E. Wijs1 and W.B.C. de Heij2
VEZET, NL, ElsW@VEZET.NL
2 ATO b.v., NL, firstname.lastname@example.org
Convenience is booming business. Some thirty years ago, first attempts in
providing easy to handle and ready-to-eat foods to consumers were reported. During the
last decade developments have been fast and major progress has been made in
maintaining quality and safety of the fresh cut produce. And in that last remark not only
the progress is indicated, but the major problems as well: what is quality, what is safe and
what is fresh?
The chain concept and its benefits are built upon trust in predecessors and
successors in that chain. Entire food supply chains and networks are built on that concept.
For the fresh cut produce that is not different. Trust is fine, but… commercial companies
are no fools. They need some proof of trustworthiness, some proof of quality, some proof
of safety, some proof of freshness. So, even in the concept of chains and networks, some
product properties have to be measured and some indication of quality, safety and
freshness has to be provided.
About 60 companies are producing fresh cut, washed and packed vegetables in the
Netherlands, most companies produces there products for local hospitals, restaurants,
catering services and food services. Based on annual turn over, in Holland the top 6
products are mainly prepared for the supermarkets (“retails”). Sales of fresh cut produce
in the Netherlands have increased from the early nineties from €100 million to about €300
million nowadays. Roughly 80% of these sales are realised in the retail sector.
In this paper, an overview will be presented of aspects important to commercial
application of fresh cut horticultural and agricultural produce, how to acquire the proper
information, and how (and to what extent) to trust your partner. An integrated view on
fruit and vegetable quality, applicable throughout the chain will certainly make life and
INTRODUCTION TO ‘VEZET B.V.’
VEZET’s origins lie in a factory built in 1914 for salted vegetables by K.
Wagenaar. The “Vereenigde Zuurkoolfabrikanten in Nederland” the ”N.V. tot Exploitatie
van Zuurkoolfabrieken“ existed in 1956, whose objective was the manufacture and
handling of sauerkraut, salted vegetables and other food. VEZET began to look for ways
of expanding the range with products other than the well-known and trusted sauerkraut at
the beginning of the seventies, with the help of Albert Heijn (supermarket - AHOLD).
This was found in "vegetables, which were made so ready for consumption that the
consumer only had to prepare them". In short, this product was called "ready-to-cook
vegetables". This early period was marked with discussions about traditional products,
such as different sorts of cabbage, endives, carrots, leeks, soup vegetables etc. The name
was changed in 1973 to "Vereenigde Zuurkoolbedrijven B.V.", quickly abbreviated to
"the V.Z.", which gave rise to the name VEZET. The name Vereenigde
Zuurkoolbedrijven B.V. was also officially changed to "VEZET B.V." at the beginning of
1998. The factory underwent a large-scale expansion and adaptation in 1996-1999. Many
ultra-modern provisions were introduced during this reconstruction to initiate further
Now, in the year 2002, VEZET is one of Holland’s largest vegetable processing
companies and is the market leader in freshly cut, ready-to-cook vegetables. This modern
vegetable cutting company has a range of about 250 different products (different
mixtures, packages and sizes). The product range includes salads and raw vegetables,
mixed vegetables and soup vegetables. Traditional cooking vegetables are also still a part
of the total product range. Besides regular products a growing range of organically grown
Proc. Int. Conf. Quality in Chains
Eds. Tijskens & Vollebregt 29
Acta Hort. 604, ISHS 2003
products has entered the market as well. These products are owned and prepared in
accordance with the Skal guidelines.
The total annual production is about 30,000 tons of fresh vegetables. About 450
people (permanent and flexible) are currently employed at VEZET. Since October 1973
VEZET has been the exclusive supplier of ready-to-cook vegetables to Albert Heijn B.V..
The existing premises were expanded several times due to the rapid growth in this market
during the nineties An other portion of the produced goods is sold as vegetable
intermediates in bulk to industrial customers and for the food service market (e.g.
restaurant chains and food services). These customers process the intermediates into for
example soups, salads, pizzas, cheese spreads and mixed vegetables. Since 1997 ready-to-
cook vegetables are also supplied to supermarket organisations abroad.
WHAT IS QUALITY?
