Storage And Handling
The quality and safety of onions depends on proper handling and storage. Fresh market retail processing can affect the flavor and quality of the onions people take home.
Always follow proper handling procedures and safe handling guidelines as outlined by the Food and Drug Administration Food Code. Read and follow handling instructions on all processed products according to the manufactures label.
Basic Storage & Handling Tips For Dry Bulb Onions:
Always handle onions with care. Do not drop onions as this often causes bruising and internal decay.
Bagged or boxed onions should be stored at least one foot away from walls and other pallets to allow proper air movement.
Keep stacks of bags or boxes at five feet or less.
Store onions in a cool, dry, well-ventilated area.
Maintain storage temperature of 45-55°F.
Do not wrap onions in plastic or store in plastic bags. A lack of air circulation will reduce shelf life.
Onions should feel firm and dry, be free of gray or black mold, and should not have any visible sprouting. Some loose skins are normal.
Do not store onions with potatoes or other produce items that release moisture.
Keep onions out of direct sunlight and other heat sources.
Cut onions will keep for several days if sealed in plastic bags or containers and refrigerated
In 2010, the U.S. onion industry proactively developed voluntary commodity specific food safety guidelines for the dry bulb onion supply chain. This document serves as guidance for growers and shippers to adhere to best practices and regulations [i.e. Good Agricultural Practices (GAPs) and Good Manufacturing Practices (GMPs)] governing safe vegetable production. Many suppliers regularly test and monitor the aspects of their growing and distribution cycles, and maintain records of those results for filing with the appropriate auditing agencies. This ensures that onions sent fresh for market retail processing are of the highest quality.
The industry supports government efforts to provide a strong food safety regulatory framework. This assures the public appropriate standards are in place and being met by the dry bulb onion supply chain.
It is important to remember dry bulb onions, when removed from the ground, have a non-edible surface that protects the onions and should not be washed in this state. Dry bulb onions are unique. When they have water applied or are washed before the outer skins are removed, it can cause mold and decay to form on the onions. Onions should be kept at optimum storage temperatures that vary as the season progresses, and they should be kept where there is good air circulation.
These guidelines provide recommended food safety practices that are intended to minimize the microbiological hazards associated with dry bulb onions and fresh-cut/frozen onion products. The intent of drafting this document is to provide currently available information on food safety and handling in a manner consistent with existing applicable regulations, standards, and guidelines. The information provided is offered in good faith and believed to be reliable, but is made without warranty, express or implied, as to merchantability, fitness for particular purpose, and/or any other matter. These recommended guidelines were not designed to apply to any specific operation. It is the responsibility of the user of this document to verify that these guidelines are appropriate for its operation.
The publishing trade associations, their members, and contributors do not assume any responsibility for compliance with applicable laws and regulations, and recommend that users consult with their own legal and technical advisors to be sure that their own procedures meet with applicable requirements. No documented food illness outbreaks have been attributed to dry bulb onions at this time. These food safety guidelines are an attempt to be proactive and precautionary.
The guidelines presented in this edition represent a current understanding of conditions and controls that should be considered by every company in the onion supply chain for their respective operations. In some cases, a company may need to consider the guidelines in more than one module. For example, companies involved in Field Packing should also consider the recommendations in the Open Field Production module, and companies involved in Repacking should also consider the recommendations in the Packinghouse module.
Recently, efforts have been made to more prescriptively define food safety practices for some fresh produce commodities, including the use of quantitative “metrics”. While that was considered for this edition, the editors recognized that risks and controls are likely to be different between onion sub-commodities and between growing regions and concluded that sufficient science to set metrics is currently lacking.
Therefore, while the editors believe that this edition provides a comprehensive set of considerations, it is left to a future edition to identify a scientifically-based process for setting quantitative acceptance criteria for those considerations.
Introduction
In 1998, the U.S. Food and Drug Administration (FDA) issued its “Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables.” The practices outlined in this and other documents are collectively known as Good Agricultural Practices or GAPs. GAPs provide general food safety guidance on critical production steps where food safety might be compromised during the growing, harvesting, transportation, cooling, packing, and storage of fresh produce. More specifically GAP guidance alerts the entire supply chain, including fruit and vegetable growers, shippers, handler, packers, processors, and buyers to the potential microbiological hazards associated with various aspects of the production chain including: land history, adjacent land use, water quality, worker hygiene, pesticide and fertilizer use, equipment sanitation, and product transportation. The vast majority of the dry bulb onion industry had adopted GAPs as part of normal production operations. Indeed the majority of dry bulb onion producers undergo either internal or external third-party GAP audits on a regular basis to monitor and verify adherence to their GAPs programs. These audits are often shared with customers as verification of the producer’s commitment to food safety and GAPs. While the produce industry has an admirable record of providing the general public with safe, nutritious fruits and vegetables, it remains committed to continuous improvement with regard to food safety.
