Institut für Lebensmittelwissenschaft und Biotechnologie

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Now showing 1 - 20 of 201

Time-delayed cold gelation of low-ester pectin and gluten with CaCO3 to facilitate manufacture of raw-fermented vegan sausage analogs
(2025) Koenig, Maurice; Ahlborn, Kai; Herrmann, Kurt; Loeffler, Myriam; Weiss, Jochen; Kolanowski, Wojciech
To advance the development of protein-rich plant-based foods, a novel binder system for vegan sausage alternatives without the requirement of heat application was investigated. This enables long-term ripening of plant-based analogs similar to traditional fermented meat or dairy products, allowing for refined flavor and texture development. This was achieved by using a poorly water-soluble calcium source (calcium carbonate) to introduce calcium ions into a low-ester pectin—gluten matrix susceptible to crosslinking via divalent ions. The gelling reaction of pectin–gluten dispersions with Ca 2+ ions was time-delayed due to the gradual production of lactic acid during fermentation. Firm, sliceable matrices were formed, in which particulate substances such as texturized proteins and solid vegetable fat could be integrated, hence forming an unheated raw-fermented plant-based salami-type sausage model matrix which remained safe for consumption over 21 days of ripening. Gluten as well as pectin had a significant influence on the functional properties of the matrices, especially water holding capacity (increasing with higher pectin or gluten content), hardness (increasing with higher pectin or gluten content), tensile strength (increasing with higher pectin or gluten content) and cohesiveness (decreasing with higher pectin or gluten content). A combination of three simultaneously occurring effects was observed, modulating the properties of the matrices, namely, (a) an increase in gel strength due to increased pectin concentration forming more brittle gels, (b) an increase in gel strength with increasing gluten content forming more elastic gels and (c) interactions of low-ester pectin with the gluten network, with pectin addition causing increased aggregation of gluten, leading to strengthened networks.
Visual tracking of a moving target in 360-degree virtual reality: analysis of the effects on attention and mood
(2025) Sellner, T.; Ehmann, P.; Spielmann, J.; Gogolla, F.; Rösgen, A.; Mayer, J.; Schoenfeld, M. A.; Flor, H.
The training of attentional capacities is an important part of many rehabilitative efforts, for example, in the treatment of stroke. The Helix-Arena is an innovative virtual reality (VR) training device, which enables multimodal training in a 360-degree virtual environment. A pursuit training was developed for the Helix-Arena. In this study, we evaluate the effectiveness of the pursuit training in the Helix-Arena compared to a control group [CG, training on a personal computer (PC)] in 34 healthy participants. The experimental group (EG, N = 19) participated in four training sessions in the Helix-Arena over a period of 2 weeks. The control group (N = 15) completed similar training sessions in a non-VR environment on a PC. During each training session, changes in attention (Test of Attentional Performance battery, TAP) and general mood (Positive and Negative Affect Schedule, PANAS) were assessed pre- and post-training. A significantly higher pre-to-post improvement was observed in the EG for the TAP subtest attention shift in the subcategory invalid instructor ( p = 0.04) than that in the CG. In addition, we found a higher positive affect after the training in the EG but not in the CG (p < 0.01). These results suggest advantages of the VR environment for attentional and affective processes. The VR training can thus improve not only cognitive abilities but also training motivation. In a next step, the training can be used with patients in a rehabilitation context, but it is also suitable for educational and gaming contexts.
