Jurnal ” Quality Perception: Multiple Attributes – Single Acceptance “

Can we perceive quality? Do we have a sense to distinguish good from bad
quality? Being educated or not, everybody has an imagination of good or bad of almost
everything in his environment. As long as a minimum of attention and involvement is
exerted to an object, a feeling of pleasantness or unpleasantness is almost simultaneously
present. Even more than optical or acoustic signals the experience of odours and flavours
lead almost inevitably to an affective tone. We hardly can imagine eating a food without
knowing instantly if we like it or not. And when we ask someone, how a food tastes, we
expect and will receive the answer “good” or “not good” rather than “sweetish”, “salty”
or like something else.
Many of these quality experiences are well memorised, and we almost have the
impression, even before we envision the details of an object or event in the past, we have
a notion whether it was good or bad. But things can change. What was pleasant yesterday
must not be felt as pleasant today. Especially in case of food we might have eaten too
much of a specific item or consumed it too frequently. In addition, there is also a
cognitive side of quality assessment. Food scandals, information on improper production
methods or ethical considerations may affect the quality judgement. Product image
associations, the price of a product or the availability of alternatives are examples for
quality cues, too.
More and more these contextual, “external” attributes came into the focus of
quality researchers, as important for quality evaluation and were denominated as extrinsic
properties, as opposed to intrinsic properties, which refer to the attributes, physically
belonging to and being verifiable in the product item itself. Those attributes, detectable in
the product were the objects of the traditional quality research. Amongst the plenty of
product properties often attributes were selected as quality criteria based on their
measurability, accuracy and precision rather then a verified relevance for acceptability
(Shewfelt, 2000) thus contributing to consumer oriented quality.
Attributes of products are the elements, which are perceived through the senses of
sight, smell touch, taste and hearing. Thus they are the first step from product itself to a
recognised item. Widely accepted, the definition of sensory evaluation is: evoking,
measuring, analysing and interpreting human responses to those perceived sensations
(Stone and Sidel, 1993). This definition was valid also in the early beginning of sensory
investigations in the 19th century. But the focus was on the product (stimulus) side, rather
than the response side in terms of complex food or consumer matters. The starting point
was detecting the amount of a physical stimulus to be perceivable and, when further
increased, to be perceivably different. Fechner introduced these “just noticeable
differences” as a unit of measurement, which allowed to construct a relationship between
a stimulus and the sensory intensity. With his book “Elemente der Psychophysik” from
1860 he laid a foundation stone for sensory science and was among the first experimental
psychologists at all.
From stimulus to sensation
The new science: psychophysics established the functional relationships for
various stimuli and the intensities of the sensations. Fechner developed a relationship,
built on the constant just noticeable differences, used as a unit for expressing the
Proc. Int. Conf. Quality in Chains
Eds. Tijskens & Vollebregt
Acta Hort. 604, ISHS 2003

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jurnal ” Quality Modelling ”

Quality Modelling
L.M.M. Tijskens1,2
1ATO, The Netherlands 2Horticultural Production Chains, Wageningen University, The Netherlands
What is Quality?

( Jurnal bisa di lihat di ruang baca  FP)

