Journal of Food Engineering最新文献

This study investigated the impact of structural changes (particle size, potential, hydrophobicity, circular dichroism spectra) in ovotransferrin with and without Fe³⁺ (holo-OVT and apo-OVT) on their interfacial behaviors. Holo-OVT exhibited greater diffusion, penetration, and rearrangement rates at the oil-water interface, whereas apo-OVT was detected at the air-water interface owing to the reduced hydrophobicity of air phase. Reduced hydrophobicity of both the protein (apo-OVT) and the dispersed phase (oil) leads to shorter lag periods. As for the interfacial film, holo-OVT formed denser but thinner films than those formed by apo-OVT at both interfaces, as confirmed by larger viscoelastic modulus, reduced film thickness, and lower Gibbs surface excess. These findings were likely attributable to the greater structural rigidity of holo-OVT presented with significant decreases in hydrophobicity index (432.20) than apo-OVT (522.40). Ultimately, holo-OVT exhibited significant improvements in foaming and emulsifying stability than apo-OVT.

Microwave (MW) thawing and reheating of porous foods such as rice is a common practice, but uniform heating can be difficult to achieve. Computer simulation models were developed using the finite-element method to study MW thawing and reheating of packed rice. A method to obtain an apparent thermal conductivity was proposed, which accounts for heat distribution by water evaporation and condensation through the air pores in the sample. Reheating experiments of mashed compact rice and regular porous rice were carried out on a flatbed MW oven for 90 s. Similarly, thawing experiments were conducted on porous rice for 180 s. Good agreement between simulated and experimental results was obtained when correcting for thermal conductivity of the pores and for the volumetric power absorption between the frozen and thawed fractions This can help in the design of specifically designed porous foods and containers that allow for fast and homogeneous reheating.

In this work, doughs made with gluten add chickpea composite flour were mixed to reach the 500BU standard and baked into bread products. Chickpea flour was substituted at the level of 20%, 30%, and 40% by wheat gluten to provide structural support for the dough. Higher gluten concentrations improved gas bubble retention as determined by crumb image analysis, resulting in higher final loaf volume. Dough samples were taken out of the fermentation chamber at 0, 30, 60, and 90 min to study the effect of fermentation on rheology. Utilizing SPP deltoids ($G_t^{\prime }$ vs $G_t^{″}$ plot), the intracycle and intercycle network rearrangement of dough were studied in details. Obtaining deltoids as a function of fermentation time offers an insight into the impact of fermentation on dough structure. It is found that longer fermentation time makes gluten-chickpea composite dough more elastic in the linear region (<1% strain) and less elastic in the nonlinear region. This work helps to demonstrate an application of SPP analysis in facilitating the development of innovative bread products made with a mixture of pulse flour and wheat gluten.

The present study aimed to develop redispersible spray-dried powders containing curcumin-loaded Eudragit® L100 nanocapsules and evaluate their physicochemical properties and antioxidant potential. The spray drying process showed a yield of over 85%, low residual moisture content (<2%), and all the physicochemical characteristics of the nanocapsules were recovered after the aqueous redispersion of the dry powders. In addition to the dry powders, the following samples were also analyzed: pure curcumin, pure lactose, and curcumin-lactose mix. In TGA and DSC analysis, all samples were thermostable and exhibited no chemical interactions with each other. In FTIR analysis, the nanostructured powder system showed functional groups of the precursors (curcumin and lactose), confirming the effectiveness in the preparation of the nanostructured material. In the evaluation of the free radical scavenging activity of DPPH•, the dry powder containing nanoencapsulated curcumin showed antioxidant activity approximately six times higher than free curcumin. Therefore, spray drying of nanoencapsulated curcumin made it possible to obtain a dry powder with homogeneous aqueous redispersion, as well as promoting the potentiation of the antioxidant activity of curcumin.

This study examines the impact of low-frequency ultrasound on the physicochemical attributes of milk proteins, focusing on various casein-to-whey protein ratios and their interactions with lactose and calcium. Milk systems with varying casein-to-whey protein ratios (0:100, 50:50, 60:40, 80:20), lactose, and various calcium chloride (CaCl₂) concentrations (0–30 mM), were exposed to 20 kHz ultrasound for different durations (0, 1, 5, 10 min). A range of physicochemical factors, including particle size, zeta potential, calcium ion activity, pH, and water-holding capacity, were examined. The results revealed that calcium concentration and pH significantly (P < 0.05) influenced the physicochemical and structural properties of milk protein-lactose-calcium systems. FTIR analyses indicated that ultrasound promoted secondary structural changes in milk proteins and enabled the creation of lactose-protein and calcium-lactose complexes. The intermolecular and intramolecular interactions through hydrophobic and covalent bonding prevailed. Understanding these three-way interactions is crucial for innovating stable and shelf-stable dairy formulations, which is essential for advancing dairy processing.