In 2004, the FDA published a food safety action plan that specifically requested produce industry leadership in developing the next generation of food safety guidelines for fresh fruits and vegetables. These new commodity-specific guidelines focus on providing guidance that enhances the safe growing, harvesting, processing, distribution, and handling of commodities from the field to the end user. In the last 12 years, the focus of food safety efforts have been on the farm, drying and distribution points, and value-added processing operations. Fruit and vegetable processing operations have developed sophisticated food safety programs largely centered on current Good Manufacturing Practices (GMPs) and the principles of Hazard Analysis and Critical Control Point (HACCP) programs. Food Safety programs for fresh-cut and value added produce have recently been supplemented by FDA’s 2008 “Guide to Minimize Microbial Food Safety Hazards of Fresh-cut Fruits and Vegetables”. As we develop a greater understanding of food safety issues relative to the full spectrum of supply and distribution channels for fruits and vegetables, it has become clear that the next generation of food safety guidelines need to encompass the entire supply chain.
II. Scope and Use of Commodity Specific Food Safety Guidelines for the Dry Bulb Onion Supply Chain
The scope of this document pertains only to dry bulb onions, and fresh cut/frozen onion products. This document does not include considerations for products commingled with non-produce ingredients (e.g. salad kits which may contain meat, cheese, and/or dressings), although the onions used in such products should be produced, harvested, and otherwise handled in a manner consistent with the recommendations in this document. The distribution chain for dry bulb onions can be complex in that onions may be sold direct or indirect to the buyer; onions are often subject to repacking for size and/or quality. As a result, there is no single distribution chain. The distribution chain may be simple or very complex, with onions being handled by a number of entities prior to being offered for sale to the consumer. The model distribution chain for the purpose of this document provides an overview of only a few of the many paths a dry bulb onion can take prior to the end user. It is the intent of this document to cover all significant aspects of the onion supply chain, from production to delivery to the consumer.
Figure 1. General Supply Chain for Dry Bulb Onions
The processes required to store onions properly.
Once they are stored, onions undergo the following processes:
The drying process
The processes of raising or lowering their temperature
Conservation or storage proper
These processes are controlled by the Multiserver from AgroVent systems BV.
The onion drying process
The aims of the onion drying process are:
To remove all of the surface water or moisture from the onion
To dry three or four layers of the onion skin, therefore sealing the onion
To dry the stem and therefore also seal this part of the onion (remember that once the stem is cut, it is left open and must be kept as dry as possible.)
Well dried onions.
Well dried onions.
It is best to dry onions at between 25 and 30° Celsius..
Multiserver
Multiserver
The Multiserver programme for drying onions will ensure that the turbines work the maximum number of hours to extract moisture from the onions as quickly as possible, whilst maintaining the temperature between 25 and 30°C, and the relative humidity between 60% and 65%. In doing so, the aim is not to dehydrate the insides of the bulbs, but rather the 3 or 4 outer layers which separate the bulb from the outside.
This process is completely controlled by the Multiserver, which constantly searches for the mixture of air with the highest drying capacity, by managing the doors, turbines, heaters and condensers.
The processes of raising or lowering the temperature of the onions
Any changes to the temperature of the onions must be gradual and controlled, for two reasons:
To prevent the cells in the bulb from being destroyed.
To ensure that the centre of the bulb is at the same temperature as the outer layers.
This is why the Multiserver has two special programmes to control the heating or cooling of the produce.
Onion storage specialists advise cooling or heating the onions by 2 degrees per day at the very most, and recommend only 0.5 degrees per day.
Such a slow change in the temperature of the onions has important consequences when planning to move the onions from the storage facility.
Let's assume that the onions are stored at 2° Celsius.
The destination of the onions is 25° with 85% relative humidity, making the dew point 22.3°. This means that the onions must be heated by at least 20.3°, to 22.3°. At the maximum allowed increase of 2° per day, this process will take at least 10 days.
These days must be kept in mind when planning the onion delivery.
Especially in hot and humid climates, if the onions are not heated above the dew point, many of them will rot in the humidity.
The onion storage process
A well-dried onion
A well-dried onion has:
Crispy skin and a juicy middle.
Before they can be stored, onions must tick the following boxes:
The onion must be the right variety for storage.
It must be harvested when it is completely physically ripe.
The bulb must be firm and compact.
The skin must be strong.
The bulb must have a low water content.
It must be grown to Good Agricultural Practices.
It must not be fertilised with nitrogen during the last 6 weeks of its growth.
It must be applied sufficient amounts of aglime.
Onions can be stored at two ranges of temperatures.
Between 0 and 4° Celsius
Between 25 and 31° Celsius
Why these two ranges?
The onion, postharvest, is still alive. This means that it continues to respire. All plants give off water when they respire.
The more they respire, the more water they lose, and losing water means losing weight, which is the last thing we want during the storage process.
Below is a graph indicating the relationship between the storage temperature and the intensity of the onion respiration, reflected in the weight (water) loss percentage over 5 months of storage.
Onion respiration with relation to storage temperature
Onion respiration with relation to storage temperature.
The intensity of onion respiration is reflected in the percentage of weight (water) loss over 5 months of storage, with relation to the storage temperature.
