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Elk bewaarseizoen kent zijn bijzonderheden, zo ook seizoen 2004-2005. Dit werd gekenmerkt dooe schilvlekjes die al vroeg in het seizoen ontstonden, maar ook de goede tot zeer goede uitstalkwaliteit van Elstar. Bij Conference kwamen slappe nekken dankzij de extra aandacht voor dit probleem nauwelijks voor. Dit terwijl juist bij Elstar meer dan normaal werd gereclameerd over een 'slappere' appel. In dit artikel een terugblik en adviezen voor het nieuwe bewaarseizoen

De agro- en voedingsmiddelensector is een sterke cluster in Nederland. In economische zin dekt het agrofoodcluster 25 procent van de Nederlandse industriele omzet en is neemt 10 procent van het BNP voor zijn rekening. De sector biedt werkgelegenheid voor 600.000 arbeidsplaatsen en realiseert meer dan 20 procent van de nationale export. De keuze van het Innovatieplatform om het cluster 'Flowers en Food' (Bloemen en Voeding) tot een van de vier sleutelgebieden in Nederland uit te roepen bevestigt het belang van deze sector.

During wintertime Viburnum opulus var. roseum (snowball) shrubs are forced in warm greenhouses to harvest early cut flowers. Early forcing is occasionally unsuccessful. This is probably due to a lack of hours with low temperatures that is needed to break bud dormancy. To gain more insight about the effect of temperature on breaking dormancy and early forcing results, shrubs were transferred into cold storage in week 41, 43 and 45 (2009) for 4, 6 or 8 weeks at a temperature of 2, 5 or 8°C. After storage, the shrubs were forced at a day-/night temperature of 28/23°C. Shrubs stored for at least 8 weeks from week 41, 6 weeks from week 43 and 4 weeks from week 45 gave good forcing results, regardless of storage temperature. Since growing conditions outside vary every year and differ between nurseries, it is difficult to determine when forcing can be started. To prevent poor forcing results, we aimed to develop a molecular diagnostic assay to determine the moment at which winter dormancy of snowball flower buds is sufficiently broken. In order to identify genes involved in bud breaking dormancy, an experiment was performed on a commercial nursery from October 2010 to January 2011. Flower buds of snowball shrubs outside were sampled weekly and in December and January batches of shrubs were placed every week in a greenhouse to observe forcing results. Genes involved in bud breaking dormancy were identified by performing next generation Illumina RNA sequencing on bud samples with poor and good forcing results. A set of candidate genes was validated during a second trial at two different commercial nurseries in 2011-2012.

The perception of food is influenced by various parameters, many of them being different from individual to individual. What we perceive is not the same because each individual is different. Saliva volume and composition vary widely among people and will influence the chemical and structural composition of the food. Thus, the dilution and mixing of the food with saliva determines the extent of food-saliva interactions and connected to that also how the food item is perceived. It is clear from literature that saliva affects our perception and it is also clear that the rate and composition of salivation is dependent on what we perceive. However, it has not been clear to what extent. Since saliva can be measured objectively for each individual and it can be manipulated in a controlled fashion, more can be learned from the relationship between oral processing and perception. And with that various questions can be addressed, such as: Can the individual differences in sensory assessment be accounted for by their individual salivary composition? Is it possible to affect the sensory perception of an individual by modifying their salivary flow and composition? Different tastes stimulate different amounts of saliva but do they also affect the saliva composition? Or are the differences in saliva composition caused by the differences in salivary flow rate? Can different amounts of saliva, and thus also different dilution factors, affect the taste perception? Furthermore, can taste-taste interactions be explained by an increase in salivary flow rate? Is it possible that the increased salivation, induced by the increased thickness, will dilute the tastant and hence decrease the perceived intensity? Or are taste-texture interactions caused by cross-modal interactions? Or is the increased viscosity of the texture decreasing the concentration of taste molecules? The aim of this thesis is to show how and to what extent saliva influences, and is influenced by, taste and texture. The addition of amylase inhibitor reduces saliva α-amylase activity and increases perceived thickness and creaminess. However, alpha-amylase activity varies widely among subjects and therefore a decreased oral α-amylase activity will not guarantee an increase in perceived thickness and creaminess of starch-based foods. Comparisons of the different tastants show that the pH of stimulated parotid saliva increases linearly, irrespective of the nature of the tastant. Protein concentration decrease and protein amount increase with increase in flow rate for all tastants. After correcting for the effect of flow rate, the protein amount is affected by the nature of the tastant with the greatest secretion after stimulation by citric acid. Flow rate is largely responsible for pH but tastant appears to play an additional role in affecting protein secretion. Significant decreases in perception with increasing salivary flow rates are observed for citric acid and sodium chloride. This can partially be explained by a dilution effect which is in line with previous studies on detectable concentration differences. However, since the bitterness and sweetness remain unaffected by the salivary flow conditions and the dilution effect is comparable to that of saltiness, further explanations are still needed. Suppression of taste intensity in binary mixtures is not affected by the rate of salivation. This is more likely explained by psychophysics. When the taste is separated from the texture, no texture-taste effects are observed. Dilution with saliva did occur and the tastant availability was unaffected in this set-up. The conclusion is therefore that texture-taste interactions are not caused by dilution effects or cross-modal interactions but can best be explained by the release of tastants. The work described in this thesis shows how the individual perception can be affected by the salivary flow and composition and how the individual salivary flow and composition can be affected by the sensory stimuli taste and texture.

