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Although much information on the endocrine activity of bisphenol A (BPA) is available, a proper human hazard assessment of analogues that are believed to have a less harmful toxicity profile is lacking. Here the possible effects of BPA, bisphenol F (BPF), bisphenol S (BPS), as well as the brominated structural analogue and widely used flame retardant tetrabromobisphenol A (TBBPA) on human glucocorticoid and androgen receptor (GR and AR) activation were assessed. BPA, BPF, and TBBPA showed clear GR and AR antagonism with IC50 values of 67 μM, 60 μM, and 22 nM for GR, and 39 μM, 20 μM, and 982 nM for AR, respectively, whereas BPS did not affect receptor activity. In addition, murine MA-10 Leydig cells exposed to the bisphenol analogues were assessed for changes in secreted steroid hormone levels. Testicular steroidogenesis was altered by all bisphenol analogues tested. TBBPA effects were more directed towards the male end products and induced testosterone synthesis, while BPF and BPS predominantly increased the levels of progestagens that are formed in the beginning of the steroidogenic pathway. The MA-10 Leydig cell assay shows added value over the widely used H295R steroidogenesis assay because of its fetal-like characteristics and specificity for the physiologically more relevant testicular Δ4 steroidogenic pathway. Therefore, adding an in vitro assay covering fetal testicular steroidogenesis, such as the MA-10 cell line, to the panel of tests used to screen potential endocrine disruptors, is highly recommendable.

We investigate the effect of salt on the expansion of starchy snacks during frying by means of a multiscale simulation model. This model has been developed earlier for starchy snacks without salt. The simulation results are analysed by means of the supplemented state diagram. We have found that the optimal expansion for salty snacks occurs under the same conditions as for snacks without salt. This occurs at the moisture content where the 4 bar boiling line intersects the critical isoviscosity line of 1 MPa s. Salt is shown to influence both the boiling line and the critical isoviscosity line, via a change of the glass transition. The optimal moisture content for salty snacks is lower than that of unsalted snacks. We view our findings as important for reformulations of starchy snacks with lower salt levels. Furthermore, the presented tools of the multiscale simulations and supplemented state diagram can generally be used for reformulation problems in structured foods.

Two sensory studies were carried out to compare the taste intensity, the perceived fluctuation of taste intensity and the consumer preference of food products with homogeneous and inhomogeneous distributions of tastants using 2-alternative forced choice tests. The first study evaluated pairs of gels, breads and sausages (1 homogeneous product and 1 inhomogeneous product). The second study evaluated 4 types of gel and 4 types of sausage (1 homogeneous product and 3 inhomogeneous products varying in the magnitude of tastant concentration differences). In the first study, all products with an inhomogeneous distribution of tastants were perceived sweeter or saltier than the respective homogeneous products. Tastant concentration differences were perceived as fluctuations of taste intensity in inhomogeneous gels and breads, but not in inhomogeneous sausages. Inhomogeneous gels and sausages were more preferred than the homogeneous products, whereas inhomogeneous and homogeneous breads were equally preferred. In the second study, inhomogeneous gels with large tastant concentration differences were perceived sweeter than the homogeneous gel. The taste intensity of homogeneous and inhomogeneous sausages did not differ. Tastant concentration differences induced perceivable taste intensity fluctuations in inhomogeneous gels, but not in inhomogeneous sausages. The inhomogeneous gel with the largest tastant concentration difference was more preferred than the homogeneous gel. Homogeneous and inhomogeneous sausages were equally preferred. Results suggest that the enhancement of taste that is caused by tastant concentration differences does not require the conscious perception of taste intensity fluctuations. We conclude that products in which tastants are heterogeneously distributed are equally or more preferred than products in which tastants are homogeneously distributed. Therefore, the modulation of the spatial distribution of tastants might be used as a strategy to reduce sugar and salt in food products without compromising consumer preference.

We studied stem bending in cut Gerbera flowers (Gerbera jamesonii cv. Tamara). Bending might be due to turgor loss. During vase life water uptake decreased more rapidly than transpiration, hence the flowers lost water. Net water loss did not occur in the floral head, but was found in the stem. It was largest in the segment (10–15 cm below the floral head) where bending was localised. When comparing flowers that showed stem bending with those that did not, on day 7 of vase life, the fresh weight loss of 5 cm stem segments was higher in the stems that had bent. Covering the stems with a flexible, thin sleeve of polypropylene plastic reduced transpiration and increased the time to stem bending from d 7 to d 14 of vase life. Additionally, stem bending might relate to stem elongation and to stem morphology and anatomy. Stems elongated by 1–1.5 cm, in the uppermost 10 cm, during the first two days of vase life. No relationship was found between stem elongation and bending. At harvest, the stems contained a large central cavity, starting at about 5 cm from the root–shoot junction, and ending about 10 cm below the floral head. The cavity extended upwards and laterally during vase life, but no relationship was found between cavity formation and stem bending. A cylinder of sclerenchyma in the stems was found to end about 20 cm below the floral head, in summer. Bending was correlated with the extent of sclerenchyma formation and stem lignin levels. It is concluded that stem bending is due to net water loss from the stem, particularly in the area of bending, and to low mechanical strength in the upper part of the stems, which lack a sclerenchyma cylinder.

