Exploring conventional and emerging dehydration technologies for slurry/liquid food matrices and their impact on porosity of powders: A comprehensive review

The contribution of dehydration to the growing market of food powders from slurry/liquid matrices is inevitable. To overcome the challenges posed by conventional drying technologies, several innovative approaches have emerged. However, industrial implementation is limited due to insufficient information on the best-suited drying technologies for targeted products. Therefore, this review aimed to compare various conventional and emerging dehydration technologies (such as active freeze, supercritical, agitated thin-film, and vortex chamber drying) based on their fundamental principles, potential applications, and limitations. Additionally, this article reviewed the effects of drying technologies on porosity, which greatly influence the solubility, rehydration, and stability of powder. The comparison between different drying technologies enables informed decision-making in selecting the appropriate one. It was found that active freeze drying is effective in producing free-flowing powders, unlike conventional freeze drying. Vortex chamber drying could be considered a viable alternative to spray drying, requiring a compact chamber than the large tower needed for spray drying. Freeze-dried, spray freeze-dried, and foam mat-dried powders exhibit higher porosity than spray-dried ones, whereas supercritical drying produces nano-porous interconnected powders. Notably, several factors like glass transition temperature, drying technologies, particle aggregation, agglomeration, and sintering impact powder porosity. However, some binders, such as maltodextrin, sucrose, and lactose, could be applied in controlled agglomeration to enhance powder porosity. Further investigation on the effect of emerging technologies on powder properties and their commercial feasibility is required to discover their potential in liquid drying. Moreover, utilizing clean-label drying ingredients like dietary fibers, derived from agricultural waste, presents promising opportunities.

The Impact of the Drying Process on the Antioxidant and Anti-Inflammatory Potential of Dried Ripe Coffee Cherry Pulp Soluble Powder

Coffee fruit cascara, which is the skin and pulp of the coffee cherry, has been authorized as a novel food for commercialization in the European Union. The present research assessed the feasibility of using spray drying to produce a soluble powder called instant cascara (IC), employing sun-dried ripe coffee cherry pulp as a raw material. Although there were no significant differences (p > 0.05) in the overall antioxidant capacity between the freeze-dried and spray-dried samples, after an in vitro simulation of the digestion process, the spray-dried sample was significantly (p < 0.05) more antioxidant. Both samples reduced physiological intracellular ROS and significantly decreased (p < 0.05) the secretion of the pro-inflammatory factor NO. Alkaloids and phenolic compounds were detected in intestinal digests. In conclusion, spray drying is a good technique for producing IC as its use does not affect its properties and causes less environmental impact than freeze drying, as calculated by life cycle assessment. Sensory analysis did not show significant differences between the commercial beverage and the IC beverage in the adult population. IC at 10 mg/mL was significantly less accepted in adolescents than the commercial beverage. Future work will include the reformulation of the IC beverage at 10 mg/mL, which has antioxidant and anti-inflammatory potential, to increase its hedonic acceptance in all consumer segments.

Screening of Cyclodextrins in the Processing of Buserelin Dry Powders for Inhalation Prepared by Spray Freeze-Drying

Purpose

In this study, we prepared inhalable buserelin microparticles using the spray freeze-drying (SFD) method for pulmonary drug delivery. Raffinose as a cryoprotectant carrier was combined with two levels of five different cyclodextrins (CDs) and then processed by SFD.

Methods

Dry powder diameters were evaluated by laser light scattering and morphology was determined by scanning electron microscopy (SEM). Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis were utilized for the determination of crystalline structures. The aerodynamic properties of the spray freeze-dried powders were evaluated by twin stage impinger (TSI) and the stability of prepared samples was assessed under normal and accelerated conditions.

Results

The prepared powders were mostly porous spheres and the size of microparticles ranged from 9.08 to 13.53 μm, which are suitable as spray-freeze dried particles. All formulations showed amorphous structure confirmed by DSC and XRD. The aerosolization performance of the formulation containing buserelin, raffinose and 5% beta-cyclodextrin (β-CD), was the highest and its fine particle fraction (FPF) was 69.38%. The more circular and separated structures were observed in higher concentrations of CDs, which were compatible with FPFs. The highest stability was obtained in the formulation containing hydroxypropyl beta-cyclodextrin (HP-β-16. CD) 5%. On the contrary, sulfobutylether beta-cyclodextrin (SBE-β-CD) 5% bearing particles showed the least stability.

Conclusion

By adjusting the type and ratio of CDs in the presence of raffinose, the prepared formulations could effectively enhance the aerosolization and stability of buserelin. Therefore, they can be proposed as a suitable career for lung drug delivery.