The perception of food is influenced by various parameters, many of them being different from individual to individual. What we perceive is not the same because each individual is different. Saliva volume and composition vary widely among people and will influence the chemical and structural composition of the food. Thus, the dilution and mixing of the food with saliva determines the extent of food-saliva interactions and connected to that also how the food item is perceived. It is clear from literature that saliva affects our perception and it is also clear that the rate and composition of salivation is dependent on what we perceive. However, it has not been clear to what extent. Since saliva can be measured objectively for each individual and it can be manipulated in a controlled fashion, more can be learned from the relationship between oral processing and perception. And with that various questions can be addressed, such as: Can the individual differences in sensory assessment be accounted for by their individual salivary composition? Is it possible to affect the sensory perception of an individual by modifying their salivary flow and composition? Different tastes stimulate different amounts of saliva but do they also affect the saliva composition? Or are the differences in saliva composition caused by the differences in salivary flow rate? Can different amounts of saliva, and thus also different dilution factors, affect the taste perception? Furthermore, can taste-taste interactions be explained by an increase in salivary flow rate? Is it possible that the increased salivation, induced by the increased thickness, will dilute the tastant and hence decrease the perceived intensity? Or are taste-texture interactions caused by cross-modal interactions? Or is the increased viscosity of the texture decreasing the concentration of taste molecules? The aim of this thesis is to show how and to what extent saliva influences, and is influenced by, taste and texture. The addition of amylase inhibitor reduces saliva α-amylase activity and increases perceived thickness and creaminess. However, alpha-amylase activity varies widely among subjects and therefore a decreased oral α-amylase activity will not guarantee an increase in perceived thickness and creaminess of starch-based foods. Comparisons of the different tastants show that the pH of stimulated parotid saliva increases linearly, irrespective of the nature of the tastant. Protein concentration decrease and protein amount increase with increase in flow rate for all tastants. After correcting for the effect of flow rate, the protein amount is affected by the nature of the tastant with the greatest secretion after stimulation by citric acid. Flow rate is largely responsible for pH but tastant appears to play an additional role in affecting protein secretion. Significant decreases in perception with increasing salivary flow rates are observed for citric acid and sodium chloride. This can partially be explained by a dilution effect which is in line with previous studies on detectable concentration differences. However, since the bitterness and sweetness remain unaffected by the salivary flow conditions and the dilution effect is comparable to that of saltiness, further explanations are still needed. Suppression of taste intensity in binary mixtures is not affected by the rate of salivation. This is more likely explained by psychophysics. When the taste is separated from the texture, no texture-taste effects are observed. Dilution with saliva did occur and the tastant availability was unaffected in this set-up. The conclusion is therefore that texture-taste interactions are not caused by dilution effects or cross-modal interactions but can best be explained by the release of tastants. The work described in this thesis shows how the individual perception can be affected by the salivary flow and composition and how the individual salivary flow and composition can be affected by the sensory stimuli taste and texture.

Biomass as a renewable energy source has many advantages and is therefore recognized as one of the main renewable energy sources to be deployed in order to attain the target of 20% renewable energy use of final energy consumption by 2020 in Europe. In this paper the concept of a biomass Energy Conversion Park (ECP) is introduced. A biomass ECP can be defined as a synergetic, multi-dimensional biomass conversion site with a highly integrated set of conversion technologies in which a multitude of regionally available biomass (residue) sources are converted into energy and materials. A techno-economic assessment is performed on a case study in the Netherlands to illustrate the concept and to comparatively assess the highly integrated system with two mono-dimensional models. The three evaluated models consist of (1) digestion of the organic fraction of municipal solid waste, (2) co-digestion of manure and co-substrates, and (3) integration. From a socio-economic point of view it can be concluded that it is economically and energetically more interesting to invest in the integrated model than in two separate models. The integration is economically feasible and environmental benefits can be realized. For example, the integrated model allows the implementation of a co-digester. Unmanaged manure would otherwise represent a constant pollution risk. However, from an investor's standpoint one should firstly invest in the municipal solid waste digester since the net present value (NPV) of this mono-dimensional model is higher than that of the multi-dimensional model. A sensitivity analysis is performed to identify the most influencing parameters. Our results are of interest for companies involved in the conversion of biomass. The conclusions are useful for policy makers when deciding on policy instruments concerning manure processing or biogas production. (C) 2012 Elsevier Ltd. All rights reserved.

The virtual microwave oven is computer software wich simulates the workings of the microwave oven. It can simplify the design of packaging for microwave meals which enables these meals to be warmed up in such a way the temperature differences (warm spots and cold spots) in the various food items during the warming-up proces are minimised. The results compromise 3-dimensional visuals of the meal indicating temperature distribution. These results can enhance communication druing the development process among those concerned, such as food and packaging designers

In many food-processing industries laboratory analyses are applied to monitor the quality of products. Depending on results of analyses decisions are made in the conduct of industries, for example whether the quality of a final product is satisfactory, whether an adaption has to be made to the production process. The measuring inaccuracy of laboratory analyses is often noticed insufficiently. This article describes how statistical methods quantify the measuring inaccuracy, expressed in repeatability and reproducibility. With the help of this quantification the benefit of repeated analyses on the same sample can be calculated. Moreover control charts as used in Statistical Process Control (SPC) are applied to monitor quality of measurements by performing laboratory analyses on reference samples

Dit seizoen wordt een omvangrijke appel- en perenoogst verwacht. Belangrijk is de bewaarkwaliteit van het fruit. Overzicht van belangrijke aandachtspunten en optimale ULO-condities voor de belangrijkste appel- en perenrassen

Ultra High Temperature (UHT) sterilisation is a commonly applied technique to preserve liquid food products. Stork Food & Dairy Systems has marketed coiled tubular UHT-sterilisers. For viscous and especially for gelatinising foods (e.g. custard and pudding) spiral sterilisers bring superior performance. Heat transfer greatly increases and required temperatures are attained faster, thus reducing processing time. Coiled sterilisers are therefore shorter and more compact, minimising the loss of quality factors due to the heat treatment. Finally, gelatinisation occurs rapidly and uniformly, and de reduced thermo-mechanical stresses enable a potentially lower amount of starch needed to obtain a target consistency