Genome-wide association reveals host-specific genomic traits in Escherichia coli
(2023) Tiwari, Sumeet K.; van der Putten, Boas C. L.; Fuchs, Thilo M.; Vinh, Trung N.; Bootsma, Martin; Oldenkamp, Rik; La Ragione, Roberto; Matamoros, Sebastien; Hoa, Ngo T.; Berens, Christian; Leng, Joy; Álvarez, Julio; Ferrandis-Vila, Marta; Ritchie, Jenny M.; Fruth, Angelika; Schwarz, Stefan; Domínguez, Lucas; Ugarte-Ruiz, María; Bethe, Astrid; Huber, Charlotte; Johanns, Vanessa; Stamm, Ivonne; Wieler, Lothar H.; Ewers, Christa; Fivian-Hughes, Amanda; Schmidt, Herbert; Menge, Christian; Semmler, Torsten; Schultsz, Constance
Background: Escherichia coli is an opportunistic pathogen which colonizes various host species. However, to what extent genetic lineages of E. coli are adapted or restricted to specific hosts and the genomic determinants of such adaptation or restriction is poorly understood. Results: We randomly sampled E. coli isolates from four countries (Germany, UK, Spain, and Vietnam), obtained from five host species (human, pig, cattle, chicken, and wild boar) over 16 years, from both healthy and diseased hosts, to construct a collection of 1198 whole-genome sequenced E. coli isolates. We identified associations between specific E. coli lineages and the host from which they were isolated. A genome-wide association study (GWAS) identified several E. coli genes that were associated with human, cattle, or chicken hosts, whereas no genes associated with the pig host could be found. In silico characterization of nine contiguous genes (collectively designated as nan-9 ) associated with the human host indicated that these genes are involved in the metabolism of sialic acids (Sia). In contrast, the previously described sialic acid regulon known as sialoregulon (i.e. nanRATEK-yhcH , nanXY , and nanCMS ) was not associated with any host species. In vitro growth experiments with a Δ nan-9 E. coli mutant strain, using the sialic acids 5- N -acetylneuraminic acid (Neu5Ac) and N -glycolylneuraminic acid (Neu5Gc) as sole carbon source, showed impaired growth behaviour compared to the wild-type. Conclusions: This study provides an extensive analysis of genetic determinants which may contribute to host specificity in E. coli . Our findings should inform risk analysis and epidemiological monitoring of (antimicrobial resistant) E. coli .
Investigation of biochars in terms of vitamin E adsorption capacity
(2025) Witte, Franziska; Dinh, Ngoc Huyen Anh; Juadjur, Andreas; Heinz, Volker; Visscher, Christian; Weiss, Jochen; Terjung, Nino; Gao, Bin; García Rodríguez, Juan
Featured Application: This study provides insights into optimising biochar as a carrier for vitamin E delivery in ruminant nutrition. By demonstrating the correlation between pore size distribution and adsorption capacity, the findings suggest that theoretical models can reduce the number of experimental trials needed to identify effective adsorbents. This approach could improve the efficiency of vitamin E supplementation in animal feed, potentially enhancing nutrient absorption and animal health. Abstract: Vitamin E is important for ruminants’ health. To increase the rate of vitamin E resorption, the use of a carrier is recommended. One authorised porous feed additive is biochar. Biochar’s adsorption capacity is affected by its pore volume, which is determined, among other factors, by the biomass and the production process applied. For this purpose, the vitamin E adsorption capacity of ten commercial biochars with a varying surface area in the range of 2.6 to 20 nm was investigated. The results of these single-point batch experiments were compared to the theoretical results using a monolayer adsorption model. Our hypothesis was proven, as the theoretical model could predict the experimental adsorption capacity. This generally suggests that the number of trials required to identify optimal adsorbents can be reduced. A high percentage of vitamin E adsorption (>90%) was obtained with a short adsorption time of 10 min using an adsorbent dosage of 15.78 g/L and a vitamin E concentration of 1.70 g/L. The highest correlation of vitamin E adsorption existed for the mesopore class, ranging from 3.22 to 4.03 nm in Barrett–Joyner–Halenda surface area. This indicates the necessity of knowing the size of the adsorptive and the adsorbent in order to optimise sorption kinetics.
Application of AprX from Pseudomonas paralactis for the improvement of the emulsifying properties of milk, plant and insect protein and estimation of their hydrolysate’s bitter potential
(2025) Volk, Veronika; Ewert, Jacob; Longhi, Miriam; Stressler, Timo; Fischer, Lutz
Protein properties can be modified by selective enzymatic hydrolysis. In this study, the alkaline metalloendopeptidase AprX (Serralysin; EC 3.4.24.40) from Pseudomonas paralactis was used for the tailored hydrolysis of different food proteins resulting in the production of protein hydrolysates with improved emulsifying properties. Sodium caseinate, wheat gluten and buffalo worm protein were used for AprX hydrolysis at 40 °C and pH 8 to cover a spectrum of different protein sources. A maximum degree of hydrolysis (DH) of 13.1 ± 0.2%, 14.2 ± 0.1% and 20.7 ± 0.1% was reached for sodium caseinate, wheat gluten and the worm protein, respectively. The corresponding hydrolysate properties were analyzed regarding their particle size, peptide composition, solubility, viscosity, surface hydrophobicity and interfacial tension. The emulsifying properties were investigated by the oil-droplet size, ζ-potential and stability of emulsions prepared from the hydrolysates. Using partially hydrolyzed sodium caseinate (DH = 10.6%) as an emulsifier lead to an eightfold increase of the emulsion stability (t1/2 = 180 ± 0 min) compared to unhydrolyzed sodium caseinate. The emulsion stability using wheat gluten hydrolysates (DH = 11.9%) was increased 30-fold (t1/2 = 45 ± 5 min). Simultaneously, the solubility of gluten was increased by 60%. Buffalo worm hydrolysates (DH = 14.6%) had a twofold (t1/2 = 85 ± 5 min) increased emulsion stability. In conclusion, AprX can be used to improve the solubility and emulsifying properties of food proteins at a relatively high DH.