There are two ranges in which the onion respires relatively little, and consequently loses less weight:
Cold storage between 0 and 4° Celsius
Heat storage between 25 and 31° Celsius
Danger range:
The temperature range between 20 and 25° Celsius is very dangerous for the onion. It is inside this range that bacteria and fungi, enemies of the onion, are most active. Below and above this range, they remain inactive.
The graph demonstrates that within the range from 0 to 4° Celsius, weight loss is considerably less than within the range from 25 to 31° Celsius. On top of this, between 0 and 4° Celsius, onions can be kept healthy and suitable for storage for up to 12 months. Between 25 and 31° Celsius, they can be kept healthy and suitable for storage for up to 8 or 9 months.
However, when deciding at which range of temperatures to store your onions, you must bear in mind the local climate during storage time.
Why is this?
1) Temperate climates.
In a climate where the temperature varies between -10° Celsius and 15° Celsius it is much cheaper to cool your storage facility to between 0 and 4° Celsius. Less energy is wasted on keeping it cool.
2) Hot or tropical climates.
In a climate where the temperature fluctuates around 30° Celsius it is much cheaper to heat your storage facility to 25 to 31° Celsius. Less energy is wasted on keeping it at the right temperature.
Another consideration is storing onions between 25 and 31° Celsius in the tropics.
Condensation.
As soon as an onion at 2° Celsius is exposed to humid air at 30° Celsius, it becomes moist.
This is what happens if you store onions at between 0 and 4° Celsius in the tropics:
When removing the onions from storage, they must be heated up to the outside temperature. This requires great energy and a lot of time. Meanwhile, onions stored at 30° Celsius can be removed immediately without the risk of moisture.
In both cases:
Relative humidity must be constantly kept between 55% and 65%.
The temperature must remain constant; temperature fluctuations must be avoided during storage.
Bulbs must be kept in darkness. Whenever a light is switched on inside the storage facility, the onions in the light (on top of a pile) will react as if they were in direct sunlight, and start to sprout.
Please note: The onion bulb will lose significant weight through respiration (the bulb is still alive) if it is stored between 5 and 25° Celsius . The range between 20 and 25° is particularly dangerous because bacteria and mould thrive at this temperature.
During storage proper, ventilation must be kept to a minimum, because the onions are already dry (dry means dry!) and we do not want them to lose more weight through respiration, no matter how little that may be at this temperature. The little ventilation required is to avoid an increase in CO2 levels, and to eliminate the heat which the onions generate as they continue to respire slowly.
Onion, a widely consumed vegetable across the country throughout the year, is mainly cultivated in three seasons i.e. during kharif, late kharif, and rabi. The crop being harvested during the rabi accounts for 60% of onion production, hits the markets from March to June. The same crop continues to meet the consumer demand till October-November every year before the kharif crop is harvested and brought to the market. Therefore, it becomes pivotal to successfully store rabi onion so as to maintain its supply in the markets. The Onion is a semi-perishable crop and 30-40% of the crop gets lost during the storage. During natural calamities, the losses go beyond 40% that leads to heavy stress both on demand and supply. The supply volatility creates market distress causing a steep rise in the price of onion that eventually affects the end consumers. A adequate storage facility will help in checking the supply volatility and steep rise in onion prices.
Storage facility available in India
Naturally ventilated structures: In India, the onions are mostly stored in the ventilated storage structures without any control of temperature and relative humidity. The farmers construct the different types of ventilated storage structures based on the capacity required.
Low cost thatched roof bamboo storage structure: This type of storage structure is usually constructed with bamboo framework having the roof made up with sugarcane leaves. This type of storage structure is low cost and easy to construct, but leads up to 42% losses of onion during four months of storage.
Bottom and side ventilated storage structure: This type of structure has a provision of ventilation from bottom and sides. But, still results in increasing the losses up to 46% in four months storage.
Cold storage structure: In such types of storage facilities, the onions are stored at 0-5°C and 60-65% RH that leads to much lesser losses as comparative to ventilated storage structure. The cost of construction and running cost are very high as energy required to maintain the storage facility in the temperature range of 0-5°C is high. The other problems are condensation and require lot of energy and time. The bulbs start sprouting immediately after they are removed from the cold storage.
Design of New Cold Storage
Design of DOGR-cold storageThere is an urgent requirement to develop a well-engineered onion storage structure that can help to maintain the controlled conditions (temperature and relative humidity) that are required to reduce storage losses of onion with low cost of construction and running.
The present invention developed by ICAR-Directorate on Onion and Garlic Research, Pune aims at storing onion bulbs in controlled conditions having proper ventilation that enhances their storage life significantly by utilizing low energy while minimizing sprouting, rotting, and physiological weight loss. The design and development of the cold storage was done under Public Private Partnership mode.
The storage structure was designed for maintaining the temperature of 27 ± 2 °C and RH of 60 to 65% with air circulation system. The losses in the ventilated storage structure were also recorded during the same storage period. The storage structure designed has maintained conditions that are necessary for significantly reducing physiological weight loss, unwanted sprouting and rotting in stored onion bulbs. The concept of DOGR-cold storage has been filed for patent at Patent Office, Mumbai with the application number 201821049581 titled “A storage structure for storing onion bulbs and a method thereof”.