Elevated CO2 can inhibit ethylene effects. The mechanism of this inhibition is not exactly known. It was investigated whether competition with ethylene at the receptor binding-site is involved. The receptor binding-site was blocked by 1-methylcyclopropene (1-MCP). In this case CO2 can not have an effect via ethylene perception. The influence of 10 kPa CO2 was studied at 1-MCP treated tomato on the vine (cv. `Tradiro`) during storage. The ethylene production rate of tomato on the vine at 20 °C was inhibited by 1-MCP and by CO2. After 1-MCP pre-treatment, CO2 still inhibited ethylene production. It can be concluded that the effect of CO2 on ethylene action is not (always) directed via inhibition of ethylene binding at the receptor site. It was also investigated whether CO2 can inhibit fruit abscission. After 5 days of storage, the required force to remove fruits from the vine was measured. The fruit removal force of control and of CO2 treated fruit decreased. However, treatment with 1-MCP prevented this decrease

Biologische bestrijding van bewaarrot bij Elstar. Gegevens in bijgaande figuren: 1) De invloed van een behandeling in de boomgaard met een plantversterker vier en twee weken vòòr de pluk op het percentage blos bij een eerste pluk van Elstar in vergelijking met de controle op vier percelen, en als gemiddelde; 2) Percentage rot bij uitslag na zeven maanden bewaring in de eerste en tweede pluk Elstar van één herkomst in de onbehandelde partijen in verschillende combinaties van tijdsduur (minuten) en temperatuur (°C); 3) De invloed van een behandeling met antagonist PBGY1 in de boomgaard (Abg, twee en vier weken vòòr pluk), na de oogst (Ano, dompeling) en als combinatie van beide (Abg+Ano) op het percentage rot bij Elstar van vier percelen bij uitslag na zeven maanden bewaring; 4) Aanpak van de proeven in 2001/02 en 2002/03

Optimale bewaaradviezen voor de belangrijkste appel- en perenrassen in het seizoen 2003/04

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.

De situatie waarbij de aanleg van blad en bloem in goed evenwicht is, zodat de gewenste fysiologische en productieve stadia van de plant bereikt worden, is van groot belang voor de aardbeien sector. In opdracht van het Productschap Tuinbouw en onder begeleiding en advies van Plantum is een literatuurstudie uitgevoerd naar de moleculaire kennis op dit gebied bij planten in het algemeen en de vertaling ervan naar meerjarige aardbei planten. Recent onderzoek op dit gebied heeft geleid tot de identificatie van een aantal sleutelgenen die de regulatie van bloemaanleg en ontwikkeling bepalen.

De situatie waarbij de aanleg van blad en bloem in goed evenwicht is, zodat de gewenste fysiologische en productieve stadia van de plant bereikt worden, is van groot belang voor de aardbeien sector. In opdracht van het Productschap Tuinbouw en onder begeleiding en advies van Plantum is een literatuurstudie uitgevoerd naar de moleculaire kennis op dit gebied bij planten in het algemeen en de vertaling ervan naar meerjarige aardbei planten. Recent onderzoek op dit gebied heeft geleid tot de identificatie van een aantal sleutelgenen die de regulatie van bloemaanleg en ontwikkeling bepalen.

Stikstof is noodzakelijk voor alle vormen van leven. Het is bijvoorbeeld een belangrijke bouwsteen van eiwitten. Planten, dieren en mensen nemen het op als reactief stikstof. Dat moet uit stikstof in de buitenlucht worden gevormd. In de natuur wordt reactief stikstof slechts op beperkte schaal gevormd, hoofdzakelijk door micro-organismen. De kunstmatige vorming van reactief stikstof werd een eeuw geleden mogelijk gemaakt door de uitvinding van een proces voor de synthese van ammoniak. Deze uitvinding legde de basis voor de fabricage van kunstmest. Daarmee werd een enorme toename van de voedselproductie per hectare grond mogelijk. Naast ammoniak vallen onder reactief stikstof nog vele stikstof bevattende verbindingen, waaronder ammonium- en nitraatzouten. Rijke werelddelen en landen, waaronder Europa, en zeker Nederland, hebben te maken met een teveel aan reactief stikstof in het milieu. Dit leidt tot aantasting van dit milieu en van de volksgezondheid. De overmaat aan reactief stikstof heeft twee belangrijke oorzaken: de landbouw en veehouderij, en de verbranding van fossiele brandstoffen. De Gezondheidsraad heeft zich over de mogelijke effecten van reactief stikstof op de Nederlandse volksgezondheid gebogen. Een commissie van de raad, de Commissie Signalering Gezondheid en milieu, heeft beoordeeld in hoeverre de volksgezondheid gebaat is bij het terugdringen van de hoeveelheid reactief stikstof in ons land.

Stikstof is noodzakelijk voor alle vormen van leven. Het is bijvoorbeeld een belangrijke bouwsteen van eiwitten. Planten, dieren en mensen nemen het op als reactief stikstof. Dat moet uit stikstof in de buitenlucht worden gevormd. In de natuur wordt reactief stikstof slechts op beperkte schaal gevormd, hoofdzakelijk door micro-organismen. De kunstmatige vorming van reactief stikstof werd een eeuw geleden mogelijk gemaakt door de uitvinding van een proces voor de synthese van ammoniak. Deze uitvinding legde de basis voor de fabricage van kunstmest. Daarmee werd een enorme toename van de voedselproductie per hectare grond mogelijk. Naast ammoniak vallen onder reactief stikstof nog vele stikstof bevattende verbindingen, waaronder ammonium- en nitraatzouten. Rijke werelddelen en landen, waaronder Europa, en zeker Nederland, hebben te maken met een teveel aan reactief stikstof in het milieu. Dit leidt tot aantasting van dit milieu en van de volksgezondheid. De overmaat aan reactief stikstof heeft twee belangrijke oorzaken: de landbouw en veehouderij, en de verbranding van fossiele brandstoffen. De Gezondheidsraad heeft zich over de mogelijke effecten van reactief stikstof op de Nederlandse volksgezondheid gebogen. Een commissie van de raad, de Commissie Signalering Gezondheid en milieu, heeft beoordeeld in hoeverre de volksgezondheid gebaat is bij het terugdringen van de hoeveelheid reactief stikstof in ons land.

