Carrot color is a warm and bright tone. Protection measures

Plan.

1. Basic indicators of carrots. GOST quality requirements.

2. Average daily sample.

3. Pests of grain stocks. How do they affect product quality?

Basic indicators of carrots. GOST quality requirements.

Quality indicators for fresh carrots are determined in accordance with GOST R 51782-2001 “Fresh table carrots sold in retail chains” (Appendix A).

Carrots, depending on quality, are divided into three classes: extra, first and second. Extra class carrots must be washed, first and second class carrots must be washed or dry peeled.

According to GOST R 51782-2001, carrots must have the following organoleptic characteristics and root size (Table 1):

Table 1. “GOST requirements and standards for carrots by quality class.”

The content of radionuclides, toxic elements, pesticides and nitrates in carrots should not exceed the permissible levels established by #M12291 9052436 SanPiN2.3.2.560 S. According to sanitary and hygienic standards approved by the USSR Ministry of Health in 1988, the maximum permissible level nitrate content (MPC) in early carrots (before September 1) is 400 mg/kg wet weight, in late carrots - 250 mg/kg wet weight.

Non-standard vegetables include root vegetables (over acceptable standards): size of the largest transverse diameter is less than 2.5 cm (up to 1.5 cm inclusive) and more than 6 cm; cracked; broken at least 7 cm long; ugly in shape; branched; with cuts to the heads; damaged by agricultural pests; withered.

Waste includes root crops that are wrinkled, rotten, rotten, frozen, damaged by rodents, crushed, parts of root crops less than 7 cm, steamed, with a transverse diameter of less than 1.5 cm.

Diseases and defects of carrots

Great damage to carrots during the growing season of the seeds and during storage of root crops is caused by fungal, viral and bacterial diseases.

The most common are black, white, dry, gray, bacterial rot and other diseases. See Appendix B for photographs of carrots affected by diseases and pests.

Black rot, or Alternaria

The causative agent is the fungus Alternaria radocina, which affects carrots, celery, parsley, and parsnips. The disease mainly develops during storage. Dry, dark, slightly depressed spots form on root vegetables. At high humidity a dark olive coating appears on them - fungal spores.

On a cut, the affected tissue is coal-black in color and differs sharply from healthy tissue. A rotten root crop does not lose its hardness.

Protective measures. Cultivation of carrot varieties with increased resistance to black rot: Nantes 4, Chantenay 2461, Vita Longa and heterotic hybrids F1 Gribovchanin, Camarillo, Canterbury, Champion.

White rot

White rot is especially dangerous. The causative agent of the disease, the fungus Sclerotinia sclerotiozum, is found on many vegetable crops, but most often carrots and parsley suffer from it. White rot rarely develops in carrot crops, but as soon as the root crop is pulled out of the ground, the carrots lose resistance to this disease. On the affected root crop, a loose white cotton-like coating first appears - mycelium, which in some places becomes denser, curls into white, then blackening hard nodules - sclerotia. Droplets of liquid are released on their surface. The affected root crops soften, and the color of the tissue does not change. White rot is brought into storage with infected root crops and soil and spreads from diseased root crops to healthy ones when they come into contact, so the infection is localized in the form of nests (foci).

The most susceptible to white rot are injured, lethargic and frostbitten root crops. Increasing the temperature in storage to 4-5° increases the damage to root crops.

Wet bacterial rot

Wet bacterial rot (caused by the bacterium Erwinia carotovora Holl) affects parsley, celery, and parsnips along with carrots.

Watery spots form on the tail part of the carrots and the plants wilt. The disease develops especially intensively during storage: rot quickly spreads throughout the entire root crop. It becomes slimy, watery, its tissues decompose, emitting bad smell. Affected carrots turn into soft pulp and infect healthy root crops lying next to them.

Gray rot

Gray rot (causative agent Botrytis cinerea) also affects withered, mechanically damaged or frostbitten root crops. A thick grayish coating of mold appears on them. Later, small (2-7 mm) round or slightly flattened black sclerotia form among the gray plaque, and the affected tissue turns brown. The number of diseased root crops increases when carrots are stored in the same room as cabbage, which is also affected by gray rot.

