Bernd Hitzmann

• Head of Department at University of Hohenheim

Background and Objectives Spectroscopy of wheat kernels and flour has been used as a rapid tool to assess wheat quality, but predictions still lack in accuracy for most quality parameters except for protein content. To enable an improved prediction of further quality characteristics, new approaches are needed. This study investigates if the preproc...

Baking quality, defined as loaf volume, is one of the most important quality attributes of wheat. An accurate and rapid determination is of great interest for the wheat supply chain. However, this remains difficult to date, because reported predictions based on other wheat characteristics (e.g. protein content) or flour spectroscopy are poor. This...

Roasting is a fundamental step in coffee processing, where complex reactions form chemical compounds related to the coffee flavor and its health‐beneficial effects. These reactions occur on various time scales depending on the roasting conditions. To monitor the process and ensure reproducibility, the study proposes simple and fast techniques based...

This investigation aims to elucidate the dissociation of CO 2 gas from gas hydrates (GH) over a 60-minute duration at varying temperatures, with the objective of understanding the entrapment of CO 2 gas within GH with the use of GH promoters. The study examines four food-grade amino acids possessing surfactant capabilities—cysteine, leucine, methio...

Background and Objectives Research in crop science is usually conducted in studies with a small number of plants and crops. The aim of this project was to investigate whether NIRS (near‐infrared spectroscopy) can contribute to the analysis of such small data sets. For this purpose, NIR spectra of a small sample set of whole grain wheat flours of tw...

Background and Objectives Quality assessment of bread wheat is time‐consuming and requires the determination of many complex characteristics. Because of its simplicity, protein content prediction using near‐infrared spectroscopy (NIRS) serves as the primary quality attribute in wheat trade. To enable the prediction of more complex traits, informati...

The present-day diet contains a variety of breads and confectionary types, making bakery products an essential component. Ammonium bicarbonate, a chemical leavening agent used in black-and-white cookies can, however, have unfavourable side effects, such as the production of acrylamide which is a carcinogen. This research aims to use carbon dioxide...

Roasted ground coffees are targets of concern regarding intentional adulteration with cheaper foreign materials because, in this form, it may be difficult to detect due to the small particle size and the dark color. Therefore, a significant interest is developing fast, sensitive, and accurate methodologies to quantify adulterants in roasted coffees...

Sourdough can improve bakery products’ shelf life, sensory properties, and nutrient composition. To ensure high-quality sourdough, the fermentation has to be monitored. The characteristic process variables for sourdough fermentation are pH and the degree of acidity measured as total titratable acidity (TTA). The time- and cost-intensive offline mea...

In this unprecedented study, the application of CO2 gas hydrates (GH) as a leavening agent to produce black-and-white cookies by replacing ammonium bicarbonate is investigated. Ammonium bicarbonate, the principal leavening ingredient in black-and-white cookies, has been linked to the creation of a carcinogenic substance known as acrylamide. Three d...

Online fluorescence monitoring has become a key technology in modern bioprocess development, as it provides in‐depth process knowledge at comparably low costs. In particular, the technology is widely established for high‐throughput microbioreactor cultivation systems, due to its noninvasive character. For microtiter plates, previously also multi‐wa...

Chemometrics is a tool for data mining and unlocking the door for solving big data queries. Apiaceae is a family species which is commonly cultivated worldwide. Although members of this species are widely used as antioxidant, antibacterial, antifungal, and anti-inflammatory agents, their metabolites profiling remains ambiguous. Based on WHO support...

Due to its “generally recognized as safe status” (GRAS) and moderate treatment temperatures, non-thermal plasma (NTP) has lately been considered a suitable replacement for chemicals in the modification of food properties and for preserving food quality. One of the promising areas for the application of NTP is the treatment of wheat flour, leading t...

The demand for probiotic bacteria-fermented food products is increasing; however, the monitoring of the fermentation process is still challenging when using conventional approaches. A classical approach requires a large amount of offline data to calibrate a chemometric model using fluorescence spectra. Fluorescence spectra provide a wide range of o...

