Commercial pea protein isolates tend to form weak, heat-induced gels, limiting their application in solid plant-based dairy alternatives. Enzymatic cross-linking with microbial transglutaminase (mTGase) is a promising approach to improve gelation. However, its efficiency depends on the balance between protein unfolding and aggregation. Partial denaturation exposes reactive sites, while excessive aggregation reduces solubility and enzyme accessibility. This study investigated how the interplay between protein solubility, aggregation state and particle size governs mTGase-induced cross-linking and gel properties of high-protein pea emulsions. Two commercial protein isolates, B9 and HV, were separated into water soluble (supernatant) and insoluble (sediment) fractions, freeze-dried, and characterized. Emulsion gels containing 15% (w/w) protein powder and 10% (w/w) oil were prepared with (10 U/g) or without mTGase. Gelation behavior and cross-linking at the molecular scale were assessed using oscillatory rheology and SDS-PAGE. Highly soluble proteins with small particle sizes and a higher abundance of low-molecular-weight fractions (B9 supernatant) showed the highest gelation rate and formed stiff, elastic, and strong gels with a tough texture. In contrast, poorly soluble, aggregated proteins (isolates and sediment fractions) showed little rheological improvement after mTGase treatment. Using the difference in complex modulus between mTGase-treated and reference samples (Delta G*) enabled separation of enzymatic from non-enzymatic stiffening and provided a kinetic measure of cross-linking efficiency. SDS-PAGE revealed that all samples contained suitable mTGase substrates (globulins >= 35 kDa), which disappeared after mTGase treatment, confirming that cross-linking occurred at the molecular scale. In conclusion, solubility and particle size should be considered or tailored when developing plant-based foods using mTGase.

Curcumin (CUR) is a bioactive polyphenol with significant health potential; however, its use in food systems is limited by poor aqueous solubility. Hetero-protein aggregation offers a promising encapsulation strategy; however, its performance is highly dependent on formulation conditions. Here, an experimental screening approach was used to evaluate the effects of pH (4-10), whey protein isolate (WPI): lysozyme (LYS) ratio (3:1-1:3), and CUR concentration (905-54 mu M) on the formation and encapsulation performance of WPI-LYS hetero-protein aggregates. The screening identified pH, protein ratio, and CUR loading as interdependent drivers of aggregation behaviour, surface charge, particle size, crystallinity, and encapsulation efficiency. Maximum encapsulation efficiency (97.56 +/- 0.50%) was achieved at pH 7, 494 mu M, and a WPI: LYS ratio of 1:1.5; however, structural analyses revealed that high CUR loadings resulted in residual crystallinity despite the high apparent encapsulation efficiency. In contrast, lower CUR loading (106 mu M; 1:50 CUR: protein) produced amorphous hetero-protein aggregates with high encapsulation efficiency and improved structural homogeneity. Spectroscopic evidence indicates that, in the ternary WPI-CUR-LYS system, CUR is stabilised within a reorganised protein network through localised hydrophobic interactions and hydrogen bonding. In contrast, single-protein systems rely on less restrictive associations. Overall, WPI-LYS hetero-protein aggregates outperformed singleprotein systems, demonstrating that reliable CUR encapsulation cannot be inferred from encapsulation efficiency alone. This work highlights the critical role of systematic screening in establishing formulation-dependent design rules for hetero-protein-based delivery systems in food applications.