Protective measures. There are no varieties resistant to these diseases. If white and gray rot are detected, foci of the disease are carefully removed. But the root vegetables are not sorted, otherwise the infection can be spread. The place where the diseased carrots were located is pollinated with chalk or fluff lime.

Rhizoctoniosis (felt disease)

The causative agent of the disease is the fungus Rizoctonia violaceae. Infection occurs in the second half of summer. The leaves of diseased plants wither, turn yellow and die. Subcutaneous gray-lead spots appear on root crops. Gradually they turn red, are slightly pressed in and are covered at first with a colorless, later with a reddish-violet dense felt coating of mycelium. Then numerous, very small black sclerotia of the fungus form on the root crop. The affected root crop dries out and sometimes rots. The disease continues to develop in the storage facility.

The source of infection is soil and diseased plants. In the garden, rhizoctonia appears in patches during heavy rainfall, warm weather, in low places, on acidic heavy soils.

Protective measures. Acidic soils are limed. Carrots and other vegetables that are affected by rhizoctonia disease should be returned to their original place no earlier than after four years.

Fomoz, or dry rot

The causative agent of the disease is the fungus Phoma Rostrupii Sacc.. It appears on plants in the form of dry rot at the end of the growing season and during winter storage carrots.

Slightly depressed dark brown spots form on the head of the root crop (small black dots the size of poppy seeds are sometimes visible on them - these are pycnidia with fungal spores). On a section, the tissue is brownish-brown, loose, often with voids lined with white fluff - the mycelium of the pathogen.

The source of infection is contaminated seeds, roots and plant debris. The carrot varieties Nantskaya 4 and Moskovskaya Zimnyaya are relatively resistant to Phoma.

Fusarium rot

The disease manifests itself in the form of dry and wet rot. With dry rot, depressed light spots are observed on carrot roots, which, growing, form concentric folds. The affected tissue is light or light brown, strongly compacted in the center, with small voids, and a sharp border.

Powdery mildew

Widespread and harmful during the growing season of plants. The causative agent is the fungus Erysiphe umbelliferarum. It affects all above-ground parts of carrot plants of the first and second years of life, on which a powdery white coating forms. The affected leaves are depleted by pathogenic mycelium and prematurely become coarse, age and dry out.

Cercospora

The causative agent is the fungus Cercospora carotae. The disease often occurs together with Alternaria, but manifests itself earlier. It affects young leaves, sometimes stems, and flower stalks of seed plants. Forms oval spots, often red or white. Root crops are not affected.

Diseases manifest themselves in the form different types carrot rots developing with the participation of fungi of the genus Pythium. Pythiosis, in addition to the death of seedlings, causes rusty-brown rot of root crops, accompanied by wilting of leaves and dwarfing of carrot plants.

The causative agent is mycoplasma, which causes jaundice in aster. A bunch of leaves gradually acquires a pale yellow color, and sometimes the leaves curl. The root crop decreases, and bundles of small roots develop on the surface. Root vegetables have an unpleasant appearance and bitter taste.

Nematode damage

Nematodes attack root crops by penetrating the roots. As a result, shortening, deformation and lignification of root crops occur. There are also root-knot nematodes that form swellings called galls on the roots.

Pest damage

Storage and transportation conditions.

Carrots are stored in accordance with GOST 28275-94 “Fresh table carrots. Storage Guidelines", according to which carrots are stored in stationary storage facilities with natural cooling, and, if necessary, long-term storage- in refrigerators.

Storing carrots in stationary storage facilities

Carrots can be stored in pallets, boxes, bags or in bulk. If it is placed in bulk, then the height of the embankment should be taken depending on the strength properties of a given botanical carrot variety, the quality of the batch and ventilation conditions. The recommended height of the embankment is 2-3 m. When storing carrots in bags maximum height stacks - 3 m.

