overview of the risk assessment of berries

8/16/2019 Overview of the Risk Assessment of Berries

1/12

Food Safety and Security Risk Assessment of Fresh, Minimally Processed and Frozen Berries

1 | P a g e J a n u a r y 2 0 1 6

Overview of the Risk Assessment of Fresh, Minimally-Processed and Frozen Berries

Anamaria DAVID

Food Quality Management, 2nd Year, Faculty of Food Science and Technology, University of

Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania.

Abstract

Berries are a perishable food which can be consumed as fresh or minimally-processed as well

as a frozen ingredient added to many foods. Strawberries, raspberries, blackberries and

blueberries are the most commonly consumed in the EU. In the past few years, several

European Union/ European Economic Area (EU/EEA) countries reported food-borne

outbreaks and clusters of hepatitis A virus (HAV) and norovirus (NoV) infections. Analytical

epidemiological studies conducted as part of the outbreak investigations identified frozen

berries as the main vehicle of infection in several of them. Preliminary food trace back

investigations revealed large scale distribution of these products in the EU/ EEA area, and

pointed to producers in countries both inside and outside of the EU/EEA. In 2013, outbreaks

affecting an unprecedented large number of people in a number of countries have occurred in

the EU/EEA and beyond, highlighting the role of frozen berries as a vehicle of infection.

This research tries to provide an overview on the hazards that can be encountered in the

processing chain of fresh, minimally-processed and frozen berries, starting from the crop

production until the product arives at the consumer. Also for this stages there are some good

manufacturing practices and handling practices of berries to avoid contaminations.


2/12


2 | P a g e J a n u a r y 2 0 1 6

Keywords

Berries, frozen, risk, miinimally-processed, fresh, norovirus, hepatitis

1. Introduction

Berries, defined according to commercial production, are small, ovoid or spherical, fleshy and

juicy fruits. This definition does not resemble to the botanical definition of berries, which

refers to „an indehiscent fruit derived from a single ovary and having the whole wall fleshy,

such as a grape or tomato.” [http://www.thefreedictionary.com/Berry+(botany)] Some

examples of berries, for the scope of this research are: bilberry (Vaccinium myrtillus L.),

raspberry (Rubus idaeus L.), Lingonberry (Vaccinium vitis-idaea L.), blackberry (Rubus

fructicosus L.), strawbeberry ( Fragaria vesca L.), currant (Ribes nigrum L.) etc.

Although there are a lot of plant species grown for berries production, the most significant

ones on the market are strawberries, raspberries, blackberries and blueberries. (Freshfel 2013,

Appendix A). Berries consumed all over the world come most of theem from cultivated crops,

but there is also a part which derive from wild crops, the last one is gaining more and more

popularity because of the so called ecological/natural type.

Berries can be processed to many different products such as jams, juices, yogurt, sauces and

others but many people prefer to consume them fresh, because in this way all their bioactive

compounds for which are so popular, vitamins, and other benefic compounds are preserved.

Consumed fresh, because berries are perishable and sensitive, it is very difficult to assure their

security, since even washing them it is pretty hard to do without distoying their skin.

Even though berries are generally free from noxious substances such as poisonous chemicals,

toxins and pathogenic organisms, in the last few years there were some severe contamination

problems of fresh or frozen berr ies. „In one of the EFSA’s Opinion from 2013 ((EFSA Panel

on Biological Hazards (BIOHAZ), 2013), they risk ranked the combination of raspberries

together with Salmonella spp. and Norovirus as the fourth most often linked to foodborne

human cases originating from food of non-animal origin(FoNAO) in the EU. In addition, the

combination of strawberries and other berries with Norovirus were risk ranked as the sixth

most often linked to foodborne human cases or iginating from FoNAO in the EU.” (EFSA

Journal 2014;12(6):3706).

http://www.thefreedictionary.com/Berry+(botany)%5dhttp://www.thefreedictionary.com/Berry+(botany)%5dhttp://www.thefreedictionary.com/Berry+(botany)%5d


3/12


3 | P a g e J a n u a r y 2 0 1 6

2. Risks of contamination in the field and during harvesting and processing

Starting from the filed production, berries can be contaminated with different hazards. The

safety of our food supply begins with grower practices on the farm. Before harvest, berries

can become contaminated with chemicals (e.g., fertilizers, pesticides) and pathogenic

microorganisms (bacteria, fungi, protozoa, and viruses). Fecal coliforms can be spread to

farmland through compost, manure fertilizers, and unclean surface water used for irrigation.