This article brings together the application of ice-like CO2 gas hydrates (GH) as a leavening agent in wheat bread along with the incorporation of some natural gelling agents or flour improvers into the bread to enhance the textural properties of the wheat bread. The gelling agents used for the study were ascorbic acid (AC), egg white (EW), and ric...

The aim of this study is to examine how CO2 gas hydrates (CO2 GH) are used in baking, notably in the creation of wheat bread, as a leavening agent. CO2 GH were produced with the use of food grade amino acids called promoters. The article emphasizes an interesting approach by using a hybrid combination of yeast and CO2 GH. The current study is based...

Background Non-invasive online fluorescence monitoring in high-throughput microbioreactors is a well-established method to accelerate early-stage bioprocess development. Recently, single-wavelength fluorescence monitoring in microtiter plates was extended to measurements of highly resolved 2D fluorescence spectra, by introducing charge-coupled devi...

Coffee authenticity is a foundational aspect of quality when considering coffee's market value. This has become important given frequent adulteration and mislabelling for economic gains. Therefore, this research aimed to investigate the ability of a deep autoencoder neural network to detect adulterants in roasted coffee and to determine a coffee's...

The use of 2D fluorescence spectra is a powerful, instantaneous, and highly accurate method to estimate the state of bioprocesses. The conventional approach for calibrating a chemo-metric model from raw spectra needs a large number of offline measurements from numerous runs, which is tedious, time-consuming, and error-prone. In addition, many proce...

Makespan dominates the manufacturing expenses in bakery production. The high energy consumption of ovens also has a substantial impact, which bakers may overlook. Bakers leave ovens running until the final product is baked, allowing them to consume energy even when not in use. It results in energy waste, increased manufacturing costs, and CO2 emiss...

In the presented research, the use and technical realization of CO2 gas hydrate (GH) as a novel baking agent is investigated. GH are ice-like structures where one mole of hydrate typically consists of about 85% water and 15% gas. Hydrates were formed in a lab-scale 1.1 L stirred tank reactor at 1-2°C and 3.5 MPa, and transferred into a temperature-...

For optimization of production processes and product quality, often knowledge of the factors influencing the process outcome is compulsory. Thus, process analytical technology (PAT) that allows deeper insight into the process and results in a mathematical description of the process behavior as a simple function based on the most important process f...

Gas (guest) molecules are trapped in hydrogen-bonded water molecules to form gas hydrates (GH), non-stoichiometric solids that resemble ice. High pressure and low temperature are typical conditions for their development, with van der Waals forces joining the host and guest molecules. This article study investigates the application of CO2 gas hydrat...

Multi-wavelength (2D) fluorescence spectroscopy represents an important step towards exploiting the monitoring potential of microtiter plates (MTPs) during early-stage bioprocess development. In combination with multivariate data analysis (MVDA), important process information can be obtained, while repetitive, cost-intensive sample analytics can be...

Background Cereals are known to trigger for wheat allergy, celiac disease and non-celiac wheat sensitivity (NCWS). Inflammatory processes and intestinal barrier impairment are suspected to be involved in NCWS, although the molecular triggers are unclear. Aims We were interested if different bread types influence inflammatory processes and intestin...

Minimizing the makespan is an important research topic in manufacturing engineering because it accounts for significant production expenses. In bakery manufacturing, ovens are high-energy-consuming machines that run throughout the production time. Finding an optimal combination of makespan and oven idle time in the decisive objective space can resu...

The important quality parameters of cow’s milk for barista applications are frothability and foam stability. In the past, quality assessment was very time-consuming and could only be carried out after milk treatment had been completed. Since spectroscopy is already established in dairies, it could be advantageous to develop a spectrometer-based mea...