The temperature in storage facilities is maintained between 0 and 5 °C. The optimal temperature for storing carrots is from 0 to 1 °C.

The relative humidity in chambers with a forced ventilation system (with natural cooling) should be maintained between 90 and 95%.

Air circulation must ensure that the temperature and relative humidity of the air can be constantly maintained. Air circulation should be quite intense, i.e. from 100 to 120 m/t h, if carrots are stored in bulk and the height of the embankment is close to the established maximum value.

Shelf life of carrots specified conditions storage period is at least 4 months.

Storing carrots in refrigerators

Long-term storage of carrots is carried out in refrigerators with general ventilation.

Carrots are loaded into the chamber packed in box pallets with open liners made of polyethylene film 80-120 microns thick or without these liners, as well as in boxes S. To load the chamber with carrots packed in boxes, packages are formed on flat pallets S, stacking them in fives of 20-25 pieces. for each pallet. The length of the protruding parts of the package on each side of the flat pallet is no more than 0.04 m. The distance between the boxes in the package is not less than 0.02 m.

Before loading carrots, the air temperature in the chamber should be reduced to -1-0°C. After the chamber is fully loaded, the air temperature in it is brought to 0-1°C no more than 24 hours in advance, and then maintained within these limits until the end of storage. In this case, the air temperature at the cold point of the free space of the useful volume of the chamber should not be lower than -1°C.

Relative humidity in refrigeration chamber should be 90-95%. Air circulation in the chamber during cooling of carrots is carried out continuously with a multiplicity of 10-12 volumes of an unloaded chamber per hour.

At the end of storage or when unloading carrots from the chamber, provide conditions that prevent moisture condensation on its surface (for example, blowing warm air).

The shelf life of carrots after removal from storage should not exceed 10 days.

Storing carrots in a retail chain (according to GOST 51782-2001)

Relative air humidity during storage should be 85-90%.

Carrots are transported by covered road transport in accordance with the rules for the transportation of perishable goods in force for this type of transport. It is allowed to transport carrots in open vehicles that protect the products from precipitation and temperatures below 0 °C.

PLAN

Diseases and injuries

Lecture 10

Topic: Root vegetables. The nutritional value. Expertise.

1 Requirements for the quality of carrots

2 Requirements for beet quality

Root vegetables are vegetables whose thickened, overgrown roots are used for food. These include vegetable plants from different botanical families: Umbelliferae - carrots, parsley, celery and parsnips; goosefoot - beets; Cruciferous vegetables - rutabagas, radishes, radishes and turnips.

Carrot(Daucus carota L.) is one of the main vegetable crops in Russia. Carrot roots have high nutritional and dietary value. Root vegetables are especially rich in sugars, the content of which is the best varieties reaches 12%. Carrots are a source of carotenoids, in particular /3-carotene, many vitamins and minerals. Daily consumption of carrots strengthens the body and increases its resistance to infectious diseases.

The taste benefits of carrots are due to the presence of aromatic and phenolic compounds in them. There are few phenolic compounds in fresh carrots; during storage and especially when the carrots wither, their amount increases, which leads to the appearance of bitterness. Energy value carrots is 33 kcal/100 g of edible portion. The recommended consumption rate for fresh carrots is 11 kg per year.

Carrot roots consist of a skin, an outer layer - the bark, or pulp - and an inner layer - the core. The bark has a large nutritional value than the core, so carrots with a small core are preferable.

The main characteristics used in identifying the economic and botanical variety of carrots include: length and shape of root crops, color, surface condition, core size, carotene content, shelf life, taste. The shape of root crops can be round, cylindrical, conical; By length, there are short root vegetables (carotels) - up to 8 cm, semi-long ones - up to 20 cm and long ones - more than 20 cm. Karoteli have a small core, bright orange pulp, but are poorly preserved. Varieties with elongated root crops are well preserved, but most of them have a large core and coarse pulp, which is why they are inferior to other varieties in terms of taste.

The quality of fresh carrots is assessed according to GOST 1721-85 “Fresh table carrots prepared and supplied” and GOST 26767-85 “Fresh table carrots sold in retail chains”.

