Food Structure-Netherlands最新文献

Food structure and addition of encapsulated compounds can impact the gastro-intestinal digestion of food. Flaxseed oil was encapsulated by complex coacervation using soluble pea protein and gum arabic as shell materials, dried by either spray or electrostatic spray drying and incorporated into sourdough dough before baking. Three bread formulations were prepared using spray-dried (B-SD), electrospray-dried coacervates (B-ES) and free ingredients used in the encapsulation (B). The standardised semi-dynamic INFOGEST in vitro digestion method was used. Cumulated protein/free NH₂ release and cumulated free fatty acids (FFA) release were used to assess protein and lipid digestion. Coacervates were resistant to bread preparation since they were visible in B-SD and B-ES. The total release of protein, free NH₂ and FFA by the end of intestinal digestions ranged between 41.58–45.23%, 1.08–1.22 µmol/g protein and 22.26–63.54%, respectively. There were no significant differences between formulations. There was a statistically significant increase (p < 0.5) of about three times in FFA release between the oral and gastric phases. Our findings help to understand the behaviour of coacervates when incorporated into solid food. In this study, the delivery structures did not affect in vitro digestion and may be used to increase the polyunsaturated fatty acid content by 50%.

This study aimed to prepare soybean oil oleogels with glycerol monostearate (GMS) and native surfactin organogelators. The effects of surfactin addition on the properties and microstructure GMS oleogel properties were evaluated. Gelation time, rheological and thermal properties, microscopy, Fourier transform infrared spectra, X-ray diffraction patterns, and oil binding capacity were determined. Results showed that addition of surfactin shortened the gelation time, enhanced hardness, oil binding capacity, apparent viscosity and gel strength, reduced crystals size and melting temperatures, increased crystallization temperature. GMS-surfactin oleogels showed larger mechanical resistance on compression. Hydrogen bonds were the main force for the formation of three-dimension oleogel network. Surfactin addition changed the crystal structure and β and β′ coexisted in oleogels. Oleogels with more stable texture and desirable properties were formed due to the addition of surfactin. Results indicated that surfactin addition could adjust the properties and micro-structure of GMS oleogels.

Lipid oxidation is a major cause of product deterioration in protein stabilised oil-in-water food emulsions. The impact of protein emulsifiers on lipid oxidation and the stability depends on the specific type of protein emulsifiers used and the redox conditions in the emulsion. However, the exact impact of these protein emulsifiers at the oil-water interface on lipid oxidation and the mechanism of lipid-protein co-oxidation are currently unknown. Here, we developed a cryo-correlative light and electron microscopy (cryo-CLEM) platform for co-localising the oxidation of lipids and proteins. For this first implementation of cryo-CLEM for food oxidation studies we optimised specifically the part of cryo-fluorescence microscopy (cryo-FM) by adding parts that prevent fogging on the sample and enable homogeneous laser illumination. We showed that lipid oxidation in food emulsions can be observed at cryogenic temperature using fluorescence imaging of the fluorophore BODIPY 665/676 that we employed earlier as a lipid oxidation sensor at room temperature. Using cryo-transmission electron microscopy (cryo-TEM), we observed that more protein aggregates are found at the droplet interfaces in oxidized emulsions compared to fresh emulsions. Our cryo-CLEM platform paves the way for future cryo-correlative oxidation studies of food emulsions.

This study assessed the changes in processed and natural cheese during heating from 5 to 95 °C, at 2 °C per min, using confocal laser scanning microscopy (CLSM), Raman micro-spectroscopy and rheological analysis. The CLSM images showed that the cheese samples varied in fat droplet size and distribution. CLSM micrographs of processed cheese with lower fat content (<10%) showed no substantial structural changes during heating, which were consistent with the absence of cross-over in temperature rheology sweep curves. Cheese containing starch showed uniformly distributed fat and cohesive protein network, leading to reduced cheese flow. At temperatures > 70 °C, cheeses with a fat content ≥ 25% showed greater coalescence of fat globules, which finally merged into large fat pools. The results of this study demonstrate the potential of dynamic in situ CLSM and rheological analysis for evaluating the changes in cheese matrices during heating. The Raman spectral region corresponding to C-H stretching vibrations (2800–3000 cm^-1) could be used to track fat melting in cheese samples with minimum 10% fat.

Texture profile of meat-analog (MA) based fried food products is a complex structure, and rarely studied subject. MA-based fried products mechanical-texture-profile were considered as “fractal geometry” to characterize their textural properties by employing complex statistical approach namely multifractal analysis (MFA). Wheat and rice flour-based batter systems were used to coat the MA, and were fried (at 180 °C) for 2, 4, and 6 min in canola oil. Instrumental puncture test was employed to get mechanical-texture-profile of MA-based fried products and obtained profile was evaluated by MFA. Results revealed that batter-formulation and frying time (FT) impacts the evolution of textural attributes (hardness, brittleness, crispiness), moisture-fat profile and microstructural properties of MA-based coated fried product. The MFA outcomes (Singularity spectra & Rényi spectra) depicts that breakage structure (force distribution) of studied MA-based fried products are non-homogeneous and possesses multifractal scaling behavior. Higher heterogeneity of force distribution is observed in lower concentration of force at outer-crust region compared to inner-core region of coated MA. Heterogeneity of force distribution are positively correlated with FT. Batter-formulation showed substantial impact on texture-profile of MA-based coated fried products and consequently influenced the obtained multifractal parameters. Principal component analysis (PCA) reveals varying extent of correlation between moisture-fat, textural attribute, microporosity and selected multifractal parameters (Δα, Δfα, R-L, ΔD) of fried MA.