Seasonal variation in the diurnal activity pattern of Eurasian blackbirds (Turdus merula) in the forest
(2024) Schlindwein, Xenia; Randler, Christoph; Kalb, Nadine; Dvorak, Jan; Gottschalk, Thomas K.
Camera traps are increasingly used to estimate the density of animals as well as their activity patterns. As camera traps allow monitoring of animals over long periods of time without disturbance, they are especially useful to observe changes in diurnal activity patterns over time. In ornithology, camera trapping is still in its infancy. To our knowledge, no study has yet investigated the activity pattern of a songbird over the full annual cycle. We used camera traps in the Rammert, a small mountainous forest area near Rottenburg in Southwest Germany to monitor the diurnal activity pattern of forest-dwelling Eurasian blackbirds ( Turdus merula ). As the activity level of animals is known to be affected by day light, we used double-anchoring transformation of day times to account for the variation in sunrise and sunset across the different seasons. By generating activity models, we investigated the pattern of blackbird activity during the four seasons of the year and compared the patterns of male and female birds, respectively. A significant difference between a unimodal activity pattern in spring and a bimodal pattern for the rest of the year was found which might be related to breeding and territorial behaviour in spring. Moreover, we observed that the activity pattern of males and females overlapped greatly but still showed some variation in the number and timing of density peaks.
Using ground oyster mushroom and chia seeds for the fortification of wheat bread-Nelder–Mead simplex optimisation
(2025) Schneider, Yannik; Zettel, Viktoria
Wheat bread was enriched with ground chia and ground oyster mushroom to improve its nutritional properties regarding protein and fibre content within the context of food fortification while maintaining a high specific volume and a soft crumb. A bread made from 100% wheat flour was used as reference. The Nelder–Mead simplex algorithm was used to determine the optimal proportions of chia and oyster mushroom substitution in the recipe. Bread quality was analysed and rated. Chia has a positive effect on the baking result due to its water-binding capacity, while mushrooms have a rather negative effect caused by the enzymes they contain. It was possible to replace 1.6% of wheat flour with ground oyster mushroom and 1.2% chia without any deviations from the control within 7 steps Furthermore, the partially substituted breads showed 3.8% lower contents of carbohydrates with a reduction of 4.1% of total sugar and higher contents of dietary fibre and protein, 22.7% and 2.3% respectively in comparison with the control sample. The wheat flour in bread can be replaced by chia flour and ground oyster mushrooms in small quantities without compromising the quality of the bread while improving some nutritional values.
Process development for spray drying of aroma rich herbs and spices : challenges, strategies and experimental results
(2025) Heimbach, Julia; Kohlus, Reinhard
Conventional air drying of herbs and spices is associated with a loss of quality due to degradation reactions that occur during the process. Spray drying was introduced to the processing of herbs and spices to evaluate the suitability of this method in an attempt to create a dried product of improved quality. Basil and ginger were used as model systems. Different options for the conversion of the frozen raw material into an atomisable feed liquid were reviewed. For basil, milling with a mincer with subsequent particle removal by a screw press gave the best results. Rapid and oxygen-free processing was crucial to prevent the development of bitterness. Ginger was juiced and subjected to a split-stream process, where the ginger fibres were dried and milled separately before being reintroduced to the juice as drying aid to prevent stickiness. The resulting feed material was dried in a pilot plant spray dryer and the effect of process parameters on volatile retention was investigated. Increasing air inlet temperature and decreasing air outlet temperature enhanced essential oil retention for both systems. In addition, large particle sizes and short residence times improved retention when drying basil. The dry matter content of the feed material was identified as key factor for volatile retention in all systems studied. Additional approaches to improve volatile retention were explored using a maltodextrin-linalool model system. The aim was to reduce the volatile partial pressure gradient between the atmosphere and the droplet in order to reduce volatile transition. While the use of zeolite for selective dehumidification and volatile enrichment did not show the desired effect, elevating the condenser temperature and increasing linalool loading of the feed proved to be effective. A relationship was found between volatile organic compound content in the atmosphere and volatile retention in the powder. The experimental results obtained were used to assess the accuracy of a retention prediction model based on the selective diffusion theory. Good estimates were obtained for linalool- and methanol-maltodextrin systems. The linalool model was transferred to basil material to test the prediction quality in a highly heterogeneous food material, which was successfully represented. Analysis of the influence of process parameters on the retention model emphasized the significance of particle size in maximising retention. This work highlights the challenges of processing and spray drying aromatic herbs and spices. While the process without carrier it is not an alternative to conventional drying, the addition of encapsulation material significantly improves the result.