The following was adapted by Roger Bullard for EDN from the book reviewed in this issue, Onion Storage In The Tropics – a practical guide to methods of storage and their selection. The wild species giving rise to the bulb onion (Allium cepa) came from southwestern Central Asia, and from it a variety of landraces and cultivars have been developed which flourish under a wide range of climatic conditions.
Onions are normally harvested at the end of the bulbing process when “the leaf blades are no longer able to support themselves, the neck softens and the leaves collapse. At this point the bulb has reached maturity. It then enters a period of dormancy during which little change appears to occur…"
“Onions grow best under dry conditions and at moderate temperatures. Under these conditions onions mature fully and, if they are cured before storing, may last for a long time without loss of quality.” Onions grown under very hot or wet conditions face difficulties from fungal and bacterial diseases. In addition to lower yields, the storage losses will probably be higher because bulbs may have been infected before they went into storage. Harvesting after the leaves have completely dried but before the bulbs have begun to resprout, and topping (cutting off the leaves) after most of59-5 Permanent shed for outdoor drying of onions (Ministry of Agriculture, Jamaica). the leaf has dried, will decrease storage losses to these plant pathogens. Poor quality “culls” should be removed before the onions are dried and stored.
It is best not to promote excessive bulb growth with too much nitrogen fertilizer and irrigation.
Cultivars vary considerably in how well they store. Cultivars suitable for storage should produce a number of outer dry scales or skins which form a vapor barrier around the bulb, thereby minimizing moisture loss and the entry of fungi or bacteria. Locally adapted onion varieties, selected over many years within the tropics, will probably store better than the imported types, especially the ‘short-day’ varieties from temperate climates.
Permanent shed for outdoor drying of onions (Ministry of Agriculture, Jamaica)
Permanent shed for outdoor drying of onions (Ministry of Agriculture, Jamaica)
Before storing, bulbs should be properly dried and cured. Use some technique that will both remove surface moisture and allow high temperature formation of strong, intact outer protective skins and neck closure of the onion. High temperatures (e.g. 27° C or 80°F), low humidity (< 60% RH) and good ventilation are important in drying. Laying the onions on the soil in windrows is the simplest form of field drying. Alternatively, they may be removed from the field and placed in a heap, or spread in a shallow layer, preferably on a cement slab to avoid contamination of soil-borne pathogens. Problems associated with outdoor drying can include poor drying rates, sun scald, and rain.
A simple outdoor shaded structure can avoid these problems. A good design for natural ventilation is to make shallow trays with screen or woven bottoms. Arrange trays vertically, spaced sufficiently apart to catch the prevailing winds. If clear corrugated plastic sheeting is available, heat required for the curing process can be achieved by using it in the roof structure and thereby capturing passive solar energy.
Maintaining the bulbs at suitable temperature and humidity is vital to the successful storage of onions. The optimum relative humidity range is from 65-75%. There are two favorable temperature regimes. Minimal storage losses occur at 0-5°C (32-41° F), but for the farmer or villager not having refrigeration, 25-30°C (77-86° F) would be the best choice. Temperatures that are either too high or too low will increase rotting or sprouting. These are the greatest enemies to successful storage of onions. A high technology solution to the sprouting problem is to add chemical "sprout suppressants” prior to storage.
Having been cultivated for 5 thousand years, onion has been crowned our salads and meals along with its countless health benefits and strong aroma.
A traditional method of storing onions is drying them with their stalks on and storing in a cool cellar, cave or a dark storage after they are harvested until they are consumed. However, between 40-80% of the onions stored with this method result in spoilage. At the moment, neither economy nor our aged planet can afford these kinds of spoilage anymore.
Onions cannot be stored immediately in cold storage after the harvest. First, onions need to be dried for a few days. Then starts the maturing stage that enables skin and colour formation specific to the onion cultivar. Onions are prepared for cold storage by lowering the temperature at maximum by 0.5 °C per day to reach the ideal cold storage temperature little by little. Depending on the onion variety, they are stored at between 0 °C and +2 °C in cold storage. Onions can be stored in cold storage up to ten months without deterioration. Ventilation is vital in onion storage. After storing, onions are not transported straight from the cold storage before they are put on the market, but heated in temperature-controlled conditions in order to prevent condensation.
It’s a little difficult and complicated process, but worth it. However, only 20 million tonnes of global onion production of 100 million tonnes are stored with modern storage methods and spoilage still continues.