The objective was to prepare fibers from an aqueous solution of maltodextrin DE2 (MD) and lysozyme (LYS) by needleless electrospinning and their characteristic morphological properties were investigated. The different conditions were 80, 85, or 90 g MD and 5, 10, 15, 20, or 25 g LYS plus 100 g of ultrapure water. The electrospinning rate and yield, the protein concentrations in the spinning solution and fibers, and the fiber diameter were determined by scanning electron microscopy (SEM). The highest spinning rate was observed in spinning solution using 80 g MD and 20 g LYS (80-20) with 7.6 f 0.03 g/h. The lowest spinning rate was 1.93 f 0.01 g/h for 80-15 (MD/LYS). The determination of the protein content in the spinning solution and in the fibers showed that there is a difference between fibers and solutions. The difference between the protein concentration in the solution to the fibers ranged from 7.9 % to 13.5 % (80-10, 85-10 and 90-10) from 13.7 % to 11.8 % (80-25, 85-25 and 90-25). The SEM images showed that the blend (85-10) had the smallest diameter of 3.63 f 1.18 mu m, while the blend (90-25) had the largest diameter of 5.95 f 4.03 mu m. The fibers with the highest protein content (80-25, 85-25, and 90-25) had larger diameters than the fibers with the lowest protein content (80-5, 85-5, and 90-5). The structure and surface of the fibers were mostly smooth, with occasional bead formation and thicker or thinner areas within a fiber. FTIR analysis showed no further chemical reaction between MD and LYS in the fibers.

The influence of low oxygen concentrations on the development of color and the myoglobin redox states over storage time was analyzed, to determine whether there are conditions that increase discoloration. Beef slices were packaged in atmospheres containing nitrogen gas and 0 %, 0.5 %, 1 %, 1.5 %, 3 %, and 5 % of oxygen. The samples were stored at 2 degrees C for 14 days. During storage, color, reflectance and oxygen concentration were measured optically through the packaging. The color difference Delta E-2000 and the relative oxymyoglobin (OMb), deoxymyoglobin (DMb), and metmyoglobin (MMb) levels were calculated. After 14 days, the oxygen concentrations changed to 0.09 % (0 %), 0.36 % (0.5 %), 0.92 % (1 %), 1.28 % (1.5 %) 2.55 % (3 %), and 4.29 % (5 %). Regarding MMb formation, the 0 % samples (Delta MMb(0-14d) 11.1 %) were significantly (p < 0.05) more stable compared to the other samples, which showed an increase of MMb formation with rising oxygen concentration after 14 days. The other samples reached a Delta MMb(0-14d) increase of 21.1 % (0.5 %), 26.7 % (1 %), 30.0 % (1.5 %), 31.1 % (3 %), and 34.4 % (5 %). The color stability showed significantly (p < 0.05) increasing Delta E values of 2.49 (0 %), 3.39 (0.5 %), 4.66 (1 %), 5.14 (1.5 %), 6.03 (3 %), and 7.34 (5 %) with rising oxygen contents. These findings suggest that to ensure the color stability of beef with minimal MMb formation, it is important to completely exclude oxygen from the packages, since the destabilizing effect of oxygen already started at 0.5 %. The non-invasive measurement of the oxygen concentration and the reflectance data over 14 days gave new insights into the discoloration process of beef stored in low-oxygen atmospheres.

Hybrid patties produced by partially replacing beef with plant proteins represent a promising strategy to reduce meat consumption while maintaining the functional attributes of conventional meat products. Because consumer acceptance is strongly influenced by texture, it is critical to evaluate how such substitutions alter product appearance and structural integrity. However, the structural basis of texture changes remains poorly understood when beef is replaced with complex, multicomponent plant systems rather than single plant proteins. This study investigated how a soy‐based, multicomponent meat analog influences the texture, microstructure, and gelation behavior of beef burger patties across the full substitution range. Beef was replaced at 0%, 25%, 50%, 75%, and 100% with a mixture containing isolated and texturized soy proteins, wheat gluten, coconut oil, canola oil, and methylcellulose. Increasing the level of substitution progressively reduced hardness, cohesiveness, gumminess, chewiness, and shear force, although hardness was maintained at 25% replacement. Cooking losses were similar across all formulations, whereas the diameter shrinkage and thickness increase during cooking were more pronounced in patties with higher beef contents. Microstructural analysis revealed a less compact, coarser matrix with fewer interactions between meat and plant proteins as substitution increased, contributing to the observed textural changes. Rheological measurements showed decreasing storage moduli ( G ’) and a shift in network formation to higher temperatures with lower beef content, indicating weaker gel structures. Collectively, these results demonstrate that the textural limitations of soy‐based hybrid patties stem from a disrupted, weakly cross‐linked protein network. By resolving texture–structure relationships across the complete 0%–100% substitution range for a complex, multicomponent analog, this work provides a mechanistic foundation for targeted formulation strategies and the optimization of hybrid meat products.