Effect of cutting set variations on structural and functional properties of hamburgers
(2024) Berger, Lisa M.; Adam, Felix; Gibis, Monika; Witte, Franziska; Terjung, Nino; Weiss, Jochen
Meat grinders are composed of a combination of individual functional elements (e.g., screw conveyor, perforated plates, knives). This setup, and in particular the chosen cutting set, influences the characteristics of ground meat and hamburgers produced. In this study, we took a closer look at the effect of cutting set variations and process parameters on structural, functional, and physicochemical properties of beef hamburgers produced. It was found that the specific mechanical energy input during grinding increased when cutting levels, i.e., a set of one hole plate and one knife, were increased, causing more cell disintegration ( r = 0.387, p = 0.02). Surprisingly though, an influence on the functional and quality parameters of the hamburgers could not be found for most parameters tested. The findings indicate that variations in the cutting set affect the process parameters and the stress applied to the meat, but residence times in this zone are too small to cause noticeable effects on the analytical and qualitative properties of hamburgers. As such, there are options for energy and cost optimization of industrial grinding processes without sacrificing quality.
Decoding the aroma of Jägermeister liqueur through sensory-directed flavor analysis combined with solvent-assisted flavor evaporation and headspace-stir bar sorptive extraction
(2025) Zhu, Lin; Lin, Zexin; Zheng, Yan; Liang, Jiaqi; Li, Yupan; Kramp, Sarah; Zhang, Youfeng; Xiang, Can; Chen, Leyin; Rigling, Marina; Hannemann, Lea; Oellig, Claudia; Zhang, Yanyan
Jägermeister liqueur is one of the most famous herbal liqueurs worldwide, distinguished by its unique anise-like, bitter, and caramel-like flavor. This study comprehensively analyzed its aroma components using sensory-directed flavor analysis combined with gas chromatography-mass spectrometry and gas chromatography-sulfur chemiluminescence detector. Results identified eugenol (clove-like, OAV = 1260), anethole (anise-like, OAV = 723), p-anisaldehyde (almond-like, OAV = 97), linalool (flowery, OAV = 25), and terpinen-4-ol (apple-like, OAV = 119) as key aroma-active compounds in Jägermeister. Two sulfur-containing compounds with meaty and caramel-like aromas were detected; however, their OAVs were below 1. Ethers (53.2 mg/L), phenolics (27.8 mg/L), and terpenoids (10.5 mg/L) were the most abundant compounds in Jägermeister, while esters were present at relatively low concentrations (254 μg/L). A comparative analysis revealed that Jägermeister exhibits a unique aroma profile among ten European herbal liqueurs, particularly enriched in caramel-like and licorice-like notes, which showed positive correlations with key aroma compounds such as vanillin. This work not only provides the first systematic aroma deconstruction of Jägermeister, but also offers new insights into the compositional patterns and classification of European herbal liqueurs, contributing to quality control, product authentication, and flavor optimization.
Food fermentation: an essential unit operation towards secure, sustainable, safe, and sustaining food systems
(2025) Gänzle, Michael G.; Seifert, Jana; Weiss, Jochen; Zijlstra, Ruurd T.