Probiotic beverages made from cereals become interesting in the recent food industries. In this contribution, a fermented teff‐based probiotic beverage was produced using whole grain teff flour and co‐culture strains of Lactiplantibacillus plantarum (LPA6) and Lacticaseibacillus rhamnosus GG (LCGG). Then, effect of 25 days refrigerated storage on c...

Chemometric models for on-line process monitoring have become well established in pharmaceutical bioprocesses. The main drawback is the required calibration effort and the inflexibility regarding system or process changes. So, a recalibration is necessary whenever the process or the setup changes even slightly. With a large and diverse Raman datase...

The aim of this study is to compare the application of ozone with that of air during the dough kneading process. Experiments were performed on doughs made from two wheat flours of different protein contents by changing the treatment time and oxidative gas. All samples were analyzed by Farinograph, oscillatory rheometer, and dough extensibility test...

Bakery and cereal products are a basic part of today's diet, which includes a wide variety of breads, biscuits, and confectionery varieties. The elastic gluten structure, that is formed during the kneading of flour, can contain the increasing leavening gases produced during rising for any type of baked product. However, some chemical leavening ingr...

Production scheduling is one of the most important research topics in the discipline of industrial engineering and management. The use of a flow shop model and optimization algorithm to find an optimum schedule with the lowest production cost is common. The approach begins with the collection of production data in order to have a better understandi...

Published manuscripts about cereals have been increasing in numbers over the last 20 years by an average of 160 manuscripts per year [...]

This contribution investigates the performance of nature-inspired multi-objective optimization algorithms to reduce the makespan and oven idle time of bakery manufacturing using a hybrid no-wait flow shop scheduling model. As an example, the production data from a bakery with 40 products is investigated. We use the non-dominated sorting genetic alg...

The dissociation of CO2 gas hydrates (GH) with amino acid kinetic promoters and without promoters was studied at a high temperature of 90 °C for a period of 20 min to understand the percentage of CO2 gas and to select the best promoter that aids CO2 gas entrapment along with stability at a high temperature. The possibility of using four hydrophobic...

There is increasing demand for cereal-based probiotic fermented beverages as an alternative to dairy-based products due to their limitations. However, analyzing and monitoring the fermentation process is usually time consuming, costly, and labor intensive. This research therefore aims to apply two-dimensional (2D)-fluorescence spectroscopy coupled...

Background and Objectives A high amount of the world wheat production is used for bread making. Due to its simplicity, wheat samples are traded based on protein content, although this is only an indirect measurement of baking quality. As direct bread quality traits like loaf volume, water absorption, and dough properties are cumbersome to measure a...

There is a growing demand for new strategies to tailor the texture of fat-free fermented concentrated milk products, also referred to as milk protein-based (MPb) microgel dispersions. Methods should be easy to incorporate into the production scheme, offer labelling without added components and be cost-efficient. Thermal treatments are traditionally...

Excitation-emission matrix (EEM) fluorescence data can be explored by using deep convolutional neural networks to enhance the predictive performance of bioprocess variables. This article proposes the use of residual neural networks (ResNet) for the prediction of ethanol, glucose, and biomass concentrations of S. cerevisiae cultivations based on flu...

The present study compared whole grain teff flours grown in Ethiopia (ETF) and South Africa (STF) for their chemical composition (proximate, mineral, and amino acid) and pasting, thermal, and functional properties. The proximate composition of flours was determined using methods of the European Commission Regulation (152/2009). Atomic Spectrometer,...

This review provides an overview of recent studies on the potential of spectroscopy techniques (mid-infrared, near infrared, Raman, and fluorescence spectroscopy) used in coffee analysis. It specifically covers their applications in coffee roasting supervision, adulterants and defective beans detection, prediction of specialty coffee quality and co...

Bakery and cereal products are a significant part of the present-day diet comprising a vast range of bread, cookies, and innumerable varieties of confectionaries. Flour when combined with water, forms an elastic gluten structure, which stretches to hold the increasing leavening gases throughout rising for each type of baked item. However, some ingr...