In this study, we investigate a technological approach to reduce the sodium content of bread whilst retaining its sensory profile by creating taste contrast using encapsulated salt. We demonstrate that sensory contrast in bread induced by encapsulated salt can enhance saltiness and allows for a salt reduction of up to 50% while maintaining saltiness intensity. The magnitude of the saltiness enhancement depends on the size of the salt encapsulates. Small encapsulates lead to small concentration gradients of salt which do not affect saltiness intensity and consumer liking. Large encapsulates lead to large concentration gradients which enhance saltiness intensity significantly and reduce consumer liking. To achieve maximum salt reduction while maintaining saltiness and liking of the bread, the dimensions of the encapsulated salt particles need to be optimized. Taste contrast is a technology to modulate taste perception and to create sodium reduced products while retaining their saltiness intensity and consumer liking. © 2011 Elsevier Ltd.

This study compares emission pathways aimed at limiting temperature increase to 2°C under varying constraints. In a first set of pathways, the timing of emission reductions is such that over the 2010–2100 period, assuming full participation from 2013 onwards, mitigation costs are minimized. In a second set of pathways, we set emissions in 2020 at a level based on the pledges of the Copenhagen Accord. In the ‘Copenhagen Potential’ scenario, climate talks result in satisfying conditions linked by countries to their ‘most ambitious’ proposals. Contrasting, in the ‘Copenhagen Current’ scenario, climate talks fall short of satisfying the conditions to move beyond current unilateral pledges. We include scenarios with and without the availability of bio-energy in combination with carbon capture and storage. We find that for a ‘Copenhagen Potential’ scenario, emissions by 2020 are higher (47 GtCO2eq/yr) than for a least-cost pathway for 2°C (43 GtCO2eq/yr with a 40–46 GtCO2eq/yr literature range). In the ‘Copenhagen Potential’ scenario the 2°C target can still be met with a likely chance, although discounted mitigation costs over 2010–2100 could be 10 to 15 % higher, and up to 60 % in the 2040–2050s, than for least-cost pathways. For the ‘Current Copenhagen’ scenario, maintaining an equally low probability of exceeding 2°C becomes infeasible in our model, implying higher costs due to higher climate risks. We conclude that there is some flexibility in terms of 2020 emissions compared to the optimal pathways but this is limited. The 2020 emission level represents a trade-off between short-term emission reductions and long-term dependence on rapid reductions through specific technologies (like negative emission reductions). Higher 2020 emissions lead to higher overall costs and reduced long-term flexibility, both leading to a higher risk of failing to hold warming below 2°C.

Programmed cell death (PCD) is an integral part of plant development and of responses to abiotic stress or pathogens. Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death, the cell contents are removed by a combination of autophagy-like process and release of hydrolases from collapsed lytic vacuoles. Necrosis is characterised by early rupture of the plasma membrane, shrinkage of the protoplast and absence of vacuolar cell death features. Vacuolar cell death is common during tissue and organ formation and elimination, whereas necrosis is typically found under abiotic stress. Some examples of plant PCD cannot be ascribed to either major class and are therefore classified as separate modalities. These are PCD associated with the hypersensitive response to biotrophic pathogens, which can express features of both necrosis and vacuolar cell death, PCD in starchy cereal endosperm and during self-incompatibility. The present classification is not static, but will be subject to further revision, especially when specific biochemical pathways are better defined.

The vase life of cut tulips (Tulipa spp.) is limited by a combination of leaf yellowing, tepal senescence, and tepal abscission. In many cultivars, moreover, high rates of stem elongation result in stem bending during vase life. In tests with the cvs. Apeldoorn and Frappant, stem bending could be prevented by treatment with ethylene or ethephon. However, these treatments resulted in poor flower opening. The ethephon treatment also resulted in precocious tepal abscission. The negative effect of ethephon on flower opening was overcome by a treatment with gibberellic acid (GA3). GA3 also somewhat delayed early leaf yellowing, but did not prevent the early tepal abscission induced by ethephon. The latter problem was overcome by a treatment with benzyladenine (BA). In addition, BA effectively delayed leaf yellowing and also delayed tepal senescence. However, BA produced browning of the lower stem end. This was prevented by the inclusion of calcium ions in the solution. The combination of chemicals (ethephon, GA3, BA, and calcium ions) was similarly successful in a large number of other tulip cultivars tested. After adaptation of the concentrations the four chemicals were also effective if given as a pulse treatment shortly after harvest.

The concentration of cations in the xylem sap influences the rate of xylem water flow in angiosperm plants. It has been speculated that this is due to the shrinking and swelling of pectins in the pit membranes. However, there is as yet minimal evidence for the presence of pectin in pit membranes of angiosperms. The little pectin that has been found at the pit membrane edges of some species might not be adequate to explain the swelling and shrinking phenomena. The presence of hemicelluloses is also not certain. Lignin, by contrast, seems to be sometimes present, apart from cellulose, which is the main component. An alternative hypothesis is formulated, which involves the shrinking of any polyelectrolyte polymers in the pit membrane and a change in volume of the mobile phase in the pit pores. These phenomena are the result of electrostatic events. Some pit membrane polymers are negatively charged because of proton dissociation from functional groups. This charge is compensated by cations in the aqueous phase, which form a diffuse double layer (DDL). Inside the pit pores, an increase of the electrolyte concentration in the xylem sap will reduce the extent of the DDL. This will result in an increase in water flow. Additional flow enhancement, upon increase of the cation concentration, can be due to shrinkage of all membrane polymers. This contraction will also lead to an increase of the pit pore diameter. These processes will only be partly counteracted by forces that decrease the diameter of the pit pore due to relaxation.