This study investigates the influence of wood type on the pyrolysis behavior, sensory properties, and texture of Vienna sausages. Two hardwoods, beech and oak, and one softwood, alder, were used for smoke generation. Analyses of the ember bed temperature showed that alder exhibited higher temperatures due to its terpene content and lower density. Smoke color evaluation revealed minimal visual differences with AE2000 values below 3.0, suggesting that the changes were not easily perceptible to the human eye. Texture analysis revealed no significant influence of wood species on initial bite or casing tensile strength. Sensory evaluation revealed significant differences in sensory properties between samples, but no consistent preference for a particular wood species, with differences decreasing during the 28-day storage period. The results demonstrate the complexity of the smoking process and the need to consider multiple factors when optimizing it.

Abstract Natural waxes are functional ingredients in food, pharmaceutical, and cosmetic products, yet their crystallographic investigations remain superficial. This study characterized sunflower (SFX), candelilla (CLX), carnauba (CRX), rice bran (RBX), yellow beeswax (BYX), and white beeswax (BWX), each from two suppliers, focusing on crystal structure. Supplier differences were minor except in color. Scanning electron microscopy revealed platelet-like morphologies in all samples, with SFX and RBX showing the smallest particle sizes. X-ray diffraction distinguished highly ordered lamellar structures in SFX and RBX from less ordered layering in the other waxes. All waxes shared short spacings consistent with a perpendicular orthorhombic subcell, while beeswaxes indicated a parallel orthorhombic subcell. Crystallite anisotropy, quantified across samples, decreased in the order BYX > BWX > RBX > CRX > SFX > CLX. Melting and crystallization temperatures also varied by wax type. A schematic hierarchy of natural wax structures is proposed to guide future applications and research.

In the production of plant-based meat alternatives, texturized vegetable proteins (TVP) are a popular choice as base ingredients. However, these can have undesired off-flavors, which negatively affects consumer experience. Examples are distinctive green, and beany notes as well as a lack of desired meat flavor. This can be counteracted by using microbial fermentation as a processing step, with the potential to reduce off-flavors and create new odor-active compounds. Therefore, pea protein texturates produced via high-moisture (HMPT) and low-moisture (LMPT) extrusion cooking were fermented for 4 weeks at 15 °C, using Staphylococcus carnosus and Kluyveromyces marxianus in otherwise sterile microaerophile conditions. Microbial and metabolic activity were assessed, aroma profiles were determined by headspace solid-phase microextraction-gas chromatography-mass spectrometry-olfactometry (HS-SPME-GC-MS-O), key odor-active compounds were identified and relative peak areas of these compounds compared. High viable cell counts (cfu/g) were documented over the course of 4 weeks. Assessment of metabolic activity revealed increased tyrosine levels in LMPT compared to HMPT samples. Similarly, 53 (LMPT) and 41 (HMPT) perceivable odor-active compounds were identified prior to fermentation in the TVP samples. Of these, 17 compounds were identified as commonly known key off-odors in pea proteins which were significantly reduced throughout the fermentation. S. carnosus led to more characteristic final odor profiles, with desirable and undesirable flavors depending on the raw material. K. marxianus led to reduction beyond perceivability of several odor-active compounds, causing less intense odor profiles.