Since quality of perishable produce is a rather subjective attribute, you know all
more about that, it is very difficult to develop viewpoints, preferably measurable, that can
be shared by the actor in the chain. A system that does work in practice is the so-called
manufacturing approach (Sloof et al 1996). It is once defined what can be understood
by quality in measurable attributes, and these findings are laid down in the product
specifications. So, whenever a batch of produce does comply with the specifications, that
batch is acceptable for the chain. The danger of this system arises when the specifications
no longer reflect the preferences of the consumers / buyers. This happened a few years
ago with tomatoes produced for Germany. No one in the chain, not even the companies
where the tomatoes were supplied to, had anticipated the fierce and sudden rejection of
the quality of the produced tomatoes. So, when applying this simple and appealing
system, somebody has to watch continuously the changing trends and preferences of the
When including constantly the preferences of the market, we gradually shift
towards the User based approach (Sloof et al 1996). In this system, the psychology on
consumers, his preferences and his constantly changing buying behaviour is an essential
part. Although this system reflects more accurately the actual situations, for practical
purposes it is at the moment quite out of reach for commercial companies. As a matter of
fact, as far as I understood, for scientific purposes as well, a very popular and workable
intermediate between the two systems is the system of keeping quality.
Among the factors that affect the way consumers understand concepts of food
quality and safety, the multiple food retailers, or supermarkets, are significant. As more
food produce is moved through a reducing number of supermarket chains the power of
supermarkets over food supply businesses grows. What consumers believe to stand for
quality has become more closely aligned to the supermarkets’ own definitions of quality,
of which food safety is a part. Consequently, as greater numbers of consumers shop in
supermarkets, suppliers are forced to adjust their own understanding of quality in line
with that of supermarkets if they are to stay in business (Jongen, 2002). We come back to
keeping quality as applied by commercial companies in the sector of cutting vegetables in
the next section.
WHAT IS KEEPING QUALITY?
Keeping quality has been defined as the time a commodity remains acceptable far
a large group of consumer (Tijskens et al. 1996). Problems arise immediately from this
definition: what is a large group of consumers? What is still acceptable? Is it the always
the same quality attribute that is limiting? All three questions can (and will) affect the
eventual outcome of quality assessment and acceptability further down the chain. As
already mentioned, the chain is largely built upon thrust among the actors in a chain. The
chains actors nevertheless need a clear description of what to measure (and to provide) to
be a reliable partner.
Bacterial load (CFU) is largely accepted as the prime indication of freshness and
keeping quality. So, washing the delivered commodities is a very central process in the
preparation of cut vegetables. There are however, indications that bacterial load is not at
all so tightly connected to the keeping quality of the produce. And during continuous
washing, the water itself tends to get a high bacterial load. In practice the bacterial load of
leafy vegetables can be reduced by roughly one log-cycle, with (USA) or without
(Holland) the legal permission to use chlorinated washing water. On top of that, by
excessive washing in large tanks produce can pick up as much as 20% of their weight by
sucking in water. Polluted water, Chlorinated water!? What is the effect of this on the
What else do we have as an indication of quality and keeping quality?
Appearance! But how to express appearance in a numerical way to be able to
communicate with the partners in the chain? What to measure? Bacterial spots? Slimy
patches? Then we are already too late. Wilting? Picking up that amount of water surely is
an adequate remedy to that. Does it last? Maybe the technology developed during the last
couple of years at the ATB (e.g. Herppich 2000) can provide some useful concepts. But
what is needed above all are simple measuring techniques. Freshness of produce? In the
USA the term freshness may be used as long as the produce is respiring. But that is not
what is meant by freshness in the vegetable cutting and packaging business or even the
freshness definition as being used by consumers.
Price? Expensive products will have a better quality! But does it? Always? Price
mechanisms depend on more factors then careful production. And it certainly cuts down
your profits. Higher quality can be paid a higher price. That is not impossible. People in
the western world are most of the time willing to pay a higher price for quality and
convenience. That is what the cutting business is all about. But again, how to evaluate
quality? Instead of being a solution to the problem, economic factors seem to be the
initiator of the problem. What can be done, and what is done on a regular basis, is making
price covenants with suppliers and retailers, based on trust and previous experience.
