Search Results (225)

One of the main factors constraining the growth of the tea business is the low use rate of summer tea. To enhance the utilization rate and improve the quality of summer tea, this study innovatively integrated shaking, freezing, and rolling into the traditional processing methods of white tea. Processing parameters were optimized through single-factor experiments combined with an L₉(3⁴) orthogonal experimental design. The quality of summer teas was systematically evaluated using sensory analysis, gas chromatography–mass spectrometry, and high-performance liquid chromatography. This study found that the optimal processing for summer tea was as follows: fresh leaves, room-temperature cold-air withering for 6.5 h, shaking at 10 rpm for 10 min, −20 °C freezing for 5 h, 25% strength rolling for 9 min, and drying at 75 °C for 2 h. The relative content of esterified catechins in summer tea produced by the optimal processing method was reduced by 14.62% compared with the control group. There were alterations in the content of amino acid components, with fresh and sweet amino acids increasing by 4.96% and 2.95%, respectively, and bitter amino acids reducing by 2.15%. Furthermore, γ-aminobutyric acid and L-theanine contents increased by 0.51% and 5.77%, respectively. Five characteristic volatile compounds were identified, namely, methyl salicylate, phenethyl formate, linalool, dimethyl sulfide, and isobutyraldehyde. The volatile profile was dominated by floral and fruity notes, except for dimethyl sulfide, which exhibited a distinct cooked corn-like aroma characteristic. This process was shown to improve the quality of summer tea. The results of this study provide a metabolite-level grounds for improving the quality of summer tea. Full article

Aerogels (AGs) are highly porous, low-density, disordered, ultralight macroscopic materials with immense surface areas. Traditionally synthesized using aqueous sol–gel chemistry, starting by molecular precursors, the nanoparticles (NPs) dispersions gelation method is nowadays the most used procedure to obtain AGs with improved crystallinity and broader structural, morphological and compositional complexity. The Sol–gel process consists of preparing a solution by hydrolysis of different precursors, followed by gelation, ageing and a drying phase, via supercritical, freeze-drying or ambient evaporation. AGs can be classified based on various factors, such as appearance, synthetic methods, chemical origin, drying methods, microstructure, etc. Due to their nonpareil characteristics, AGs are completely different from common NPs, thus covering different and more extensive applications. AGs can be applied in supercapacitors, acoustic devices, drug delivery, thermal insulation, catalysis, electrocatalysis, gas absorption, gas separation, organic and inorganic xenobiotics removal from water and air and radionucleotides management. This review provides first an analysis on AGs according to data found in CAS Content Collection. Then, an AGs’ classification based on the chemical origin of their precursors, as well as the different methods existing to prepare AGs and the current optimization strategies are discussed. Following, focusing on AGs of inorganic origin, silica and metal oxide-based AGs are reviewed, deeply discussing their properties, specific synthesis and possible uses. These classes were chosen based on the evidence that they are the most experimented, patented and marketed AGs. Several related case studies are reported, some of which have been presented in reader-friendly tables and discussed. Full article

