Jan F.M. Van Impe

• ir., PhD, Dr.h.c. ULB
• Head of Department at KU Leuven

The dairy industry faces significant challenges from climate change, requiring a deeper understanding of how climatic factors influence raw milk composition and quality. The aim of this study was to evaluate the impact of climatic variables, such as temperature, solar radiation, and carbon dioxide levels, on raw milk parameters, including somatic c...

Individual-based modeling (IbM) is an instrumental tool for simulating spatial microbial growth, with applications in both microbial ecology and biochemical engineering. Unlike Cellular Automata (CA), which use a fixed grid of cells with predefined rules for interactions, IbMs model the individual behaviors of cells, allowing complex population dyn...

Radio Frequency (RF) bacterial inactivation has been successfully used in several food products. However, RF dielectric heating can be affected by several factors, including food composition. Changes in the food matrix can not only influence microbial inactivation but also potentially alter RF inactivation mechanisms. Despite this, limited studies...

This study evaluated the effect of green tea and Moringa oleifera extracts (at 1 % and 2 % concentration) on DOX-treated breast cancer mice. 36 Balb/C female mice with breast cancer were split into healthy mice, 4 T1 cell cancer-induced, and Doxorubicin-induced malignancies. Assessments included weight, tumor size, liver enzymes, antioxidant enzyme...

Motivation Analysis of metabolic networks through extreme rays such as Extreme Pathways and Elementary Flux Modes has been shown to be effective for many applications. However, due to the combinatorial explosion of candidate vectors, their enumeration is currently limited to small- and medium-scale networks (typically less than 200 reactions). Part...

Transforming the food system while addressing climate change requires proactive measures based on quantitative projections of anticipated future conditions. A key component of the food system that must be considered during this transformation is food safety, which is the focus of this paper. Milk safety has been selected as a case study. Future mil...

Radio frequency (RF) is a dielectric heating technology that allows rapid and volumetric heating of milk powder, outperforming the heating uniformity of conventional powder heating methods. Typically, RF milk powder processing consists of a fast RF heating phase, followed by an oven heating phase in temperatures around 90 °C. This methodology can r...

The presence of heavy metals and metalloids (metal(loid)s) in the food chain is a global problem, and thus, metal(loid)s are considered to be Potentially Toxic Elements (PTEs). Arsenic (As), lead (Pb), mercury (Hg), and cadmium (Cd) are identified as prominent hazards related to human health risks throughout the food chain. This study aimed to carr...

Flavor is a major sensory attribute affecting consumers’ preference for cheese products. Differences in cheesemaking change the cheese microenvironment, thereby affecting cheese flavor profiles. A framework for tuning cheese flavor is proposed in this study, which depicts the full picture of flavor development and modulation, from manufacturing and...

With the increasing food demand, it is essential to plan for a future where climate change affects the food sector. The policy making necessary to ensure the food demand must be driven by a thorough assessment of the impact climate change has on the food sector. Such an assessment can be facilitated by building impact models focusing on different a...

Spray drying is used in the pharmaceutical industry for particle engineering of amorphous solid dispersions (ASDs). The particle size of the spray-dried (SD) powders is one of their key attributes due to its impact on the downstream processes and the drug product’s functional properties. Offline and inline laser diffraction methods can be used to e...

Spread products have an important market share as they have high nutritional value and they are increasingly consumed, especially by children as a source of energy. The purpose of this work was to evaluate the potential use of powdered chickpea, black rice, carob, doum, date seeds, and beetroot to produce novel functional spreadable products as coc...

Plastics are essential in modern life, but their conventional production is problematic due to environmental pollution and waste management issues. Polylactic acid (PLA) is a widely used bioplastic that is bio-based and biodegradable, making it a key player in the bioeconomy. PLA has been proven to be degradable in various settings, including aqueo...

