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TOMRA Food defect glossary
Lemon Defects and Blemishes
About the TOMRA Lemon Defects and Blemishes Glossary
The lemon defects and blemishes glossary was developed by the TOMA Food Applications Engineering, Research and Development, and Product Management teams. The information on this page focuses on defects and blemishes observed globally and includes notes on regional naming conventions and variations of defects.
Learn more about TOMRA's sorting machines for citrus defects.
Lemon Scar
Defect Name |
Scar |
Other Names |
Russet Claro Ruggine |
Subcategory |
Light scars, Silver Scars, Dark Scars; Russeting |
Type |
Blemish |
Symptoms and Signs |
|
Cause & Disease Development |
Lemon scars occur when the wind causes the fruit to move against the tree branches or other fruit. The friction between the lemon and the other surface creates the lemon scars.
Light scars are the most common blemish. The differences between Light, Silver and Dark scars can be very subjective and depend on the QC and grading standard.
Lemon scars can change over the season, so sorting what blemishes are acceptable can require active management. |
More Information |
Russetting is usually just the same as lemon scaring. It’s also caused by the friction created when the fruit moves against branches or other fruit. |
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
An example of a light lemon scar collected by the TOMRA Food Applications Engineering team
Juice Black
Defect Name |
Juice Black |
Alternative Defect Name |
Juice black, ugly black Macha Negra Piedra o granizo Donker merke of vrot Grave or macchia |
Type |
Defect |
Symptoms and Signs |
|
Cause & Disease Development |
Juice black defects may be a large dark scar. However, they can also be an indicator of early rot. |
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Example of the juice black defect captured by the TOMRA Food Applications Engineering team
Lemon Oleo
Defect Name | Lemon oleo |
Alternative Defect Name | Oil spots Oleo Oleocelosis
|
Type | Defect |
Symptoms and Signs |
|
Cause & Disease Development | Oleo is a defect that occurs when the lemon is picked while wet. When a lemon is picked while it is still wet, the pressure from picking causes damage to the oil sacks. It can then be made worse by degreening. |
More Information | The damage doesn’t show up immediately after picking. It becomes visible after several days in storage. |
Approved by | Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated | 14 August 2024 |
Example of the lemon oleo defect captured by the TOMRA Food Applications Engineering team
Skin Damage
Defect Name |
Skin damage |
Alternative Defect Name |
Pull: Stem Pull Desgarro Dano en la piel Uit stingel Gambo rotto
Split: Dano mecanico/herida Corte Split/kraak Taglio
Scratches: Magulladura Piccolo
Puncture: Piquete Pinchazo Puncture Puntura |
Subcategory |
Pull, Split, Scratches, Puncture |
Type |
Defect |
Symptoms and Signs |
|
Cause & Disease Development |
Pull occurs when fruit is not correctly clipped from the tree. When lemons are pulled off with force, the skin can break open.
Split is usually the product of mechanical damage during harvest, transport, post-harvest, or storage.
Scratches are a minor version of splits. They’re also caused by mechanical damage during harvest, transport, post-harvest, or in storage.
Puncture is also caused by mechanical damage. It is usually caused by long stems. |
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Lemon puncture defect generated by the TOMRA Food Applications Engineering team
Lemon scratches defect generated by the TOMRA Food Applications Engineering team
Endoxerosis
Defect Name |
Endoxerosis |
Alternative Defect Name |
Decaimiento Petica
|
Symptoms and Signs |
Brown spots on the outer skin when developed. Early stages are seen as internal browning
|
Cause & Disease Development |
The cause is believed to be related to water and the physiological conditions within the tree and fruit and temperature conditions in the air and soil influencing transpiration and water stress. |
More Information |
It is suggested therefore that water conditions in the soil be kept as favorable for tree heath as possible and pick on time so that they are not over mature. |
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Lemon endoxerosis defect collected by TOMRA Food Applications Engineering team
Rot
Defect Name |
Rot |
Subcategory |
Clear; brown; black; sour; Alternaria; other rot |
Alternative Names |
Clear rot: Andpodrido Vrot Marcio
Brown rot: Bruin
Black rot Suur
|
Symptoms and Signs |
|
Cause & Disease Development |
Clear Rot
A translucent rot caused by the fungus Penicillium digitatum (green mold) or Penicillium italicum (blue mold) (Barmore & Brown, 1980). The Fungi infection results in cell breakdown particularly in the albedo due to the creation of pectolytic enzymes which degrade the pectin within the albedo cell structure. The initial infection is normally via an injury to the fruit such as a puncture but health fruit can be infected via close contact with infected fruit.
Brown Rot
The fungi Phytophthora hlbemalls or Phytophthora cltrophthora are the cause of brown rot.
Black Rot
Citrus black rot is caused by phylogenetically distinct lineages of Alternaria alternata.
Sour Rot
This defect is aused by Geotrichum citri-aurantii fungi or a yeast infection of an existing rot. The only difference from clear rot is the sour smell.
