Postharvest handling of Brassica vegetables
Respiration and transpiration are the most important postharvest processes affecting storage life and quality of vegetables.
Postharvest life can be prolonged and quality can be maintained by reducing the rate of respiration and transpiration.
Brassica vegetables are also known as crucifers and include broccoli, cauliflower, cabbage, Chinese cabbage and Brussels sprouts.
To reduce the rate of respiration and transpiration of vegetables, care should be taken to ensure temperature, humidity and air movement are optimised for storage. Good practice for vegetable storage starts immediately after harvest.
Temperature
Freshly harvested high quality brassica vegetables should be cooled rapidly to below 2°C and stored between 0 and 2°C.
Pre-cooling and storage at low temperatures slow down the physiological and biochemical processes associated with deterioration and decay. Low temperatures also reduce water loss through transpiration and delay the growth of micro-organisms which cause rot. An increase in the temperature of 10°C can increase the rate of deterioration and decay by two to three times.
When and how to pre-cool?
Start cooling to remove field heat to less than 2°C within four hours after harvesting.
The most common and effective pre-cooling method for Brassica vegetables is forced-air cooling to cool vegetables within two to six hours. This draws cool air through the product in ventilated containers, bins, crates or packages — usually on pallets — and rapidly lowers the temperature of the produce. The main advantages of forced-air cooling is that it is simple to use and can be easily accommodated into grading/packaging/storage systems.
Hydro-cooling is another effective method. This cools the produce with chilled, chlorinated water (temperature 0.5°C; chlorine 100 to 300ppm; pH 7.3 to 7.6) but is more difficult than forced-air cooling as more sophisticated equipment is needed.
With broccoli, crushed or flaked ice is sometimes used to remove field heat quickly but there is a danger the ice may injure the florets, causing an entry point for soft rot micro-organisms such as Erwinia and Pseudomonas.
Relative humidity
Brassica vegetables should be stored at relative humidity higher than 90%.
Although relative humidity of air increases when air is cooled, it is still necessary to check that the relative in a coolroom is satisfactory. In low temperature coolrooms (1°C), water is continually lost during defrost cycles. This is because the water which comes from the air, the vegetables and which freezes the evaporator coil, is melted and drained out of the coolroom.
Minimise water loss from a coolroom and the vegetables by using a large evaporator coil to keep defrosting to a minimum. A large coil allows a low temperature differential (TD) of around 3°C to be maintained between the coolroom air returning to the evaporator and the refrigerant within the evaporator coil, thereby minimising icing up.
Adding moisture
Moisture can be added to coolroom air in a variety of ways including wetting down the floor and hanging wet hessian ‘curtains’. Water can also be added by using humidifiers, wetting containers and sprinkling products with water.
Controlling air movement
Rapid air movement over exposed perishables can sweep water molecules away from the vegetables resulting in higher rates of water loss, dehydrating the vegetables. Stop this problem by controlling air circulation in the coolroom and using protective covers over the products.
Postharvest handling of Brassica vegetables
Page last updated: Tuesday, 17 October 2017 - 8:43am
Other storage life factors
Harvesting and maturity
Harvest vegetables early in the morning when temperatures are cool. The higher the temperature of the products, the greater the need for refrigeration for cooling and the greater the cost. High temperatures increase the rate of respiration and deterioration. Once harvested, exposure of vegetables to the sun causes shrivelling and rapid quality deterioration.
Before transport to a packing shed, ensure vegetables are kept in the shade in a shed or at least under a tree in a paddock. They should be transported with a cover to the packing shed for pre-cooling no more than four hours after harvesting.
It is very important to harvest vegetables at the correct maturity and size for marketing. The requirements for local and overseas markets often differ.
Environmental factors and nutrition
Keeping quality depends on temperature, light and mineral nutrition during growth, and balanced use of irrigation and pesticides. Calcium is an important nutrient for long storage life.