Model systems consisting of layers of mixed agar/gelatin gel were used to investigate the effect of the spatial distribution of sucrose on perceived sweetness intensity. 2-Alternative forced choice tests were performed with consumers to compare the sweetness of layered samples with an inhomogeneous distribution of sucrose to the sweetness of a reference sample with a homogeneous distribution. All samples had the same overall sucrose concentration (10%) and similar mechanical and rheological properties. Inhomogeneous samples that had large concentration gradients of sucrose between layers were perceived sweeter than the homogeneous reference. No differences in sweetness were observed between the reference and samples with small concentration gradients of sucrose. Additionally, the position of the layers containing sucrose did not affect sweetness. Results showed that an inhomogeneous distribution of sucrose can be used to reduce sucrose content by 20% without a decrease in sweetness intensity.

This paper presents the use of receding horizon optimal control (RHOC) for optimal climate control in storage facilities for potatoes and onions. RHOC is used on a supervisory level above the classical feedback climate controller. Some theoretical issues on RHOC are discussed, amongst which a convenient way to handle state constraints. Both simulation and full-scale experimental results are presented. Temperature control is improved and electricity costs are reduced. In view of the positive experimental results, Tolsma Techniek Emmeloord B.V. has started introduction of the control technique as an industrial product.

Loosening of cell walls is an important developmental process in key stages of the plant life cycle, including seed germination, elongation growth, and fruit ripening. Here, we report direct in vivo evidence for hydroxyl radical ((OH)-O-center dot)-mediated cell wall loosening during plant seed germination and seedling growth. We used electron paramagnetic resonance spectroscopy to show that (OH)-O-center dot is generated in the cell wall during radicle elongation and weakening of the endosperm of cress (Lepidium sativum; Brassicaceae) seeds. Endosperm weakening precedes radicle emergence, as demonstrated by direct biomechanical measurements. By H-3 fingerprinting, we showed that wall polysaccharides are oxidized in vivo by the developmentally regulated action of apoplastic (OH)-O-center dot in radicles and endosperm caps: the production and action of (OH)-O-center dot increased during endosperm weakening and radicle elongation and were inhibited by the germination-inhibiting hormone abscisic acid. Both effects were reversed by gibberellin. Distinct and tissue-specific target sites of (OH)-O-center dot attack on polysaccharides were evident. In vivo (OH)-O-center dot attack on cell wall polysaccharides were evident not only in germinating seeds but also in elongating maize (Zea mays; Poaceae) seedling coleoptiles. We conclude that plant cell wall loosening by (OH)-O-center dot is a controlled action of this type of reactive oxygen species.

Here we present a summary of our study on cadmium-induced cell death signaling in a model system of suspension-cultured tomato cells. Exposure of the cells to CdSO4 induced typical for PCD (cytoplasm shrinkage and nuclear condensation) morphological changes of the dead cells. Ethylene and hydrogen peroxide were established to increase in response to Cd stress. By inhibitory studies we have demonstrated that CdSO4 induces cell death in tomato suspension cells that involve plant caspase-like proteases, indicating that Cd-triggered cell death is a form of programmed cell death. It is also shown that serine peptidases, oxidative stress, lipid signaling and ethylene are players in the Cd-induced cell death signaling. Cd-induced cell death in tomato suspension cells was categorised as non-lysosomal type.

The goal of ISAFRUIT to increase fruit consumption has strong foundations in the new knowledge created by a multidisciplinary team of natural and social scientists addressing critical aspects of the multi-faceted fruit chain. Bridging the gap between disciplines proved to be a substantial challenge, as they have quite different languages, methods, and networks. In March 2008, ISAFRUIT launched an initiative to address this gap and named it the “Vasco da Gama process”, after the Portuguese explorer who, early in the 16th century, embarked in the first ships to sail directly from Europe to India and to bridge the gap between continents and cultures. ISAFRUIT’s process for bridging between research disciplines was to discover if the research conducted indeed contributed to increased fruit consumption in Europe. For this purpose, the Quality Function Deployment (QFD) method was applied. This includes the construction of a House of Quality (HoQ), which is a conceptual and graphical tool that presents the positive and negative relationships between technical quality traits, as studied and influenced by pre- and post-harvest experiments, and consumer-demand terms. This paper explains the methodology in greater detail. The first experience with this process showed that, even if scientists from different disciplines were keen to be involved, there was a need for a sustained effort to drive such a process. The process is still underway, and specific results will be published later

Counting the number of flowers in a plant is an example of agricultural quality inspection issues in which a simple 2D image of the product does not suffice. It is essential to see the object under inspection from multiple viewpoints to get a clear estimation of the quality of the product. In order to use multiple viewpoints to obtain a proper quality assessment, a multi-target tracking algorithm that accurately identifies relevant features of the product under inspection is proposed in this paper. The approach is illustrated with an experiment in which the flowers in a number of plants are counted. For the presented method, the plant rotates in front of a camera and a number of consecutive images is taken. The tracking algorithm detects, predicts, and matches the (partially occluded) flowers in the image. The experiments provide a proof of principle of the proposed method. The conclusion of this paper is that the presented multi-target tracking algorithm can be used to solve many similar quality assessment issues for agricultural objects.