These microbial contaminants can survive in the soil for 3 months or more. In one instance,

Cyclospora contamination of raspberries was linked to an unsanitary water source. Berries are

produced using various systems, depending on the type, the intended use, the geographical

origin and the economic choices of the growers. Berries intended for processing are almost all

grown in open fields. Berries can also be picked commercially from the wild (e.g. forests,

upland grasslands and bogs). Harvest of berries (particularly bilberries and blackberries) can

also take place from forests and other land, including from public areas where biosecurity is

minimal.

In this stage of growing berries, for a better crop there are used different types of fertilisation,

irigation systems, insecticids and others chemicals, chemicals which can remain on the fruit

surface or inside them and could cause harm to people health. Production practices, growth

conditions and the location of the berries on the growing plant (soil surface, aerial part) in

combination with intrinsic and extrinsic factors as well as harvesting and processing will

affect the microbial status of berries at the time of consumption. Variability in the production

systems and associated environments for berry production can lead to a wide range of

unintentional or intentional events that may be potential sources of food safety hazards and

these will vary considerably from one type of crop production to another and from one

particular setting/context to another, even for the same crop (EFSA Journal 2014;12(6):3706).

Berries are pulpy fruits with high moisture and sugar content and a soft skin, which makes

them particularly susceptible to physical damage that accelerates their deterioration by

increasing water loss and providing conditions to increase microbial contamination and

spoilage during production, harvest, transport and storage. Strawberries and raspberries do not

support growth of the enteric bacterial pathogens because of their internal high acidity (pH

3.1-3.6) (Siro et al., 2006). Furthermore, spoilage microorganisms that are present in

refrigerated produce are psychrotrophic and therefore, have a competitive advantage over

most pathogens (Ahvenainen, 1996). Dennis (1976) reported bacterial counts of 105-106/g on


4/12


4 | P a g e J a n u a r y 2 0 1 6

freshly harvested strawberries, raspberries and blackberries and a fungal flora which varied

between different types of berry. Risk factors for physical damage to berries may occur during

harvesting as well as by the action of various pests (rodents, insects, birds and wild mammals)

and plant pathogens. This may lead to increased microbial spoilage.

Very few outbreak investigations or experimental studies have examined risk factors for

contamination of berries by Salmonella and Norovirus during agricultural production. Data

are available from outbreaks associated with berry consumption and other infectious agents:

e.g. hepatitis A virus and frozen berries (Gillesberg Lassen et al., 2013; Rizzo et al., 2013),

hepatitis A virus and raw blueberries (Calder et al., 2003), and Cyclospora cayetanensis and

fresh raspberries (Herwaldt and Ackers, 1997). Risk factors presented below are also deduced

from those presented for leafy greens in a previous Opinion (EFSA BIOHAZ Panel, 2014)

and may not be supported by epidemiological or experimental evidence, unless specified in

the relevant sections.

Improper worker hygiene can spread Salmonella, Cryptosporidium, and other pathogens

through human fecal matter. For example, Hepatitis A outbreaks associated with strawberries

have been linked to infected workers who did not observe basic hygiene when harvesting,

sorting, and packing the berries. Improperly composted manure can become a direct source of

pathogens for a berry crop. Or, contamination can occur when crops are irrigated with

equipment that was used to apply liquid manure. The presence of animals (both domestic and

wild) can increase the risk of field contamination. Cattle manure and the feces of sheep and

deer may harbor Escherichia coli O157:H7, resulting in contamination of fresh produce

during harvesting. In one instance, E. coli O157:H7 was traced to apples collected from a

field where infected livestock had grazed. Northwest berry crops can flourish or fail based on

environmental conditions such as weather. The risk of microbial contamination also can vary

from year to year. When the fruiting season is especially rainy, berries are susceptible to

fungal diseases such as Botrytis fruit rot. Another problem is flooding, which may occur in

low-lying berry fields, resulting in Botrytis spores and bacteria being transported from the soil

to the fruit. Seasons that are especially hot during harvest will produce rapid ripening. This

leads to soft berries that are at increased risk from fungal contamination. Late spring frost,

hail, insects, and nematodes also can damage berries, leaving them more susceptible to

microbial attack.