Adding triblock copolymers to hydrophilic films is an option to improve the functional properties and water resistance under high equilibrium relative humidity (RHeq) environments. Sorption isotherms of corn starch-chitosan based films added with triblock copolymers (L64 and P123) measured at 4, 20, and 36 °C were fitted using the Guggenheim-Anderson-De Boer equation. Thermodynamic analysis allowed allocating the minimum integral entropy value between 0.09 and 0.50 of water activity. The compensation enthalpy-entropy showed that the entropy driven the process at low water activities (0.10–∼0.33) and the enthalpy driven the water sorption at high water activities (∼0.33–∼0.90).

The purpose of this study was to improve the 3D printing accuracy of pineapple gel and its subsequent microwave freeze drying (MFD) solidification precision based on infill percentage control (30%, 50%, 70%, and 90%) and internal models design (Hilbert curve, honeycomb, and rectilinear). Through comparing the designed models with the physical dimensions of the printed and dehydrated products, the optimal regulation strategy was obtained. Results showed that the printing deviation of samples decreased initially and then increased with higher infill percentages, with the 70% infill percentage having the lowest deviation. Among all internal models, the rectilinear infill pattern showed the best printing accuracy. Porosity and the shape deformation rate of MFD solidification products initially decreased and then increased with higher infill percentages. The 70% infill percentage products had the lowest shape deformation rate. The honeycomb infill pattern performed best in reducing solidification sample shrinkage and deformation. Additionally, micro-CT scans revealed that the honeycomb infill pattern helped maintain the integrity of each layer's lines of MFD solidification products, closely matching the model's line distribution. In the 50% and 70% infill percentage, honeycomb and rectilinear samples exhibited better crispness. A 70% honeycomb infill pattern was recommended for optimal printing and post-solidification accuracy.

Atmospheric freeze-drying (AFD) is a method of freeze-drying conducted at atmospheric pressure and low temperatures below the freezing point of water, using dry air for the preservation of foods and pharmaceutical products. AFD shows promise as a cost-effective alternative to traditional vacuum freeze-drying (VFD), particularly for industrial-scale applications. This review aims to explore recent advancements in AFD over the past two decades, focusing on numerical simulations and novel experimental systems. It highlights the integration of technologies such as Ultrasound (US), Infrared Radiation (IR), and Microwave radiation (MW) to enhance drying kinetics. Key processing parameters, including temperature, air velocity, and product geometry, are examined for their impact on drying kinetics and food quality attributes like texture, colour, and nutritional properties. The review also assesses the economic and environmental impact of AFD. Innovative systems, such as fluidized beds, spray freeze, tunnel freeze, and vibro-fluidized bed drying, have improved the kinetic rate of AFD. The integration of advanced technologies has notably reduced drying time by up to 70% without substantially compromising food quality, depending on the power applied. AFD demonstrates up to 30% less energy consumption compared to vacuum freeze-drying (VFD) and, while slightly lower in quality than VFD, surpasses hot air drying in product attributes. AFD presents a cost-effective, energy-efficient alternative to VFD with promising industrial scalability.

In the industrial production of tofu, controlling the coagulation rate is crucial. A controlled-release Mg²⁺-loaded water-in-oil emulsion coagulant was employed in tofu manufacturing, and its effects on the physical properties and gel behavior of tofu were studied. Compared with MgCl₂, the emulsion coagulant could extend the initial coagulation time of soybean protein from 3 s to about 30 s due to its sustained release effect on Mg²⁺, which significantly decelerated the tofu gelation rate. In addition, different Mg²⁺ release rates significantly influenced the physical properties of the final tofu gel. At an appropriate Mg²⁺ release rate (at 7000 r min⁻¹), it promoted the formation of a uniform and denser gel network, increased protein β-sheet structures, and benefited tofu in terms of moisture retention, yield, color, springiness, and appearance quality improvement. However, under low Mg²⁺ release rate, the emulsion coagulant weakened the disulfide bond and hydrophobic action, resulting in a weaker network. It also enhanced the moisture mobility in the tofu gel, with a dehydration rate of up to 17.72%. Similarly, too fast Mg²⁺ release rate also resulted in uneven networks with voids, leading to reduced moisture retention, yield, and color quality of tofu. These findings aim to provide a theoretical basis for the industrial production of tofu.