According to GOST 26767-85, carrots for retail and public catering, depending on quality, are divided into two commercial grades: ordinary and selected. Selected carrots must be washed or dry-cleaned and packaged.

The quality requirements for fresh carrots harvested and supplied according to GOST 1721-85 basically correspond to the requirements for ordinary variety carrots.

It must be fresh, unfaded, disease-free, whole, uncracked, dry, uncontaminated, free from damage by pests, uniform in color characteristic of the given botanical variety, not ugly in shape, with petioles no more than 2 cm long and a maximum transverse diameter of 2 .5-6.0 cm. In standard carrots, the following are allowed in % of weight, no more: root vegetables with deviations from the established sizes by 0.5 cm - 10; root crops are cracked, broken, ugly in shape (but unbranched), with improperly cut tops (cut heads) - in total 5.0. Cracked and broken root vegetables are not allowed for canning enterprises. The presence of soil adhering to root crops should be no more than 1% of the mass.

Separately, only standards for the content of broken root vegetables are established for canning industry enterprises - no more than 2%. Cracked root vegetables are also not allowed.

Non-standard ones include root crops (exceeding the permissible norms): with a maximum transverse diameter of less than 2.5 cm (up to 1.5 cm inclusive) and more than 6 cm;

cracked; broken at least 7 cm long; ugly in shape; branched; with cuts to the heads; damaged by agricultural pests; withered.

Waste includes root crops that are wrinkled, rotten, rotten, frozen, damaged by rodents, crushed, parts of root crops less than 7 cm, steamed, with a transverse diameter of less than 1.5 cm.

Most often, carrots are affected by the following diseases: bacterial rot (white, gray, black, red, wet), fomoz, gray mold and white scab.

Phoma - caused in carrots by the fungus Phoma rostrupii Sac, in beets - Phoma betae Frank. When harvesting carrots, fomoz is found on the top of the root crop in the form of dry rot; during winter storage, gray spots appear, around which the flesh becomes rotten and acquires a dark brown or brown color. In beets, the disease starts from the head and affects inner fabrics, forming dark brown or black spots. In root crops, this disease can only be detected on a cut.

Quality indicators for fresh carrots are determined in accordance with GOST R 51782-2001 “Fresh table carrots sold in retail chains” (Appendix A).

Carrots, depending on quality, are divided into three classes: extra, first and second. Extra class carrots must be washed, first and second class carrots must be washed or dry peeled.

According to GOST R 51782-2001, carrots must have the following organoleptic characteristics and root size (Table 1):

Table 1. “GOST requirements and standards for carrots by quality class.”

The content of radionuclides, toxic elements, pesticides and nitrates in carrots should not exceed the permissible levels established by #M12291 9052436 SanPiN2.3.2.560 S. According to sanitary and hygienic standards approved by the USSR Ministry of Health in 1988, the maximum permissible level of nitrates (MPC) in early carrots (before September 1) - 400 mg/kg wet weight, in late carrots - 250 mg/kg wet weight.

Non-standard ones include root crops (exceeding the permissible norms): with a maximum transverse diameter of less than 2.5 cm (up to 1.5 cm inclusive) and more than 6 cm; cracked; broken at least 7 cm long; ugly in shape; branched; with cuts to the heads; damaged by agricultural pests; withered.

Waste includes root crops that are wrinkled, rotten, rotten, frozen, damaged by rodents, crushed, parts of root crops less than 7 cm, steamed, with a transverse diameter of less than 1.5 cm.

Diseases and defects of carrots

Great damage to carrots during the growing season of the seeds and during storage of root crops is caused by fungal, viral and bacterial diseases.

The most common are black, white, dry, gray, bacterial rot and other diseases. See Appendix B for photographs of carrots affected by diseases and pests.

Black rot, or Alternaria

The causative agent is the fungus Alternaria radocina, which affects carrots, celery, parsley, and parsnips. The disease mainly develops during storage. Dry, dark, slightly depressed spots form on root vegetables. With high humidity, a dark olive coating appears on them - fungal spores.