Detached tobacco leaves were infiltrated with an AT toxin preparation from the foliar pathogen Alternaria alternata tobacco pathotype. The AT toxin preparation caused formation of necrotic lesions within 5 days post-infiltration in a concentration-dependent manner. Cell death was accompanied by increased levels of the stress metabolites hydrogen peroxide, malondialdehyde, free proline and by enhanced total protease activity. Lesion development and the production of stress metabolites were suppressed if the infiltration site was pre-infiltrated with caspase-specific peptide inhibitors (irreversible caspase-1 inhibitor acyl-Tyr-Val-Ala-Asp-chloromethylketone (Ac-YVAD-CMK) and the broad range caspase inhibitor benzyoxycarbonyl-Asp-2,6-dichlorobenzoyloxymethylketone (Z-Asp-CH2-DCB)), the serine protease inhibitor N alpha-p-tosyl-L-lysine chloromethylketone and the polyamine spermine. Extensive accumulation of reactive oxygen species (ROS), as determined by staining with 3-3'-diaminobenzidine and 2',7'-dichlorofluorescein diacetate, was found in the AT toxin-challenged lesions. The data show that AT toxin-induced cell death in tobacco is a type of programmed cell death in which caspase-like proteases and ROS signalling play a prominent role.

The goal of ISAFRUIT to increase fruit consumption has strong foundations in the new knowledge created by a multidisciplinary team of natural and social scientists addressing critical aspects of the multi-faceted fruit chain. Bridging the gap between disciplines proved to be a substantial challenge, as they have quite different languages, methods, and networks. In March 2008, ISAFRUIT launched an initiative to address this gap and named it the "Vasco da Gama process", after the Portuguese explorer who, early in the 16th century. embarked in the first ships to sail directly from Europe to India and to bridge the gap between continents and cultures. ISAFRUIT's process for bridging between research disciplines was to discover if the research conducted indeed contributed to increased fruit consumption in Europe. For this purpose, the Quality Function Deployment (QFD) method was applied. This includes the construction of a House of Quality (HoQ), which is a conceptual and graphical tool that presents the positive and negative relationships between technical quality traits, as studied and influenced by pre- and post-harvest experiments, and consumer-demand terms. This paper explains the methodology in greater detail. The first experience with this process showed that, even if scientists from different disciplines were keen to be involved, there was a need for a sustained effort to drive such a process. The process is still underway, and specific results will be published later.

International audience; Food supply chains are confronted with increased consumer demands on food quality and sustainability. When redesigning these chains the analysis of food quality change and environmental load of new scenarios is as important as the analysis of efficiency and responsiveness requirements. Simulation tools are often used for supporting decision-making on supply chain (re)design when logistic uncertainties are in place, building on their inherent modelling flexibility. Mostly, the underlying assumption is that product quality is not influenced by or does not influence chain design. Clearly, this is not true for food supply chains, as quality change is intrinsic to the industry. We propose a new integrated approach towards logistics, sustainability and food quality analysis, and implement the approach by introducing a new simulation environment, ALADIN(TM). It embeds food quality change models and sustainability indicators in discrete event simulation models. A case example illustrates the benefits of its use relating to speed and quality of integrated decision making, but also to creativity in terms of alternative solutions.

Food structuring is discussed from the viewpoints of soft matter physics and molecular gastronomy. Food is one of the most complex types of soft matter, with multiple dispersed phases and even hierarchical structure. Food structuring seems to be a kind of art, comprising a careful balance between forces driving the system towards equilibrium and arresting forces. A more scientific approach to this complex matter is desirable, using (1) concepts from soft matter physics, e.g. free energy and jamming, and (2) complex disperse system (CDS) notation as developed for molecular gastronomy. Combining CDS with state diagrams renders a new tool for the qualitative description of the complex process of making structured foods.

In this paper we have performed an extensive study of the effects of various dimensionless numerical parameters used in the Lattice Boltzmann implementation of the diffuse interface model describing deformation and breakup of an emulsion droplet in 2D. Such an extensive study on these parameter is absent in scientific literature of diffuse interface models. We have found that parameters like the dimensionless interface thickness and the Peclet number have to be within certain ranges for correct physical behavior. Outside these ranges droplets either dissolve, show incorrect Laplace pressures, or do not deform to stable shapes at subcritical capillary numbers. Furthermore, we have found that droplet breakup is sensitive to these parameters.

Food intake regulation comprises numerous components from peripheral and central pathways, including sensory and cognitive elements. This study investigated if congruency in different aroma–texture combinations within a dairy product influences satiation and food consumption in humans. Among seven different aromas, vanilla was rated as congruent and lemon as incongruent aroma in the context of creamy texture, while both aromas were highly liked and familiar. Creamy custard, either vanilla- or lemon-aromatised, was given to 32 subjects in a preload – ad libitum regimen. Satiation was measured on visual analogue scales and by salivary α-amylase concentration. Finally, the amount of ad libitum intake was determined. No effects of congruency were found on ad libitum consumption and perceived satiation. Subjects felt more satiated when preload and ad libitum intakes shared the identical aroma compared to varied aromas. This was not supported by increased salivary α-amylase levels, although those increased overall with intake. In conclusion, there was no relation between congruency in aroma and texture in dairy custard and food intake, but aroma perception possibly modulates perceived satiation.