Safe production, packing, processing, distribution, and handling of dry bulb onions and fresh-cut onions depend upon a myriad of factors and the diligent efforts and food safety commitment of all parties throughout the distribution chain. No single resource document can anticipate every food safety issue or provide answers to all food safety questions. These guidelines are not intended to replace other food safety programs, but are meant to be used in conjunction with them to address food safety hazards known to affect the onion supply chain. These guidelines focus on minimizing the microbial safety hazards by providing actions, based on the best available science, that have been shown to be effective to reduce, control, or eliminate microbial contamination of onions in the field to fork supply chain. Because of varietal, regional, and operational practice differences, not all of these actions will be applicable to all onion handling operations. However, it is suggested that all companies involved in the dry bulb onion farm to table supply chain consider the recommendations contained within these guidelines in developing their company-specific food safety program. Every effort to provide food safety education to supply chain partners should be made as well, to ensure that opportunities to prevent contamination are not lost as onions pass from one point of the supply chain to the next. Together with the commitment of each party along the supply chain to review and implement these guidelines, the fresh produce industry is doing its part to provide a consistent, safe supply of produce to the market.
For the purpose of this guidance, the onion supply chain had been divided into seven primary modules:
• open field production,
• harvest practices,
• field packing,
• packinghouse,
• repacking and other distribution operations,
• fresh-cut/frozen processing (value-added), and
• foodservice and retail.
Multiple modules will apply to many users of these guidelines. Users should not assume that a single module will cover their entire dry bulb operation.
Each of these modules contain key considerations for potential sources of contamination of public health concerns that may occur in the absence of control.
III. Open Field Production
The development of good agricultural practices for field dry bulb onion production must consider all the elements of the field production system: field site, land use, adjacent land use, agricultural inputs (e.g., irrigation water, fertilizers), workers, and production practices. Producers are responsible to follow all local, state, and federal labor laws. Food safety risks can occur from a number of sources; evaluation of these risks, and their management, are essential to proper food safety procedures in the production of dry bulb onions.
1. Preventing/Minimizing Risks in the Field ― Field Management
Field producers must give consideration to potential sources of microbial, chemical, and physical food safety risks in the selection and management of production sites.
a. Onion growers should determine previous usage of land if at all possible and should assess and mitigate conditions that may pose food safety risk in and near production fields.
b. Conduct an environmental assessment including topography, land history, risk of flooding, adjacent land use, and domestic animal and wildlife presence.
i. Routinely review field environments and maintain records of assessments and any corrective actions.
ii. Consider the potential for flooding to create conditions that may pose a food safety risk. Flooding is the uncontrolled introduction of “flowing or overflowing of a field with water outside of the grower’s control, that is reasonably likely to contain microorganisms of significant public health concern and is reasonably likely to cause adulteration of the edible portion of fresh produce in that field”. Additional guidance related to flood events can be found in the Appendix.
c. Onion fields should not be located in any area that can receive direct runoff or drainage from a dairy, landfill, other waste, chemical storage, or any other likely source of microbial, chemical, or physical food safety hazards.
d. Steps shall be taken to avoid, prevent, or mitigate run-off into the field from any animal operation or other conditions that may pose a food safety risk.
e. Measures shall be taken to remove or prevent the harvest of onions that have been contaminated by runoff from an animal operation.
f. Procedures used to mitigate risks shall be documented.
2. Animal Exclusion
a. Measures shall be taken to exclude domestic animals and livestock from onion fields.
b. Measures shall be taken to minimize the presence of “Animals of Significant Risk”, such as cattle, goats, sheep, deer, pigs, and other wild and domestic animals. These measures may include the use of barriers or other deterrents, minimizing wildlife attractants and opportunities for harborage, redirecting wildlife to non-sensitive areas, and/or by other methods identified by wildlife experts.
c. If animal intrusion is detected, measures shall be taken to remove or prevent the harvest of any contaminated product.
3. Adjacent Land Use
a. Assess adjacent land use for activities or conditions that may pose a risk to onion safety. Hazards may include, but not be limited to: livestock, wildlife, landfills, sewage treatment, chemical plants, or other conditions that pose a food safety risk.
b. Appropriate measures shall be taken to mitigate any identified food safety hazards. These measures may include berms, fences, ditches, buffer zones, or other strategies to effectively mitigate any hazards.
4. Agricultural Water for Field Use
a. General Requirement:
Water quality shall be adequate for its intended use and shall meet all applicable federal and state laws and regulations.
b. Assessment of Water Source:
i. The responsible party shall identify, assess the adequacy for its intended use, and document all water sources.
ii. When microbial testing is deemed necessary to verify adequacy of source water quality:
1.) Testing shall be performed and documented using standard indicators of fecal pollution, such as E. coli tests. The frequency of testing and point of water sampling shall be determined based on the water source, its particular history, and the outcome of the risk assessment.
