Consumer Acceptability in Flower Chains: How Can We Determine What the Final Customers Really Want?

When we look at the ornamental supply chain in the Netherlands as a Value Chain (Porter, 1998) it strikes us that most actors in the chain are obsessed by the product and have no idea how the value of these products is developed throughout the entire production and supply chain. Any value chain starts with the value a group of consumers attributes to the product. So it all starts with finding out what consumers want and then finding the most cost effective way of delivering that product with the desired attributes to these consumers. In the USA the South American producers expected to be able to compete with the local production by offering the product (cut flowers) at a lower price (Reid, 2002). In the first instance this worked very well and the local production virtually disappeared. However the quality of the imported product was a dismal failure and while imports surged, total flower consumption plummeted in the 90s. In the UK the retail chains such as Sainsbury’s and Tesco wanted to improve their ornamental categories. They invented the ‘Vase Life Guarantee’ and improved their quality considerably. This resulted in an increase in market share from 18 to 60% over 15 years, while the total flower consumption in the UK doubled in the past 15 years. A research will be shown on the response of stakeholders in the ornamental industry and consumers on the question whether they would see the ‘Vase Life Guarantee’ as a value addition in the supply chain. This research was done in the UK and the Netherlands (where no vase life guarantee was used explicitly in the retail) at the turn of the millennium. It clearly shows the difference between the judgements of the stakeholders versus the opinions of the consumers. If we want to create Value Added Chains in the ornamental industry it is about time to find out what the consumer really wants

External quality measurements reveal internal processes

With the present developments in CA technology it becomes possible to fine tune the storage conditions to the specific needs of the product. This generates the need to know the exact quality conditions of the product before storage starts. By measuring the initial quality we can determine these conditions optimally. At present the most likely candidates to assess the initial quality with fast and non-destructive measurements are colour, chlorophyll fluorescence, and maybe NIR spectroscopy. Two examples are presented where initial colour measurements on all products in a batch can be shown to be indicative for the keeping quality of that batch. The first example focuses on how initial colour measurements using a 3CCD video camera can be utilised to predict the keeping quality of a batch of cucumbers where colour itself is regarded as the most important quality attribute. The second example focuses on how colour measurements can be used to predict the keeping quality of a batch of strawberries where the ability to suppress a Botrytis cinerea infection is the most important quality attribute. Furthermore, attention is given to the use of modulated chlorophyll fluorescence imaging as a possible initial quality indicator for rose leafy stem cuttings. The level of inhomogeneity in the quantum yield of photochmistry od PSII of leaves of rose cuttings may be an indictor of the capability of the cutting to recover from severance, and to form roots and generate regrowt

New Development in Greenhouse Technology can Mitigate the Water Shortage Problem of the 21st Century

The world's fresh accessible water situation is deteriorating at a dismal pace. Though the situation is already quite dramatic in Africa, the near future will bring us great problems in Asia as well, considering the pace at which the population is growing and the rise in water use per capita as the economy induces a raised demand. Agricultural consumption of fresh water is one of the main water uses world wide; however, it appears that protected cultivation of horticultural crops can alleviate the problem. Drip irrigation already reduces water use dramatically. However, novel high technological solutions in greenhouse production can lead the way to highly efficient water use production techniques. Adoption of more efficient water use techniques will contribute to sustainability, especially in highly populated urban areas. The novel Dutch technology of closed greenhouses could help develop water efficient production system