Om in de glastuinbouw een succesvol camerasysteem te realiseren, zijn er bekende, maar ook minder bekende technieken toe te passen. In dit artikel laten we een aantal relevante technieken de revue passeren om helder aan te geven wat deze technieken inhouden en op welke wijze ze toegepast kunnen worden. Dit artikel is geschreven door Erik Pekkeriet en Rick van de Zedde, beide werkzaam bij Wageningen UR

In this paper we present models predicting thermophysical properties of frozen meat products purely using their composition data. Based on our previous model, predicting the water activity of (frozen) meat and fish products, while taking into account the non-ideality of the unfrozen solution, we can compute the ice fraction as a function of temperature. Knowing the composition and ice formed, the temperature dependency of heat capacities and latent heat, we can readily compute the enthalpy. For predicting the thermal conductivity a model is constructed taking into account the meat (fibrous) structure, the anisotropy of ice cyrstals, and the distribution of the composition over dispersed and continuous phases. Comparison model predictions to literature data on enthalpy and thermal conductivity shows that we can obtain reasonable prediction within engineering accuracy of 10%. The thermal conductivity model gives significant differences in conductivity parallel and perpendicular to meat fibres, in accordance with experimental data.

Arable farmers and their suppliers, consultants and procurers are increasingly dealing with gathering and processing of large amounts of data. Data sources are related to mandatory and voluntary registration (certification, tracing and tracking, quality control). Besides data collected for registration purposes, decision support systems for strategic, tactical and operational tasks yield enormous amounts of mainly digital information. Data of similar nature but with often varying definitions are collected and processed separately for different purposes. This paper describes for an important arable crop - the processing potato - which data requirements and flows exist at present and how they could possibly be described in a unifying ontology. An ontology describes the concepts, attributes and relations in a specific knowledge domain using a standardized representation language. Important concepts in this domain are for example crop, parcel, soil, treatment and farm. The ontology - once elaborated - will reduce the overlap between information models and helps to overcome the problem of data definition and representation. It is a key element for the development of systems that can automatically learn either with the help of expert knowledge or through adequate numerical techniques.

Fresh hot pepper (Capsicum annuum L.) fruit were harvested on days 15, 20 or 25 after flowering (DAF) and were stored at 5 and 10 °C. Seed browning was severe in fruit stored at 5 °C, but only if harvested at 15 DAF. Severe browning was positively correlated with visible cell damage, the rate of electrolyte leakage, initial levels of free phenolics, and levels of thiobarbituric acid (TBA) reactive compounds. Browning was related to initial higher levels of saturated fatty acids and lower levels of unsaturated fatty acids. Browning was also positively correlated with higher initial activities of polyphenol oxidase (PPO), and continuously higher activities of phenylalanine ammonia lyase (PAL), superoxide dismutase (SOD), and lipoxygenase (LOX). In contrast, browning was negatively correlated with the activities of catalase (CAT) and peroxidase (POD). The results suggest that loss of membrane integrity in young seeds is a cause of browning at low temperature, and that the higher levels of unsaturated fatty acids of older seeds might protect against chilling-induced browning. The negative correlation of browning with CAT and POD might indicate that these enzymes protect against chilling injury.

We have viewed cooking meat from the perspective of soft condensed physics and posed that the moisture transport during cooking can be described by Flory-Rehner theory of swelling/shrinking polymer gels. This theory contains the essential physics to describe the transport of liquid moisture due to the denaturation and shrinkage of the heated protein matrix. The validity of our hypothesis is shown by a numerical model, which comprises a linearization of the Flory-Rehner theory augmented with Darcy's law for porous media flow, applied to the simulation of cooking experiments performed on a rectangular piece of beef. Reasonably, comparable results are obtained from simulations and experiments. Further analysis of simulations resolves yet another unexplained phenomena observed during heating of meat. Literature review suggests that Flory-Rehner is applicable to cooking of other gel-like foods

Control of product quality and process yields in innovative food production processes can be largely improved through better understanding of the relations between process design and product quality.The effects of intensive heating processes such as frying, baking, roasting and microwave on product quality are still poorly understood. Currently, when designing new food processing lines, empirical knowledge of the effects of various process types on product quality is leading.With upcoming `new¿ heating methods, more fundamental insight is essential

This paper presents a physical model for predicting climate dynamics in ventilated bulk-storage of agricultural produce. A well-ordered model presentation was obtained by combining an object-oriented zonal decomposition with a process-oriented decomposition through matrix-vector notation. The objective of this paper is twofold: (1) to present the modelling procedure and (2) to present the resulting model, validated with real data. The model is a suitable simulator to assess potential effects of changes in ambient climate, design, and controller tunings. The model predictions fit well to extensive real data from three different cases. The good fit for all three cases was achieved with the five calibration parameters calibrated on the basis of data from one case only.