What is Quality?
In one way or another, all research and technological efforts in agriculture are
related to quality. Massive efforts have been conducted to produce quality, to maintain
quality as good as possible, and in the long run, to improve the quality of our lives. It is,
however, amazing that this ever-present and always important quality is so ill defined. It
differs from person to person, from situation to situation, from product to product. In
working with quality of agricultural produce, researchers are implicitly and often
unknowingly involved in the field of psychology, and the changing behaviour and desires
of man. Furthermore, the behaviour and decisions of individual consumers with respect to
acceptability and actually acceptance, is strongly affected by the economic boundaries
and market situation in which that particular consumer operates. So, when conducting
research on product behaviour and properties, it is necessary at least to realise that these
three areas (product, psychology and economics) each affect quality, or rather acceptability,
in a specific and mutually independent manner.
So, we have to grasp the meaning that quality has for each individual consumer,
how he translates his observation of the product and how he evaluates his perception. This
whole process will eventually result in an acceptability of the product by an individual
consumer for an individual purpose (fulfilling expectations MacFie 1995, 1996, Sloof et
al. 1996).
For research on quality, acceptance, product behaviour and consumer behavioural
patterns targeted at practical applications in production trade and processing of food
products, this individual perception and evaluation of quality has to be extended to
include group behaviour, both with respect to the product as to the consumer. That is the
realm of consumer and market research and is well out of the scope of this lecture.
Nevertheless, to provide some information to consumer and market research, and to
provide some guidelines for product research, for food production, for trade and for
processing, it would be very advantageous to uncouple these three interacting fields that
are associated with what is normally called quality.
Also for modelling product behaviour, with respect to quality for users and
consumers, it is essential to have at least a fundamental notion what quality really is, and
which product properties determine the quality assigned by the consumer to a product. In
other words, what is allowed and what is to be avoided when modelling product
behaviour in terms of quality and acceptability.
So, a more philosophical view on quality was developed with the sole purpose of
determining how and what to model when describing food quality as objective as possible
(Tijskens et al. 1994b, Sloof et al. 1996, Wilkinson et al. 2001). Meanwhile, it turned out
to be a satisfactory theory for quality in general. The central and crucial aspect of the
viewpoint is the decomposition of evaluation and appreciation into a more (although not
completely) objective assessment of quality called the assigned quality that is valid for the
majority of consumers and users. The more subjective appreciation in term of
acceptability is postponed to the market and consumer part of the acceptance chain.
What is modelling?
The ultimate goal of modelling is to provide reliable predictions of occurrences
that did not yet take place, for any product, from any source and in any situation. In the
formulation of Rickert (2001): Models can be regarded as a repository for past research
since they collate and integrate information from past research. This goal, although
agreed upon by every modeller and every user of models, is however at the present time
Proc. Int. Conf. Quality in Chains
Eds. Tijskens & Vollebregt
Acta Hort. 604, ISHS 2003


Jurnal ” Quality in the Market – Technology Push versus Market Pull ”

Keywords: food quality, texture, sensory attributes, physical and chemical properties,
chain model, processing, recipe.

Klik: quality in the market,technology push versus market Pull


Jurnal ” Quality in Handling in Fruit and Vegetable Chains – a Challenge for Retailers ”

Quality in Handling in Fruit and Vegetable Chains –
a Challenge for Retailers

klik : quality in handling in fruit and vegetable chains a challenge for retailers


Global forces of change
Worldwide, the food retailing sector is becoming more concentrated, more
competitive, and more demanding of its supply chains. The paradox for managers is that
in such an environment, large transnational food retailers have more to offer their
suppliers, but they also have more to lose when suppliers fail to deliver, so both retailers
and suppliers are under increasing pressure to perform (Fearne, 1998).
To many retailers, the fresh fruit and vegetable category is a key driver of profit,
but it is also a category that is diverse, dynamic and among the most difficult to manage.
Fresh may be best, but fresh is also seasonal, perishable, subject to weather, and produced
by a large number of operators using a vast array of different systems. Take this
variability and multiply it across the range of different countries from which product is
sourced, and it is clear why retailers that are expanding globally face a particular
challenge in ensuring the performance of their fresh produce supply chains across a broad
sweep of markets.
In spite of some integration between the two sectors, food service is well ahead of
the retail sector in resolving its fresh produce supply chain issues (Kaufman et al. 2000).
The fast food sector is a good example. Like the retail sector, it is dominated by a
relatively small number of highly competitive global operators, yet it is able to achieve
consistently very high levels of physical and economic performance in fruit and vegetable
supply chains that handle millions of tonnes of product annually (Kaufman et al., 2000).
For example, membership of a MacDonalds’ supply chain for a perishable product such
as lettuce is driven by very tight product specifications, the achievement of exacting
levels of handling and processing efficiency, and very low margins, yet it is regarded as
very rewarding from a supplier’s perspective. These levels of reward and performance are
in sharp contrast to the average levels of performance and variable relationships that
typify the fresh produce retail sector. While retailers are beginning to learn valuable
lessons from food service operators, there are also important differences between the two
sectors and the lessons do not transplant directly. Fresh produce handling systems unique
to retailing are being developed, but evidence from around the world suggests that they
are not yet meeting the needs of producers, consumers or retailers with anything like the
reliability achieved by food service operators.


Jurnal ” Quality on the Edge: Quality from a Manufacturing Perspective “

klik : quality on the edge,quality from a manufacturing perspective

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
business easier.