Alternaria
Alternaria alternata fungi is washed into the blossom during fruit development and caused a rot.
|
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Lemon rot defect collected by TOMRA Food Applications Engineering team
Long Stem
Defect Name |
Long stem |
Alternative Defect Name |
Palo largo Tallo largo Lang stingel Gambo allungato
|
Symptoms and Signs |
The stem is longer than the desired standard |
Cause & Disease Development |
The cause of long stem is the result of failing to cut the stem correctly during harvest. |
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Lemon long stem defect collected by TOMRA Food Applications Engineering team
Botrytis
Defect Name |
Botrytis |
Alternative Defect Name |
Botritis Malformations Botritus Botrite
|
Symptoms and Signs |
Bumps on the fruit |
Cause & Disease Development |
This defect is caused by the botrytis cinerea fungi. |
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Lemon botrytis defect captured by TOMRA Food Applications Engineering team
Peteca
Defect Name | Peteca |
Alternative Defect Name | Peteca Petica Virosi
|
Symptoms and Signs |
|
Cause & Disease Development | Peteca is caused by a phostharvest physiological disorder characterized by the collapse of an oil gland. This can occur form harvest and in through cold storage. |
More Information |
|
Approved by | Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated | 14 August 2024 |
Lemon peteca defect captured by TOMRA Food Applications Engineering team
Ridge
Defect Name |
Ridge |
Alternative Defect Name |
Ridge; ribbing Cresta
|
Symptoms and Signs |
One or more raised areas that go from the stem to navel |
Cause & Disease Development |
|
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Lemon ridge defect captured by the TOMRA Food Applications Engineering team
Black Tips
Defect Name |
Black tips |
Alternative Defect Name |
Puntas negras
|
Symptoms and Signs |
Black tip (nose) |
Cause & Disease Development |
The cause of black tips is usually mechanical friction. It can also be a symptom of early rot. |
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Scale
Defect Name |
Scale |
Alternative Defect Name |
Piojo negro Dopluis Cocciniglia |
Symptoms and Signs |
|
Cause & Disease Development |
Scale is caused by insect damage. |
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Sunburn
Defect Name |
Sunburn |
Alternative Defect Name |
Quemaduras
|
Symptoms and Signs |
Depends on the severity, this could be a flat area with no color change or have a range of color changes which are not acceptable compared to the overall fruit color |
Cause & Disease Development |
Sunburn occurs when the temperature on one side of the fruit suddenly changes. These temperature swings are usually caused from the heating effect of picking a fruit next to it. |
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Thrip
Defect Name |
|
Alternative Defect Name |
|
Symptoms and Signs |
|
Cause & Disease Development |
Insect damage generally around the stem in a ring shape that has a similar appearance to light scaring. It can also continue down the fruit. |
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Spider
Defect Name |
Spider |
Alternative Defect Name |
Bigote
|
Symptoms and Signs |
|
Cause & Disease Development |
Spider damaged where it gets into the lemon to make its nest. Often found in the crease at the base of the tip (nose) or around the stem |
More Information |
|
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Citrus Canker
Defect Name |
Citrus canker |
Alternative Defect Name |
Cancro Groen Verde
|
Symptoms and Signs |
Circular brown boarder with black inside that is rough in texture. |
Cause & Disease Development |
Citrus canker is caused by the bacterium Xanthomonas axonopodis. The bacterium spreads by wind and water. |
More Information |
Xanthomonas axonopodis is believed to be from Asia. There have been outbreaks in USA, Brazil and Argentina. It has been eradicated from Australia. |
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
Black Spot
Defect Name |
Black spot |
Alternative Defect Name |
Citrus black spot |
Symptoms and Signs |
Black spot appears as small black lesions on the lemon rind. The most common lesion is the hard spot, which appears as small, round lesions with gray centers and red margins. These lesions are sunked into the rind.
Other black spot lesion types include virulent spots, cracked spots, freckle spot, and false melanose and each presents differently.
Virulent Spots
Found on mature fruit experiencing heavy infection. These lesions are sunken and may extend into the flesh of the fruit. They cover a large area of the fruit usually because of the expansion of the fusion of existing lesions. Cracked Spots
These lesions are also irregular in size but are dark and smooth. They form on green fruit and remain on mature fruit. Crack spots occur in the Americas.
Freckle Spots
Freckle spotsare small, slightly depressed lesion that may be red in color. These spots are usually 1-3 mm in diameter. At the end of the season or during storage, these may progress to form virulent spots. False Melanose
False melanose are the smallest black spot lesions and are usually less than 1 mm. Unlike others, they are also raised and dark brown. These are found on green fruit. |
Cause & Disease Development |
Black spot is the result of a fungal infection caused by Phyllosticta citricarpa. |
More Information |
Phyllosticta citricarpa develops during the cold, wet climactic conditions of winter. |
Approved by |
Dr. Chris Johnston, Manager, Applications Engineering, TOMRA Food |
Last Updated |
14 August 2024 |
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