Commercial ripening of banana fruit occurs at high relative humidity (RH), which prevents browning of damaged skin areas. In experiments with ripening at high RH (94 ± 1%) the individual fruit (fingers) of ‘Sucrier’ ( Musa acuminata , AA Group) banana exhibited a high rate of drop. The falling off of the fingers is due to rupture of the peel at the pedicel. In contrast, if the fruit was held at low RH (68 ± 3%) finger drop was absent. Water-soluble pectin in the peel at the rupture area was higher at high RH, indicating increased pectin degradation. However, the activities of polygalacturonase (PG) in the peel at the rupture zone were the same in both treatments. The activity of pectinmethylesterase (PME) was only slightly higher prior to rupture in the high RH treatment, whereas, that of pectate lyase (PL) was considerably higher. The lower rate of pectin degradation at low RH may explain, at least partially, why finger drop is inhibited. The decrease in pectin degradation was not accounted for by the measured PG activity, but could be partially accounted for by the measured PME and PL activities.

Elicitors of different origin (fumonisin B1, fungal toxin), camptothecin (alkaloid from Camptotheca acuminata), mastoparan (wasp venom) and the heavy metal (cadmium) were tested for their ability to induce programmed cell death (PCD) in a model system of tomato cell culture, line MsK8. By employing a pharmacological approach the involvement of proteolysis, oxidative stress and ethylene in the suicidal cascade is shown. The caspase-specific peptide inhibitors: irreversible caspase-1 (ICE)-inhibitor acyl-Tyr-Val-Ala-Asp-chloromethylketone and the broad range caspase inhibitor benzyoxycarbonyl-Asp-2,6-dichlorobenzoyloxymethylketone effectively reduced cell lethality providing a sound indication that in tomato suspension cells the applied inducers promote cell death that resembles features typical for PCD. A lack of inhibition occurred at mastoparan-induced cell death in response to the caspase inhibitors, while the serine protease inhibitor aminoethylbenzenesulphonyl fluoride caused substantial reduction of cell mortality. Significant inhibition was detected after administration of ethylene inhibitor, aminoethoxyvinyl glicine and the antioxidants Lgalactonic acid -¿-galactone and catalase. The results indicate that the cell death response at the exposure to biotic and abiotic stressors may employ an activation of similar cell death pathways and that caspase-like- and non-caspase-like-dependent biochemical processes may be operative. In addition, the presented comparative study suggests that the reaction of tomato suspension cells to diverse cell death stimulating compounds at least partially coincides with the cell death machinery involved in the plant hypersensitive response and during PCD in animal cells.

Sucrier¿ bananas (Musa acuminata, AA Group) show peel spotting when the peel is just about as yellow as green, which coincides with optimum eating quality. As consumers might relate the spotting to overripe fruit, early spotting is considered undesirable, especially for export markets. Fruit were left uncoated (controls) or coated with polyethylene parafilm wax at concentrations of 20%, 25%, and 30% (v/v) and then held at 29¿30°C for 5 days. Compared with controls, each of the concentrations delayed early peel spotting. Eating quality was not affected by the 20% coating, but was negatively affected by the higher concentrations. Further tests, using 20% coating, showed that the delay of peel spotting was not associated with a change in peel total free phenolics or with polyphenol oxidase (PPO) activity, but it was accompanied by reduced in vitro phenylalanine ammonia lyase (PAL) activity. Results suggest that the delay in peel spotting, after surface coating, is a result, at least in part, of reduced PAL activity. Low rate of oxygen diffusion through the coating might be the factor that limits the last step to blackening.

SUMMARY Susceptibility was evaluated of host and non-host plants to three pathogenic Botrytis species: the generalist B. cinerea and the specialists B. elliptica (lily) and B. tulipae (tulip). B. tulipae was, unexpectedly, able to infect plant species other than tulip, and to a similar extent as B. cinerea. To study host and non-host interactions in more detail, the three Botrytis species were inoculated on Arabidopsis wild-types and 23 mutant genotypes. Disease development was monitored macroscopically by quantifying the lesion area and microscopically by bright-field and fluorescence microscopy following histochemical staining. B. cinerea and B. tulipae were very similar in their ability to infect the tested Arabidopsis genotypes, whereas B. elliptica caused disease only on a few Arabidopsis mutant genotypes. Arabidopsis mutants with a delayed or reduced cell death response were generally more resistant to Botrytis infection, whereas mutants in which cell death was accelerated were more susceptible. Differences in susceptibility between genotypes were generally gradual. Only the camalexin-deficient mutant pad3 was fully susceptible to all three Botrytis species. Cellular changes were monitored during compatible and incompatible interactions. The formation of papillae, the presence of lysosome-like vesicles and the intracellular accumulation of H(2)O(2) and nitric oxide were visualized in the infection zones using fluorescent probes. Based on histology and responses of Arabidopsis mutants, a model is proposed in which resistance against Botrytis, besides the production of camalexin, depends on the balance between cell death and survival.

An adaptive optimal scheduling and controller design is presented that attempts to improve the performance of beer membrane filtration over the ones currently obtained by operators. The research was performed as part of a large European research project called EU Cafe with the aim to investigate the potential of advanced modelling and control to improve the production and quality of food. Significant improvements are demonstrated in this paper through simulation experiments. Optimal scheduling and control comprises a mixed integer non-linear programming problem (MINLP). By making some suitable assumptions that are approximately satisfied in practice, we manage to significantly simplify the problem by turning it into an ordinary non-linear programming problem (NLP) for which solution methods are readily available. The adaptive part of our scheduler and controller performs model parameter adaptations. These are also obtained by solving associated NLP problems. During cleaning stages in between membrane filtrations enough time is available to solve the NLP problems. This allows for real-time implementation.