Product quality
Products should be as free as possible from breaks, bruises, decay and other damage which increases moisture loss and provides entry points for bacteria and fungi.
Ethylene
Storage areas must be free of ethylene. A natural ripening hormone, ethylene leads to deterioration in vegetables. It is produced by fruit and vegetables as part of their physiological processes. Any damage, bruise, mechanical injury or other kind of stress sustained during harvesting, storage and transportation process will promote ethylene production.
Do not store vegetables with apples, pears, avocados, kiwifruit, stone fruits, tomatoes and melons. More information on Storage of fresh fruit and vegetables and Mixed storage of fruits and vegetables is available.
Packaging
Suitable packaging can facilitate handling, protect the produce, extend storage/shelf life and help to maintain good quality. Vegetables should be tightly packed with a plastic liner to maintain moisture content in storage, reducing water loss and shrivelling helping to maintain quality.
Active packaging, for example, modified atmosphere packaging using sealed polyethylene bags, creates an atmosphere inside the package which slows the ageing/deterioration process. Active packaging material is a plastic film which can be used as a wrap or liner for produce inside a carton or a pallet.
Additionally, sachets of an ethylene absorber can be added to the packaging. This limits the availability of oxygen and builds up the level of carbon dioxide while absorbing the ethylene. The active packaging film partially blocks the escape of carbon dioxide, but does not allow oxygen to remain above certain limits.
CAULIFLOWER PACKING
CAULIFLOWER
Cauliflower, that is free of any handling damage, and that has
been pre-cooled quickly following harvest to temperatures below
5ºC, can be stored successfully in PEAKfresh carton liners for three
to four weeks. The market value of cauliflower is determined by its
appearance and in particular the cleanliness of the white flower or
curd. Keeping the curd clean is an important part of handling,
particularly when a full cauliflower is trimmed of its protective leaves
ready for sale. Cauliflower is also subject to freezing damage which
results in browning of the curd and the appearance of soft rot
bacteria. Temperature control is important in maintaining the storage
life of the cauliflower. Cauliflower is very sensitive to the presence of
ethylene gas.
Recommended Post Harvest Temperatures
0ºC (32ºF) above 95% humidity.
Packaging Method:
Bulk storage of cauliflower should be kept in slatted crates to allow maximum air flow. Cauliflower can be successfully
wrapped individually in PEAKfresh bags. It is not necessary to use a carton liner when individual heads of cauliflower
are wrapped. Bulk cauliflower flower that is wrapped in tissue paper can be packaged into aPEAKfresh carton liner and
folded at the top, not sealed. Where cauliflower is being transported to areas where there is a likelihood of inadequate
refrigeration, then PEAKfresh sheets should be used to line the bottom and top of the packaging carton and as a divider
between two separate layers of cauliflower.
Complete line for processing cauliflower, including raw material reception; feeding; automatic floretting machines; inspection conveyors; machinery for washing, draining, spin drying, sorting by size, and packaging (in collaboration with EFS Packaging www.efs-packaging.com, Spanish industry leader).
Backed by our ample experience in cauliflower processing, we design the machinery according to your needs with production levels starting at 1,000 kg/ hour. We listen to your processing needs, offer advice and assist you in your choice of the best equipment for your specific requirements. We design and manufacture the machinery, install and start up the machinery and offer post-sales service.
Line fully integrated into your facility, adapted to your production needs and available space.
CAULIFLOWER HARVESTING AND PACKING
Cauliflower processing line
Basic or complete, fully integrated processing line for freshly cut, packaged, ready-to-use cauliflower. Different optional and fully customised levels of automation depending on preference and requirements. Advice and turnkey delivery.
Vegetables like lettuce, broccoli, cabbage and cauliflower are highly perishable products, and have a very short shelf life, usually around six days after harvest.