Detecting the types of anomalies that can occur throughout the milk processing process is an important task since it can assist providers in maintaining control over the process. The Raman spectrometer was used in conjunction with several classification approaches—linear discriminant analysis, decision tree, support vector machine, and k nearest ne...

In bakery production, to perform a processing task there might be multiple alternative machines that have the same functionalities. Finding an efficient production schedule is challenging due to the significant nondeterministic polynomial time (NP)-hardness of the problem when the number of products, processing tasks, and alternative machines are h...

Drought stress is playing an increasingly important role in crop production due to climate change. To investigate the effects of drought stress on protein quantity and quality of wheat, two Iranian (Alvand, Mihan) and four German (Impression, Discus, Rumor, Hybery) winter wheat genotypes, representing different quality classes and grain protein lev...

Consumers are demanding healthier foods, and the increasing drawbacks associated with dairy-based products have driven efforts to find plant-based probiotic alternatives. Consequently, this study aimed to evaluate the suitability of a teff-based substrate for delivering the potential probiotics, Lactobacillus rhamnosus GG (LGG) and Lactobacillus pl...

Fat-free fermented concentrated milk products, recently classified as dispersions of (fat-free) fermented concentrated milk protein-based microgel particles, are basically produced by upstream, fermentation, and downstream processing. Development of production parameters aimed at, e.g., increasing yield, shelf-stability, and reducing acid whey, has...

Chia oil is a valuable source of omega-3-fatty acids and other nutritional components. However, it is expensive to produce and can therefore be easily adulterated with cheaper oils to improve the profit margins. Spectroscopic methods are becoming more and more common in food fraud detection. The aim of this study was to answer following questions:...

Background/objectives: Cereal products like flour and bread are known to trigger diseases such as wheat allergy, celiac disease and non-celiac wheat sensitivity (NCWS). Some of these diseases are caused by allergenic proteins, the expression of which might vary depending on the grain type and manufacturing processes. Therefore, we examined the pro...

Controlling milk processing steps is a crucial task as it affects the quality and safety of the final product. Using Raman spectrometer in combination with various evaluation techniques such as principal component analysis and regression, Gaussian process regression, and the autoencoder were checked to define an accurate method for detection of dev...

The volume fraction of the dispersed phase in concentrated soft (dairy) microgels, such as fresh cheese, is directly related to structure and rheology. Measurement or modeling of volume fraction for soft and mechanically sensitive microgel dispersions is problematic, since responsiveness and rheological changes upon mechanical input for these syste...

Gas hydrates constitute of gas as a guest molecule in hydrogen-bonded water lattices. This review covers ongoing hydrate research in food technology with a spotlight on carbon dioxide (CO 2 ) application as a hydrate. The application of gas hydrates in the concentration of juices, desalination, carbonation, and food preservation has been covered in...

Chia seeds are becoming more and more popular in modern diets. In this contribution NIR and 2D‑fluorescence spectroscopy were used to determine their nutritional values, mainly fat and protein content. 25 samples of chia seeds were analysed, whereof 9 samples were obtained from different regions in Kenya, 16 samples were purchased in stores in Germ...

DOI: 10.1002/elsc.202000058 Successful operation, control and optimization of biotechnological process depend on reliable real‐time available measurements of the process variables. Although some hardware sensors are readily available, they often have several drawbacks: cost, sample destruction, discrete‐time measurements, processing delay, steriliz...

Anomaly detection during milk processing (such as changes in fat or temperature, added water or cleaning solution) can assure a satisfactory final product quality, including compositional and hygienic characteristics, as well as adulteration with water. The use of near-infrared (NIR) spectroscopy for change detection in complex dairy matrix is disc...

Dough fermentation is an important step during the preparation of fermented baking goods. For the supervision of dough fermentation, a continuous-discrete extended Kalman filter was applied, which uses an image analysis system as the measurement. By estimation a fixed number of gas bubbles inside the dough, the radius of an average bubble was deter...