Fermented foods such as table olives are produced through a spontaneous process that has been improved over the years, ensuring the safety and quality of the final product. The aim of the present work was to study the action of starter cultures of lactic acid bacteria (Lacticaseibacillus rhamnosus GG ATCC53103, Levilactobacillus brevis ATCC8287, an...

Biorefinery systems that are embedded in their local setting provide an attractive framework for the valorisation of locally available food- and other bio-waste streams. They can aid in the provision of local bio-waste processing facilities as well as the targeted revalorisation of local bio-waste feedstocks by converting them in locally desired bi...

Heat stress is a major challenge for dairy farmers, as it can have a significant impact on milk production. The purpose of this research was to investigate the differences in the compositions of colostrum and mature milk from various animal species (Aberdeen Angus cows (AC), Baladi cows (BC), and Baladi goats (BG)) under a desert climate in the New...

Nowadays adulteration of meat products, especially of ground meat products which form an easy case scenario for implementing adulteration practices due to their structure and texture, emerges a critical issue of raised concern threatening fair trade, food quality and consumers’ health and protection. Food authentication testing is the tool to addre...

Pichia pastoris is a popular yeast platform to generate several industrially relevant products which have applications in a wide range of sectors. The complexities in the processes due to the addition of a foreign gene are not widely explored. Since these complexities can be dependent on the strain characteristics, promoter, and type of protein pro...

The global carbon dioxide in the atmosphere is predicted to rise due to fossil fuel emissions during the next century. Carbon dioxide is soluble in water and partially dissociates into bicarbonate and carbonate, releasing protons that decrease the pH. This change in pH is expected to play a critical role in some earth systems, such as the hydrosphe...

The effect of Listeria monocytogenes, Salmonella Typhimurium, and Saccharomyces cerevisiae on RF heating was studied in sterilized Milli-Q water and saline solution during treatments at 27.0 ± 0.6 MHz and 3.0 ± 0.02 MHz for 30 min. The presence of microorganisms caused a significant increase in temperature (maximum to 54.9 °C), with no significant...

This study examined five species of the Lamiaceae family, Origanum vulgare L., Origanum dictamnus L., Origanum majorana L., Mentha spicata L. and Lavandula angustifolia L., and one species of the Hypericaceae family, Hypericum perforatum L., for their potential to enhance health and wellbeing or to prevent diseases. An analysis of secondary metabol...

The properties of probiotics such as lactic acid bacteria (LAB) have been widely studied over the last decades. In the present study, four different LAB species, namely Lactobacillus gasseri ATCC 33323, Lacticaseibacillus rhamnosus GG ATCC 53103, Levilactobacillus brevis ATCC 8287, and Lactiplantibacillus plantarum ATCC 14917, were investigated in...

Sweet protein thaumatin, a promising alternative to table sugar, can overcome several drawbacks imposed by other sugar alternatives in the market today. Recombinant technology involving Komagataella phaffii (previously known as Pichia pastoris) has the potential to facilitate a uniform and large-scale production of this protein. To ensure maximal y...

The application of several sublethal stresses in hurdle technology can exert microbial stress resistance, which, in turn, might enable foodborne pathogens to overcome other types of lethal stresses, such as the gastrointestinal barriers. The present study evaluated the survival of Salmonella Typhimurium and Listeria monocytogenes during simulated d...

Aims The global level of carbon dioxide and temperature in the atmosphere is expected to increase, which may affect the survival of the stress-adapted bacteria. In this study, the effect of temperature and dissolved carbon dioxide on the growth rate of Escherichia coli was studied, thus assessing its response to induced environmental stress factors...

Model-based multi-objective optimization is a useful tool to compute optimal trade-offs between multiple conflicting objectives such as minimizing energy consumption while maximizing productivity. However, the computational cost of solving such optimization problems is high. In addition, a model approximates the real process, meaning uncertainty is...