Background/Objectives: The intranasal (IN) route of administration is a promising non-invasive approach for brain targeting, bypassing the blood–brain barrier and enhancing bioavailability. Citalopram hydrobromide (CT), a widely prescribed sparingly water-soluble selective serotonin reuptake inhibitor (SSRI), faces challenges with oral and intravenous administration, including delayed onset, adverse effects, and patient compliance issues. Methods: This study aimed to develop a novel thermoresponsive polymeric micelle (PM) system based on Pluronic^® copolymers (Pluronic F127 and Poloxamer 188) improving CT’s solubility, stability, and nasal permeability for enhanced antidepressant efficacy. A preliminary study was conducted to select the optimized formulation. The preparation process involved using the thin-film hydration method, followed by freeze-drying. Comprehensive evaluations of optimized formulation characteristics included Z-average, polydispersity index (PdI), thermal behavior (lower critical solution temperature, LCST), encapsulation efficiency, X-ray powder diffraction (XRPD), thermodynamic solubility, and biological stability. Additionally, in vitro CT release and CT permeability in nasal conditions were studied. Stability under storage was also evaluated. Results: The optimized CT-PM formulation showed nanoscale micelle size (Z-average of 31.41 ± 0.99 nm), narrow size distribution (polydispersity index = 0.241), and a suitable thermal behavior for intranasal delivery (lower critical solution temperature (LCST) ~31 °C). Encapsulation efficiency reached approximately 90%, with an amorphous structure confirmed via XRPD, leading to a 95-fold increase in CT solubility. The formulation demonstrated appropriate biological and physical stability. In vitro studies showed a 25-fold faster CT release from optimized formulation compared to the initial CT, while CT-PM permeability in nasal conditions increased four-fold. Conclusions: This novel nanoscale thermosensitive formulation is a value-added strategy for nasal drug delivery systems, offering enhanced drug solubility, rapid drug release, stability, and improved permeability. This smart nanosystem represents a promising platform to overcome the limitations of conventional CT administration, improving therapeutic outcomes and patient compliance in depression management. Full article

To identify the optimal drying methods for turnip slices, vacuum freeze-drying (VFD), air impingement drying (AID), infrared-assisted hot air drying (IR-HAD), and conventional hot air drying (HAD) were evaluated. The physicochemical properties of dried samples were comprehensively assessed under varied drying conditions. The results demonstrated that AID achieved the shortest drying time (240 min). At identical temperatures, AID samples exhibited significantly lower total color difference (ΔE) compared with IR-HAD and HAD, alongside superior retention of total phenols and enhanced antioxidant activity. VFD yielded the highest quality attributes, including optimal rehydration capacity, maximal phenol retention, and the strongest antioxidant activity (DPPH: 16.56 ± 0.26 μmol Trolox/g; FRAP: 13.99 ± 0.04 μmol Trolox/g). SEM analysis revealed that VFD produced a loose, porous microstructure, explaining its enhanced rehydration. Overall, both AID (efficiency) and VFD (quality) show promise for industrial turnip processing. Full article

Oranges are popular worldwide, due not only to their refreshing taste but also to their high content of bioactive compounds. The main phytochemicals in oranges are phenolic compounds, vitamins, and carotenoids, which contribute to their antioxidant and anti-cancer activities. Various drying methods are used to remove the high moisture content in orange products to extend their shelf life. This review summarizes and compares the effects of different drying methods such as hot air drying, freeze drying, vacuum drying, spray drying, microwave drying, solar drying and innovative pretreatment on the physicochemical quality of orange products including slices, peels, and by-products. It lists the key parameters, advantages, and disadvantages of drying methods, as well as a decision tree for “product type-constraints-recommended drying method with pretreatment”. For example, the results indicate that vacuum microwave drying is effective in drying orange slices, and control techniques are employed to assist the drying process. Freeze drying preserves more phytochemicals in orange peels and their by-products, which results in higher antioxidant activity. Pretreatments like pulsed electric field and ozone enhance drying efficiency and phytochemical retention. Different drying methods are adopted to treat different by-products. This work can be used as a guide for selecting the optimal drying technique to balance efficiency, nutritional quality, and industrial scalability for different orange products. Full article

Oil-in-water emulsions are widely used to enhance the solubility, stability, and bioactivity of essential oils in aqueous systems. Advancing the functionality and sustainability of these emulsions using renewable, eco-friendly ingredients remains an important research focus. This study developed and evaluated a lemongrass essential oil nanoemulsion stabilized by Tween 80, NaCl, and soybean stover-derived cellulose nanocrystals. After freeze-drying, the nanoemulsion was redispersed in water and analyzed for particle size, zeta potential, polydispersity index, and essential oil recovery. Freeze-drying led to significant bioactivity losses, with antifungal and antioxidant activities reduced by 77% and 31%, respectively. Antioxidant activity declined rapidly within the first two weeks of storage at room temperature but was not significantly impacted by light exposure. Storage conditions also altered the sample composition, with one new compound detected in samples stored without light exposure and eleven new peaks observed in light-exposed samples. This study provides insights into the effects of freeze-drying and storage on lemongrass essential oil-loaded nanoemulsion stabilized by Tween 80, NaCl, and cellulose nanocrystals. The findings highlight the challenges of preserving bioactivity and composition in lyophilized essential oil-loaded emulsions and suggest avenues for optimizing drying processes and formulations to improve storage stability and efficacy. Full article

