Food Structure-Netherlands最新文献

The role of cell wall permeability and rate of starch digestibility in intact cotyledon cells from four different varieties of pea seeds was studied. Pulsed-field gradient nuclear magnetic resonance (PFG NMR) coupled with light and confocal microscopy were employed to evaluate the cotyledon cells' diffusion coefficients and cell wall permeability. The cotyledon cells' diffusion coefficients and cell wall permeability followed a decreasing trend: White/yellow pea > Marrowfat pea > Maple pea > Blue pea. The varying size of internal cavities in the microstructure in the cotyledon cells, as observed by the light and confocal micrographs, may be responsible for this trend. The extent of starch hydrolysis recorded from the cotyledon cells followed the same trend of the cell wall permeability except for Blue pea cotyledon cells. Thus, indicating that the more permeable the cotyledon cell to the starch-degrading enzymes, the higher the extent of intracellular starch hydrolysis. The microstructure changes in the cotyledon cells during digestion also confirmed this observation.

Soybean lipophilic protein (SLP), which comprises approximately 10 % polar lipids (especially phosphatidylcholine (PC)) in glycinin (11S) and β-conglycinin (7S), is a potentially effective delivery for nutraceuticals. Herein, we successfully engineered a stable spherical soybean lipophilic protein nanogel through a pH−shift treatment at its isoelectric point, designed for the efficient delivery of curcumin (Cur) to enhance its bioavailability. The analysis of the physicochemical and structural properties of the SLP−nanogel revealed its exceptional encapsulation efficiency, achieving 93.52 %, surpassing that of soybean isolated protein at 83.67 %. Moreover, the loading ability experienced a remarkable 8.7−fold increase, reaching 13.02 μg/mg. Fluorescence kinetics analysis reveals that Cur selectively binds to a single site on 7SPC/11SPC, predominantly through van der Waals forces and hydrogen bonds. Molecular dynamics results revealed that the pH−shifted treatment expanded the beta−barrel volume of 7SPC/11SPC, enhancing the binding affinity between 7SPC/11SPC and Cur by forming H−bonds and pi−H interaction in the beta−barrel regions of K232−Y388 (7SPC) and D300−I410 (11SPC). Our findings provided a novel and effective way to prepare stable spherical nanogels for delivering Cur and a novel insight into the binding mechanism between Cur and 11SPC/7SPC.

Bigels, a hybrid gel system combining organogels and hydrogels, offer a versatile platform with enhanced properties derived from both gel types. This review examines the extensive developments in bigel formulations over the past decade, focusing on the modulation of bigel properties through adjustments in organogel and hydrogel components. Notably, the pharmaceutical industry has recognized bigels as promising carriers for drug delivery, while the food industry has begun exploring their potential in diverse applications such as fat mimetics, bioactive compound carriers, and 3D printing materials. This review highlights the burgeoning interest and practical applications of food-grade bigels, showcasing their versatility across various domains.

The intake of food products that provide adequate amounts of nutrients is a strategy to deal with the changes in physiological functions that occur during aging that can lead to malnutrition. In this work heat-set mixed protein gels (MPG) composed of soy protein isolate (SPI) and whey protein isolate (WPI) are developed, with different SPI:WPI ratios (15 g protein isolate/100 g gel) and enriched with vitamins D₃ and B₁₂. Different protein ratios formed gels with different microstructures and rheological properties. The gel containing 70 % of WPI had a more homogeneous microstructure. The influence of the MPG microstructure on the digestion and bioaccessibility of proteins and vitamins using elderly static in vitro digestion was evaluated. An important result is that mixing SPI and WPI increased the proteolysis. Regarding vitamins bioaccessibility, vitamin D₃ became more bioaccessible after the intestinal phase, and there was no difference in vitamin B₁₂ concentration in the intestinal and gastric phases. Therefore, mixing SPI and WPI to produce MPG resulted in improved digestion of proteins, as well as higher bioaccessibility of the vitamins. The results indicated the MPG are promising protein matrices to be used in food products for the elderly.

The current research examines the effect of transglutaminase (TG) addition on novel bigel formulation based on a mixture of a chickpea-potato protein hydrogel and a glycerol monostearate (GMS)-oleogel processed using a hot emulsification procedure. Enzyme addition led to an increase in hardness and storage modulus values while similar melting behavior was found for both bigels with the main peak between 53–55 °C resulting from the GMS-oleogel melting. TGA thermograms of both bigels exhibited similar four weight-loss regions, with the control bigel having higher amount of bound water (∼56 %) compared to the TG-crosslinked bigel (∼50 %), which can be related to the higher stickiness of the control bigel. Confocal and cryo-HR-SEM imaging revealed the formation of a chickpea/potato protein network embedded with GMS oleogel droplets. Upon cooking, both bigels had crispy orange-brown surface with higher hardness and moderate browning due to the Maillard reaction.