Even though a plethora of barriers are employed by the human gastrointestinal tract (GIT) to cope with invading pathogens, foodborne diseases are still a common problem. The survival of food pathogens in the GIT is known to depend on food carrier properties. The aim of this study was to investigate the influence of food buffering capacity and food...

The manufacturing of recombinant proteins is increasing phenomenally, and yeasts serve as one of the most popular platforms for the large-scale production of these industrially relevant products. Protein analysis is a traditional step for the control and optimization of such bioprocesses and often necessitates the combination of laborious sample tr...

The human gastrointestinal tract (GIT) harbors numerous defensive mechanisms to impede pathogen colonization, including gastric acidity and bile acids in the small intestine. This study aims to elucidate the survival of Salmonella Typhimurium and Listeria monocytogenes under different levels of gastric pH (2.0–3.5) and bile acid concentrations (2.5...

Multiobjective optimisation is used when a system needs to be optimised for multiple conflicting objectives. However, the solution of such a problem is not one point but a set of equally optimal points called Pareto points which highlight the trade-off required to achieve optimisation of one objective over another. As any computer aided approaches...

Anaerobic digestion is a widely employed technique that converts waste into biogas, which can be employed as renewable energy. To improve its efficiency, but also to treat recalcitrant waste, mixes involving several types of feedstock with different biodegradability rates are fed to the process. Finding the proper mix is difficult and involves exte...

The PROTECT Training Network develops and integrates modelling capabilities to assess the effects of climate change on food safety. This comic is aimed at primary school children (ages 6 years upwards) to illustrate the main concepts and outcomes from the PROTECT Training Network in an uncomplicated and fun way. This Training Network is Funded by...

In this study, an observer for estimating the state and unknown inputs is proposed for monitoring anaerobic digestion processes. This estimator is based on a dynamic model considering acidogenesis and methanogenesis, and consists of three sub-observers: (a) a gramian-based fixed-time convergent observer for the inlet chemical oxygen demand (COD) an...

In this work, we present a biomimetic sensor for the sensitive and fast (< 15 minutes) detection of yeast cells (S. cerevisiae) and hydrophobins (e.g. HFB) in food and beverages. While unwanted yeast contaminations can cause off-flavors and stability issues, hydrophobin contaminations are a less-known but equally serious economic concern in beer pr...

Microbial conflicts have a particularly aggressive nature. In addition to other chemical, mechanical, and biological weapons in their repertoire, bacteria have evolved bacteriocins, which are narrow-spectrum toxins that kill closely related strains. Bacterial cells are known to frequently use their arsenal while competing against each other for nut...

Methanol, a simple polar solvent, has been widely identified as an attractive carbon source to produce chemicals and fuels in bioprocesses. Specifically, to achieve recombinant protein production from methylotrophic yeasts, such as Pichia pastoris, this organic solvent can be used as a sole carbon source for growth and maintenance as well as an ind...

As plastic packaging becomes nearly indispensable in the plastic economy, rigorous efforts have been made to recapture the material value form this waste stream, which is mostly composed of highly resistant plastics. Biodegradation offers an attractive alternative for conventional plastic waste treatment as this approach is environmentally friendly...

Aims: This research aimed to develop and validate a cultivation and monitoring protocol that is suitable for a surrogate microbial community that accounts for the gut microbiota of the ileum of the small intestine. Methods and results: Five bacterial species have been selected as representatives of the ileal gut microbiota and a general anaerobi...

The sweet protein thaumatin is emerging as a promising sugar replacer in the market today, especially in the food and beverage sector. Rising demand for its production necessitates the large-scale extraction of this protein from its natural plant source, which can be limited in terms of raw material availability and production costs. Using a recomb...

Second-generation biomass is an underexploited resource, which can lead to valuable products in a circular economy. Available locally as food waste, gardening and pruning waste or agricultural waste, second-generation biomass can be processed into high-valued products through a flexi-feed small-scale biorefinery. The flexi-feed and the use of local...