Abstract Intrinsic factors of vacuum-packaged, discolored beef samples found in the early stages of wet aging at the slaughterhouse were measured and compared to a control group. The aim was to identify possible differences in intrinsic factors that could explain the discolorations. L *, a *, b * values, and myoglobin redox state levels were measured to characterize the extent of discoloration and the oxidation state of myoglobin. pH value, redox potential, total reducing activity, and the concentrations of lactate, α -tocopherol, β -carotene, and NAD + /NADH were analyzed to identify differences. Significant ( p < 0.05) differences and correlations were observed in color values and myoglobin redox states between the control and discolored samples, e.g., a * = 11.21 (control) and 9.42 (discolored); metmyoglobin = 0.79 (control) and 1.01 (discolored). Except for directly color-related parameters, only a significant difference in lactate concentration was observed (3.90 mg/g (control) and 5.60 mg/g (discolored) without a significant change in pH [5.60 (control) and 5.61 (discolored)]. Since lactate is reported to stabilize the color of meat rather than causing discoloration, the cause of the discoloration might be attributed to a multifactorial interaction of intrinsic parameters, or extrinsic parameters during the slaughtering, deboning, cutting, and packaging process. Although the cause of the discoloration could not be identified, this study displays important data on the interactions between intrinsic parameters. Therefore, this study can be considered an exploratory investigation that lays the foundation for further research to identify the causes of discoloration.

The influence of incomplete evacuation in vacuum packages on the color stability of beef was investigated. Silverside (M. semitendinosus, M. gluteobiceps, and M. gastrocnemius) slices were vacuum packaged with 15, 60, 125, 250, 500, and 750 mbar residual pressure and stored at 2 degrees C for 14 days. L*a*b*-values, myoglobin redox states, and oxygen concentration were measured non-invasively over the storage period of 14 days. After 14 days of storage, the alpha-tocopherol, (1-carotene, and retinol contents were measured. An increase in residual pressure resulted in an increase in oxygen concentration in the packages. The increased oxygen concentration led to oxidative processes in the form of metmyoglobin (MMb) formation, a decrease of the contents of alpha-tocopherol and (1-carotene, and visible discolorations after 14 days of storage, that increased in severity with the residual pressure. E.g. on day 14, the oxygen concentrations were 0.02% (15 mbar) and 12.49% (750 mbar), the MMb levels 0.71 (15 mbar) and 1.11 (750 mbar), the alpha-tocopherol content 4.34 & micro;g/g (15 mbar) and 3.36 & micro;g/g (750 mbar), and the (1-carotene content 0.66 & micro;g/g (15 mbar) and 0.14 & micro;g/g (750 mbar). The results showed that an incomplete evacuation of the vacuum packages led to air pockets which resulted in discoloration. Non-invasive measurements of the packaging during the storage period, combined with measurements of antioxidants, provided detailed insights into the discoloration mechanisms of the beef samples and the development of oxygen concentration in the air pockets.

In this study, two air classified, protein-enriched lentil flour fractions with different starch content (0 %, 12.1 %) were used to investigate the influence of heat treatment on the structure of 60 wt% O/W emulsions and interfacial layer properties. Therefore, mixtures of different ratios of native and heated samples of these fractions were compared, showing that at high ratios (>80 %) of heated sample, gelatinized starch altered the adsorption kinetics of the interfacial layer. The strain resilience of the interfacial layer was determined by the protein's state and was decreased by a factor of 5-6 by heat treatment, while starch had a neglectable influence. Structure and rheology of the emulsions were significantly altered by starch content at high ratios of heated sample. Gelatinized starch increased the power law consistency coefficient K from 100 to more than 250, and oil droplet diameter (d43) from 15 to 35 mu m in emulsions of heat-treated samples. Overall, the thermal treatment of dry fractionated lentil flour had a significant influence on functionality, which was more pronounced at higher amounts of non-protein components. Thus, when selecting a specific degree of refinement of air classified legume flour, the impact of subsequent thermal processes on functionality should be considered.