Predicting Fresh Produce Quality in Supply Chains

Klik : predicting fresh produce quality in supply chans

Keywords: Blueberries, temperature, mass, firmness, model, simulation
Models for predicting blueberry mass and firmness losses during distribution
through supply chains were developed from storage studies. The models were then
applied to each link in a typical supply chain for fresh produce. The initial mass and
firmness at harvest and the time and temperature in the field were the values used
for calculating the loss percentages for the first link. Inputs to subsequent links were
the outputs from the previous links. Models and calculations were made in a
computerized spreadsheet (Microsoft Excel). A noteworthy result of the model is the
visibility of rapid mass losses when simulating short times at high temperature at an
open dock and in a car. Also, the rapid initial decrease in mass and firmness
indicates the importance of reducing delays before cooling. Finding the horizontal
distance between the two curves shows the benefit of low temperatures. Similar
models are being developed for other crops.


Pre-harvest Factors and Fresh-cut Vegetables Quality

Klik : pre harvest factors and fresh cut vegetables quality


Keywords: postharvest, maturity stage, lettuce, ascorbic acid, leaf expansion grade
The characteristics and the quality of vegetable crops during storage are
influenced by environmental conditions and production technology. Some preharvest
factors are closely related while others act independently. To provide high
quality product throughout the year, it is required to start from high quality
material and to optimize the different postharvest stages. Modified atmospheres
depend on the properties of the packaging material and on the respiration activity.
This last one is affected by intrinsic factors, such as size, variety and maturation
stage, and extrinsic factors, such as temperature, processing conditions, relative
humidity and fresh-cut vegetable volume. The objective of this study was to evaluate
the influence of preharvest factors on the quality of fresh cut lettuce. Three
experiments were conducted with different maturity stages (harvest time and leaf
expansion grade) and lettuce types. Measurements were made of weight loss,
ascorbic acid and chlorogenic acid concentrations, colour changes, O2, CO2 and
ethylene production in the package atmosphere, general overall visual quality and
organoleptic quality. Preliminary results showed that variation in enzymatic
activities was related to the lettuce type and the permeability of the packaging
material to O2 and CO2. In general, a lower chlorogenic acid concentration was
related to a better organoleptic quality depending on the film permeability. A higher
postharvest quality on butterhead fresh cut lettuce was found with lettuce heads
harvested at 45 days. Fresh cut lettuce with moderately expanded leaves showed the
best general overall visual quality. Ascorbic acid concentration decreased during
storage in all lettuce types. Optimization of all the steps of production, preparation
and distribution of fresh cut vegetable and selection of the most suitable cultivar will
yield products of extended shelf life with fresh-like quality.


Modelling for Decision Support in the Vegetable and Fruit Supply Chain

Klik :

modelling for decision support in the vegetable and fruit supply chain

P.O. Box 17, 6700 AA Wageningen, The Netherlands 2VU Amsterdam
Mathematics & Computer Science
De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands

Quality modelling in agri-supply chains has become increasingly popular in
R&D environments, because of the availability of large amounts of experimental
data and mathematical models. At the same time, in industrial supply chains a
strong need exists for support in making complex decisions with respect to logistic,
commercial, technical, financial and other aspects. Nevertheless, the majority of
research models is not being used in real world applications. Our claim is that a
more explicit analysis of specific decision-making processes will help to construct
models that will be of use in practice. Therefore we propose to pay special attention
to this aspect of the modelling process and to separate it from behavioural
modelling. We distinguish between decision and control variables on one hand and
behavioural variables on the other. Common modelling practice only deals with the
latter. We review three cases from our own project experience with this conceptual
distinction in mind: fresh-cut vegetables in MA-packaging, ripeness of mangoes and
optimal planning of sowing and harvesting. This analysis has resulted in a
systematic procedure to analyse the decision-making process and to construct
context relevant models. Careful examination of potential applications along these
lines will improve the interaction between users and developers of product and
process models.

Keywords: decision support, modelling, quality, fresh products, supply chain.


Budayakan ” Senyum – Salam – Sapa – Santun – Sabar ”

Budayakan ” Senyum – Salam – Sapa –  Santun – Sabar ” 


19 bb 2007 Methods of Teaching Agriculture, Third Edition LH. Newcomb, dkk ISBN 0-13-113418-3