Three-dimensional (3D) surface-enhanced Raman scattering (SERS) substrates have demonstrated remarkable abilities of ultrasensitive and reproducible molecular detection. The combination of both electromagnetic and chemical enhancement processes, light trapping, and multiple scattering effects of 3D structures are what enhance their performance. The principles of underlying enhancements are summarized systematically, and the main types of 3D substrates—vertically aligned nanowires, dendritic and fractal nanostructures, porous frameworks and aerogels, core–shell and hollow nanospheres, and hierarchical hybrid structures—are categorized in this review. Advances in fabrication techniques, such as template-assisted growth, electrochemical and galvanic deposition, dealloying and freeze-drying, self-assembly, and hybrid integration, are critically evaluated in terms of structural tunability and scalability. Novel developments in the field of biosensing are also highlighted, including non-enzymatic glucose sensing, tumor biomarker sensing, and drug delivery. The remaining limitations, such as low reproducibility, mechanical stability, and substrate standardization, are also noted, and future directions, such as stimuli-responsive designs, multifunctional hybrid platforms, and data-driven optimization strategies of SERS technologies, are also included. Full article

The concerning increase in respiratory infections that are resistant to multiple drugs has led to a growing interest in bacteriophage therapy as a potential alternative to conventional antibiotics. Effective phage delivery to the lungs, however, presents several formulation and stability issues, particularly for inhalation-based methods. This review highlights current developments in the creation of dry powder formulations that can be inhaled for pulmonary phage therapy, with a focus on encapsulation methods based on nanoparticles, such as solid lipid nanoparticles (SLNs) and polymer-based nanoparticles. These carriers enhance the aerodynamic characteristics of phages, making them suitable for deep lung deposition, while also protecting them during processing and storage. Several drying methods have been investigated to create powders with optimal morphologies, porosity, and dispersibility, including spray drying and spray freeze drying. The review also emphasizes how the phage morphotype affects stability, especially when nebulization stress is present. Furthermore, the advantages of nanoparticle matrices are confirmed by the reduced viability loss (usually< 0.5 log PFU) of encapsulated phages. Standardizing production processes, scaling up, and ensuring regulatory compliance remain challenging despite encouraging preclinical results. The combination of phage therapy with nanotechnology creates new avenues for the utilization of inhalable delivery methods to treat multidrug-resistant pulmonary infections. To translate these novel formulations from preclinical development to clinical application, sustained multidisciplinary collaboration across pharmaceutical sciences, microbiology, and clinical pharmacology is essential. Full article

The milling process is a critical technological step that regulates wheat flour characteristics and ultimately determines end-product quality. This study systematically evaluated the effects of three key milling parameter adjustments in a laboratory-scale roller mill—double sifting (2S), double break milling (2BM), and increased roll gap (IRG)—on the physicochemical properties of wheat flour and the quality of microwave freeze-dried non-fried instant noodles. The results demonstrated that milling processes significantly influenced the particle size and composition of flour. The 2BM-IRG process increased the volume mean diameter of flour to 86.38 μm, while significantly improving flour extraction rate (69.80%), protein content (10.98%), and ash content (0.54%). In contrast, the 2S process significantly reduced the volume mean diameter (65.27 μm). These changes in flour properties directly affected noodle quality—noodles made from 2BM-IRG flour exhibited the highest rehydration ratio but also the greatest cooking loss, along with the lowest expected glycaemic index (eGI); noodles produced from 2S flour showed the highest hardness, while the 2BM process endowed noodles with superior elasticity. A correlation analysis revealed that the digestibility characteristics of noodles (eGI) were predominantly and significantly influenced by flour protein and ash content (p < 0.01), while also being significantly affected by particle size (p < 0.05). The study confirmed distinct quality trade-offs between different milling strategies. Therefore, by optimizing combinations of break milling and sifting processes, it is possible to develop specialized flour tailored for specific quality requirements. Full article