This paper investigated the differences in the structure and properties of diglyceride (DAG) oleogels (DAG as the oil phase) and triglyceride (TAG) oleogels (TAG as the oil phase) with different gelator concentrations of beeswax (BW) and monoacylglycerol (MAG). When BW was used as gelator, compared with TAG oleogels, the mass of β′ crystals in DAG-oil based oleogels increased, the crystal network stability improved, and the G′ increased. In addition, the DAG-oil based oleogels prepared with BW showed hydrogen bonds. When MAG was used as gelator, the G′, the thermal and crystal network stability of DAG-oil based oleogels decreased compared to TAG oleogels, and large number of crystal clusters were formed. In addition, DAG-oil based oleogels showed lower oxidative stability than TAG oleogels. These results contribute to a better understanding the properties of DAG oil based oleogels and facilitate the development of low-fat functional plastic products.

Crystallization behavior within oil-in-water emulsion is a key factor for the properties and stability of many food products. Confocal Raman microscopy is a promising method to study such complex structures in situ. This study aimed at evaluating the feasibility of confocal Raman microscopy for visualizing milk fat crystallization and establishing a reliable data acquisition and processing methodology. Milk fat globules from raw milk were fixated in an agarose gel and crystallized at different temperatures. Confocal Raman microscopy was applied to collect two-dimensional area scans and supporting images were obtained by polarized light microscopy. The results revealed differences in lipid characteristics, crystal formation, and spatial distribution as a result of crystallization. Specific C-C stretching vibrations at 1063, 1083, and 1125 cm-1 were found to indicate lipid chain mobility and provide quantitative information on crystallinity. Additionally, the study successfully identified the triple-layered milk fat globule membrane. Different approaches for processing spectroscopic data were compared, emphasizing the importance of proper data handling. This novel spectroscopy imaging approach has significant potential in enhancing our understanding of structural heterogeneities of crystallized structures within complex food matrices.

Polyethylene terephthalate (PET) is a commonly used polymer in many industry sectors including confectionery industry. In the latter, PET is utilized for single-use moulds for chocolate manufacturing. Despite the broad application of PET in these areas, information regarding its influence on chocolate gloss and surface properties is not available. Meanwhile, it is already well established that fat crystal modification influence these properties (including gloss) distinctly. To bridge this disparity, this study examined how amorphous and glycol-copolymerized PET sheets influence non-pre-crystallised and pre-crystallised dark chocolate properties throughout a 28-day storage period. Polymorphic properties of cocoa butter were analysed via DSC. Non-pre-crystallised and pre-crystallised chocolate surfaces were characterised regarding colour, gloss, polarity, adhesion, roughness, and topography. While pre-crystallised chocolate shows consistent results, non-pre-crystallised chocolate experiences considerable changes in surface properties due to fat crystal transitions during storage. The findings show that the polymorphic state had a major impact on chocolate surface properties. Furthermore, results demonstrated that the type of PET had a significant impact on chocolate surface properties as well. Pre-crystallised chocolate gloss was significantly impacted by the choice of PET contact material. As a result, pre-crystallised chocolates exhibited a larger tendency to gloss inhomogeneities following amorphous PET monolayer sheet contact.

The gelation behaviour of two different pea protein isolates and one soy protein isolate were investigated with a focus on the role of the protein properties. Protein solubility was the lowest in pH 3 citrate-phosphate buffer (<10% w/w), increased in pH 7.4 phosphate-buffered saline (12–21% w/w), and was the highest in pH 7.6 MilliQ water (∼20–40% w/w). Heat-induced gelation conditions for the protein sources were sensitive to both the soluble and the insoluble fractions as obtained during extraction. At low protein concentrations (≤5% w/v), the proteins started to lose their viscoelastic behaviour and exhibited predominantly viscous properties. Fitting of the fractional Kelvin-Voigt model to the frequency sweeps showed an increase in the fractal gel strength with increasing protein concentration. Secondary structures of the soluble species showed mostly unordered proteins, suggesting that the proteins were denatured during the commercial extraction process although gelation has to date been suggested to be highly dependent on the denaturation of soluble proteins. Synchrotron Radiation Circular Dichroism measurements of the insoluble proteins showed a significant amount of ordered protein structures. SEM imaging of the gels also suggested a new gelation pathway in which insoluble proteins act as dispersed fillers within a continuous matrix of soluble proteins. This research elucidated the role of different protein fractions, globulins and albumins, and their secondary structure in the formation of a gel network and how this affects their viscoelastic behaviour.

Gloss is an important criterion for chocolate quality and hence consumer acceptance. Gloss inhomogeneities, meaning glossy and matt spots on chocolate surfaces, remain a problem as they occur even after apparently optimal pre-crystallisation and cooling of chocolates. The presented study dealed with clarifying the complex interactions between dark chocolate with different surface-active substance (SAS) in contact with several mould materials by focusing on changes in chocolate surface properties and formation of gloss inhomogeneites. Contact materials used were polycarbonates (PC) and silicone. They varied in surface properties, specifically in roughness and surface free energy (SFE). PGPR, soy, and sunflower lecithin were used as SAS to alter the chocolate mass’ interface properties. Beside mould material’s surface properties, gloss (inhomogeneities), color, surface topography, roughness, and SFE were examined. Results showed that gloss and its inhomogeneities were significantly influenced by the contact material. Compared to PC, silicone had a significantly different impact on chocolate’s SFE and roughness. Topography images obtained by Atomic Force Microscopy revealed microstructural variations in the different gloss areas. Contact material and SAS had an impact on the microstructure as well. A statistical analysis further revealed that the contact materials' SFE and its dispersive share influence the formation of gloss inhomogeneites.