Effects of ca treatments and temperature on broccoli colour development

Broccoli combines high contents of vitamins, fibres and glucosinolates with a low calorie count and is sometimes referred to as the ‘crown jewel of nutrition’. Colour is one of the most important quality attributes of broccoli, and yellowing due to senescence of broccoli florets is the main external quality problem in the broccoli supply chain. Controlled Atmosphere (CA) is a very effective method to maintain broccoli quality but the effects of CA on colour retention have not been studied extensively. The aim of this paper is to characterise the colour behaviour (measured by RGB colour image analysis) of broccoli as affected by CA and temperature. Data on colour behaviour and gas exchange were gathered for broccoli heads that were stored in containers at three temperatures and subjected to four levels of O2 and three levels of CO2. Gas conditions and temperature have a clear effect on the colour change of broccoli especially at low O2 in combination with high CO2. An integrated colour model is proposed that combines a colour model with a standard gas exchange model. The colour model is based on three differential equations describing the formation of (blue/green) chlorophyllide from the colourless precursor, the bidirectional conversion of chlorophyllide into (blue/green) chlorophyll, and the decay of chlorophyllide. During the first step of building the integrated model, gas exchange data were analysed simultaneously using multi response regression analysis. No fermentation was encountered for this batch of broccoli. During the second step it was found that only one of the reactions of the colour model, the decay of chlorophyllide, is affected by the gas conditions. In the final step, a multi-response approach was applied where gas exchange parameters were estimated using the gas exchange model, the colour parameters were estimated using the colour model with both models linked via the reaction rate constant affected by the gas conditions. Such a calibrated, integrated, model could be used as a tool for predicting colour change in the postharvest chain

Photosynthetic free energy transduction : modelling electrochemical events = [Fotosynthetische vrije energie omzetting : modelbeschrijvingen van elektrochemische verschijnselen

This thesis is concerned with a particular part of the photosynthesis process. This part consists of the light-induced transmembrane electric potential gradient, the electrochemical pH gradient and the subsequent transformation of the energy contained in these gradients into chemical free energy of adenylates (ATP). This transformation of energy, originally in the form of an electromagnetic quantum, into a metabolic useful and stable chemical bond is called photosynthetic free energy transduction. After this process, which is sometimes inadequately referred to as the light reaction, the chemical energy is used, together with reduction equivalents from the electron transport chain, to bind protons and carbon molecules in order to form sugar molecules. In this last process, i.e. the Calvin cycle or the "dark reaction", free energy is not transduced, but shifted from one chemical bond to another. The reactions pertaining to the transduction of free energy are linked to the thylakoid membranes and are described in a general fashion in chapter 1.Three different approaches were used to study the free energy transduction. First the electrophysiological approach, i.e. measurements of the transmembrane electric potential with a microelectrode inserted in a single chloroplast. Second the spectrophotometric approach, in which a light-induced absorbance change of an ensemble of chloroplasts was studied with the aid of a spectrophotometer (P515). And third the modelling approach, from whence we have tried to encompass the host of experimental results in photosynthesis research in a rigorous mathematical formulation. The description of the methods used can be found in chapter 2.The basic model of photosynthetic free energy transduction, as it was originally developed to explain our electrophysiological results, is presented in chapter 3. It is based on the chemiosmotic hypothesis of membrane linked free energy transduction. Potential traces simulating the light-induced electric potential changes across the thylakoid membrane of an obligate shade plant like Peperomia metallica L. tend to reproduce experimental recordings measured with a microelectrode impaled in a chloroplast of that plant. A crucial role in this model is played by the formalism for the proton flux through the ATPase. The formalism developed by braber et al. (1984, 1987) for an oxidized ATPase was adapted to be applied in our model.Applications of the model and a comparison with earlier experiments are given in chapter 4. There it becomes evident that the model can be used for other techniques in photosynthesis research such as chlorophyll fluorescence induction curves. We compare simulations with microelectrode traces of the thylakoid membrane electric potential. Measurements by Remish et al. (1986a, b) of the combined pH gradient and the electric potential also confirm our model calculations.In chapter 5 we present electrophysiological (microelectrode) and spectrophotometric (P 515 ) results, which appear to challenge the premises on which the model presented in the previous chapters is based, namely Mitchell's hypothesis of chemiosmotic free energy transduction (Mitchell 1961). These results pertain to a deviation from a single exponential decay expected after a flash-induced rise in the electric potential. When measured with the microelectrode this is called a "new" response by us as opposed to the "classical" response. When measured with the P 515 technique it is called reaction II plus reaction I as opposed to reaction I alone. The P 515 response and the "new" response measured with the microelectrode show a striking similarity.In chapter 6 the phenomena underlying reaction II and the "new" response are explained. It appears that the Q-cycle, an explanation generally used for a particular component of reaction II (i.e. the relative slow rise), cannot be used to explain the P 515 measurements in view of the experiments and on theoretical grounds. We develop a model for reaction II based on stabilization of protons within the membrane matrix. This implies a dielectric separation of charges. Some charges reach the lumen and others stay within the membrane. The protons remaining within the membrane appear to leave the membrane via the membrane bound proton ATP synthase complex. This is incompatible with a basic assumption of the chemiosmotic hypothesis, i.e. all charges are transferred from the stroma to the lumen and both stroma and lumen are highly conductive and homogeneous phases. It appears that our model of reaction II is more in accord with an alternative hypothesis for membrane linked free energy transduction and usually referred to by the name of "localized" chemiosmosis (Williams 1961, Westerhoff et al. 1984). Although the "new" response measured by the microelectrode is similar to the P 515 response, it is explained by a different phenomenon. The structural effects of a microelectrode tip of 0.15 μm diameter penetrating a thylakoid membrane structure (granum) of 1.5 μm diameter is taken into consideration. This combined with the effect of a large concentration of "immobilized" buffer groups gives a completely different explanation for the "new" response.In chapter 7 we deliberate wether the "new" response and reaction II can be considered as an indication that the basic assumption of the chemiosmotic theory is violated. For the "new" response this is clearly not the case, since it is a consequence of the measuring method and its explanation can only lead to temporary inhomogeneities in the lumen. While for a true violation of the chemiosmotic theory the concept of a heterogeneous lumen must be sustained even under steady-state actinic illumination. For reaction II the answer is not so simple since an obvious connection exists between the membrane stabilized protons and the ATPase. However reaction II saturates after a short illumination period and stays saturated while the ATPase stays active. Thus it is not clear wether these protons play an active role during steady-state photophosphorylation. As was also shown by others it is likely that these protons play a role in the activation of the ATPase