So, all these attributes and product properties, however important for the
evaluation of the quality for fruits and vegetables, can hardly be measured by objective
means, and one is in practice stuck with the good visual and manual inspection of samples
of batches of produce. And that is not too reliable to communicate up or down the supply
chain. A great research opportunity!
INTERACTIONS IN THE CHAINS
VEZET puts quality high on its list of priorities. Quality is important in the whole
chain from the raw materials to the final product as being seen (Figure 1), bought and
eaten by consumers. VEZET is therefore very closely involved in the cultivation of
vegetables and has been working for many years with growers, who follow a controlled
cultivation programme. This is now being extended to a Eurep-GAP (Eurep = Euro-
retailer produce working group, GAP= Good Agricultural Practice) certified cultivation.
Quality is also an important item during the production process. During the whole
production process from the incoming raw materials to the outgoing final products daily
checks are therefore made to guarantee the (keeping) quality the client expects. Tracking
and tracing is a subject that is receiving increasing attention since the whole chain is
important in relation to keeping quality and clients wants to know more about what has
happened to a product and where it has gone to. Everything is becoming clearer and the
chain has become more transparent with the increased implementation of automation
methods. It becomes possible to take action in the chain at the right moment to guarantee
the quality and safety of the final product. Certification of the production process and the
methods of working, play an important role as well. VEZET is therefore certified
according to EDI, BRC and SKAL regulations. It has the HACCP-certificate since 1998.
With these certifications our costumers are ensured that a minimum set of (hygienic)
procedures have been implemented.
VEZET, however, continuously tries to improve the product quality. The
laboratory plays an important role in this. Continual checks and assessments are
conducted in the laboratory, starting from the delivery of raw materials. A produce that
does not comply with the specifications, is returned to the supplier. Samples are regularly
taken during the production process as well, so that the quality is guaranteed up to the end
of the production process. For example metal detectors are used, to check each individual
product package. Other attributes that are being monitored regularly are: microbial count
(bacterial load), optical quality and the smell / odour of the product. Besides the benefits
of having an own specialised laboratory, both the product and process are regularly
innovated. A good way to innovate is to work together with skilled scientists from
research institutes like ATO. These scientists are able to translate fundamental knowledge
to practical applications and vice versa. An example of such a collaboration is the
research project involving twelve companies, the branch organisation (Frugi Venta) and
ATO. This project focuses on the efficiency of the (submerged) washing processing and
the relation of this process with the overall product quality.
FUTURE RESEARCH NEEDS
As the reader of this articles probably noticed right now, more questions arose
than answers were provided. The world, hence also the fresh produced companies,
changes rapidly due to economical, political but above all consumer demands. Based on
the wish of these modern emancipated consumers, new (European) legislations,
commercial companies have to, and will improve their processes and the quality of their
products. As a short conclusive summary and with the intention to tickle the reader, a
short list of research needs from the perspective of the vegetable fresh cut industries is
From a product point of view:
• Thorough overview for all single and mixed produced products will be
o What are essential attributes (colour, smell, microbial load?) that
determine the product quality and the keeping quality?
o Which attribute will drop most probable below a certain threshold or
quality acceptance limit?
o What is the (main) mechanism of deterioration?
o Prediction of keeping quality and shelf-life as a function of the relevant
external factors: temperature, moisture content, initial quality of the raw
• A Keeping Quality knowledge management system to store and share product
From a process and technology point of view:
• Fundamental research to the effects of (industrial) processes on the overall
product quality. Hence, how does the keeping quality interact with the
processes used in the industry?
o What is the optimal washing method (type, temperature, residence time
etc.) to produce an optimum (keeping) quality?
o What is the optimal method to dry washed products, what are the optimal
o What is the optimal product specific packaging material, modified
atmosphere (MAP) and storage temperature?
• Mathematical modelling of most important process steps (cutting, washing,
drying). Process oriented modelling can be used to support the design of and
adjustments to equipment (e.g. what is the effect of implementing additional
cooling into washing equipment).
• Further implementation of measuring and controlling systems in all processing
steps to enhance the functionality (flexibility of process lines), to reduce
processing costs and to improve product quality.
• Development of product quality probes / sensors / monitoring systems to
independently quantify the essential attributes of both the raw material and the
final product. The system or method must be accepted by all actors in the chain.
