950 e−3. The 5MIC molecule has four types of intermolecular transitions. The first‐order hyperpolarizability (β) value of 5MIC molecule is 5.48×10−30 esu. The 5MIC crystal is thermaly stable up to 146 °C. The photoluminescence emission is observed from 400 to 600 nm. The 5MIC crystal shows SHG characteristics.

Impact of fat types on the visual, textural, and sensory properties of Nanberenji (a traditional gluten-free cookie)

Abstract The objective of this research was to evaluate the effects of various fat types (Bakery fat, Ghee, and Olive oil) on visual characteristics, baking behavior, textural, and sensory properties of a traditional gluten-free rice-based cookie (Nanberenji). The ability of image analysis for measuring some quality properties of prepared samples were also assessed. The obtained data demonstrated that the dough prepared with bakery and olive oil had maximum and minimum hardness values, respectively. However, after baking, the samples prepared with olive oil showed the highest hardness, meaningfully. The given outputs from image processing depicted that cookie prepared with bakery fat (NBF) and samples prepared with olive oil (NOO) had the highest and lowest surface color uniformity, respectively. Over baking time, the intensity and changes in the behavior of image textural features of NG and NBF samples were the same, while NOO samples showed a different behavior. Based on sensory analysis results, olive oil, as a healthy unsaturated fat, is advised to be used in the formulation of Nanberenji to produce a gluten-free cookie with a desirable texture, color, and flavor.

Influence of Hempseed Meal on Fresh Goat Meat Characteristics Stored in Vacuum Packaging.

The objective of this study was to determine the influence of hempseed meal (HSM) on goat meat characteristics. Goats (N = 10/treatment) were allocated to a diet concentration (0, 10, 20, or 30%) of HSM, fed for 60 days, and harvested. Carcass measurements were collected after chilling, and subsequently fabricated into wholesale subprimals. From the subprimals of the shoulder and leg, steaks were cut 2.54 cm thick, vacuum packaged, and assigned to laboratory methods: cook yield, instrumental color, lipid oxidation, microbial spoilage, and instrumental tenderness. HSM did not alter (p > 0.05) carcass characteristics, microbial spoilage, cook loss, or the thiobarbituric acid reactive substance (TBARS). However, a decrease in objective tenderness measurements (p < 0.05) was observed with greater concentrations of HSM supplementation in the diet. Instrumental surface color values for lightness (L*) indicated that steaks became lighter and less red (a*) as storage time increased (p < 0.05). Results suggest that HSM and storage time do not alter some goat meat traits, but HSM or storage time separately may influence goat meat quality. HSM may be an effective feed ingredient that does not alter carcass quality or meat yield.

Universal and One-Step Modification to Render Diverse Materials Bioactivation.

Bioactive materials that can support cell adhesion and tissue regeneration are greatly in demand in clinical applications. Surface modification with bioactive molecules is an efficient strategy to convert conventional bioinert materials into bioactive materials. However, there is an urgent need to find a universal and one-step modification strategy to realize the above transformation for bioactivation. In this work, we report a universal and one-step modification strategy to easily modify and render diverse materials bioactivation by dipping materials into the solution of dibutylamine-DOPA-lysine-DOPA (DbaYKY) tripeptide-terminated cell-adhesive molecules, β-peptide polymer, or RGD peptide for only 5 min. This strategy provides materials with a stable surface modification layer and does not cause an undesired surface color change like the widely used polydopamine coating. This one-step strategy can endow material surfaces with cell adhesion properties without concerns on nonspecific conjugation of proteins and macromolecules. This universal and one-step surface bioactivation strategy implies a wide range of applications in implantable biomaterials.

Perceiving Surface Color Requires Attention

Perceiving Surface Color Requires Attention

Generating colours through a novel approach based on spatial ALD and laser processing

This work studies the combination of direct femtosecond laser structuring of metal surfaces and Spatial Atomic Layer Deposition (SALD) of metal oxides as a novel approach to generate colours on different types of day-to-day metallic objects. In particular, a stainless-steel knife and an outdated 25 ct Dutch florin coin have been selected for the study. Our results show that it is possible both, to preserve the iridescence properties produced by laser processing and to tune the final metal surface colour by controlling the thickness of the ZnO coating. At the same time, this oxide coating could act as a protecting layer for the original material. We thus explore two different strategies to generate colour, namely, iridescence and interference, which can be even developed selectively. This novel methodology to colour metallic surfaces is a promising route to achieve cheap, scalable, and high-throughput processing methods and opens up a new avenue of possibilities and applications related to colour.