This study investigates the effects of fracture strain and fracture stress on oral breakdown, bolus formation and sweetness intensity of semi-solid food gels containing sucrose heterogeneously distributed in layers. The sweetness intensity of gels was mainly affected by the total surface area of gel fragments formed upon chewing. Gels with low values of fracture strain and fracture stress broke down into a large number of small fragments. These gels were perceived sweeter than gels with high values of fracture strain and fracture stress. Fracture strain had a larger impact on oral breakdown behavior and sweetness intensity than fracture stress. Results indicate that the oral breakdown behavior (i.e. formation of a large number of small fragments, which leads to an increase in the total surface area) is the driving factor for taste perception in semi-solid gels that have a heterogeneous distribution of sucrose. We suggest that the differences in sweetness intensity in gels containing sucrose heterogeneously distributed in layers and differing in fracture properties result from differences in the frequency of stimulation of taste receptors. An increase in the total surface area of fragments containing sucrose facilitates the release of tastants and increases the frequency of stimulation of taste receptors. Consequently, the taste intensity of gels is enhanced.

One of the major challenges in computer vision is to create automated systems that perform tasks with at least the same competences as human experts. In particular for automated inspection of natural objects this is not easy to achieve. The task is hampered by large in-class variations and complex 3D-morphology of the objects and subtle argumentations of experts. For example, in our horticultural case we deal with quality assessment of young tomato plants, which requires experienced specialists. We submit that automation of such a task employing an explicit model of the objects and their assessment is preferred over a black-box model obtained from modelling input-output relations only. We propose to employ ontologies for representing the geometrical shapes, object parts and quality classes associated with the explicit models. Our main contribution is the description of a method to develop a white-box computer vision application in which the needed expert knowledge is defined by: (i) decomposing the task of the inspection system into subtasks and (ii) identifying the algorithms that execute the subtasks. This method describes the interaction between the task decomposition and the needed task-specific knowledge, and studies the delicate balance between general domain knowledge and task-specific details. As a proof of principle of this methodology, we work through a horticultural case study and argue that the method leads to a robust, well-performing, and extendable computer vision system.

Programmed cell death (PCD) was studied in the petals of Antirrhinum majus, Argyranthemum frutescens, and Petunia hybrida, using DNA degradation and changes in nuclear morphology as parameters. The petals exhibit loss of turgor (wilting) as a visible symptom of PCD. DNA degradation, as shown on agarose gels, occurred in all species studied, prior to visible wilting. The number of DNA masses in all the petals of a flower, determined by flow cytometry, markedly increased in Argyranthemum and Petunia, but decreased in Antirrhinum. Many small DNA masses were observed in Argyranthemum and Petunia. The surface of each small DNA mass stained with the lipophilic fluorochrome 3,3'-dihexyloxacarbocyanine iodide (DiOC6), indicating that these masses were surrounded by a membrane. In Antirrhinum, in contrast, the chromatin fragmented into several small spherical clumps that remained inside a large membranous structure. Nuclear fragmentation, therefore, did not occur in Antirrhinum, whereas nuclear fragmentation possibly was a cause of the small DNA masses in Argyranthemum and Petunia. It is concluded that at least two contrasting nuclear morphologies exist during PCD. In the first, the chromatin fragments inside the nucleus, not accompanied--or followed--by nuclear fragmentation. In the second, a large number of DNA masses were observed each enveloped by a membrane. The second type was probably due, at least partially, to nuclear fragmentation.

For a vast number of ornamental species, blocking the plant's response to ethylene is an efficient strategy to enhance the longevity of the flowers. The most effective ways to conduct such interference will be reviewed in this paper. A large number of chemical compounds have been evaluated for their effects on ethylene production and perception. Among these are a range of strained olefines. This has resulted in the discovery that cyclopropenes, among them 1-methylcyclopropene (1-MCP) and a number of other substituted cyclopropenes effectively block ethylene responses at the receptor level. A lot of testing remains to be done to uncover the full potential of these compounds, but they do offer promising new ways to extend the postharvest life of ornamentals. Also genetic modification appears to be a very effective way in controlling of ethylene synthesis and perception. Attempts to use both a reduced endogenous ethylene production and a reduced sensitivity to ethylene will be reviewed. Among these the use of the mutant ethylene receptor gene, etr1-1, from Arabidopsis seems most promising, especially when it is expressed under the control of a flower specific promoter.

Fruit drop of banana is due to breaking at the junction of the pedicel and pulp, and we found no true abscission zone. The breakage seems therefore due to weakening of the peel. We investigated pectin hydrolysis and some properties at the rupture zone, using ‘Hom Thong’ (Musa acuminata, AAA Group) and ‘Namwa’ (Musa x paradisiaca, ABB Group) fruit, which show massive drop and no drop, respectively. During the period of finger drop, the water content of the peel in ‘Namwa’ was similar to that of ‘Hom Thong’ and thus water content does not account for the high breakage in ‘Hom Thong’. The peel thickness at the rupture area in the two cultivars was not significantly different. During the period of finger drop, the level of water-soluble pectin in the peel at the rupture area of ‘Hom Thong’ was higher than that of ‘Namwa’, indicating pectin degradation. CDTA soluble pectin and insoluble pectin was lower in ‘Hom Thong’, also indicating more pectin breakdown in this cultivar. Polygalacturonase activity in the peel at the rupture area of ‘Hom Thong’ bananas rapidly increased, but not clearly more than in ‘Namwa’ bananas. Pectinesterase activity in the peel at the rupture area of ‘Hom Thong’ was much lower than that of ‘Namwa’ bananas, and thus does not account for the breakage. Pectate lyase in the peel of ‘Hom Thong’ was considerably higher than in that of ‘Namwa’. The present data indicate that the much higher pectate lyase activity in ‘Hom Thong’ might be responsible, at least partially, for the finger drop. © 2005 Elsevier B.V. All rights reserved.