On a cut, the affected tissue is coal-black in color and differs sharply from healthy tissue. A rotten root crop does not lose its hardness.

Protective measures. Cultivation of carrot varieties with increased resistance to black rot: Nantes 4, Chantenay 2461, Vita Longa and heterotic hybrids F1 Gribovchanin, Camarillo, Canterbury, Champion.

White rot

White rot is especially dangerous. The causative agent of the disease, the fungus Sclerotinia sclerotiozum, is found on many vegetable crops, but carrots and parsley most often suffer from it. White rot rarely develops in carrot crops, but as soon as the root crop is pulled out of the ground, the carrots lose resistance to this disease. On the affected root crop, a loose white cotton-like coating first appears - mycelium, which in some places becomes denser, curls into white, then blackening hard nodules - sclerotia. Droplets of liquid are released on their surface. The affected root crops soften, and the color of the tissue does not change. White rot is brought into storage with infected root crops and soil and spreads from diseased root crops to healthy ones when they come into contact, so the infection is localized in the form of nests (foci).

The most susceptible to white rot are injured, lethargic and frostbitten root crops. Increasing the temperature in storage to 4-5° increases the damage to root crops.

Wet bacterial rot

Wet bacterial rot (caused by the bacterium Erwinia carotovora Holl) affects parsley, celery, and parsnips along with carrots.

Watery spots form on the tail part of the carrots and the plants wilt. The disease develops especially intensively during storage: rot quickly spreads throughout the entire root crop. It becomes slimy, watery, its tissues decompose, emitting an unpleasant odor. Affected carrots turn into soft pulp and infect healthy root crops lying next to them.

Gray rot

Gray rot (causative agent Botrytis cinerea) also affects withered, mechanically damaged or frostbitten root crops. A thick grayish coating of mold appears on them. Later, small (2-7 mm) round or slightly flattened black sclerotia form among the gray plaque, and the affected tissue turns brown. The number of diseased root crops increases when carrots are stored in the same room as cabbage, which is also affected by gray rot.

Protective measures. There are no varieties resistant to these diseases. If white and gray rot are detected, foci of the disease are carefully removed. But the root vegetables are not sorted, otherwise the infection can be spread. The place where the diseased carrots were located is pollinated with chalk or fluff lime.

Rhizoctoniosis (felt disease)

The causative agent of the disease is the fungus Rizoctonia violaceae. Infection occurs in the second half of summer. The leaves of diseased plants wither, turn yellow and die. Subcutaneous gray-lead spots appear on root crops. Gradually they turn red, are slightly pressed in and are covered at first with a colorless, later with a reddish-violet dense felt coating of mycelium. Then numerous, very small black sclerotia of the fungus form on the root crop. The affected root crop dries out and sometimes rots. The disease continues to develop in the storage facility.

The source of infection is soil and diseased plants. In the garden, rhizoctonia blight appears in patches during heavy rainfall, warm weather, in low places, and on acidic heavy soils.

Protective measures. Acidic soils are limed. Carrots and other vegetables that are affected by rhizoctonia disease should be returned to their original place no earlier than after four years.

Fomoz, or dry rot

The causative agent of the disease is the fungus Phoma Rostrupii Sacc.. It appears on plants in the form of dry rot at the end of the growing season and during winter storage of carrots.

Slightly depressed dark brown spots form on the head of the root crop (small black dots the size of poppy seeds are sometimes visible on them - these are pycnidia with fungal spores). On a section, the tissue is brownish-brown, loose, often with voids lined with white fluff - the mycelium of the pathogen.

The source of infection is contaminated seeds, roots and plant debris. The carrot varieties Nantskaya 4 and Moskovskaya Zimnyaya are relatively resistant to Phoma.

Fusarium rot

The disease manifests itself in the form of dry and wet rot. With dry rot, depressed light spots are observed on carrot roots, which, growing, form concentric folds. The affected tissue is light or light brown, strongly compacted in the center, with small voids, and a sharp border.