Comparison of climate and production in closed, semi-closed and open greenhouses

A (semi-)closed greenhouse is a novel greenhouse with an active cooling system and temporary heat storage in an aquifer. Air is cooled, heated and dehumidified by air treatment units. Climate in (semi-)closed greenhouses differs from that of conventional open greenhouses. The aims of our research were first, to analyze the effect of active cooling on greenhouse climate, in terms of stability, gradient and average levels; second, to determine crop growth and production in closed and semi-closed greenhouses. An experiment with tomato crop was conducted from December 2007 until November 2008 in a closed greenhouse with 700 W m-2 cooling capacity, two semi-closed greenhouses with 350 and 150 W m-2 cooling capacity, respectively, and an open greenhouse. The higher the cooling capacity, the more independent the greenhouse climate was of the outside climate. As the cooling ducts were placed underneath the plants, cooling led to a remarkable vertical temperature gradient. Under sunny conditions temperature could be 5°C higher at the top than at the bottom of the canopy in the closed greenhouse. Cumulative production in the semi-closed greenhouses with 350 and 150 W m-2 cooling capacity were 10% (61 kg m-2) and 6% (59 kg m-2) higher than that in the open greenhouse (55 kg m-2), respectively. Cumulative production in the closed greenhouse was 14% higher than in the open greenhouse in week 29 after planting but at the end of the experiment the cumulative increase was only 4% due to botrytis. Model calculations showed that the production increase in the closed and semi-closed greenhouses was explained by higher CO2 concentratio

Keeping Quality of Strawberry Batches

Post-harvest life of strawberries is largely limited by Botrytis cinerea infection. It is assumed that there are two factors influencing the batch keeping quality: the botrytis pressure and the resistance of the strawberry against infection. The latter factor will be discussed here. A model is presented that describes the development of red colour and anti-fungal function of individual strawberries over time. The model was fitted to colour data from strawberries batches from the same growing conditions stored per batch at 5, 10 or 16 °C after harvest. Batches are considered to be all strawberries from one harvest. Spoilage per batch was recorded during storage. The fitted initial spoilage per batch was found to relate to the fitted amount of precursor of both the colour and the anti-fungal compounds. Batch keeping quality could be predicted from the initial batch colour distributions. An explanation for the predictive ability of the model without having to use a term describing the pH is presented from pigment HPLC measurements

Modelling for Globalisation

The world is getting smaller and smaller. All participants to this conference are the best example for that: we come from all over the world to discuss themes related to our daily food. Living in a small world has great advantages but also some drawbacks. We like to think we are ready for a major up scaling of our food supplies, but are we really? What do we need to answer to this challenge? How can we manage these large scale operations? Where do we get useful information? How do we discriminate useful information from misinformation