How did the forced migration of nearly 11 million enslaved Africans to the Americas influence their knowledge of plants? Vernacular plant names give insight into the process of species recognition, acquisition of new knowledge, and replacement of African species with American ones. This study traces the origin of 2,350 Afro-Surinamese (Sranantongo and Maroon) plant names to those plant names used by local Amerindians, Europeans, and related groups in West and Central Africa. We compared vernacular names from herbarium collections, literature, and recent ethnobotanical fieldwork in Suriname, Ghana, Benin, and Gabon. A strong correspondence in sound, structure, and meaning among Afro-Surinamese vernaculars and their equivalents in other languages for botanically related taxa was considered as evidence for a shared origin. Although 65% of the Afro-Surinamese plant names contained European lexical items, enslaved Africans have recognized a substantial part of the neotropical flora. Twenty percent of the Sranantongo and 43% of the Maroon plant names strongly resemble names currently used in diverse African languages for related taxa, represent translations of African ones, or directly refer to an Old World origin. The acquisition of new ethnobotanical knowledge is captured in vernaculars derived from Amerindian languages and the invention of new names for neotropical plants from African lexical terms. Plant names that combine African, Amerindian, and European words reflect a creolization process that merged ethnobotanical skills from diverse geographical and cultural sources into new Afro-American knowledge systems. Our study confirms the role of Africans as significant agents of environmental knowledge in the New World.

The reduction of labour cost is the major motivation to develop a system for robot harvesting of roses in greenhouses that at least can compete with manual harvesting. Due to overlapping leaves, one of the most complicated tasks in robotic rose cutting is to locate the stem and trace the stem down to locate the cutting position. Computer vision techniques like stereo imaging, laser triangulation, röntgen imaging and a new technique, called reverse volumetric intersection, are evaluated in this paper to determine which technique is most feasible for the task. Experiments with the techniques applied on different rose plant indicate that reverse volumetric intersection shows that this technique is most promising to locate the stem down to the cutting position in terms of robustness and costs.

Flower senescence is accompanied by the rapid death of large numbers of cells. In situ DNA degradation was studied in gypsophila (Gypsophila paniculata) petals during flower opening and senescence, using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL). In flowers that had just opened, TUNEL staining was exclusively observed in nuclei in the vicinity of (developing) vessels, presumably reflecting xylem vessel differentiation. In fully open flowers, TUNEL positive nuclei appear in all the cells well before the increase in ethylene production and visible signs of senescence. Occurrence of TUNEL positive nuclei was stimulated by ethylene but not prevented by silver thiosulphate. The results show that gypsophila petal senescence is a form of PCD with features of animal apoptosis and suggest that nuclear DNA degradation is an early regulatory event rather than a result of massive cell death in the final stage of senescence.

Gravistimulation induced differential ethylene production in Antirrhinum majus L. cut flower stems with highest levels in the lower halves of the gravistimulated stems. Expression levels of three different 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS) genes, an ACC oxidase (ACO) and an ethylene receptor (ETR/ERS homolog) gene were studied in the bending zone after 9 h of gravistimulation. One of the ACS genes (Am-ACS3) was abundantly expressed in the lower halves but not in the upper halves of gravistimulated stems. This strongly suggests that Am-ACS3 is responsible for the observed differential ethylene production in gravistimulated stems. Am-ACO and Am-ETR/ERS gene expression was increased in both the lower and upper halves of gravistimulated stems, suggesting that they play no role in differential ethylene production. When gravistimulation was performed in an environment enriched with either 20 µL/L ethylene or 100 nL/L 1-methylcyclopropene (1-MCP), a slight stimulation of bending by 1-MCP and a slight inhibition of bending by ethylene were observed. The regulation and role of ethylene in gravitropism of cut snapdragon flowering stems is discussed.

In this paper we predict the water activity and initial freezing point of food products (meat and fish) based on their composition. The prediction is based on thermodynamics (the Clausius–Clapeyron equation, the Ross equation and an approximation of the Pitzer equation). Furthermore, we have taken the effect of bound water into account, by using a linear relation between mass fractions of bound water and the mass fractions of soluble biopolymers. Model parameters are estimated using data of meat. The validity of the model is checked against data of fish. Good agreement with experimental data are obtained in the range of aw > 0:70. Furthermore, our results remove the inconclusiveness on the prediction of bound water that exists in literature. 2004 Elsevier Ltd. All rights reserved.

Bij verse producten wil de afnemer een zo groot mogelijke resterende houdbaarheid. Met behulp van sensoren kunnen zwakke plekken met relatief slechte bewaarcondities in de toeleverketen worden opgespoord. Een computersimulatie kan dan helder maken waar het beste geïnvesteerd kan worden.