Industrial relevance

Complex structural pattern of batter coated fried meat-analog (MA)s mechanical texture profile have been successfully and statistically characterized by employing multifractal analysis. This study unraveled the interdependencies among batter-formulation, frying process, mass-profile, microstructure, textural attributes and multifractal parameters. Findings of this study could be used to customize textural attributes of the low fat-containing fried foods. Overall, this work will serve as a ground for designing the production process of emerging MA-based batter-coated fried product.

Buckwheat flour is a pseudocereal that can be used to improve the nutritional value of staple food, such as bread. However, substituting wheat flour can be challenging due to potential loss of the final product's technological quality. Therefore, understanding the influence of buckwheat inclusion level on dough rheology and bread quality is essential. This study evaluated the effect of wheat flour substituted by buckwheat flour on dough rheology and bread quality over the staling process. Wheat flour was replaced by 0%, 10%, 20% and 30% of buckwheat flour and the resulting dough mixing properties, viscosity profile, gel texture, rheology behaviour and extensibility properties were analysed. Internal bread structure (C-Cell and confocal microscopy), specific volume, density and crumb texture profile were also assessed. The increase in buckwheat level gradually decreased flour water absorption (p < 0.05), dough stability and development time, with increased gluten weakening as evidenced by decreased C2 values (protein strength) of Mixolab. As a result, the dough was less resistant to extension, with decreased extensibility. The highest viscosity profile of the starch paste was observed with 30% buckwheat inclusion level, which may lead to faster bread staling process. A solid-like and elastic behaviour was observed in the rheology evaluation, suggesting an interaction between fibre and starch from buckwheat with gluten proteins. Although changes in dough rheology occurred, the bread quality remained unchanged at levels of up to 20% buckwheat level (p > 0.05), with similar specific volume, density, internal structure and texture profile compared to the control bread (0% buckwheat). In conclusion, buckwheat was found to be a viable wheat flour substitute with only minimal changes in dough behaviour and maintenance of bread technological quality, while enhancing the nutritional profile by increasing fibre content and total essential amino acid.

Hybrid cell-based meats consisting of in vitro cultured animal cells within non-animal protein matrices pose a challenge in achieving sensory equivalence to conventional meats. The relationship between food matrix structure and functionality is crucial for designing desirable hybrid cell-based meats. Understanding individual food matrices and their interactions is crucial for achieving desired organoleptic properties in hybrid cell-based food systems. This work critically reviews current techniques used to study multiscale food matrix structures in animal-origin meats and plant-based meats and considers their application in the engineering of hybrid cell-based meat food matrices. Currently, research focusses on cell-line development, media composition, tissue functionality, and food matrix properties of scaffolds, hydrogels, and non-animal derived proteins to use in hybrid cell-based meat products. However, the interactions between plant-protein and animal-origin cells within hybrid cell-based meats have not been studied but are key to forming novel overall food matrices. We will need to adapt techniques from adjacent fields to characterise and achieve sensory equivalence of animal-origin meat products. This review aims to serve as a guide for current and emerging techniques being used to study the food matrix structure of hybrid foods to improve their organoleptic properties and mimic animal-origin meats.

The purpose of this study was to reveal the mechanism of the improvement of SPI emulsifying properties after complexation with NL. The binding between NL and SPI led to a static fluorescence quenching of SPI and the significant change of SPI FTIR spectra. It indicated that the advanced structure of SPI after interaction with NL was altered appreciably. Moreover, it was observed that the free sulfhydryl content, contact angle, particle size, zeta potential, and surface hydrophobicity of SPI after complexation increased, and the interfacial tension reduced. Hydrophobic forces and hydrogen bonds played a vital part in the interaction between NL and SPI. Furthermore, the emulsifying properties of SPI were significantly improved after complexation with NL. Emulsifying activity index (EAI) and emulsifying stability index (ESI) of SPI increased from 50.52 to 104.28 m²/g and from 17.30 to 25.10 min with the NL-to-SPI mass ratio increasing from 0:1–1:1, respectively. Meanwhile, the emulsifying properties of NL-SPI (the NL-to-SPI mass ratio at 1:1) were also influenced by environmental factors (pH, temperature, and ionic strength). The improvement of the emulsifying properties of SPI after interaction with NL derived from the alteration of advanced structure and surface characteristics of NL-SPI complexes.

Exopolysaccharides (EPS) are commonly used to improve the texture of yogurt. These polysaccharides interact with casein micelles, the major protein in milk, via electrostatic and depletion mechanisms during fermentation by lactic acid bacteria (LAB). However, the relationship between the physicochemical properties and monosaccharide composition of EPS and their impact on yogurt texture is not yet fully understood. To address this knowledge gap, we studied the effects of polysaccharides commonly used as food additives on acid-induced milk protein networks. Confocal laser scanning microscopy (CLSM) was used to image the network microstructures. Image analysis, including Fourier transform, autocorrelation, and binarization-based techniques, was applied to quantify key structural features of the mixed milk protein/polysaccharide gels. These parameters were then related to the macroscopic properties of the model food matrices, such as elastic and viscous moduli and yield point. We found that the addition of neutral polysaccharides resulted in a concentration-dependent increase in structure factor, protein domain size, and pore fraction. In contrast, the presence of charged polysaccharides led to an increase in protein domain size, a decrease in pore fraction, and a decrease in elastic and viscous moduli. These results demonstrate the use of a quantitative image analysis method for selecting LAB with favorable EPS properties to improve yogurt texture.