2.) The results of a microbial analysis of a water source available from a public source, such as the local water authority, may serve as acceptable documentation in lieu of testing by the grower.
c. Assessment of Water Distribution System
i. The responsible party shall prepare a description of the water system in use. This description should be sufficient to facilitate an assessment of the risk. This description may use maps, photographs, drawings (hand drawings are acceptable), or other means to communicate the location of water source(s), permanent fixtures, and the flow of the water system (including holding systems, reservoirs, or any water captured for re-use).
ii. The responsible party shall perform an initial assessment, followed by a review (or new assessment) any time there is a change made to the system or a situation occurs that could introduce an opportunity to contaminate the system. A water-system assessment shall include an inspection of the water system under the control of the responsible party for the purpose of identifying conditions that may result in contamination with pathogens of concern.
iii. Water systems intended to convey untreated human or animal waste shall be separated from conveyances utilized to deliver agricultural water.
iv. In the event that the assessment identifies conditions that may result in contamination with pathogens of concern, actions shall be taken to correct these conditions.
d. Assessment of Water Use in Crop Production
i. Growers shall assess the use and quality of water, water application methods, application schedules with respect to crop characteristics, and the degree of contact with the edible portion of the crop for the purpose of identifying conditions that may result in contamination with the pathogens.
ii. Based on this assessment, growers shall take appropriate action to eliminate or minimize the potential for contamination.
e. Microbial Testing of Agricultural Water
i. The responsible party shall review the assessments of the water source, water distribution system, and water use in regard to the crop characteristics, pathogens of concern, proximity to harvest, and other relevant factors, and determine the need for microbiological testing of water.
ii. When microbial testing is deemed necessary, it shall be performed at a frequency and sampled at a location based on the assessments, and it shall be documented. When microbial testing is deemed necessary to verify adequacy of source of water quality, testing shall be performed as described in the Model Code for Produce Safety by the Association of Food and Drug Officials (AFDO). Section IV B 2 b) (1) of the AFDO code reads: Testing shall be performed and documented using standard indicators of fecal pollution, such as generic E. coli tests. The frequency of testing and point of water sampling shall be determined based on the water source, its particular history, and the outcome of the risk assessment.
5. Hygienic Practices in Onion Fields
Ensure that production crews, visitors, and other field personnel are aware of food safety risk reduction principles and they agree to adhere to the firm’s practices and policies.
a. Written Policies and Employee Training
i. Operations shall develop and implement written GAP and Employee Hygiene Practices.
ii. All employees shall receive mandatory safe product handling and personal hygiene education at time of hire, with periodic reinforcements, at least seasonally.
iii. Training sessions shall be documented with records of topics covered, date, names, and acceptable verification of those in attendance.
iv. Routine oversight and periodic self-audits shall be used to verify and document compliance with worker hygiene and sanitation policies and practices.
b. Cleanliness/Sanitation
i. Sanitary facilities shall be provided for all field workers and visitors during planting, harvesting, or other field activities. Toilet facilities shall be provided with minimum of one per twenty employees and be readily accessible, located not more than ¼ (0.25) mile of all employees.
ii. Toilet facilities shall be designed, located, operated, and serviced in a manner that does not pose a source of contamination of the field.
iii. Toilet facilities shall have appropriate hand washing stations, including collection of gray water.
iv. Toilet facilities shall be maintained in a clean and sanitary condition and properly stocked with soap. Water for hand washing that meets the microbial standard for potable water, single-use towels, toilet paper, etc., and a written record of cleaning shall be kept.
v. Restroom cleaning equipment shall be labeled and segregated so as not to pose a risk of contamination.
vi. Policies shall require hand washing with soap and water at appropriate times such as before starting work, after breaks, using the restrooms, sneezing, or coughing.
c. Health
i. Employees, visitors, and other field personnel with symptoms of diarrhea, fever, vomiting, or other potentially infectious illnesses shall be restricted from working with or in the vicinity of onions or onion-contact surfaces.
ii. Employees, visitors, and other field personnel with open sores, cuts, burns, boils, etc., shall report to a supervisor before working or entering the field. The supervisor shall determine if the employee will be allowed to work with, or in the vicinity of, onions or onion-contact surfaces.
d. Hygiene
i. Employees, visitors, and other field personnel with symptoms of diarrhea, fever, vomiting, or other potentially infectious illnesses shall be restricted from working with, or in the vicinity of, onions or onion-contact surfaces.
ii. There shall be a written policy prohibiting eating, drinking, chewing gum, and using tobacco in fields except in clearly designated areas.
iii. Drinking water shall be provided with either fountains or single-use containers. Drinking water containers shall be handled in a manner that prevents them from becoming sources of contamination.
iv. Other good food handling techniques shall be developed as appropriate to the specific operation to prevent cross contamination.
6. Crop Production Practices
Assess risk of all production inputs to reduce contamination risk.
a. Chemical Fertilizers
i. Follow manufacturer’s instructions for usage and storage.
b. Fertilizers Containing Manures, Composts, or Biosolids
i. Only properly treated manures and biosolids are allowed for use in onion fields.
ii. If treated manures or biosolids are used, records of composition, dates of treatment, methods utilized, application dates and any test results, or process verification data demonstrating compliance with microbial standards must be documented.
c. Pesticides (Crop Protection Treatments)
i. Pesticide chemicals used must comply with all requirements of EPA registration and any federal, state, or local regulations.
ii. Pesticides must be appropriately registered for such use and must be used in accordance with label directions. Pesticides used shall be documented.
iii. Pesticides shall be applied by trained, licensed, or certified pesticide personnel, as required by regulation.
iv. Pesticides for foliar application shall be mixed with water that meets Model Code for Produce Safety (AFDO) standards (page 4, Sec. 4).
d. Chemicals Used on Product
i. Chemicals used on product that are not registered pesticides may be permitted for food-contact use if allowed under regulations of the U.S. Food and Drug Administration (FDA).