Glucoselipid biosurfactant biosynthesis operon of Rouxiella badensis DSM 100043T: screening, identification, and heterologous expression in Escherichia coli
(2025) Harahap, Andre Fahriz Perdana; Treinen, Chantal; Van Zyl, Leonardo Joaquim; Williams, Wesley Trevor; Conrad, Jürgen; Pfannstiel, Jens; Klaiber, Iris; Grether, Jakob; Hiller, Eric; Vahidinasab, Maliheh; Perino, Elvio Henrique Benatto; Lilge, Lars; Burger, Anita; Trindade, Marla; Hausmann, Rudolf; Seo, Myung-Ji
Rouxiella badensis DSM 100043T had been previously proven to produce a novel glucoselipid biosurfactant which has a very low critical micelle concentration (CMC) as well as very good stability against a wide range of pH, temperature, and salinity. In this study, we performed a function-based library screening from a R. badensis DSM 100043T genome library to identify responsible genes for biosynthesis of this glucoselipid. The identified open reading frames (ORFs) were cloned into several constructs in Escherichia coli for gene permutation analysis and the individual products were analyzed using high-performance thin-layer chromatography (HPTLC). Products of interest from positive expression strains were purified and analyzed by liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) and nuclear magnetic resonance (NMR) for further structure elucidation. Function-based screening of 5400 clones led to the identification of an operon containing three ORFs encoding acetyltransferase GlcA (ORF1), acyltransferase GlcB (ORF2), and phosphatase/HAD GlcC (ORF3). E. coli pCAT2, with all three ORFs, resulted in the production of identical R. badensis DSM 100043T glucosedilipid with Glu-C10:0-C12:1 as the main congener. ORF2-deletion strain E. coli pAFP1 primarily produced glucosemonolipids, with Glu-C10:0,3OH and Glu-C12:0 as the major congeners, predominantly esterified at the C-2 position of the glucose moiety. Furthermore, fed-batch bioreactor cultivation of E. coli pCAT2 using glucose as the carbon source yielded a maximum glucosedilipid titer of 2.34 g/L after 25 h of fermentation, which is 55-fold higher than that produced by batch cultivation of R. badensis DSM 100043T in the previous study.
Integrating sensor data, laboratory analysis, and computer vision in machine learning-driven E-Nose systems for predicting tomato shelf life
(2025) Senge, Julia Marie; Kaltenecker, Florian; Krupitzer, Christian
Assessing the quality of fresh produce is essential to ensure a safe and satisfactory product. Methods to monitor the quality of fresh produce exist; however, they are often expensive, time-consuming, and sometimes require the destruction of the sample. Electronic Nose (E-Nose) technology has been established to track the ripeness, spoilage, and quality of fresh produce. Our study developed a freshness monitoring system for tomatoes, combining E-Nose technology with storage condition monitoring, color analysis, and weight-loss tracking. Different post-purchase scenarios were investigated, focusing on the influence of temperature and mechanical damage on shelf life. Support Vector Classifier (SVC) and k-Nearest Neighbor (kNN) were applied to classify storage scenarios and storage days, while Support Vector Regression (SVR) and kNN regression were used for predicting storage days. By using a data fusion approach with Linear Discriminant Analysis (LDA), the SVC achieved an accuracy of 72.91% in predicting storage days and an accuracy of 86.73% in distinguishing between storage scenarios. The kNN yielded the best regression results, with a Mean Absolute Error (MAE) of 0.841 days and a coefficient of determination of 0.867. The results highlight the method’s potential to predict storage scenarios and storage days, providing insight into the product’s remaining shelf life.
Tackling the rich vehicle routing problem with nature-inspired algorithms
(2022) Lesch, Veronika; König, Maximilian; Kounev, Samuel; Stein, Anthony; Krupitzer, Christian
In the last decades, the classical Vehicle Routing Problem (VRP), i.e., assigning a set of orders to vehicles and planning their routes has been intensively researched. As only the assignment of order to vehicles and their routes is already an NP-complete problem, the application of these algorithms in practice often fails to take into account the constraints and restrictions that apply in real-world applications, the so called rich VRP (rVRP) and are limited to single aspects. In this work, we incorporate the main relevant real-world constraints and requirements. We propose a two-stage strategy and a Timeline algorithm for time windows and pause times, and apply a Genetic Algorithm (GA) and Ant Colony Optimization (ACO) individually to the problem to find optimal solutions. Our evaluation of eight different problem instances against four state-of-the-art algorithms shows that our approach handles all given constraints in a reasonable time.