The practical application of powdered photocatalysts is significantly hindered by challenges in recyclability and structural instability. This work proposes a sustainable immobilization strategy by integrating BiVO₄ nanoparticles into a sodium alginate (SA) aerogel scaffold through a facile freeze-drying approach. The abundant hydroxyl/carboxyl groups of SA enable uniform dispersion of BiVO₄ within the porous network, while the aerogel architecture enhances light-harvesting efficiency and mass transfer kinetics. Innovatively, peroxymonosulfate (PMS) was introduced to synergistically couple photocatalysis with sulfate radical-based advanced oxidation processes (SR-AOPs), where the photogenerated electrons from BiVO₄ effectively activate PMS to yield high-activity ·SO₄⁻ radicals. The optimized BiVO₄/SA aerogel achieves nearly complete removal of Rhodamine B within 2 h under visible light, which is competitive to pure BiVO₄ powders. In addition, the mechanically robust aerogel exhibits exceptional reusability, retaining ~90% efficiency after five cycles without structural collapse. This work provides a paradigm for designing recyclable photocatalyst carriers with dual oxidation pathways, demonstrating significant potential for industrial wastewater treatment. Full article

Sb-based anodes have great potential in lithium-ion batteries because of their relatively high theoretical capacities. However, in general, their volume changes (>150%) during charge and discharge process have a significant impact, which affects their electrochemical performances. In this paper, nano-alloy FeSb wrapped in three-dimensional honeycomb graphite carbon (FeSb@C) was prepared by the freeze-drying method using sodium chloride as a template. The three-dimensional carbon can buffer the volume change in the reaction process, increasing the contact area between the electrode and electrolyte. Furthermore, the addition of metallic iron also increases the overall specific capacity and improves its electrochemical performance. As the anode of a lithium-ion battery, the optimized FeSb@C shows excellent electrochemical performance with a specific capacity of 193.0 mAh g⁻¹ at a high current density of 5 A g⁻¹, and a reversible capacity of 607.8 mAh g⁻¹ after 600 cycles of 1 A g⁻¹. It provides an effective strategy for preparing high-performance lithium-ion batteries anode materials. Full article

Wild edible plants, historically valued for their medicinal properties, can be a sustainable source of food, cosmetics, and pharmaceuticals. The blue berries of Prunus spinosa L., known as blackthorns, have antioxidant, astringent, and antimicrobial benefits. To preserve these properties after harvesting, understanding the best storage methods is essential. In this study, blackthorns were preserved using different methods (air-drying, freezing, or freeze-drying) to determine the optimal procedure for preserving their antioxidant activity. The fruits were extracted using a 50:50 (V/V) mixture of ethanol and water. The different extracts were phytochemically characterized for their phenolic content and antioxidant activity. The Folin–Ciocalteu test revealed total phenolic contents of 7.97 ± 0.04, 13.99 ± 0.04, and 7.39 ± 0.08 (mg GAE/g raw material) for the three types of extracts, respectively. The total flavonoid contents were 2.42 ± 0.16, 3.14 ± 0.15, and 2.32 ± 0.03 (mg QE/g raw material), respectively. In line with the polyphenol analysis, the antioxidant activity as determined by DPPH method was higher for the frozen extract, with a value of 91.78 ± 0.80%, which was confirmed by the ROS test on keratinocytes. These results show that both air-drying and freeze-drying processes negatively impact the preservation of antioxidant activity in blackthorns, suggesting that freezing may be the best preservation method before bioactive compound extraction. Full article