From chain point of view:
• Optimisation and further collaboration between all actors in the chain:
o Research to the demands and preferences of consumers. Based on the
outcome of this research, an accepted definition of product specific quality
may be introduced based on relevant attributes. The sector needs a better
insight of food quality and safety and they have to come to terms with
consumers’ changing perceptions of food quality and increasing awareness
of food safety issues.
o How to increase the trust between the actors in the chain and provide a
sustainable relations vertically between the different suppliers? The focus
will be on food quality through the entire food chain and the consumer
demands in stead of short term profits of individual companies inside that
chain (Van Kooten, 2002).
o Transparency of the chain by further implementation of knowledge
management systems (tracking-and-tracing). Modern consumers want to
know what the origin of their vegetables is and how the food is being
processed. Greater involvement of the public will decide how to manage
and regulate technology innovation (e.g. averse of chlorination, with or
without additives etc.).
Sloof M., Tijskens L.M.M., Wilkinson E.C. (1996): Concepts for modelling quality of
perishable products. Trends in Food Science & technology, 7, 165-171
Tijskens L.M.M., Polderdijk J.J. (1996): A generic model for keeping quality of vegetable
produce during storage and distribution. Agric. Systems 51, 431-452
Herppich W.B., Hemple H, Geyre, M (2000): Carrot water relations during postharvest :
effects on internal and external product quality. Proceedings 2 International
conference An integrated view on fruit and vegetable quality p. 64-72.Technomic
Publ. Co. USA.
Kooten O. van, (2002): Transparante ketens: een kwestie van vertrouwen ! (transparent
chains: a matter of trust), ISBN 90.5059.151.5, Den Haag.
Jongen, W. (ed.), (2002): Fruit and vegetable processing – improving quality Woodhead
Publishing Ltd, Cambridge
Table 1. Difference between manufacturing and user based approach.
Manufacturing approach User-based or perceived quality
oriented to non-perishables oriented to perishables
only objectively measured properties Subjective aspect of consumer evaluation
(appearance, colour, …)
Formalised into technical specifications Perspective of the consumer
quality is replaced by ‘meeting specs’ ‘fitness for use’
substitute for consumer preference
Perspective of producer
Keeping Quality = “Quality-in-chains”
Grower VEZET b.v. DC Supermarket Consumer
Cultivar (See Figure 3) Keeping Quality Refrigeration (type) Refrigeration
Green house vs Wholesale Temperature/time Keeping Quality Temperature/time
field grown Handling Temperature/time Transport to home
Dutch vs EU Grade Handling Handling
vs … Keeping Quality Receipt
Classical vs Temperature/time
Responsibility / influence of actors in the chain
Fig. 1. Overview of the vegetable chain.
Fig. 2. Examples of products being produced. Mixed vegetables (left above); cooking
vegetables (right above), salad bowls (left below), food service market (right
VEZET b.v.VEZET b.v.
Raw materialRaw material ProcessingProcessing Storage of productStorage of product transporttransport
Temperature/timeTemperature/time Temperature production facilityTemperature production facility HumidityHumidity HumidityHumidity
Packaging (crate)Packaging (crate) Humidity production facilityHumidity production facility Temperature/timeTemperature/time Temperature/timeTemperature/time
Relative humidityRelative humidity Certification (e.g. HACCP)Certification (e.g. HACCP) Packaging (crate)Packaging (crate) HandlingHandling
CultivarCultivar Training of employeesTraining of employees HandlingHandling DistanceDistance
CuttingCutting MixingMixing WashingWashing DryingDrying MixingMixing PackagingPackaging
Cutting methodCutting method Submerged vs sprayingSubmerged vs spraying Method (e.g. centrifuge)Method (e.g. centrifuge) Modified atmosphereModified atmosphere
Particle sizeParticle size Residence time productResidence time product RPM vs timeRPM vs time MaterialMaterial
SprayingSpraying Temperature waterTemperature water LoadLoad SizeSize
CleaningCleaning Quality of waterQuality of water Air/product ratioAir/product ratio
Water refresh rateWater refresh rate PressurePressure
Control of product quality = management, technicians, laboratory, purchase, …Control of product quality = management, technicians, laboratory, purchase, …
Fig. 3. Vegetable processing chain of Vezet. Key-words mentioned influences the overall
(keeping) quality of the produce.