5/12


5 | P a g e J a n u a r y 2 0 1 6

Food-borne illnesses have been linked to improper practices during harvest. Berries can

become contaminated with bacteria from manure fertilizers in the soil, or from fungi,

protozoa, and viruses from unsanitary conditions during harvest, transport, and storage.

Freshly picked berries are very perishable. The principal causes of decreased fruit quality

after harvest include spoilage by microorganisms, bruising, water loss, chilling injury, and

compositional changes. These factors are important to food safety because they can increase

the susceptibility of berries to infection by pathogens. In some cases, microorganisms that

cause fruit spoilage can directly affect humans. For example, Botrytis has been classified as a

human allergen. Others can produce toxic substances within the fruit.

Risks associated with contamination and cross-contamination from equipment and handling

can occur at any point in the farm-to-plate continuum and are equally applicable to berry

production, and cross-contamination of food contact surfaces by workers handling

contaminated berries is also possible. In some countries, when many small producers are

involved, central collection points are used prior to transportation to freezing processors.

Salmonella survives better on cut strawberries than on intact fruits (Knudsen et al., 2001),

fruit damage is likely to be a risk factor for the contamination and persistence of pathogens

during production and storage of berries. Therefore, poor handling of berries both in the field

and at packing stations is detrimental to both fruit quality and safety. Damage can occur to berries as a result of sharp edges or poorly designed storage containers. Since increased

spoilage and quality deterioration will occur as a result of fruit damage, there is likely to be

increased manual handling by pickers and packers to sort into categories and remove

substandard fruit. Stals et al. (2013) demonstrated that Norovirus GII4 could be transferred

from gloves to a stainless steel surface and then to foodstuffs, and vice versa.

People working with leafy greens eaten raw as salads can transfer microorganisms of

significant public health concern to plants by direct contact (EFSA BIOHAZ Panel, 2014) and

this risk is also important for berries, particularly as they are often consumed whole and do

not have outer parts which are removed. Poor hygienic practices by agricultural workers in the

field (including leakage from portable toilets to fields and in-field defecation) has also been

identified as potential source of contamination (Suslow et al., 2003) and these poor practices

as well as deliberate contamination with faecal material will also significantly increase the

risk of contaminating berries.


6/12


6 | P a g e J a n u a r y 2 0 1 6

Risks of foodborne pathogen contamination can occur due to cross-contamination with

microorganisms associated with harvesting methods and can be via soil or extraneous debris

on the fruit during and after harvesting. An analysis of outbreaks linked to fresh produce in

the US identified that fruits (not berries) that had been dropped on the ground or were in

contact with the soil represented a factor that could increase the risk of contamination of intact

fruits with bacterial pathogens (Sivapalasingam et al., 2004). Poor sorting and selection of

berries is a risk factor for contamination, and in order to prevent cross-contaminating healthy

berries during harvest, harvest workers should not handle diseased, damaged or fallen fruit in

the field. Failure to segregate and remove culled fruit from the field is a risk factor for

contamination of healthy fruit, which will further attract pests and encourage spoilage.

Processing raw agricultural products such as berries requires prevention of biological,

physical, and chemical contamination. Food processors must be aware of potential food safety

hazards, as well as preventive measures for each. For example, microorganisms from soil and

water can be brought into a food processing plant by insects, wild and domestic animals,

transport containers and vehicles, equipment and utensils, wash water, ice, air (dust), and food

handlers.

3. Safety hazards in berries processing

Processing raw agricultural products such as berries requires prevention of biological, physical, and

chemical contamination. Food processors must be aware of potential food safety hazards, as well as

preventive measures for each. For example, microorganisms from soil and water can be brought into a

food processing plant by insects, wild and domestic animals, transport containers and vehicles,

equipment and utensils, wash water, ice, air (dust), and food handlers. There are three types of hazards

that must be considered during postharvest processing of berries — biological, chemical, and physical.

