Food Structure-Netherlands最新文献

In this paper, the effect of superheated steam treatment (SST) on the thermal， structural and rheological properties of wheat gluten were investigated. The results of low-field nuclear magnetic resonance (LF NMR) illustrated that SST weakened the interaction between water and gluten during hydration. The denaturation of gluten proteins under high temperature broadened exotherm and increased the enthalpy (ΔH) values of differential scanning calorimeter (DSC), increasing from 2.35 J/g (native gluten) to 2.76 J/g (native gluten treated at 150 °C for 4 min). In addition, the increase of degradation temperature indicated that SST enhanced the thermal stability of hydrated gluten. Confocal laser scanning microscopy (CLSM) was employed to observe the micro-structure of hydrated gluten network, indicating that hydrated gluten could not form network structure after SST. This weakened viscoelastic characteristics were linked to the weakened hydrated gluten network structure. The results of the current work help to understand the improvement of wheat flour quality following SST.

Sucrose oleate was assessed as an alternative lipophilic emulsifier to polyglycerol polyricinoleate (PGPR) for the stabilisation of the internal aqueous phase of a water-in-oil-in-water emulsion formulation designed for salt release from the internal aqueous phase during oral processing. A water-in-oil emulsion (30 g water/100 g oil), containing an internalised salt solution (1.5 g salt/100 g), was successfully incorporated as droplets into a salt containing external aqueous phase (0.5 g salt/100 g) with in-situ gelatinised waxy rice starch (WRS) stabilising the oil droplet interface. The droplets of the sucrose ester stabilised water-in-oil emulsion were aggregated, and this microstructure carried over into the water-in-oil-in-water emulsion. The PGPR stabilised water-in-oil emulsion showed no evidence of aggregation, and the primary droplet size was smaller. Mean oil droplet size was comparable, slightly increasing for the sucrose ester containing formulation over a 3-months observation period. Nevertheless, salt encapsulation efficiency, reducing by around 10% over 3-months, as well as in vitro salt release, reducing by 20%, were comparable. This study demonstrated that sucrose ester SE O-170 is a viable alternative for PGPR in w/o/w emulsions designed for salt release during oral processing.

A viscoelastic cohesive zone model was proposed to simulate rate-dependent starch-gluten interface debonding. The debonding was believed to influence stress-strain curves of tensile and shear tests at different strain rates. The model was written as a user-defined finite element subroutine codes, which was then included into an interface element geometry between starch filler and gluten matrix. The finite element modelling results showed agreement with experimental data under uniaxial tension and simple shear at different strain rates (5/min and 0.5/min). This was due to the viscoelastic effect of the interface model, which caused difference between traction initiation at different rates for the cohesive zone model (i.e. ∼1.1kPa and ∼0.5kPa at 5/min and 0.5/min, respectively). In addition, it was shown that critical shear stress is a very important debonding parameter, where slight changes of the shear traction values caused the model stress-strain curve to deviate from the experimental results. Simulations of starch-gluten dough deformation were then conducted at different strain rates to imitate dough processes like baking, extrusion and proving (0.003/s, 1/s and 10/s, respectively). The interface model was shown to influence stress-strain curve at lower strain rate processes like baking and extrusion.

The purpose of this study was to determine the effect of psyllium and cellulose fiber additions on starch digestion behavior, as well as the structural and textural characteristics of bread and cracker samples. Fiber-added samples were created by replacing 10% of the wheat flour in the recipes with fibers. Fibers reduced the porosity of the bread samples, increased their hardness and chewiness, and decreased the hardness of the crackers. Due to its high water-holding capacity, psyllium fiber interfered more than cellulose fiber with the formation of a gluten network and dough structure. At this concentration, psyllium fiber was effective at slowing the digestion of bread and crackers, whereas cellulose fiber had no effect. Psyllium fiber inhibited starch digestion by acting as a physical barrier and limiting enzyme mobility. Due to the structural differences between bread and crackers, they digested differently. The findings indicated that variations in the development of food structures caused by processing methods and the solubility of the fibers used could have a differential effect on starch digestion. Across the board, food processing methods, ingredients, and textural characteristics can all have an effect on starch digestion.

For centuries people around the world enjoyed traditional sausages made from meat stuffed into natural casings. An alternative new technology is to extrude collagen gel, originating from bovine hides, directly onto the product and later cross-link it. Collagen producers are searching for other sources and consequently they are interested in factors influencing extracted collagen quality. One of the alternative sources is chicken skin, where extracted collagen properties have been shown to be influenced by the age of the chickens. In this study, the biochemical and physical properties of chicken skin collagen preparations from two different broiler strains (slow and fast-growing) and two different weights (1.6 and 2.2 kg) were investigated. Rheological measurements showed for all dispersions a decrease in elasticity at 40 °C. Differential Scanning Calorimetry (DSC) measurements of the dispersions showed T_onset ranging from 38.7° to 39.1°C. After salt precipitation, the T_onset increased to 50.1 – 55.9 °C. Mechanical strength of the films from fast and slow growing chickens ranged from 63 to 67 KPa and 53–57 KPa, respectively. Considering the biochemical and physical properties, all four chicken collagen dispersions have the potential of being a suitable collagen source for the co-extrusion process of sausages.