Real‐time information about the concentrations of substrates and biomass is the key to accurate monitoring and control of bioprocess. However, on‐line measurement of these variables is a challenging task and new measurement systems are still required. An alternative are software sensors, which can be used for state and parameter estimation in biopr...

The quality by design approach was introduced to the biopharmaceutical industry over 15 years ago. This principle is widely implemented in the characterization of monoclonal antibody production processes. Anyway, the early process phase, namely the inoculum expansion, was not yet investigated and characterized for most processes. In order to increa...

In the era of technology and digitalization, the process industries are undergoing a digital transformation. The available process models, advance sensor technologies, enhanced computational power and a broad set of data analytical techniques enable solid bases for digital transformation in the biopharmaceutical industry. Among various data analyt...

The ethanol concentration in batch cultivation with the yeast Saccharomyces cerevisiae was predicted on-line using a gas sensor array. Headspace samples were pumped past the gas sensors array for 10 s every five minutes and the voltage changes of the sensors were measured. For the calibration procedure no off-line sampling was used. Instead, a theo...

Bioprocesses can be found in different areas such as the production of food, feed, energy, chemicals, and pharmaceuticals [...]

de Verarbeitungsprozesse von Getreide erfordern häufig eine Wasseraufnahme der Getreidekörner. Verschiedene Wasserabsorptionsmodelle (das Peleg‐Modell, das erweiterte Peleg‐Modell, das Modell nach Thakur und das Becker‐Modell) wurden an die Messdaten von Weizen, Roggen, Gerste, Hafer, Reis und Mais angepasst. Die besten Ergebnisse wurden für alle G...

Background: Nitrogen losses is an economic problem for wheat production and a high risk to the environment. Therefore, improved N fertilizer management is a key to increasing the N efficiency and minimizing N losses. To increase N efficiency, enhanced fertilizers such as urea combined with urease inhibitor can be used. Aims: The aim of present stud...

This research represents an evaluation study of the linear and non-linear mathematical methods applied to predict the biogas flow rate in anaerobic digestion processes. The anaerobic digestion model No.1 was used to generate the process data. For the prediction of the biogas flow rate the partially least squares regression, the locally weighted reg...

This paper presents a fast and reliable approach to analyze the biogas production process with respect to the biogas production rate. The experimental data used for the developed models included 15 process variables measured at an agricultural biogas plant in Germany. In this context, the concentration of volatile fatty acids, total solids, volatil...

A new Two‐Dimensional Fluorescence (2DF) sensor system was developed for in‐line monitoring of mammalian cell cultures. Fluorescence spectroscopy allows for the detection and quantification of naturally occurring intra‐ and extracellular fluorophores in the cell broth. The fluorescence signals correlate to the cells’ current redox state and other r...

A fuzzy logic control system is designed and applied to a proofing system. The controller is experimentally evaluated and the performance is compared to the ones from a PID controller. Dough pieces with different amounts of yeast added in the ingredients and in different temperature starting states are prepared and proofed with the supervision of t...

Background: A glucose concentration is an important factor for a fed-batch process of Saccharomyces cerevisiae. Therefore, it is necessary to be controlled under a critical concentration to avoid overflow metabolism and to gain high productivity of biomass. In the study, 2D fluorescence spectroscopy was applied for an online monitoring and controll...

Zusammenfassung Glutenfreie Backwaren erfreuen sich einer immer größer werdenden Beliebtheit, nicht nur bei Zöliakie-Patienten. Allerdings übernimmt Gluten technologisch wichtige Funktionen im Brotteig und ist für die Verbrauchererwartung von Weizenbroten essentiell. Dieser Artikel zeigt die Schwierigkeiten bei der Herstellung qualitativ hochwertig...

The influence of the sunflower protein (SP) on the freshness of wholegrain wheat bread was studied. The doughs were supplemented with sunflower protein as substitution or addition to the flour. The resulting breads were evaluated by determining gravimetric moisture content, and analysis of texture profile. In order to assess the effects of sunflowe...