Little is known about the influence of visual characteristics other than colour on flavor perception, and the complex interactions between more than two sensory modalities. This study focused on the effects of recognizability of visual (texture) information on flavor perception of odorized sweet beverages. Participants rated the perceived sweetness of odorized sucrose solutions in the presence or absence of either a congruent or incongruent visual context. Odors were qualitatively reminiscent of sweet foods (strawberry and caramel) or not (savoury). Visual context was either an image of the same sweet foods (figurative context) or a visual texture derived from this product (non-figurative context). Textures were created using a texture synthesis method that preserved perceived food qualities while removing object information. Odor-taste combinations were rated sweeter within a figurative than a non-figurative context. This behaviour was exhibited for all odor-taste combinations, even in trials without images, indicating sustained priming by figurative visual context. A non-figurative context showed a transient sweetening effect. Sweetness was generally enhanced most by the strawberry odor. We conclude that the degree of recognizability of visual information (figurative versus non-figurative), influences flavor perception differently. Our results suggest that this visual context priming is mediated by separate sustained and transient processes that are differently evoked by figurative and non-figurative visual contexts. These components operate independent of the congruency of the image-odor-taste combinations.

In the light of increasing rates of nutrition related diseases, such as obesity, diabetes, high blood pressure and stroke it is necessary to reduce sugar, salt and fat contents of industrial produced food. Reduction of those components generally leads to changes of the sensory properties of the products and rejection by the consumer. Traditional compensation strategies like the use of taste enhancers, artificial sweeteners or fat replacers often lead to off-flavours and consequently to consumer rejection. This thesis describes cross-modal interactions as an alternative strategy to reduce sugar, salt and fat. In the past cross-modal interactions have been describe to influence taste and texture perception, however up to now research focused on simple model systems lacking in perceptual, as well as chemical complexity. This thesis aimed on the application of cross modal interactions involving aroma modification to complex food systems, such as apple juice and cheese. It was investigated whether aromas are able to modify taste perception in complex food matrices and what the driving factors are to which extend aromas can enhance taste perception. Furthermore different cross modal approaches were combined in order to investigate possible additive or synergistic effects on taste enhancement. At first, the question whether individual aroma components can be identified that have the capacity to enhance taste perception in a complex beverage was addressed [chapter 2]. Apple juice was choosen to represent a complex matrix where interactions between taste and aroma are a natural product characteristic. Ethylhexanoate was identified to significantly enhance sweetness in apple juice, while three other esters selected on the same basis did not show sweetness enhancement. Ethylhexanoate induced sweetness enhancement appeared to be concentration dependent. Concentrations of 5 ppm were found to be most effective to enhance sweetness in this specific system. However, next to sweetness undesired attributes such as flowery and synthetic were also increased significantly. As a conclusion it has to be noticed that flavour balance in complex food is fragile and has to be carefully altered in order to use odour induced taste enhancement as a tool in sugar, salt and fat reduction. Chapter 3 describes the masking of off-flavours induced by ethylhexanoate as described in chapter 2. It was hypothesised that ethylhexanoate induced off-flavours can be masked by restoring flavour balance by equally adding combinations of all four esters. A combination of ethylhexanoate, ethylbutanoate and ethyl-2-methylbutanoate was found to be most effective to restore flavour quality while maintaining ethylhexanoate induced sweetness enhancement. It was concluded that all components that are naturally part of an aroma are needed to achieve a balanced product. Optimisation of odour presentation time in order to achieve maximum taste enhancement was subject to the study described in chapter 4. Swallowing is the key to aroma release during food consumption. It was demonstrated that aroma is most presented most effectively either 1.7 – 2.5 seconds before or 2.6 – 3.6 seconds after the moment of swallow. Aroma presented directly at the moment of swallow was found to be least effective to enhance taste. It is assumed that olfactory receptor neurons (ORN) do not transmit the activation signal to the brain at the exact moment of swallow in order to spare energy and function most effective, as during normal food consumption the aroma is released shortly after swallowing. This hypothesis was further tested in an fMRI study. Preliminary results support this theory, however at the moment of completion of this thesis data evaluation was still in progress. In chapter 5 further optimisation of odour/taste interactions was studied, by investigating the influence of temperature on odour induced taste enhancement. Consumption temperatures differ strongly among products. As aroma release strongly depends on the temperature of the food, it was hypothesised that the magnitude of aroma effects on taste perception changes over consumption temperature. Subjects consumed a sweet and a savoury system at four different temperatures (7, 25, 37 and 50°C). Stimuli temperature and odour presentation were fully controlled by temperature optimised gustometry and olfactometry. Both aroma/taste systems were known to have induced taste enhancement in the past (sweet: apple flavoured tea/ethylhexanoate; savoury: broth/sotolon). No significant effect of temperature was found for either of the stimulus pairs. Results indicate that the complexity of the experiment led to confusion by the panelists under fully randomised stimuli delivery conditions. It was therefore concluded, that temperature effects on the magnitude of odour induced taste enhancement need to be studied in a reduced experimental design. Temporal contrast as a strategy to enhance salty taste was studied in the experiments described in chapter 6. Salty solutions of different NaCl concentrations were presented in alternating sequence by a gustometer, creating a sensory contrast of low-in salt and high-in salt pulses. It was demonstrated that the sensory contrast induced by the pulsed delivery led to significant taste enhancement. It was shown that high concentrations of NaCl delivered in short pulses were most effective to enhance salty taste. It was concluded that pulsed stimulus delivery can be an additional tool to reduce salt and sugar concentrations in industrial produced food. Chapter 7 combines both cross-modal strategies to enhance taste in this thesis so far, odour induced taste enhancement and temporal contrast of stimulus delivery. Subjects were presented with taste and aroma pulses timed via a gustometer. The aroma was either presented in-phase or out-of-phase with the taste stimulus. A cumulative effect of aroma/taste interactions and temporal contrast of tastant delivery was found, resulting in higher taste enhancement than each of the strategies alone. Overall highest sweetness enhancement was observed when aroma and taste pulses were presented out-of-phase. Texture modification is a third cross-modal strategy to enhance taste perception. Combinatory effects of texture modification and odour induced taste enhancement are subject to the study reported in chapter 8. Apple juice containing gels were engineered differing in textural properties, aroma and sugar concentration. In contrast to the results presented in chapter 7, only an additive but no synergistic effect was found for those strategies. Texture modification was found to be more effective than aroma modification. Chapter 9 studies effects of aroma on the taste and the texture of cheese and dairy model gels. In the first study subjects consumed different types of cheese with and without a nose-clip. This way the contribution of the aroma phase on the flavour and texture perception of cheese was studied. Saltiness was influenced significantly by the aroma. It was concluded that the aroma of cheese strongly contributes to a cheeses salty taste. Furthermore it was observed that a decrease in cheese firmness strongly correlated with an increase in buttery aroma notes. This was further studied in fully controlled dairy model gels. For gels tasting of cream cheese a significant decrease in firmness was found upon increasing aroma concentration. No effect of butter aroma on firmness was found for yoghurt-like gels. This once more demonstrates the importance of congruency between stimuli. Only congruent sensory impressions can influence each other. In addition, an increase in creaminess was observed with increasing aroma concentration. The results described in chapter 9 clearly show that aromas cannot only modify taste perception, but also are a valid tool for texture modification. This thesis demonstrates for the first time, that flavour and texture modification and subsequently the reduction of sugar, salt and (possibly also) fat can be achieved by using cross modal interactions in complex food matrices. New methods have been developed and existing methods have been combined to study aroma/taste interactions in fully controlled settings. Its multidisciplinary approach combines chemical, physical and psychological knowledge in order to discuss and explain results. It furthermore shows that combinations of different strategies are most effective in order to achieve healthier products reduced in sugar, salt and fat.

