Product Physiology

Low temperature and low light intensity storage to increase shelf-life of butterhead lettuce

We have found before that quality deterioration of lettuce during postharvest storage is delayed by low temperature in combination with very low light levels (about 5 µmol m^-2 s^-1). This is likely caused by ongoing photosynthesis ...

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Stomatal malfunction in Chrysanthemum and/or Arabidopsis

Stomatal malfunction leads to increased water loss and reduces postharvest keeping quality in plant products. It is induced by growing plants at high relative humidity (RH) and is an intriguing scientific and practical problem in modern horticulture. To reduce energy us in ...

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Vase life of cut flowers

Cut flower quality is affected by a wide range of features, like flower number, size, shape, colour (patterns), fragrance, uniformity of blooming, leaf and stem colour, plant shape and developmental stage, and absence of pests and diseases. Postharvest performance involves preserving these specific features ...

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Strawberry quality and shelf life

We have projects to study the effect of preharvest conditions on postharvest quality, shelf life and flavour life. We have projects to study the link between strawberry colour, proanthocyanidins content and Botrytis incidence. We would like to identify genes and gene products that are involved with shelf life and ...

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Metabolic engineering of colour and scent

Petunia hybrida cv. V26 (left) and W115 (right) both make volatile benzenoid/phenylpropanoids. V26 also produces anthocyanins, but earlier in floral development (Verdonk et al., 2005). Volatiles and anthocyanins in petunia, are both phenylpropanoid pathway derived. Phenylalanine Ammonia Lyase (PAL) is ...

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Marigold regulation of carotenoid biosynthesis

Tagetes erecta (Marigold or ‘Afrikaantje’ in Dutch) produces high levels of carotenoids. To exploit the health benefits of carotenoids (Lutein, Blue light filters for high screen time, etc.), breeding has generated elite lines that produce high lutein, zeaxanthin, etc. We research to ...

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Transcription factors and quality traits

MYB transcription factors are involved in the regulation of many quality related traits, such as the biosynthesis of phenylpropanoids, anthocyanins, volatiles, but also cell shape, and stress resilience (Allan and Espley, 2018). We are interested in the MYB TF family of Petunia, because of many ...

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Stay Green Protein (SGR) in tomato and/or Petunia

During tomato ripening, chlorophyll breakdown and lycopene biosynthesis coincide and are regulated by a STAY GREEN PROTEIN (SGP). But not only colour, also firmness is regulated by this amazing protein family! This means that SGP are vital to tomato quality attributes such ...

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Mango projects

Mangoes hardly ripens on tree, but quickly ripens after harvest. We want to identify the 'tree factor' compound in e.g., the milky white sap from the harvest wound. Also, we want to investigate the effect of e.g., removing leaves from mango branches in a Spanish orchard. Study the production of mango volatiles ...

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Tomato quality: the effects of nutrient composition in combination with different light regimes

It is known that increasing the electro conductivity of the nutrient solution generally lead to more tasty fruit, however, disadvantages also shown as yield decreases and fruit disorders. High light level could also leads to better ...

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PH Quality by Laser Backscattering in blueberry

Blueberries are a soft fruit that are prone to quality disorders such as loss of firmness, mealiness and internal breakdown. Current methods to measure these disorders are either insufficient, subjective, or lacking. As such, there is a demand for objective ways to measure ...

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Modelling non-destructive firmness in pears

Non-destructive measurements of ripening-related firmness are generally strongly influenced by fruit dehydration. Vis-NIR and hyperspectral imaging, despite their sensitivity to water-related aspects in the fruit, can model ripening-related firmness to a certain extent, but this can certainly ...

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Next-gen ripening inhibitors

Picked fruit and flowers ripen quickly if not subjected to appropriate post-harvest storage conditions. However, when still connected to the mother plant, fruit and flowers show inhibited ripening, even in the presence of ethylene. This phenomenon is well known in tropical fruit, such as mango ...

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Dependency of firmness measurement devices on dehydration and ripening

Firmness is a key quality feature that is classically linked to ripeness. Over the last decades, an increasing number of non-destructive firmness measurement devices have been developed to assess the ripening-related firmness of products. However, ...

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Investigating contribution of LED intra-canopy lighting in spring greenhouse tomato

Vine crops, specifically tomatoes and cucumbers, represent one of the largest segments for electric lighting in horticultural applications. Typically, cultivators aren't constrained by inadequate lighting conditions in the spring or ...

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Dynamic Lighting and Lettuce in the Context of Vertical Farming

Vertical Farming provides a unique opportunity to have complete control of plant growth; this allows for reproducible and customizable growth of fresh vegetables and herbs. In this project, the effects of a dynamic lighting spectra on lettuce (including physiological, photosynthetic ...

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Non-destructive quality measurements: image analysis

We are developing a colour cabinet together with Track32, a start-up that is specialized in computer vision and artificial intelligence. We are looking for a student that will set up the first pilot experiments, and pilot analyses. The colour cabinet can be used to segment individual ...

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Questions or other ideas for thesis topics? Please contact the HPP student coordinator Katharina Hanika.