Positive frequency dependent selection is a natural selection regime where the fitness of a phenotype increases with its frequency in the population. Examples can be typically found in the spread of disease tolerance strategies in a population. A characterizing feature of PFDS is that the focal allele may experience favorable selection only when it...

In this paper, the tuning of economic model predictive control (EMPC) applied to drinking water transport networks (DWTNs) is addressed using multi-objective optimization approaches. The tuning strategies are based on Pareto front calculations of the underlying multi-objective problem. This feature represents an improvement with respect to the stan...

The influence of food product viscosity on the temperature evolution inside distilled water and a high-viscosity liquid food model system during agitated retort processing (i.e., Shaka process) was investigated by simulations via a previously developed mathematical model. On the one hand, the volume average temperature increased at a faster rate in...

Although the Cold Atmospheric Plasma (CAP) technology proved promising for inactivation of biofilms present on abiotic food contact surfaces, more research is required to examine the behavior of the CAP surviving biofilm-associated cells. It was therefore examined whether (i) CAP treated (Listeria monocytogenes and Salmonella Typhimurium) biofilm-a...

Quorum sensing is a cell-cell communication system that bacteria use to express social phenotypes, such as the production of extracellular enzymes or toxins, at high cell densities when these phenotypes are most beneficial. However, many bacterial strains are known to lack a sensing mechanism for quorum signals, despite having the gene responsible...

There are two major views toward the role of antibiotics in microbial social interactions. The classical view is that antibiotics serve as weapons, produced by a bacterial species, at a significant cost, to inhibit the growth of its competitors. This view is supported by observations that antibiotics are usually upregulated by stress responses that...

As the chemical and energy producing industries are steadily transitioning towards more sustainable processing practices, renewable biomass resources are becoming increasingly more valuable. Recently, following the realisation that renewable resources for the chemical and energy industry should not compete with food supplies, the use of plant-based...

Process models include a variety of parameters that need to be estimated from experimental data. To obtain an accurate estimate of the parameters, it is imperative that the experiments provide sufficient informative data. To ensure the information content with reduced experimental efforts, model-based design of experiments can be used. In this chap...

The process of optimization of chemical/ biochemical processes can often involve multiple conflicting objectives. This gives rise to a class of problems called multi-objective optimization problems. Solving such problems results in an infinite set of points, the Pareto set, which includes all the solutions in which no objective can be improved with...

Sustainable food systems embrace a range of aspects such as security of the supply of food, health, safety, affordability, quality, a strong food industry in terms of jobs and growth, and environmental sustainability in terms of issues such as climate change, biodiversity, water and soil quality. In recent years, quantitative modelling and engineer...

Uncertainty is inherent in bioprocess modelling and control. Typically, uncertainties are handled using either the stochastic approach or the robust approach. Recently, the risk-averse approach, i.e., an interpolation between the stochastic and worst-case robust approach is gaining popularity. Risk-averse formulations are very useful in avoiding co...

Fermentation is one of the most important stages in the entire brewing process. In fermentation, the sugars are converted by the brewing yeast into alcohol, carbon dioxide, and a variety of by-products which affect the flavour of the beer. Fermentation temperature profile plays an essential role in the progression of fermentation and heavily influe...

Featured Application Radio frequency (RF) heating is a promising novel technology for food pasteurisation and sterilisation applications. However, knowledge on the (thermal) inactivation mechanisms of RF against foodborne pathogens (e.g., bacteria) is limited thus far. Therefore, in the current study, a small-scale laboratory RF setup that is appro...

Background: The identification of bacterial species in fermented PDO (protected designation of origin) cheese is important since they contribute significantly to the final organoleptic properties, the ripening process, the shelf life, the safety and the overall quality of cheese. Methods: Ten commercial PDO feta cheeses from two geographic regions...