A normal harvest consists of removing the vegetables from the ground, placing them into plastic crates and transporting them to cleaning, weighing and packing facilities. This usually takes around 24 to 36 hours (more than 20% of the already short shelf-life), with the by-product of the cleaning process (the damaged outer layers that are trimmed off) being transferred to the packing station, before they are disposed of elsewhere.
A field with lettuce ready to be harvested
A field with lettuce ready to be harvested
All of the vegetables displayed below were harvested, cleaned, weighed, labelled and boxed in the field, using one of Brimapack's mobile harvesting units.
Iceberg brocoli
Nicely packeged Iceberg
Radicchio
Nicely wrapped red cabbache
Melons
Nicely wrapped and boxed melons
China lettuce
Nicely wrapped and boxed China Lettuce
Lettuce
Nicely wrapped and labeled lettuce
Broccoli
Nicely, wrapped, labeled and boxed broccoli
Mobile harvesting units for cleaning, weighing and packing vegetables
Instead of transporting the harvest in plastic boxes to a fixed packing station, the packing station comes to the field. These mobile and adaptable units drive slowly through the field, where the cutters, in front of the unit, cut and clean the produce by hand and place it in the front end of the unit. The produce is then lifted inside the mobile unit, where it is cleaned (the damaged outer layers are removed) and placed into the packaging machine. After being wrapped, the finished product is weighed, labelled and placed into boxes, ready to be transported directly to supermarket chain storage facilities, for example.
The cuttings from the cleaning process are returned to the field, where after the harvest they are ploughed back into to the soil as organic material. The waste does not need to be handled or transported.
Mobile harvesting and packing unit for vegetables
Mobile harvesting and packing unit for vegetables
What happens inside this self-propelled unit?
Take a closer look at how the produce is harvested and fed into the unit. It is cleaned, wrapped, weighed, labelled, and sorted into boxes, ready to be delivered straight onto the shelves of a shop or, in the case of a supermarket, to its central storage facility.
Harvesting and packing lettuce in the field
Cutters working in the tent in front of the unit harvest the produce at its stem and place it into containers which take it to the cleaning and packaging area of the unit.
Harvesting the lettuce
The freshly harvested produce is lifted into an area where it is cleaned, before being moved into another set of containers to be automatically weighed, wrapped and labelled. Once wrapped, weighed and labelled, the produce is placed into boxes by hand.
The waste cuttings are placed on small conveyors at either side of the cleaning equipment and returned to the field to the rear of the mobile unit.
Harvesting the lettuce
The packaging, weighing and cleaning equipment. Please watch the video to see the complete process.
Video of the complete process: harvesting, cleaning, packaging, weighing and boxing of lettuce in the field
Harvesting the lettuce
Once cleaned, wrapped, weighed and labelled, the produce is put into boxes by hand, and is ready to be transported from the field directly to stores or storage facilities.
The whole installation can be monitored from a mobile phone. Many units are equipped with a very precise GPS system. The coordinates of the harvest are fed into the system, and these coordinates are used to direct the entire harvesting unit across the field, taking the most efficient route, and avoiding any damage to the crop.
The harvesting unit can be operated by mobile phone
Here the finished product is placed into boxes
Mobile harvesting and packing unit for vegetables
One of BrimaPack's harvesting units called the E-Drive:
Mobile harvesting and packing unit for vegetables
By day!
Mobile harvesting and packing unit for vegetables
One of BrimaPack's harvesting units, called the E-Drive, in action in Germany:
Mobile harvesting and packing unit for vegetables
By night!
Mobile harvesting and packing unit, for vegetables, at night
Mobile harvesting and packing unit, for vegetables, at night
A slghtly smaller, but more flexible harvesting machine. Can harvest Iceberg and cauliflower
Mobile harvesting and packing unit for vegetables
How does the sructure look like from the inside?
Mobile harvesting and packing unit for vegetables
Mobile harvesting and packing unit for vegetables
Next up: Onion transport & potato transport during the harvest.