7. Equipments and Containers
a. Onion storage containers need to be clean and free from foreign material and in good repair.
b. Reusable containers and food-contact equipment and utensils shall be constructed of materials that can be easily cleaned.
c. Clean and maintain containers, bins, food-contact equipment, and utensils as needed to remove sand, grit, dirt, and other residue.
d. Establish routine cleaning procedures and maintain these standard operating procedures in writing.
e. Maintain all equipment and surfaces in such a way as to minimize contamination of, and injury to, onions.
f. All containers shall be marked for their intended use (trash, etc.)
8. Record Keeping
Appropriate record keeping provides evidence of operating conditions and practices and facilitates periodic review and evaluation of those practices.
a. Records documenting adherence to these practices, such as those addressing environmental assessments, employee training, water usage, pest control, crop production practices, and any needed corrective actions, for the operations must be maintained and producible in a reasonable amount of time.
b. The source of all agricultural inputs used in the production of the crop (e.g., seeds, transplants, fertilizers, pesticides) shall be recorded.
c. Records shall be retained for at least two years, or as required by regulation.
IV. Harvest Practices
Onions for harvest shall have been produced according to GAPs and the recommendations described in the prior section on Open Field Production.
1. Preharvest Assessment
A preharvest assessment provides a last opportunity to evaluate any safety risks from the field that may impact the potential for the onions to be contaminated. The field man, ranch manager, or other responsible person shall ensure that an assessment is performed as close as practical prior to the beginning of harvest, for example, not more than 7 days prior to the beginning of harvest.
a. Conduct an environmental assessment including topography, land history, adjacent land use, and domestic and wildlife presence.
i. Review field environments and records of assessments and corrective actions performed during the current production period.
b. Onion fields should not be located in any area that can receive runoff or drainage from an animal operation or any other source of contamination.
c. Domestic animals and livestock have been excluded from onions fields.
d. Wildlife presence has been minimized.
e. If animal intrusion is detected, measures shall be taken to remove or prevent the harvest of any potentially contaminated product.
f. Run-off from any animal operation has been prevented.
g. The source of water for irrigation for each crop has been documented and criteria have been met.
h. Procedures used to identify risks and mitigate those risks have been documented, followed, and are reviewed.
i. If onions are harvested at multiple times, fields should be assessed sufficiently to assure that new risk factors have not emerged.
2. Hygienic Practices in Onion Fields
Ensure that harvest contractors and crews have been trained in food safety risk reduction principles and that they agree to adhere to the firm’s practices.
a. Written Policies and Employee Training
i. Operations shall develop and implement written GAP and Employee Hygiene Practices.
ii. Training sessions shall be documented, with records kept of topics covered, date, names, and acceptable verification of those in attendance.
iii. Periodic (e.g. daily, weekly, monthly, quarterly, as appropriate) self audits shall be used to verify and document compliance with worker hygiene and sanitation policies and practices.
b. Sanitary Facilities
i. Toilet Facilities and Hand-Washing Stations
1.) All toilet facilities and hand washing stations shall be:
a.) Kept clean, well supplied with toilet paper, water, soap, and paper towels, and shall be accessible and properly located;
b.) Directly accessible for servicing, serviced and cleaned on a schedule sufficient to ensure stability for use; and
c.) Located as to minimize the potential risk for field and produce contamination.
ii. Water used for hand washing shall meet the microbial standards for drinking water prescribed in the Code of Federal Regulations (CFR): 40 CFR Part 141.63.
c. Sewage Disposal
i. Sewage and septic systems shall be maintained in a manner to prevent contamination of growing fields or produce with pathogens, and in compliance with local laws and regulations.
1.) Portable toilet facilities shall be serviced in a location and manner that does not pose a risk of contamination of growing fields or produce with pathogens.
2.) The responsible party shall have a plan for immediate control and treatment of any effluent in the event of leakage or a spill. Leakages or spills shall be managed and disposed of in accordance with applicable federal, state, and local laws and regulations, and in a manner that prevents or minimizes contamination of growing fields or produce with pathogens.
d. Health
i. Worker health policies shall restrict employees with symptoms of diarrhea, fever, vomiting, or other potentially infectious illnesses from working with, or in the vicinity of, onions or onion-contact surfaces.
ii. Employees with open sores, cuts, burns, boils, etc., shall report to a supervisor before working. The supervisor shall determine if it is safe to allow the employee to work with, or in the vicinity of, onions or onion-contact surfaces.
e. Hygiene
i. Employees shall have designated areas for eating, drinking, smoking, breaks, personal effect, etc.
ii. There shall be a written policy prohibiting eating, drinking, chewing gum, and using tobacco in fields except in clearly designated areas.
iii. Drinking water shall be provided with either fountains or single-use containers. Drinking water containers shall be handled in a manner that prevents them from becoming sources of contamination.
iv. Other good food handling techniques shall be developed as appropriate to the specific operation to prevent cross contamination.
f. Harvest crews are trained to recognize and report any food safety risks or hazards observed during the harvest operation.