Biological hazards are food-borne pathogenic microorganisms, such as harmful bacteria, viruses,

parasites, and fungi (mycotoxins). Sources of biological hazards include raw materials, environment(air, water, equipment), and poor personal hygiene. Specific characteristics of some pathogenic

organisms have important implications for processing operations. Some bacteria can form spores that

will protect them from heat processing treatments (e.g., Clostridium botulinum, Clostridium

perfringens, and Bacillus cereus). Others, such as Staphylococcus aureus, can form toxins. Even when

the bacteria are destroyed during heat processing, a heatstable toxin may remain in the food and cause

illness. Fungi typically are postharvest spoilage agents of fruit. Yeast (unicellular organisms) and

molds (filamentous growth) can contaminate fresh produce and may form toxic substances

(mycotoxins) that can lead to illness. Some yeasts may start a fermentation process and produce

alcohol, while other yeasts and molds may trigger human allergies. Protozoan parasites such as


7/12


7 | P a g e J a n u a r y 2 0 1 6

Giardia, Cryptosporidium, and Cyclospora also have been found as contaminants on raw fruits.

Protozoa can produce cysts that are not susceptible to chlorine treatment.

Chemical hazards can cause illness due to immediate or long-term exposure. Examples of chemical

hazards are plant cleaning liquids, pest control materials, pesticides, and contaminated ingredients.These contaminants can be present in raw produce or can be introduced during processing when

compounds Generally Recognized as Safe (e.g., antioxidants, sulfiting agents, preservatives) are not

used according to government regulatory guidelines. Cleaning solutions can contaminate the product if

the rinsing step is inadequately performed. This can be avoided if SSOPs and GMPs are in place.

Processors must ensure that chemical compounds such as sanitizers and lubricants are used with strict

adherence to regulations and product specifications. Pesticides are chemicals that are intentionally

used on berries. However, regulatory limits are set for the amount and type of pesticides allowed to be

used on berries.

Physical hazards are foreign objects that can cause harm to consumers. They can enter the food supply

through contaminated raw materials, faulty processing equipment, improper packaging, or poor

employee hygiene practices. Examples of physical hazards are glass particles, metal fragments, stones,

insect fragments, plastic, jewelry, etc. These hazards affect the product’s safety and must be addressed

in the processor’s HACCP plan (see page 23). Prevention methods can rely on visual examination,

frequent inspections of equipment, and the use of metal and glass detectors.

4.

RASFF Notifications

Using RASFF portal, since November 1985 until January 2016 there have been 184

notifications related to berries. 67 of these notifications were border rejections of batches of

fresh or frozen berries. Border rejections were done to not authorise import in diferent EU

countries of berries containing high levels of different chemicals, usually pesticides residues,

for example:

methomyl (0.16 mg/kg - ppm) in chilled strawberries from Egypt, fipronil (0.014

mg/kg - ppm) in chilled strawberries from Egypt, cyfluthrin (0.19 mg/kg - ppm) in

strawberries from Egypt, oxamyl (0.03) in strawberries from Egypt, propargite (0.075 mg/kg -

ppm) in frozen berries mix from Italy, with raw material from Poland, Serbia and Romania.

There were also batches of berries rejected at the border because of the heavy metal content,

for example: lead (0.38 mg/kg - ppm) in frozen raspberries from Ukraine, lead (0.92 mg/kg -

ppm) in frozen bilberries (Vaccinium myrtillus) from Belarus.

There were also 60 alerts relating berries, and most of them were regarding the presence of a

biological hazard in the fruits. The contaminants that were often encountered were Norovirus(norovirus (GGII) in frozen strawberries from Morocco, packaged in Belgium, via France,


8/12


8 | P a g e J a n u a r y 2 0 1 6

norovirus (genogroup II) in frozen blueberries from France, with raw material from Ukraine,

norovirus (presence) in frozen blackberries from Serbia, foodborne outbreak caused by and

norovirus (2 out of 3 samples) in frozen raspberries from Serbia, norovirus (presence /25g) in

frozen raspberries packaged in Serbia, via Belgium). Hepatitis A virus is another reason for

alerts on the RASFF portal, for example: hepatitis A virus (148.3 copies) in frozen

strawberries from Morocco, via Spain, hepatitis A virus (presence /25g) in mixed frozen

berries from Poland and Bulgaria, via Belgium, hepatitis A virus (presence /g) in frozen

blackberries from Romania, hepatitis A virus in frozen berries mix processed in Italy, with

raw material from Poland, Serbia, Chile, Bosnia and Herzegovina, Belarus, Romania and

Estonia.