Variability in the behavior of microbial foodborne pathogens and spoilers causes difficulties in predicting the safety and quality of food products during their shelf life. Therefore, the quantification of the individual microbial lag phase distribution is of high relevance to the field of quantitative microbial risk assessment. To construct models...

Chocolates paired with nuts are highly marketed products, however, there is a lack of scientific research and limited understanding of consumer sentiment towards the combination of these food products. The main objective of this research was to determine the consumers’ response towards pairing five different chocolates (dark origin, milk, Gold, whi...

Bioprocesses are increasingly used for the production of high added value products. Microorganisms are used in bioprocesses to mediate or catalyze the necessary reactions. This makes bioprocesses highly nonlinear and the governing mechanisms are complex. These complex governing mechanisms can be modeled by a metabolic network that comprises all int...

Breast milk has been reported as a bacteria source that affects infant gut microbiota development. The present study utilizes a realtime PCR method to identify Lactobacillus and Bifidobacterium spp. in the breast milk of healthy women and attempts to identify factors affecting those human milk bacteria. Breast milk samples—both colostrum and mature...

Ultrasound, alone or in combination with natural antimicrobials, is a novel food processing technology of interest to replace traditional food decontamination methods, as it is milder than classical sterilisation (heat treatment) and maintains desirable sensory characteristics. However, ultrasound efficacy can be affected by food structure/composit...

Predictive microbiology has steadily evolved into one of the most important tools to assess and control the microbiological safety of food products. Predictive models were traditionally developed based on experiments in liquid laboratory media, meaning that food microstructural effects were not represented in these models. Since food microstructure...

Hydrophobins (HFBs) are a group of highly functional, low molecular weight proteins with the ability to self‐assemble at hydrophobic‐hydrophilic interfaces. The surface active, cysteine‐rich proteins are found in filamentous fungi such as Trichoderma reesei. In the present study multiple extraction solvents and conditions were screened for the myce...

Background Food systems are both affecting and being affected by climate change. Anticipated effects of climate change on microbial food safety are both direct (e.g., on microbial prevalence) and indirect (e.g., increased risk of floods on water microbial contamination). Scope and Approach This paper highlights the necessity to build a quantitativ...

The detection and quantification of sublethal injury (SI) of pathogenic microorganisms has become a common procedure when assessing the efficiency of microbial inactivation treatments. However, while a plethora of studies investigates SI in function of time, no suitable modelling procedure for SI data has been proposed thus far. In this study, a ne...

Biofilms formed by different bacterial species are likely to play key roles in photocatalytic resistance. This study aims to evaluate the efficacy of a photocatalytic immobilized nanotube system (TiO2-NT) (IS) and suspended nanoparticles (TiO2-NP) (SS) against mono- and dual-species biofilms developed by Gram-negative and Gram-positive strains. Two...

Background The dairy industry is one of the most polluting sectors globally, producing waste identified by the high content of biological and chemical oxygen demand, organic and inorganic matter. The continuous disposal of dairy waste into the environment negatively impacts ecosystems. Seasonality has been shown to affect the physicochemical compos...

Spiral jet mills are ubiquitous in the pharmaceutical industry. Breakage and classification in spiral jet mills occur due to complex interactions between the fluid and the solid phases. The study of these interactions requires the use of computational fluid dynamics (CFD) for the fluid phase coupled with discrete element models (DEM) for the partic...

In this work, the physical properties of Fe48Cr15Mo14C15B6Y2 alloy in liquid state at high temperature are studied. It was observed that the basic physical characteristics of the alloy, such as viscosity, electrical resistivity, and density, decrease with an increase of the temperature to 1700 °C. An abnormal increasing rate of viscosity for Fe48Cr...

Different methods have been used to detect milk adulteration, but in recent years the use of nanomaterials has been introduced as an interesting tool, due to their optical properties. A gold nanoparticle (AuNP) probe application was developed in order to evaluate milk adulteration. The methodology relies on the colorimetric differentiation and the...