This study employs advanced numerical simulation to investigate the influence of shelf temperature on the freeze-drying kinetics and product quality of Cordyceps militaris. Emphasis is placed on the glass transition and structural collapse mechanisms during the primary drying stage. A detailed computational model was developed to predict temperature profiles, glass transition temperature, collapse temperature, and moisture distribution under varying process conditions. Simulation results indicate that maintaining the shelf temperature below 10 °C minimizes the risk of structural collapse and volume shrinkage while improving drying efficiency and product stability. Based on the model, an optimal freeze-drying protocol is proposed: shelf heating at 0 °C, condenser plate at −32 °C, and chamber pressure at 35 Pa. Experimental validation confirmed the feasibility of this regime, yielding a shrinkage of 9.52%, a color difference (ΔE) of 4.86, water activity of 0.364 ± 0.018, and a rehydration ratio of 55.14 ± 0.789%. Key bioactive compounds, including adenosine and cordycepin, were well preserved. These findings underscore the critical role of simulation in process design and optimization, contributing to the development of efficient and high-quality freeze-dried functional food products. Full article

In alignment with the United Nations’ Sustainable Development Goals (SDGs) 12 (Responsible Consumption and Production) and 13 (Climate Action), this research explores the sustainable valorization of mangosteen peels into mangosteen peel powder (MPP), a value-added product with pharmaceutical properties. Mangosteen peels are an abundant agricultural waste in Thailand. This study evaluates six MPP production schemes, each employing different drying methods. Life Cycle Assessment (LCA) is utilized to assess the global warming potential (GWP) of these schemes, and the quality of the MPP produced is also compared. The results show that a combination of frozen storage and freeze-drying (scheme 4) has the highest GWP (1091.897 kgCO₂eq) due to substantial electricity usage, whereas a combination of frozen storage and sun-drying (scheme 5) has the lowest GWP (0.031 kgCO₂eq) but is prone to microbial contamination. Frozen storage without coarse grinding, combined with hot-air drying (scheme 6), is identified as the optimal scheme in terms of GWP (11.236 kgCO₂eq) and product quality. Due to the lack of an onsite hot-air-drying facility, two transportation strategies are integrated into scheme 6 for scenarios A and B. These transportation strategies include transporting mangosteen peels from orchards to a facility in another province or transporting a mobile hot-air-drying unit to the orchards. The analysis indicates that scenario B is more favorable both operationally and environmentally, due to its lower emissions. This research is the first to comparatively assess the GWP of different MPP production schemes using LCA. Furthermore, it aligns with the growing trend in international trade which places greater emphasis on environmentally friendly production processes. Full article

Grain drying technology is a core process for ensuring food quality, extending storage life, and improving processing adaptability. With the continuous growth of global food demand and the increasing requirements for food quality and energy efficiency, traditional drying technologies face multiple challenges. This paper reviews six major grain drying technologies, comprising hot air drying, microwave drying, infrared drying, freeze drying, vacuum drying, and solar drying. It provides an in-depth discussion of the working principles, advantages, and limitations of each technology, and analyzes their performance in practical applications. In response to challenges such as high energy consumption, uneven drying, and quality loss during the drying process, the paper also explores the research progress of several hybrid drying systems, such as microwave–hot air drying combined systems and solar–infrared drying systems. Although these emerging technologies show significant potential in improving drying efficiency, energy saving, and maintaining food quality, their high costs, scalability, and process stability still limit large-scale applications. Therefore, future research should focus on reducing energy consumption, improving drying precision, and optimizing drying system integration, particularly by introducing intelligent control systems. This would maximize the preservation of food quality while improving the system’s economic efficiency and sustainability, promoting innovation in food production and processing technologies, and further advancing global food security and sustainable agricultural development. Full article