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.

In the light of increasing rates of nutrition related diseases, such as obesity, diabetes, high blood pressure and stroke it is necessary to reduce sugar, salt and fat contents of industrial produced food. Reduction of those components generally leads to changes of the sensory properties of the products and rejection by the consumer. Traditional compensation strategies like the use of taste enhancers, artificial sweeteners or fat replacers often lead to off-flavours and consequently to consumer rejection. This thesis describes cross-modal interactions as an alternative strategy to reduce sugar, salt and fat. In the past cross-modal interactions have been describe to influence taste and texture perception, however up to now research focused on simple model systems lacking in perceptual, as well as chemical complexity. This thesis aimed on the application of cross modal interactions involving aroma modification to complex food systems, such as apple juice and cheese. It was investigated whether aromas are able to modify taste perception in complex food matrices and what the driving factors are to which extend aromas can enhance taste perception. Furthermore different cross modal approaches were combined in order to investigate possible additive or synergistic effects on taste enhancement. At first, the question whether individual aroma components can be identified that have the capacity to enhance taste perception in a complex beverage was addressed [chapter 2]. Apple juice was choosen to represent a complex matrix where interactions between taste and aroma are a natural product characteristic. Ethylhexanoate was identified to significantly enhance sweetness in apple juice, while three other esters selected on the same basis did not show sweetness enhancement. Ethylhexanoate induced sweetness enhancement appeared to be concentration dependent. Concentrations of 5 ppm were found to be most effective to enhance sweetness in this specific system. However, next to sweetness undesired attributes such as flowery and synthetic were also increased significantly. As a conclusion it has to be noticed that flavour balance in complex food is fragile and has to be carefully altered in order to use odour induced taste enhancement as a tool in sugar, salt and fat reduction. Chapter 3 describes the masking of off-flavours induced by ethylhexanoate as described in chapter 2. It was hypothesised that ethylhexanoate induced off-flavours can be masked by restoring flavour balance by equally adding combinations of all four esters. A combination of ethylhexanoate, ethylbutanoate and ethyl-2-methylbutanoate was found to be most effective to restore flavour quality while maintaining ethylhexanoate induced sweetness enhancement. It was concluded that all components that are naturally part of an aroma are needed to achieve a balanced product. Optimisation of odour presentation time in order to achieve maximum taste enhancement was subject to the study described in chapter 4. Swallowing is the key to aroma release during food consumption. It was demonstrated that aroma is most presented most effectively either 1.7 – 2.5 seconds before or 2.6 – 3.6 seconds after the moment of swallow. Aroma presented directly at the moment of swallow was found to be least effective to enhance taste. It is assumed that olfactory receptor neurons (ORN) do not transmit the activation signal to the brain at the exact moment of swallow in order to spare energy and function most effective, as during normal food consumption the aroma is released shortly after swallowing. This hypothesis was further tested in an fMRI study. Preliminary results support this theory, however at the moment of completion of this thesis data evaluation was still in progress. In chapter 5 further optimisation of odour/taste interactions was studied, by investigating the influence of temperature on odour induced taste enhancement. Consumption temperatures differ strongly among products. As aroma release strongly depends on the temperature of the food, it was hypothesised that the magnitude of aroma effects on taste perception changes over consumption temperature. Subjects consumed a sweet and a savoury system at four different temperatures (7, 25, 37 and 50°C). Stimuli temperature and odour presentation were fully controlled by temperature optimised gustometry and olfactometry. Both aroma/taste systems were known to have induced taste enhancement in the past (sweet: apple flavoured tea/ethylhexanoate; savoury: broth/sotolon). No significant effect of temperature was found for either of the stimulus pairs. Results indicate that the complexity of the experiment led to confusion by the panelists under fully randomised stimuli delivery conditions. It was therefore concluded, that temperature effects on the magnitude of odour induced taste enhancement need to be studied in a reduced experimental design. Temporal contrast as a strategy to enhance salty taste was studied in the experiments described in chapter 6. Salty solutions of different NaCl concentrations were presented in alternating sequence by a gustometer, creating a sensory contrast of low-in salt and high-in salt pulses. It was demonstrated that the sensory contrast induced by the pulsed delivery led to significant taste enhancement. It was shown that high concentrations of NaCl delivered in short pulses were most effective to enhance salty taste. It was concluded that pulsed stimulus delivery can be an additional tool to reduce salt and sugar concentrations in industrial produced food. Chapter 7 combines both cross-modal strategies to enhance taste in this thesis so far, odour induced taste enhancement and temporal contrast of stimulus delivery. Subjects were presented with taste and aroma pulses timed via a gustometer. The aroma was either presented in-phase or out-of-phase with the taste stimulus. A cumulative effect of aroma/taste interactions and temporal contrast of tastant delivery was found, resulting in higher taste enhancement than each of the strategies alone. Overall highest sweetness enhancement was observed when aroma and taste pulses were presented out-of-phase. Texture modification is a third cross-modal strategy to enhance taste perception. Combinatory effects of texture modification and odour induced taste enhancement are subject to the study reported in chapter 8. Apple juice containing gels were engineered differing in textural properties, aroma and sugar concentration. In contrast to the results presented in chapter 7, only an additive but no synergistic effect was found for those strategies. Texture modification was found to be more effective than aroma modification. Chapter 9 studies effects of aroma on the taste and the texture of cheese and dairy model gels. In the first study subjects consumed different types of cheese with and without a nose-clip. This way the contribution of the aroma phase on the flavour and texture perception of cheese was studied. Saltiness was influenced significantly by the aroma. It was concluded that the aroma of cheese strongly contributes to a cheeses salty taste. Furthermore it was observed that a decrease in cheese firmness strongly correlated with an increase in buttery aroma notes. This was further studied in fully controlled dairy model gels. For gels tasting of cream cheese a significant decrease in firmness was found upon increasing aroma concentration. No effect of butter aroma on firmness was found for yoghurt-like gels. This once more demonstrates the importance of congruency between stimuli. Only congruent sensory impressions can influence each other. In addition, an increase in creaminess was observed with increasing aroma concentration. The results described in chapter 9 clearly show that aromas cannot only modify taste perception, but also are a valid tool for texture modification. This thesis demonstrates for the first time, that flavour and texture modification and subsequently the reduction of sugar, salt and (possibly also) fat can be achieved by using cross modal interactions in complex food matrices. New methods have been developed and existing methods have been combined to study aroma/taste interactions in fully controlled settings. Its multidisciplinary approach combines chemical, physical and psychological knowledge in order to discuss and explain results. It furthermore shows that combinations of different strategies are most effective in order to achieve healthier products reduced in sugar, salt and fat.