Stability of anthocyanin extracts from chokeberry, grape, hibiscus, and purple sweet potato in ω-3-fatty acid rich oil-in-water emulsions
(2024) Klinger, Evelyn; Salminen, Hanna; Bause, Karola; Weiss, Jochen
The food industry is actively investigating the stability of natural red pigments to replace artificial food colorants from all food applications in the near future. In this study, the stability of coloring extracts from chokeberry, grape, hibiscus, and purple sweet potato was investigated in ω-3 fatty acid-rich flaxseed oil-in-water emulsion during storage. The red color of the oil-in-water emulsions faded within 4 days, indicating that the anthocyanin extracts were susceptible to lipid oxidation reactions of the ω-3 fatty acids. The color stability varied between all used extract sources: The chokeberry (degradation constant k = 19.6 h−1) and grape (k = 15.2 h−1) extracts showed similar degradation kinetics, whereas purple sweet potato extract (k = 10.7 h−1) degraded significantly slower, and hibiscus extract (k = 110.2 h−1) significantly faster. The differences can be explained by the different anthocyanins contained in the plant extract, especially by the proportion of acylated anthocyanins.
Improved prediction of wheat baking quality by three novel approaches involving spectroscopic, rheological and analytical measurements and an optimized baking test
(2025) Ziegler, Denise; Buck, Lukas; Scherf, Katharina Anne; Popper, Lutz; Schaum, Alexander; Hitzmann, Bernd
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 study investigates three novel approaches to improve the prediction of specific loaf volume determined by an optimized mini-baking test. The predictions are based on a large variety of rheological and analytical data as well as fluorescence, near-infrared (NIR) and Raman spectroscopy of flour and flour fractions. Furthermore, the influence of data fusion on the predictions is investigated. All three approaches presented promising results and showed great potential for practical application with R2CV > 0.90 for various regression models. For example, the combination of farinograph data with solvent retention capacity data or NIR flour spectra yielded R2CV of 0.91 in both cases. Combining Raman spectra of the < 32 μm and 75–100 μm fractions as well as NIR spectra of gluten, flour and starch both also yielded R2CV of 0.91. The results underline that loaf volume is a complex quality characteristic that can be better predicted when different data types are combined. Different rheological and analytical tests and different spectroscopic methods capture specific wheat quality characteristics that have different relations to baking volume and can therefore provide complementary information for improved predictions. Furthermore, the importance of rheological tests (especially farinograph, extensograph, alveograph) and the baking procedure for the prediction of baking quality are emphasized.
Fluorescence spectroscopy of flour fractions and dough: analysis of spectral differences and potential to improve wheat quality prediction
(2025) Ziegler, Denise; Buck, Lukas; Scherf, Katharina Anne; Popper, Lutz; Hitzmann, Bernd
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 preprocessing of flour into flour fractions (by air classification, sieving) or dough and subsequent spectroscopic analysis of these types of samples could be a new way to improve wheat quality predictions. For this purpose, spectral differences are investigated and predictions of farinograph parameters are compared for fluorescence spectra of flour, flour fractions, and dough. Findings: A wide variety of fluorophores present in cereal products was identified. Their peak intensities significantly differed for flour, flour fractions, and dough. Flour and sieve fractions were superior in predicting water absorption (R2CV flour = 0.79; R2CV 32–50 µm = 0.81), while gluten and dough samples strongly improved predictions of rheological properties, especially dough development time (R2CV flour = 0.64; R2CV dough = 0.90; R2CV gluten = 0.84). Conclusion: Preprocessing of flour samples greatly alters their composition (e.g., protein enrichment), which is also reflected by spectral differences. Spectra of different sample types therefore contain different information and have the potential to improve the prediction of wheat quality. Significance and Novelty: This is the first study that investigates spectral differences of a large number of different flour fractions and dough using fluorescence spectroscopy and subsequently underlines the potential of this novel approach to improve wheat quality prediction in the future.
Modeling and optimization of bakery production scheduling to minimize makespan and oven idle time
(2023) Babor, Majharulislam; Paquet-Durand, Olivier; Kohlus, Reinhard; Hitzmann, Bernd
AbstractMakespan 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 emissions. This paper investigates three manufacturing lines from small and medium-sized bakeries to find optimum makespan and ovens’ idle time (OIDT). A hybrid no-wait flow shop scheduling model considering the constraints that are most common in bakeries is proposed. To find optimal solutions, non-dominated sorting genetic algorithm (NSGA-II), strength Pareto evolutionary algorithm (SPEA2), generalized differential evolution (GDE3), improved multi-objective particle swarm optimization (OMOPSO), and speed-constrained multi-objective particle swarm optimization (SMPSO) were used. The experimental results show that the shortest makespan does not always imply the lowest OIDT. Even the optimized solutions have up to 231 min of excess OIDT, while the makespan is the shortest. Pareto solutions provide promising trade-offs between makespan and OIDT, with the best-case scenario reducing OIDT by 1348 min while increasing makespan only by 61 min from the minimum possible makespan. NSGA-II outperforms all other algorithms in obtaining a high number of good-quality solutions and a small number of poor-quality solutions, followed by SPEA2 and GDE3. In contrast, OMOPSO and SMPSO deliver the worst solutions, which become pronounced as the problem complexity grows.
