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.

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Lemon Scar

Defect Name	Scar
Other Names	Russet Claro Rameado claro Ligte merke, Windmerke Cicatrice Chiara 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	Thrip
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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