In this study, two air classified lentil protein concentrates (LPC) of different purities (43 and 54% protein) were separated into their soluble and insoluble fraction, which altered their basic composition, protein solubility profile, and amino acid composition. Proteomic analysis showed a shift in protein composition towards higher proportions of albumin and vicilin in the soluble fractions and increased proportions of legumin, glutelin and prolamin in the insoluble fractions. Interfacial shear rheology was used to compare the interfacial adsorption behavior and interfacial layer cohesiveness of LPC and its soluble and insoluble fractions at different pH (3.0, 5.0, 7.0). A viscoelastic, gel-like interfacial layer formed within seconds to minutes in all samples and pH values. The presence of insoluble components coupled with electrostatic repulsive forces resulted in thin (Gi': 0.1-5.8 mPa m), but cohesive interfacial layers with interfacial crossover strains (ICS) in the range of 65-169%, while the insoluble fractions formed comparatively fragile interfaciallayers (ICS: 7-19%) in absence of electrostatic repulsion. In contrast, the soluble fractions formed strong and cohesive interfacial layers (Gi': 10-24 mPa m, ICS: 73-226%) at all investigated pH values, showing that the soluble components were crucial for maintaining elasticity and interfacial layer cohesiveness near the isoelectric point. The study demonstrated that the aqueous extraction at native pH of soluble and insoluble fractions from dry-fractionated LPC is suited to modify the protein composition and interfacial properties in a way that might alter the stability of colloidal systems under varying pH conditions.

This study screened ten different commercial pea protein isolates in terms of composition including protein-, fat-, dry matter-, ash-, and sodium chloride content, color, molecular weight distribution, as well as functionality in aqueous suspension including solubility, native pH, water/oil holding capacity, and zeta potential. While composition did not differ strongly between the different protein isolates, excluding minor differences in protein and ash content, functionality did. Aqueous solubility ranged from 9.24% to 40.74%, native pH between 5.50 and 8.15, and water holding capacities between 2.52 g/g and 5.19 g/g. In addition, the oil holding capacity was also the lowest for the batch with the lowest water holding capacity with 1.33 g/g and the highest for the one with the highest water holding capacity with 2.21 g/g. A classification of solubility of commercial pea protein isolates was proposed with classes low (<10%), medium (similar to 20-25%) and high (>35%). Predictions regarding colloidal stability were possible due to the analysis of surface charge over a pH range of around 2.5 to 8, including the determination of the isoelectric points of the individual pea protein products. Here, differences were found between pH 3.43 and 4.76. An SDS-PAGE analysis was used to fractionate the main protein components and to determine the constituents in comparison with a standard marker. Taken together, this study showed that different pea protein isolates exhibited different physico-chemical properties, and that a selection for food product development based on the parameters such as solubility, zeta potential behavior, native pH, and water/oil holding capacity is advisable.

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.

Lipids are key compounds in foods and provide energy and nutrients to the body. They are carriers of aroma and flavor compounds and contribute to structure and texture. Nutritional research has shown that positive effects on human health are derived from the intake of specific lipids. Similarly, food science research has shown that food matrix design benefits from having tailored lipid fractions with specific functions such as melting profiles, crystal structures, and oil-binding capacities. Minor constituents such as polar lipids or waxes also have valuable functional properties such as the ability to stabilize interfaces, facilitate spreadability, provide barriers, or act as organogelators. Coupled with the emergence of new feedstocks such as new plants, microbes, or insects, this has fueled a renewed interest in designing efficient, effective, and environmentally friendly processes to extract and fractionate lipids from feedstocks. Such precision-processing approaches are intended to yield not just bulk oils and fats but also specialty lipids with tailored properties. In this review article, we discuss the extraction and fractionation approaches used to obtain lipid fractions from plants, animals, or microbial fermentation, discuss their properties and functionalities, and highlight process design approaches, with a focus on sustainable extraction technologies. Recent advances in the three main steps in obtaining food lipids are highlighted: (a) crude oil manufacture; (b) refinement; and (c) fractionization. Finally, two case studies of specialty ingredients derived from such precision-processing approaches are presented.