Chemical composition and consumer acceptability of oyster mushroom and sorghum-pearl millet based composite flours
(2024) Ndunge Charles, Alice; Mburu, Monica; Njoroge, Daniel; Zettel, Viktoria
Due to over-reliance on starchy staple foods in Kenya Micronutrient deficiency (MD) and Protein Energy Malnutrition (PEM) are the major nutritional concerns. Despite these foods being characterized by low nutrient densities, they are still used as main food ingredient especially in making porridges. Therefore, this study intended to develop composite flour of sorghum-pearl millet blends fortified with oyster mushroom and further evaluate its chemical composition and consumer acceptability. The sorghum and pearl millet were soaked in tap water then solar dried followed by milling into flour. Oyster mushrooms were also solar dried and milled. Subsequently, oyster mushroom was substituted to sorghum-pearl millet blends at 10–50 % to achieve the composite flours. Proximate composition of the samples was determined using standard methods, Inductively Coupled Plasma Optical Emission Spectroscopy and Ultra Performance Liquid Chromatography Ultraviolet Spectroscopy/Mass Spectrometry were used for mineral and vitamin analyses, respectively. In addition, consumer acceptability test was done on thin porridges was also carried out using untrained panelists. Protein content of the composite flours increased from 11.15–19.74 %, and there were significant increases in fiber (2.68–10.66 %) and ash (1.38 % to 5–79 %). Mineral content increased with Ca, P, Na, K, Mg, Zn and Fe as high as 286.25 mg/100 g, 2088.05 mg/100 g, 167.55 mg/100 g, 1833.05 mg/100 g, 136.75 mg/100 g, 4.22 mg/100 g and 9.46 mg/100 g respectively. An improvement of B1, B2, B3, B6 and B9 vitamin contents was also observed. Sensory analysis showed relatively moderate overall acceptance of thin porridges from the composite flours, although the acceptability decreased with the increase in oyster mushroom. Specifically, composite flour with 50% oyster mushroom was rich in most nutrients but it had the lowest scores for the sensory attributes. In conclusion, addition of oyster mushroom increased the overall nutritional composition of local cereal based staple foods an indication of potential solution to PEM and MD.
Flavor-boosting of Phaeodactylum tricornutum by fermentation with edible mushrooms
(2024) Rigling, Marina; Liang, Jiaqi; Entenmann, Isa; Frick, Konstantin; Schmid-Staiger, Ulrike; Xiang, Can; Kopp, Lena; Bischoff, Stephan C.; Zhang, Yanyan
Microalgae are a promising and sustainable source of nutritious food, especially for use in alternatives to fish and seafood. Among them, Phaeodactylum tricornutum (PT) stands out for its potential to revolutionize future diets with its rich nutrient profile and eco-friendly cultivation methods. However, its typically fishy and “brackish water” off-odor has been a significant deterrent. Using 13 basidiomycetes as starter cultures, the dynamic changes in the aroma were studied. To better understand the aroma development during fermentation, odor-active compounds were identified using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry–olfactometry. By submerged fermentation lasting 39 and 51 hours with Pleurotus citrinopileatus (PCI) and Pleurotus eryngii (PER), respectively, the unpalatable odor of PT was transformed into savory and seafood-like aromas, while retaining most of the valuable carotenoids (fucoxanthin and β-carotene were retained at 75 % and 90 %) and fatty acids (eicosapentaenoic acid and docosahexaenoic acid were preserved at 80 % of their initial concentrations). Throughout the fermentation process, key odorants responsible for the algae's initial green, grassy, and unpleasant odor were reduced, while compounds responsible for savory and seafood-like fragrances increased. A series of sulfur compounds, such as dimethyl disulfide, were found to be major contributors to the post-fermentation aroma.

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