Powdery mildew

Widespread and harmful during the growing season of plants. The causative agent is the fungus Erysiphe umbelliferarum. It affects all above-ground parts of carrot plants of the first and second years of life, on which a powdery white coating forms. The affected leaves are depleted by pathogenic mycelium and prematurely become coarse, age and dry out.

Cercospora

The causative agent is the fungus Cercospora carotae. The disease often occurs together with Alternaria, but manifests itself earlier. It affects young leaves, sometimes stems, and flower stalks of seed plants. Forms oval spots, often red or white. Root crops are not affected.

Diseases manifest themselves in the form of different types of carrot rots, developing with the participation of fungi of the genus Pythium. Pythiosis, in addition to the death of seedlings, causes rusty-brown rot of root crops, accompanied by wilting of leaves and dwarfism of carrot plants.

The causative agent is mycoplasma, which causes jaundice in aster. A bunch of leaves gradually acquires a pale yellow color, and sometimes the leaves curl. The root crop decreases, and bundles of small roots develop on the surface. Root vegetables have an unpleasant appearance and bitter taste.

Nematode damage

Nematodes attack root crops by penetrating the roots. As a result, shortening, deformation and lignification of root crops occur. There are also root-knot nematodes that form swellings called galls on the roots.

Pest damage

Storage and transportation conditions.

Carrots are stored in accordance with GOST 28275-94 “Fresh table carrots. Storage Guidelines,” according to which carrots are stored in stationary storage facilities with natural cooling, and, if long-term storage is necessary, in refrigerators.

Storing carrots in stationary storage facilities

Carrots can be stored in pallets, boxes, bags or in bulk. If it is placed in bulk, then the height of the embankment should be taken depending on the strength properties of a given botanical carrot variety, the quality of the batch and ventilation conditions. The recommended height of the embankment is 2-3 m. When storing carrots in bags, the maximum stack height is 3 m.

The temperature in storage facilities is maintained between 0 and 5 °C. The optimal temperature for storing carrots is from 0 to 1 °C.

The relative humidity in chambers with a forced ventilation system (with natural cooling) should be maintained between 90 and 95%.

Air circulation must ensure that the temperature and relative humidity of the air can be constantly maintained. Air circulation should be quite intense, i.e. from 100 to 120 m/t h, if carrots are stored in bulk and the height of the embankment is close to the established maximum value.

The shelf life of carrots under the specified storage conditions is at least 4 months.

Storing carrots in refrigerators

Long-term storage of carrots is carried out in refrigerators with general ventilation.

Carrots are loaded into the chamber packed in box pallets with open liners made of polyethylene film with a thickness of 80-120 microns or without these liners, as well as in boxes S. To load the chamber with carrots packed in boxes, packages are formed on flat pallets S, laying them in fives 20-25 pcs. for each pallet. The length of the protruding parts of the package on each side of the flat pallet is no more than 0.04 m. The distance between the boxes in the package is not less than 0.02 m.

Before loading carrots, the air temperature in the chamber should be reduced to -1-0°C. After the chamber is fully loaded, the air temperature in it is brought to 0-1°C no more than 24 hours in advance, and then maintained within these limits until the end of storage. In this case, the air temperature at the cold point of the free space of the useful volume of the chamber should not be lower than -1°C.

The relative humidity in the refrigerator compartment should be 90-95%. Air circulation in the chamber during cooling of carrots is carried out continuously with a multiplicity of 10-12 volumes of an unloaded chamber per hour.

At the end of storage or when unloading carrots from the chamber, provide conditions that prevent moisture condensation on its surface (for example, blowing warm air).

The shelf life of carrots after removal from storage should not exceed 10 days.

Storing carrots in a retail chain (according to GOST 51782-2001)

Relative air humidity during storage should be 85-90%.

Carrots are transported by covered road transport in accordance with the rules for the transportation of perishable goods in force for this type of transport. It is allowed to transport carrots in open vehicles that protect the products from precipitation and temperatures below 0 °C.