In this study, the encapsulation of fish protein hydrolysate (FPH), fish oil (FO), and shrimp lipid extract (SHE) was investigated; the prepared nanoliposomes were coated by different layers. Whey protein (WPC) and chitosan (CS) were applied as a mono/bilayer and composite. Physicochemical properties and oxidative stability of nanoliposomes were investigated during 0, 7, 14, and 21 days of storage at 4 °C. The average particle size in uncoated nanoliposomes was 141.3 nm and coating changed the particle size. At the end of storage, the zeta potential of uncoated nanoliposomes was decreased from − 84.7 mV to − 64.8 mV; the color intensity of nanoliposomes showed a slight decrease. The nanoliposomes coated by WPC-monolayer showed the highest encapsulation efficiency (98.38%). At the first, the uncoated nanoliposomes containing SHE showed the highest DPPH radical scavenging activity (77.74%) and reducing power (1.42). Although, during this time, bilayer-coated nanoliposomes by WPC/CS revealed superior oxidative stability. In conclusion, the findings indicated that the encapsulation of marine bioactive compounds in liposomal carriers and coating by WPC as a mono/bilayer with chitosan could be a potential approach to application with antioxidant capability in food products.

Resistant starch nanoparticles (RSN) were obtained using ultrasonication. RSN displayed a hydrodynamic diameter of 345.12 ± 0.01 nm and zeta potential of 16.78 ± 0.04 mV. A bio composite hydrogel (RSNG) was formed by incorporating RSN of varying concentration (0.2%, 0.4% and 0.8%) in gum acacia (GA) to form resistant starch nanoparticle - gum acacia hydrogel, RSNG (0.2), RSNG (0.4) and RSNG (0.8), respectively. Kaempferol was nano encapsulated in RSNG (0.2%, 0.4% and 0.8%) for its controlled release. RSNG (0.4) displayed highest encapsulation efficiency of 61.23 ± 0.56% and in vitro release of kaempferol followed Higuchi model. Toxicity evaluation of RSN and RSNG revealed no effect on calf thymus DNA and human embryonic kidney (HEK-293 T) cells. The nutraceutical potential of RSNG showed retention of anti-oxidant, anti-diabetic, anti-hypertensive, anti-lipidemic and anti-microbial properties in simulated gastro-intestinal conditions (SGID). RSNG can efficiently encapsulate flavonoids and retain bioactivity in human digestive conditions that can be applied in food and pharmaceutical areas.

This research aimed to compare the structural and colloidal properties of whey protein aggregates (WPA) produced by indirect tubular heating and direct steam injection methods. The results illustrated that WPA produced from direct steam injection had better colloidal stability and functionality compared to those produced by indirect heating. WPA obtained from direct steam injection had smaller sizes and higher surface hydrophobicity, although they had a similar surface negative charge. More importantly, WPA from direct steam injection had much better colloidal stability. Especially for the sample produced by the direct steam injection containing a higher concentration of 30 %, which remained stable during 20 days’ storage. In comparison, precipitation was noticed after ten days for the sample with a lower concentration of 10 %, indicating the functionality and colloidal stability of WPA were also affected by the protein concentration. Those results demonstrated that the functionality of WPA can be tailored by selecting appropriate materials and manufacturing techniques.

Commercial plant protein isolates contain a large fraction of non-functional proteins due to the harsh processing conditions used. Therefore, greater value can be unlocked by functionalising these “inert” plant proteins. Using commercial insoluble pea protein isolate (I-PPI) as an example, this study demonstrates the application of high-pressure homogenisation (HPH) as a physical method to improve the techno-functionality of I-PPI. The dispersions were HPH-treated at 60, 120, or 180 MPa for one, three, and five pressure cycles. HPH treatments resulted in decreased particle size (from 16.7 ± 1.3–9.4 ± 0.2 µm at 60 MPa) and increased zeta-potential. Microstructural observations revealed the formation of smaller aggregate clusters and flake-like structures after HPH treatments. The protein solubility of I-PPI (15.9 ± 2.0 %) under acidic conditions (pH 2) significantly increased at all HPH treatment levels, with the greatest increase at 120 MPa for 5 passes (27.2 ± 2.0 %). Remarkably, the non-gelling I-PPI was able to form self-standing gels (15 % w/w) after HPH treatments, with the greatest gel strength observed at 180 MPa. The emulsifying and foaming stability of HPH-treated I-PPI increased from 60 to 120 MPa but decreased at 180 MPa. Overall, our results demonstrate a key paradigm in protein modification: transforming insoluble plant proteins into functional protein ingredients.