The influence of a 1% oxygen atmosphere on the color stability of modified atmosphere packaged beef was investigated. Beef silverside slices were packed under 1%, 20%, and 70% oxygen atmospheres and stored at 2 °C for 14 days. Color and reflection data were measured non-invasively. The L*a*b* values were analyzed, the color difference ΔE2000, and the levels of myoglobin (Mb), deoxy-(DMb), oxy-(OMb), and metmyoglobin (MMb) were calculated. The 1% oxygen atmosphere resulted in a rapid MMb formation from 0.63 (day 0) to 1.27 (day 8) (p < 0.05). The other samples showed slight increases from 0.65 to 0.80 MMb (20%) and 0.65 to 0.79 MMb (70%). On day 10, the 20% oxygen sample showed an increased MMb formation (1.33 MMb). The 70% atmosphere resulted in a final value of 0.91 MMb after 14 days. These results show that an oxygen content of 1% accelerates the formation of MMb at an early stage. A higher oxygen content in the packaging delays MMb development through OMb formation, which masks MMb creation, to a certain extent. Measuring the packaged meat pieces over a 14-day storage period provides detailed insights into the development of Mb formation and critical points during storage.

The complexes of phycocyanin and pectin have received attention as a solution for stabilizing the rare, naturally blue-occurring pigment. Challenging are acidic conditions, in which the phycobiliprotein is at risk of denaturation. Structural features of these complexes are key to their colloidal stability, and understanding their formation is essential to prevent precipitation. However, effects of pH and polysaccharide properties on the size and structure of these complexes remain poorly understood. This study explores the interaction between phycocyanin and pectins with varying degrees of esterification (8.9-60%) at pH 3-6, using a 1:2 mixing ratio. Analyses included high-pressure size exclusion chromatography (HPSEC), dynamic and static light scattering (DLS, SLS), microscopy, and rheological voluminosity measurements. Confocal laser scanning microscopy revealed that pectin forms a sheath around the phycocyanin-rich core. At acidic pH, low-DE pectin promotes aggregation through pectin bridging, forming large (>10 mu m), dense complexes (54.19 mL g(-1)) caused by reduced steric hindrance and minimal electrostatic repulsion. In contrast, high-DE pectin forms smaller (<1 mu m) and less dense complexes (145.10 mL g(-1)), attributed to a predominance of associative forces over repulsive interactions. High- DE pectin appears to be especially effective in preventing precipitation at acidic pH, forming compact yet voluminous complexes that remain soluble. Overall, this study provides novel insights into the structural formation and evaluation of phycocyanin:pectin complexes. By outlining strategies for tailoring complexes over a wide pH range and by varying the type of pectin it is relevant to food and beverage applications, with potential extensions to the pharmaceutical and cosmetic industries.

Ground meat and ground meat products are very popular meat products that are usually made from beef or beef portions and are often sold directly to the end consumer or used as an intermediate product in industrial meat product production. To ensure consistent product quality, knowledge of the relationship between process, structure and functionality is crucial. These have not yet been systematically investigated, which is why there is a lack of fundamental scientific knowledge in this area. The aim of this study was to determine the influence of increasing mixing times (0.5, 3, 6, 9, 12 and 15 min) and fat contents (15.10%, 18.49%, 22.4% fat) of the beef on the structure and functionality of hamburgers. It was hypothesized that longer mixing times would introduce more energy, exposing the muscle cells to higher mechanical stress, which would lead to increased disintegration. In addition, higher fat contents of the raw material would led to a softer material with lower cutting resistance. This would lead to an uneven cutting pattern and a higher degree of non-intact cells. The chemical composition of the raw material, the structure, the cooking and drip loss, the texture and the visual and sensory properties of the hamburgers were investigated. The results only partially confirm the original hypothesis and show that both the mixing process step and the fat content of the hamburgers have only a minor influence on the structure, functional and sensory properties. The process step of grinding and the influence of the processing temperature proved to be decisive for structural changes in the ground meat.