This thesis focusses on the modelling of knowledge-intensive computer vision tasks. Knowledge-intensive tasks are tasks that require a high level of expert knowledge to be performed successfully. Such tasks are generally performed by a task expert. Task experts have a lot of experience in performing their task and can be a valuable source of information for the automation of the task. We propose a framework for creating a white-box ontology-based computer vision application. White-box methods have the property that the internal workings of the system are known and transparent. They can be understood in terms of the task domain. An application that is based on explicit expert knowledge has a number of inherent advantages, among which corrigibility, adaptability, robustness, and reliability. We propose a design method for developing white-box computer vision applications that consists of the following steps: (i) define the scope of the task and the purpose of the application, (ii) decompose the task into subtasks, (iii) define and refine application ontologies that contain the descriptive knowledge of the expert, (iv) identify computational components, (v) specify explicit procedural knowledge rules, and (vi) implement algorithms required by the procedural knowledge. The scope is one of the cornerstones of the application, since it sets the boundaries of the task. The problem owner and the domain experts are together responsible for setting the scope and defining the purpose. Scope and purpose are important for the task decomposition and for the specification of the application ontologies. The scope and purpose help the domain engineer to keep focus in creating dedicated ontologies for the application. The decomposition of the task into subtasks models the domain expert’s “observe – interpret – assess” way of performing a visual inspection task. This decomposition leads to a generic framework of subtasks alternated with application ontologies. The list of consecutive subtasks – record object, find structures, identify object parts, determine parameters, determine quality – can be reused for any visual inspection task. Application ontologies are task-specific ontologies containing the descriptive knowledge relevant for the task. We have described an interview-based knowledge acquisition method that is suited for modelling multi-domain, multiexpert task-specific ontologies. Using the knowledge of multiple experts leads to a rich application ontology; adding an outsider’s perspective from domain experts from other involved domains, leads to an expression of knowledge that may be too trivial for task experts to mention or may not be part of the usual perspective of the task experts. Knowledge acquisition based on interviews and observations only has some disadvantages. It takes a lot of modelling time for domain expert and knowledge engineer, it is difficult for the knowledge engineer to give a structured and full overview of his knowledge, and a model is created from scratch, even though reusable sources may exist. We have therefore introduced a reuse-based ontology construction component that gives domain expert a more prominent and active role in the knowledge acquisition process. This component prompts the domain expert with terms from existing knowledge sources to help him create a full overview of his knowledge. We show that this method is an efficient way to obtain a semi-formal description of the domain knowledge. With the decomposition of the knowledge-intensive task into subtasks interspersed with descriptive knowledge models completed, we focus on the subtasks. Each of these subtasks can be represented by a sequence of components that perform a clearly defined part of a task. To specify these components, we explicitly identify for each service in the computational workflow (i) the input concepts, (ii) the output concepts, and (iii) a human readable (high level) description of the service. This information is used as documentation for the procedural knowledge. Besides transparency of descriptive knowledge, transparency of processing knowledge is a desirable feature of a knowledge-intensive computer vision system. We show that blindly embedding software components in a transparent way may have an adverse effect. In some cases, transparency is not useful or desired. To support the software developer to make a balanced decision on whether transparency is called for, we have proposed a set of decision criteria – availability of expertise, application range of a component, triviality, explanation, and availability of third-party expertise. These decision criteria are paired to means of adding transparency to an application. We have elaborated several examples from the horticultural case study to show which transparency decisions are made for which reasons. Using the framework for designing knowledge-intensive computer vision applications, we have implemented a prototype system to automatically assess the quality of tomato seedlings. We have shown that the proposed design method indeed results in a white-box system that has adaptability, corrigibility, reliability and robustness as properties. We provide guidelines on how to implement tool support for the adaptability and corrigibility properties of the system, to better assist the end users of the application. Moreover, we show how organisational learning and building trust in the system are supported by the white-box setup of the computer vision application.