One Step Polishing System Difference on Bulk-Fill Composite Resin Microhardness, Surface Roughness, and Color Stability

Background: The polishing procedure was an important step in composite resin restoration as it reduces restoration surface roughness. Smooth and well-polished restoration surfaces can increase microhardness and minimize discoloration on the tooth surface. The study aims to examine the differences of one-step polishing systems on surface roughness, microhardness, and color stability of bulk-fill composite resin.&#x0D; Method: The samples were bulk-fill composite resin moulded with 4 mm of diameter and thickness (n=30) for microhardness (n=15) and surface roughness (n=15) test and moulded with 6 mm of diameter and 4 mm of thickness for color stability (n=15) test. The samples were divided into three groups consisting of 5 samples for each variable and were polished using PoGo, OptraPol, and OneGloss. Color stability test samples were immersed in tea solution for 7 days. Color stability measurement was done by comparing the results of color measurements using a spectrophotometer before and after immersion. Microhardness was tested using Vickers Microhardness Tester, while surface roughness was tested using the Stylus Profilometer Fowler Surfcorder SE1700.&#x0D; Result: The data analysis showed that PoGo produced the smoothest surface roughness significantly (p=0.006), the highest microhardness significantly (p=0.002), and the lowest color change significantly (p = 0.027)&#x0D; Conclusion: PoGo produced lowest surface roughness and color change, and highest microhardness compare with OptraPol and OneGloss.

Extended Storage of Beef Steaks Using Thermoforming Vacuum Packaging.

Extended storage duration often results in negative quality attributes of fresh or frozen beef steaks. This study focused on evaluating the fresh and cooked meat quality of beef steaks stored using vacuum packaging for 63 days. Steaks 2.54 cm thick were packaged into one of three thermoforming films VPA (250 µ nylon/EVOH/enhanced polyethylene coextrusion), VPB (250 µ nylon/EVOH/enhanced polyethylene coextrusion), or VPC (125 µ nylon/EVOH/enhanced/polyethylene coextrusion). Steaks placed in VPA were lighter (L*) and redder (a*) in surface color (p < 0.05) as the display period increased, whereas steaks packaged in VPB and VPC became darker. Yellowness, hue angle (Hue°), and chroma (C*) values were greater (p < 0.05) in steaks using VPC film as the storage period increased. Calculated spectral values of red to brown were greater (p < 0.05) for steaks in VPA and VPB than in VPC. However, steaks placed in VPC films contained greater (p < 0.05) forms of metmyoglobin and oxymyoglobin and lower calculated relative values of deoxymyoglobin. In addition, packaging treatment altered (p > 0.05) lipid oxidation, but storage time had a greater (p < 0.05) influence on purge loss, cook loss, and Warner-Bratzler shear force (WBSF). Current results suggest that the use of vacuum packaging for extended storage of beef steaks (>60) days is plausible.

Nanosecond laser coloration of Ti-based metallic glass under various laser parameters and irradiation atmospheres

Laser coloration is an emerging technique for surface functionalization of metallic glasses (MGs). Understanding the influence of laser parameters on surface color of MGs will accelerate their commercialization. Herein, surface coloration was conducted on a Ti-based MG, and the hue–saturation–intensity (HSI) color space was employed to evaluate color variation. Various colors were achieved by varying the average power and scanning speed in an ambient atmosphere. The results indicated that the overlap rate and number of repetitive scans had a negligible effect on the color and significantly changed the microscopic morphology. The irradiated surfaces were yellowish and colorless in nitrogen and argon atmospheres. Furthermore, the effect of morphology on the surface color and the mechanism of surface coloration were examined. This study demonstrates that nanosecond laser irradiation is an effective method for achieving surface coloration of MGs, which is expected to enrich the surface functionality of MG products.