3. Equipment and Containers
a. Onion storage containers need to be clean and free of foreign material and in good repair.
b. Reusable containers and food-contact equipment and utensils shall be constructed of impervious materials that can be cleaned.
c. Any containers used to hold onions that are received back from a packing house must be checked for cleanliness prior to use.
d. Clean and maintain harvest containers, bins, food-contact equipment, and utensils as needed, to remove sand, grit, dirt, and other residue.
e. Establish routine cleaning procedures and maintain those standard operating procedures in writing.
f. Maintain all equipment and surfaces in such a way as to minimize contamination of and injury to onions.
g. Records shall be maintained of cleaning procedures and their implementation.
4. Debris Removal
Dirt and chaff should be removed from onions to the degree practical in the field, in a manner that does not pose a risk of contamination.
5. Exclusion from Harvest
a. Onions contacted by fecal material shall not be harvested.
b. If animal intrusion is detected, measures shall be taken to remove or prevent the harvest of any potentially contaminated product.
c. Damaged, soft, or decayed onions should be excluded, to the degree possible.
6. Culling, Sorting, and Removal of Damaged Onions
Damaged, soft, or decayed onions should be removed, to the degree possible.
7. Storage
a. Any area or facility used to collect or store onions must be maintained in a clean and sanitary manner.
b. In bulk storage, new disposable foot covers must be worm when inspecting onions.
8. Record Keeping and Traceability
Record keeping provides evidence of reviews and evaluations to document those practices. Records shall also be kept to assure traceability of harvested onions.
a. Records documenting adherence to these practices, such as those addressing preharvest assessments and employee training for the operation must be maintained and producible in a reasonable amount of time.
b. Traceability practices shall be utilized to ensure that all onions are traceable to their origin, at least one step forward and one step back.
c. Records shall be retained for at least two years, or as required by regulation.
V. Field Packing
Field packing of onions includes any practices to grade, sort, size, clean, pack, or palletize onions in the field into containers for commerce. Field packed onions are not intended to be transferred to a packing house for further handling. Care must be taken to ensure that practices and conditions do not contribute to contamination.
1. Prerequisites for Field Packing Onions
Packing of onions in the field must meet all Good Agricultural Practices (GAPs) included in this document in Section III, Open Field Production, including management, site, and adjacent land use, water use, and hygienic practices, production practices, harvesting procedures, and record keeping, in addition to the requirements further detailed in this Section of Field Packing.
2. Field Packing Onions
Employees packing onions in the field shall be supervised in order to ensure the safety of the product. Hygienic practices for field packing employees shall be followed and verified by supervisors. These hygienic practices shall include handwashing and sanitizing.
a. Culling
Packing onions in the field generally occurs with mature onions so extra care to cull and remove any damaged onions shall occur.
b. Hygienic Procedures
Minimum legal requirements for field sanitization facilities and procedures are prescribed in the Occupational Safety and Health Act, 29 CFR, Part 1928.110.
c. A written procedure for hygienic practices for field packed operations and records showing compliance must be available.
d. Documentation of employee training on hygienic procedures for the field packing of onions shall be retained and available.
3. Exclusion from Harvest
a. Onions contacted by any fecal material shall not be harvested.
b. If animal intrusion is detected, measures shall be taken to remove or prevent the harvest of any potentially contaminated product.
c. Damaged, soft, or decayed onions should be excluded to the degree possible.
4. Containers for Field Packing Onions
All containers shall be stored in a manner to prevent contamination. Special attention shall be given to contamination risks from rodents, birds, and other pests.
a. All packaging material is inspected upon arrival and stored in a clean manner.
b. Containers used for field packing may not be stored in the field unless protected from potential contamination.
c. Picking and packing containers shall be distinguishable from those serving other purposes.
d. Reuse of single-use containers (e.g., corrugated) for field use of packing is prohibited.
e. Reusable containers, such as reusable plastic containers (RPCs) and totes, shall be clean. Ensure that labels are accurate prior to reusing for packing.
f. Containers shall be protected from direct contact with the ground.
g. Containers shall be properly labeled with information sufficient for traceability, including identification of the firm packing the onions.
5. Equipment and Packing Containers in the Field
a. Any surface that touches onions postharvest should be considered a food- contact surface and should be treated or handled in a manner so as not to be a source of contamination of the onions.
b. Harvest containers, food-contact surfaces, and utensils shall be cleaned and maintained as needed to remove sand, grit, dirt, and other residue.
6. Transportation of Field Packed Onions
a. Transportation vehicles should be sufficiently clean so as not to be a source of contamination.
b. Inspect transportation vehicles for cleanliness, odors, visible dirt, and debris before loading. If needed, the vehicle shall be cleaned prior to use.
c. If non-dedicated vehicles are used for transportation, verify from records that vehicles have been sufficiently cleaned if prior loads may be a potential source of contamination.