De tuinbouwsector in de Betuwe wil door meer samenwerking, onderling en binnen de tuinbouwketen, de gezamenlijke economische positie versterken. Ambitie is om de tuinbouw in het Rivierengebied op de (inter)nationale kaart te zetten. De samenwerking vindt plaats onder de noemer Betuwse Bloem.

The invention provides a method for the production of a flour-based food product comprising a tastant. The food product according to the invention has a tastant bulk weight percentage and an inhomogeneous tastant bulk distribution. The invention provides the use of an inhomogeneous tastant bulk distribution in a food product for providing a food product with a reduced tastant bulk weight percentage. Further, the invention provides the use of an inhomogeneous tastant bulk distribution in a food product for enhancing and/or improving the sensory perception of the tastant in a food product.

Bread and cereals contribute 30% to the daily intake of sodium (Na) in the western human diet. Since the average Na intake is double the recommended intake, pressure has built up for the food industry to lower Na in their products. Especially replacing functionality of Na as a tastant remains very difficult. In this study we describe a strategy to enhance saltiness intensity in bread using an inhomogeneous spatial distribution of Na. Our results demonstrate that sensory contrast provides a promising strategy to significantly reduce the Na content in bread without loss of saltiness intensity and without the use of sodium substitutes, taste or aroma additives. © 2010 Elsevier Ltd.

Onderzocht is hoe een domeinspecifieke vocabulaire is te construeren, waarmee voor de voedingsmiddelenindustrie het zoekproces in zeer grote databestanden efficiënt kan worden uitgevoerd

Bij de oogst van appels en peren is in een korte periode veel arbeid nodig. Het vraagt een forse inspanning om voldoende kwalitatief juiste arbeid te krijgen op het juiste moment tegen de juiste prijs, de kosten voor arbeid zijn hoog. Voor NFO en het PT hebben initiatief genomen om te komen tot robotisering van deze handeling te automatiseren. Doelstelling van dit project is één of meerdere concepten te ontwerpen voor het automatisch oogsten van appels en peren, waarbij kritische deelfuncties op eerste haalbaarheid zijn getoetst om de drempel te verlagen om een vervolg te starten. Aansluitend is het doel ontwikkelingstraject te starten dat binnen een afzienbare periode zal leiden tot implementatie. In het rapport zijn enkele perspectiefvolle concepten uitgewerkt. Verschillende deelfuncties zijn ontworpen en getest op haalbaarheid zoals: het sensorconcept globaal (waar zitten de appels); het sensorconcept lokaal (Is de appel voldoende rijp); manipulatie en end-effector en logistiek en buffering. Voor de verschillende functies zijn goede oplossingen voorhanden. De studie betreft met name een papieren studie. In een vervolg zal moeten blijken of het ook daadwerkelijk technisch haalbaar is. De focus in een vervolg dient te liggen bij de plukhandeling zelf en de daarbij horende sensoriek (de ogen, de arm en het handje). Het afvoeren van de geoogste appels, het bufferen en het transport door de boomgaard lijkt niet het probleem te zijn. Aan het einde heeft een herijking van de businesscase plaatsgevonden. De NFO/PT acht het project voldoende perspectiefvol om te starten met een initiatief voor verdere implementatie als vervolg op de conceptontwikkeling.

De tuinbouwsector in de Betuwe wil door meer samenwerking, onderling en binnen de tuinbouwketen, de gezamenlijke economische positie versterken. Ambitie is om de tuinbouw in het Rivierengebied op de (inter)nationale kaart te zetten. De samenwerking vindt plaats onder de noemer Betuwse Bloem.

In recent years, health concerns related to salt/sodium chloride consumption have caused an increased demand for salt-reduced foods. Consequently, sodium chloride (NaCl) reduction in foods has become an important challenge. The more so, since a decrease in NaCl content is often reported to be associated with a decrease in consumer acceptance. The objective of the present study was to investigate whether or not it would be possible to reduce the NaCl content in standard Western European foods by replacing it with naturally brewed soy sauce. Three types of foods were investigated: salad dressing (n = 56), soup (n = 52), and stir-fried pork (n = 57). In the 1st step, an exchange rate (ER) by which NaCl can be replaced with soy sauce without a significant change in the overall taste intensity was established per product type, by means of alternative forced choice tests. In the 2nd step, the same consumers evaluated 5 samples per product type with varying NaCl and/or soy sauce content on pleasantness and several sensory attributes. The results showed that it was possible to achieve a NaCl reduction in the tested foods of, respectively, 50%, 17%, and 29% without leading to significant losses in either overall taste intensity or product pleasantness. These results suggest that it is possible to replace NaCl in foods with naturally brewed soy sauce without lowering the overall taste intensity and to reduce the total NaCl content in these foods without decreasing their consumer acceptance.Health concerns related to salt consumption cause an increased demand for salt-reduced foods. Consequently, the development of foods with reduced salt content without decreasing the consumer acceptance is an important challenge for the food industry. A new possible salt reduction approach is described in the present article: The replacement of salt with naturally brewed soy sauce.

The Zinnia elegans mesophyll cell culture is a useful system for xylogenesis studies. The system is associated with highly synchronous tracheary element (TE) differentiation, making it more suitable for molecular studies requiring larger amounts of molecular isolates, such as mRNA and proteins and for studying cellulose synthesis. There is, however, the problem of non-uniformity and significant variations in the yields of TEs (%TE). One possible cause for this variability in the %TE could be the lack of a standardized experimental protocol in various research laboratories for establishing the Zinnia culture. Mesophyll cells isolated from the first true leaves of Z. elegans var Envy seedlings of approximately 14 days old were cultured in vitro and differentiated into TEs. The xylogenic culture medium was supplied with 1mg/l each of benzylaminopurine (BA) and alpha-naphthalene acetic acid (NAA). Application of this improved culture method resulted in stable and reproducible amounts of TE as high as 76% in the Zinnia culture. The increase was mainly due to conditioning of the mesophyll cell culture and adjustments of the phytohormonal balance in the cultures. Also, certain biochemical and cytological methods have been shown to reliably monitor progress of TE differentiation. We conclude that, with the adoption of current improvement in the xylogenic Z. elegans culture, higher amounts of tracheary elements can be produced. This successful outcome raises the potential of the Zinnia system as a suitable model for cellulose and xylogenesis research.