Cauliflower when eaten raw from your garden is moderately rich in Vitamin A, Vitamin C, calcuim, and phosphorus. Cauliflower is prepared best by steaming to save the water-soluble vitamins, such as Vitamin C. This vegetable is low in calories, fat, and sodium, however, adding cheese sauce, high fat dips, and butter or margarine will cancel these nutritional benefits.
Planting and Harvesting Cauliflower
The best time to plant cauliflower in Central Texas is January to February and September to October. Harvest will occur during April to May and November to December.
Planting and Harvesting Cauliflower
Plant Cauliflower Harvest Cauliflower
January to February April to May
September to October November to December
Storing Harvested Cauliflower
Cauliflower should be washed thoroughly and stored in the refrigerator in a plastic bag. It retains its fresh flavor better if used within one week of harvest.
Choosing Cauliflower for Freezing
Harvest the heads as soon as they turn a clean, white color. Do not choose heads that have spots or bruises (for this indicates insect damage) and do not let the heads flower out.
To prepare the heads for freezing, separate into florets and cut into 1-inch pieces. To blanch these pieces, soak for 1/2 hour in a solution of 4 teaspoons pickling salt to 1 gallon of water. Drain solution from cauliflower pieces. To blanch, use 4 teaspoons of pickling salt to 1 gallon of water and boil for 3 minutes. Drain and cool immediately in ice cold water. Drain again and place in appropriate packaging and freeze immediately.
Blanching Procedures for Cauliflower
Cut into 1-inch pieces.
Blanch for 3 minutes in salted water (4 teaspoons pickling salt to 1 gallon water).
The following recipe is presented so that you and your family may enjoy your home-grown cauliflower straight from your garden.
Cauliflower Farming Software
Farmsoft cauliflower farming software makes farming easy, reduces administration costs, and helps to improve yield across the entire farm.
Farmsoft cauliflower farming software uses best practice management systems to ensure maximum cauliflower yield by guiding employees through the farming process, ensuring spray, irrigation, and all other farm tasks are performed at the correct time using the correct materials. Download full cauliflower farming software details here, or visit our main farm software site for full details.
Contact an expert farmsoft cauliflower farming software consultant today to discuss improving your cauliflower farms yield, profit, and traceability.
Farmsoft’s cauliflower farming software includes mobile farming apps to keep you mobile, informed, and allow monitoring of your farms at all times. Use the “multi-farm” functionality of farmsoft’s cauliflower farming software to manage multiple farms independently – each farm can see their own information, but not the information from other farms in your group. Obviously head office can see information from all farms. Perfect for cooperatives or farming enterprises with many farming sites geographically dispersed across one or more countries.
Farmsoft cauliflower farming software can also be optionally integrated (seamlessly) with farmsoft cauliflower packing software. The farmsoft cauliflower packing solution manages the entire packing, sorting, grading, washing, inventory, storage, quality control, dispatch, sales, and orders processes.
Cauliflower farming software for improvements in traceability, yield, profit, and farm record keeping.
Investigations were carried out to see the impact of blanching time, pretreatment and storage and packaging on the physico-chemical properties of solar dehydrated cauliflower. The processing treatments selected for the study were blanching time of 3, 5, 7 and 9 min, potassium metabisulphite (KMS) pretreatment having 0.5%, 1.0% and 1.5% concentration level and storage in high-density polyethylene, laminated aluminium foil and polypropylene. The cauliflowers were further processed and dehydrated in solar dryer before packing it into different packaging materials. Packed dehydrated cauliflower was stored for 6 months at room temperature. The stored cauliflower samples were tested periodically for their moisture content, rehydration ratio, rehydration coefficient, ascorbic acid and browning. Ranking of blanching time, chemical concentration level and packaging materials were statistically analysed by using SAS package. The samples with 9 min blanching time, followed by dipping in 1.0% KMS solution, and packed in laminated aluminium foil showed better results in comparison with other treatments.