Due to this notifications- alerts, it was done an official control on the market, distribution was

restricted to notifying countries, and products were recalled from consumers and redrawed

from the market shelfs. There were done serious investigations, and producing companies

found out responsible were held acountable. Below can be found a graph which highlights

the distribution of number of RASFF notifications for norovirus and hepatitis A virus

contamination in frozen berries, by year and implicated pathogen, EU/EEA, 1996 – 2013

(n=42). Data was collected from www.eurosurveillance.org.

http://www.eurosurveillance.org/http://www.eurosurveillance.org/


9/12


9 | P a g e J a n u a r y 2 0 1 6

Fig. 1 Distribution of number of RASFF notifications for norovirus and hepatitis A virus contamination

in frozen berries, by year and implicated pathogen, EU/EEA, 1996 – 2013 (n=42)( www.eurosurveillance.org).

Other bacteria which were found in berries were: E. Coli (high count of Escherichia coli

(720000 CFU/g) in raspberries from Spain, Bacillus (Bacillus cereus (20000 CFU/g) in dried

mulberries from Turkey).

There were also notification and information for atention for diferent physical hazards, but

these were not serious, since the goods could be easily recalled and rechecked for these

hazards.

5. Providing safe berries for consumers

A strategy that prevents the initial microbial contamination of berries is safer than relying on

corrective actions after contamination has occurred. Because it is not practical to eliminate all

potential hazards associated with fresh produce, berry producers and processors must rely on

risk reduction rather than risk elimination. This publication contains recommendations for

minimizing the risk of contamination during the three key stages of production and

processing — preharvest, harvest, and postharvest.

It is easier to minimize microbial and chemical food safety hazards during plant growth than

to rely on corrective actions after contamination has occurred. To

prevent preharvest contamination of agricultural commodities, Good Agricultural Practices

(GAPs) have been developed. GAPs are voluntary practices for crop production that address

potential food safety issues associated with farmland, irrigation water, and contaminants

carried by insects, birds, and mammals. GAPs begin by reviewing the history of the farmland

to ensure that no prior land use has compromised the microbial or chemical safety of the site.

The adjacent land is also evaluated to verify that no contamination is being carried to produce

fields by water, wind, or vehicles. The purity of the water source is also important since

streams, reservoirs, and wells can spread microbial contaminants. Pesticide and fertilizer

usage and monitoring are important components of GAPs. Only authorized pesticides and

herbicides should be applied. GAPs encourage rigorous management techniques to ensure the

proper application of organic fertilizers such as manure and compost. Avoid applying organic

http://www.eurosurveillance.org/http://www.eurosurveillance.org/http://www.eurosurveillance.org/http://www.eurosurveillance.org/


10/12


10 | P a g e J a n u a r y 2 0 1 6

fertilizers within 120 days of harvest. Do not sidedress with uncomposted manure.

Throughout the growing season, keep records of water testing, manure and compost

applications, pesticide application, irrigation, and worker training programs. GAPs also stress

field sanitation, including an effective pest control program. Wildlife and domestic animals

should be excluded from produce fields, and worker health should be monitored to prevent ill

workers from contacting raw produce. To maintain worker hygiene, toilet facilities with hand-

washing stations must be provided, as well as potable water for drinking and hand washing.

To prevent contamination of agricultural commodities during harvest, Good Agricultural

Practices (GAPs) have been developed. GAPs are voluntary practices that address potential

food safety issues during harvesting, sorting, and transport operations for fresh berries. They

are part of a comprehensive food safety system that ensures that domestically grown berries,

as well as those imported from other countries, meet the highest health and safety standards.