Objective: Parotid saliva flow is increased by mastication and its composition is also modified. The aim of this work was to clarify the relationships between flow rate, pH and protein concentration, during resting and short-duration simulated chewing, using continuous and fractional saliva collections. Design: Parotid saliva flow rate, pH and protein concentration, as it exits the Stensen's duct, were determined on seven subjects in response to one and 30 ipsilateral jaw clenches. To achieve this, we have developed a system able to collect parotid saliva and to measure continuously flow rate, pH and protein concentration and synchronised to the values at the exit of the duct. Results: With increase in flow rate, pH increased linearly and its protein concentration decreased linearly with the logarithm of the flow rate. With an increase in flow rate from 50 to 500 μl/min, the pH increased from 5.8 to 7.0 and the protein concentration decreased from 1.0 to 0.7 g/l. Measurements made on parotid saliva fractions confirmed the variations in pH and protein concentration with flow rate and showed that α-amylase concentration was significantly related to both salivary conductivity and protein concentration. Conclusions: Continuous measurements of salivary flow and composition offer a simple and convenient way to determine the precise relationships between different types of oral stimulation and parotid salivary flow and composition. © 2009 Elsevier Ltd. All rights reserved.

This report charts and analyses the current situation regarding integrated digitalinformation facilities in the horticultural sector. It also suggests the outlines of a possible programme for improving the integration of these digital information facilities. Additionally it offers an overview of the current initiatives and projects and suggests a starting point for the role which the Dutch horticulture cluster wishes to fill. Dutch horticulture is aiming towards a guiding role as a developer and owner of operational and coordinating concepts which are used in ICT systems, data flows, and chain standards. The report emphasises the necessity of creating an integrated approach to digital information facilities. In dit rapport wordt de huidige situatie op het gebied van integrale digitale informatievoorzieningin de tuinbouwsector in kaart gebracht en geanalyseerd. Vervolgens worden de contouren geschetst van een mogelijk programma voor verbetering en integratie van deze digitale informatievoorziening. Hiermee wordt een overzicht geboden van de huidige initiatieven en projecten en een uitgangspunt gegeven voor de rol die het Nederlandse tuinbouwclusterwil vervullen. Het ziet voor zichzelf een richtinggevende rol weggelegd als ontwikkelaar en eigenaar van besturings- of coördinatieconcepten die gebruikt worden in ICT-systemen, informatiestromen en ketenstandaards. Het rapport onderstreept de noodzaak om tot een integrale aanpak van de digitale informatievoorziening te komen.

Saliva from parotid glands plays a role in taste perception. Parotid saliva is also stimulated by tastants. The aim of this work is to investigate the effects of different tastants on the parotid salivary response in six subjects. Five tastants were given in different concentrations in solution and held in the mouth for 10 s. The flow rate, protein concentration, and pH of secreted parotid saliva were monitored continuously for 5 min. Stimulation by tastants on flow rate response consists of an immediate rise in flow followed by a plateau and a rapid return to prestimulus flow. Response of pH results in a slower increase while protein concentration consists in a slower decrease, both followed by a return to prestimulus levels in about 4 min. From a resting flow rate of about 140∈μL/min, an increase in flow rate to 370∈μL/min was caused by stimulation for 10 s with 10 mL of solutions of 0.01 M citric acid, 0.13 M MgSO4, 0.25 M monosodium glutamate, 0.5 M NaCl, or 0.5 M sucrose. Comparisons of the different tastants showed that the pH of stimulated parotid saliva increased linearly (r∈=∈0.9), irrespective of the nature of the tastant. Protein concentration decreased (r∈=∈-0.45) and protein amount increases (r∈=∈0.58) with increase in flow rate for all tastants. Corrected for the effects of flow rate, protein amount depended on the nature of the tastant with the greatest secretion after stimulation by citric acid. Flow rate was largely responsible for pH but tastant appears to play an additional role with flow rate on protein secretion.

This report outlines the impact of ICT on the food economy. On the basis of a literature review from four disciplines - knowledge management, management information systems, operations research and logistics, and economics - the demand for new ICT applications, the supply of new applications and the match between demand and supply are identified. Subsequently the impact of new ICT applications on the food economy is discussed. The report relates the development of new technologies to innovation and adoption processes and economic growth, and to concepts of open innovations and living labs

Transparante beleidsafwegingen en bredere risicobeoordelingen lijken cruciaal voor het waarmaken van de maatschappelijke aspiraties die het ministerie van LNV zich op het gebied van voedselkwaliteit heeft gesteld. De implementatie van instrumenten die dergelijke afwegingen ondersteunen blijkt echter problematisch. In dit rapport wordt ingegaan op de toepassing van een TRansparant Afwegingskader (TRAK) en het instrument van een Brede Risicobeoordeling (BRB). Deze instrumenten bieden zeker kansen, maar een succesvolle implementatie zal tijd en energie vergen gezien de knelpunten die er tegenover staan. Transparent policy decisions and broader risk assessments seem to be crucial for fulfilling the social aspirations established by the Ministry of Agriculture, Nature and Food Quality with regard to food quality. However, the use of instruments which support such decision(making seems to be encountering problems. This report discusses the application of a Transparent Consideration Framework (TRansparant AfwegingsKader, TRAK) and a Broad Risk Assessment (Brede Risicobeoordeling, BRB). These instruments certainly offer potential, but successful implementation will take time and energy in view of the problems facing them.

Schilvlekjes is een Elstar-probleem dat in gevoelige jaren tot grote directe en indirecte economische schade leidt. De basis van dit probleem ligt in de teelt, maar vooralsnog zijn er geen effectieve preventieve handvaten om het probleem hier tegen te gaan