Influence of coloring techniques on the surface characteristics and color stability of a monolithic zirconia ceramic

The color of monolithic zirconia restorations is obtained by presintering or postsintering coloring techniques. However, studies on the differences in surface characteristics and their influence on color stability are lacking. The purpose of this in vitro study was to evaluate the influence of shading and staining techniques for a zirconia ceramic on the surface characteristics and colorimetric parameters (color difference, translucency, and whiteness index) after exposure to coffee or red wine and then polishing. Ceramic disks (N=30; Ø10×1mm) were allocated into 3 groups: preshaded-shaded by the manufacturer (IPS e.max ZirCAD MT, shade A2); manually shaded-unshaded zirconia (IPS e.max ZirCAD MT, bleaching shade-BL) colored by the brushing technique, before sintering; stained-unshaded zirconia (IPS e.max ZirCAD MT BL) colored by the staining technique, after sintering. Spectrophotometric color assessments ensured the same initial perceived color (Vita Classical A2) for specimens included in the study (∆E00<1.77 acceptability threshold). Surface characteristics were assessed by scanning electron microscopy and atomic force microscopy. The specimens were immersed in coffee (n=5) or red wine (n=5) for 12 and 24 days and subsequently polished. The data were statistically and descriptively analyzed for color differences (∆E00), translucency parameters (TP00), and whiteness indexes for dentistry (WID), considering acceptability and perceptibility thresholds. The shaded groups found an irregular ceramic surface with uniformly sized zirconia crystals. The stained group found a glass-covered smoother surface. Significant alterations in color parameters (∆E00, TP00, WID) were observed with immersion in pigmenting beverages (P<.001) both after 12 days, and after 24 days. The shaded specimens had greater color alterations after immersion but benefited from the polishing procedure, which reduced color differences below an acceptable threshold in comparison with the baseline. Stained specimens had lower color alterations after immersion, but the polishing protocol was detrimental as it whitened the ceramic by subsurface exposure. The coloring technique influences the surface characteristics of zirconia ceramic and also the color parameters after exposure to colored beverages and polishing.

Detecting colorectal lesions with image-enhanced endoscopy: an updated review from clinical trials.

Colonoscopy plays an important role in reducing the incidence and mortality of colorectal cancer by detecting adenomas and other precancerous lesions. Image-enhanced endoscopy (IEE) increases lesion visibility by enhancing the microstructure, blood vessels, and mucosal surface color, resulting in the detection of colorectal lesions. In recent years, various IEE techniques have been used in clinical practice, each with its unique characteristics. Numerous studies have reported the effectiveness of IEE in the detection of colorectal lesions. IEEs can be divided into two broad categories according to the nature of the image: images constructed using narrowband wavelength light, such as narrowband imaging and blue laser imaging/blue light imaging, or color images based on white light, such as linked color imaging, texture and color enhancement imaging, and i-scan. Conversely, artificial intelligence (AI) systems, such as computer-aided diagnosis systems, have recently been developed to assist endoscopists in detecting colorectal lesions during colonoscopy. To better understand the features of each IEE, this review presents the effectiveness of each type of IEE and their combination with AI for colorectal lesion detection by referencing the latest research data.

IDENTIFICATION OF MORPHOLOGY AND RELATIONSHIPS OF PORANG PLANTS (AMORPHOPHALLUS MUELLERI BLUME) IN KUMPEH ULU DISTRICT, MUARO JAMBI REGENCY

Porang (Amorphophallus muelleri Blume) is a group of tuber plants that are useful as food and medicine so that they have bright prospects for development. In Jambi Province, especially in Muaro Jambi Regency, porang plants are found growing wild among duku trees. This study aims to determine the morphological character of porang plants and to determine the level of diversity and kinship of porang plants found in Kumpeh Ulu District, Muaro Jambi Regency. The research was carried out from August to September 2021, in 18 villages located in the Kumpeh Ulu District. The research was conducted using a non-experimental descriptive method with proportionate stratified random sampling, and the sample was measured quantitatively and qualitatively. The morphological identification of porang plants from 18 villages in Kumpeh Ulu District showed similarities in bulbil shape, bulbil surface colour, bulbil surface texture, bulbil flesh colour, leaf shape and petiole colour. However, there were differences in leaf colour, tuber flesh colour, tuber surface texture and tuber shape.