The three key parts of a safe harvest system are sanitary harvest conditions, cooling berries

after harvest, and safe handling and storage practices. Most microbial contamination is on the

surface of fresh produce, necessitating a washing step to reduce the possibility of food-borne

illness before sale. Washing also helps to prevent the spread of microorganisms from one

berry to the next. To decrease the possibility of waterborne contaminants compromising the

quality of the berries, it is essential to use potable water whenever there is water-to- produce

contact. Approved sanitizers such as liquid chlorine, sodium hypochlorite, or calcium

hypochlorite can help control contamination when produce is immersed in wash water. If you

add a sanitizer such as chlorine to the wash water (pH 6.0 – 7.0) to control bacteria, test the

concentration of free (residual) chlorine frequently. It should remain at 100 – 150 ppm. Not all

produce is cooled and washed after harvest (e.g., grapes and strawberries), increasing the

possibility of microbial contamination. To minimize this risk, clean pallets and sanitized

containers should be available for freshly harvested berries. Take care to ensure that the

containers do not become exposed to soil and manure when produce is packed in the field.

Good worker hygiene and field sanitation practices are essential. All workers who handle

fresh produce should receive training on the importance of good hygiene, including the

necessity for effective hand washing. Good agricultural practices should also be promoted for

U-pick fields where customers harvest their own produce. Convenient toilets should be

available for customer use, together with hand-washing stations containing potable water,

liquid soap, and single-use paper towels. When possible, harvesting should be done at night or

in the early morning to minimize exposure to high temperatures. Whenever possible, hold


11/12


11 | P a g e J a n u a r y 2 0 1 6

freshly harvested berries in the shade with adequate ventilation. Furthermore, cover the

containers with clean, sanitized tarps to protect the berries from contamination by birds. After

harvesting, berries should be immediately cooled to reduce the deterioration rate and retain

high fruit quality. Water, ice, and forced air are among the methods used to remove field heat

from produce after harvesting. Bacteria can multiply rapidly in areas where poor sanitation is

practiced. Maintain harvest storage areas in a clean, sanitary condition. Clean and sanitize

containers prior to the arrival of fresh produce. Do not transport fresh produce in a truck

recently used to haul animals or animal products unless it first is thoroughly cleaned and

sanitized. Clean and sanitize all food-contact surfaces, including washing, grading, sorting,

and packing lines, as well as equipment, floors, and drains. Prevent cross-contamination

between raw and washed berries from sources such as wash water, rinse water, ice, dust,

equipment, utensils, and vehicles. The presence of fecal coliforms can serve as an indicator if

contaminants are suspected.

6. Safe handling practices for consumers

Consumers should only buy small fruits and berries that are intact. They should not buy fruit

with mold or other signs of damage and should also avoid buying fruit that have an obvious

infection. Buying only small amounts of berries or small fruits is another prevention method,

in this way they can be sure they will eat fresh products each time, not stored in the frigde for

many days.

Consumers should never taste unwashed berries or small fruits in stores and at home always

wash small fruits or berries before eating. Refrigerating fresh berries and small fruits

promptly is a good technique to avoid contamination. They sould always discard leftover

prepared berries or small fruits after two hours at room temperature. During preparation

washing hands with hot, soapy water before and after handling other food products, things

and animals is a must.


12/12


12 | P a g e J a n u a r y 2 0 1 6

REFERENCES

1. Amy Simonne, Berries and Small Fruits: Safe Handling Practices for Consumers,

University of Florida, IFAS Extension, FCS8741, 2006.

2. C.K. Bower, S. Stan, M. Daeschel, and Y. Zhao, Promoting the safety of Northwest fresh

and processed berries, Oregon State University, Extension Service, EM 8838, October 2003

3. EFSA Panel on Biological Hazards (BIOHAZ), Scientific Opinion on the risk posed by

pathogens in food of non-animal origin. Part 2 (Salmonella and Norovirus in berries),

European Food Safety Authority (EFSA), Parma, Italy, EFSA Journal 2014;12(6):3706, 2014.

4. L Tavoschi, E Severi1, T Niskanen, F Boelaert, V Rizzi, E Liebana, J Gomes Dias, G

Nichols, J Takkinen, D Coulombier, Food-borne diseases associated with frozen berries

consumption: a historical perspective, European Union, 1983 to 2013, Euro Surveill.

2015;20(29):pii=21193, 23 July 2015.

5. https://webgate.ec.europa.eu/rasff-window/portal/?event=searchResultList
https://webgate.ec.europa.eu/rasff-window/portal/?event=searchResultListhttps://webgate.ec.europa.eu/rasff-window/portal/?event=searchResultList

overview of the risk assessment of berries

Documents