Decarbonized and circular brine management/valorization for water & valuable resource recovery via minimal/zero liquid discharge (MLD/ZLD) strategies

Brine (saline wastewater/water) from desalination, salt lakes, and industrial activities (e.g., pharmaceutical industries, oil & gas industries) has received a lot of attention around the world due to its adverse impact on the environment. Currently, several disposal methods have been applied; however, these methods are nowadays unsustainable. To tackle this problem, brine treatment and valorization is considered a promising strategy to eliminate brine discharge and recover valuable resources such as water, minerals, salts, metals, and energy. Brine valorization and resource recovery can be achieved via minimal and zero liquid discharge (MLD & ZLD) desalination systems. Commercially successful technologies such as reverse osmosis (RO) and distillation cannot be adopted as standalone technologies due to restrictions (e.g., osmotic pressure, high-energy/corrosion). Nonetheless, novel technologies such as forward osmosis (FO), membrane distillation (MD) can treat brine of high salinity and present high recovery rates. The extraction of several ions from brines is technically feasible. The minerals/salts composed of major ions (i.e., Na⁺, Cl^-, Mg²⁺, Ca²⁺) can be useful in a variety of sectors, and their sale prices are reasonable. On the other hand, the extraction of scarce metals such as lithium, rubidium, and cesium can be extremely profitable as their sale prices are extremely higher compared to the sale prices of common salts. Nonetheless, the extraction of such precious metals is currently restricted to a laboratory scale. The MLD/ZLD systems have high energy consumption and thus are associated with high GHGs emissions as fossil fuels are commonly burned to produce the required energy. To make the MLD/ZLD systems more eco-friendly and carbon-neutral, the authors suggest integrating renewable energy sources such as solar energy, wind energy, geothermal energy, etc. Besides water, minerals, salts, metals, and energy can be harvested from brine. In particular, salinity gradient power can be generated. Salinity gradient power technologies have shown great potential in several bench-scale and pilot-scale implementations. Nonetheless, several improvements are required to promote their large-scale feasibility and viability. To establish a CO₂-free and circular global economy, intensive research and development efforts should continue to be directed toward brine valorization and resource recovery using MLD/ZLD systems.

Freeze-Dissolving Method: A Fast Green Technology for Producing Nanoparticles and Ultrafine Powder

A new technology, a freeze-dissolving method, has been developed to isolate nanoparticles or ultrafine powder and is a more efficient and sustainable method than the traditional freeze-drying method. In this work, frozen spherical ice particles were produced with an aqueous solution of sodium bicarbonate or ammonium dihydrogen phosphate at various concentrations to generate nanoparticles of NaHCO₃ or (NH₄)(H₂PO₄). The freeze-drying method sublimates ice, and nanoparticles of NaHCO₃ or (NH₄)(H₂PO₄) in the ice templates remain. The freeze-dissolving method dissolves ice particles in a low freezing point solvent at temperatures below 0 °C, and then, nanoparticles of NaHCO₃ or (NH₄)(H₂PO₄) can be isolated after filtration. The freeze-dissolving method is 100 times faster with about 100 times less energy consumption than the freeze-drying method as demonstrated in this work with a much smaller facility footprint and produces the same quantity of nanoparticles with a more uniform size distribution.

Stabilizing vaccines via drying: Quality by design considerations

Pandemics and epidemics are continually challenging human beings' health and imposing major stresses on the societies particularly over the last few decades, when their frequency has increased significantly. Protecting humans from multiple diseases is best achieved through vaccination. However, vaccines thermal instability has always been a hurdle in their widespread application, especially in less developed countries. Furthermore, insufficient vaccine processing capacity is also a major challenge for global vaccination programs. Continuous drying of vaccine formulations is one of the potential solutions to these challenges. This review highlights the challenges on implementing the continuous drying techniques for drying vaccines. The conventional drying methods, emerging technologies and their adaptation by biopharmaceutical industry are investigated considering the patented technologies for drying of vaccines. Moreover, the current progress in applying Quality by Design (QbD) in each of the drying techniques considering the critical quality attributes (CQAs), critical process parameters (CPPs) are comprehensively reviewed. An expert advice is presented on the required actions to be taken within the biopharmaceutical industry to move towards continuous stabilization of vaccines in the realm of QbD.

An integration study of microalgae bioactive retention: From microalgae biomass to microalgae bioactives nanoparticle

Microalgae metabolites include biologically active compounds with therapeutic effects such as anticancer, anti-inflammatory and immunomodulation effects. One of the most recent focuses is on utilizing microalgae lipid-based biologically active compounds in food applications. However, most microalgae biological active compounds in their natural forms have common drawbacks like low solubility, low physicochemical stability and strong susceptibility to degradation, which significantly limits their application in foods, therefore, it is important to find solutions to retain their functional properties. In the present work, a comprehensive review on multi-product biorefinery was carried out from upstream processing stage to downstream processing stage, and identify critical processes and factors that impact bioactive material acquisition and retention. Furthermore, since nanoencapsulation technology emerges as an effective solution for microalgae nutraceutical product's retention, this work also focus on the nanoparticle perspective and comprehensively reviews the current nanoencapsulation solutions of the microalgae bioactive extract products. The aim is to depict advances in the formulations of microalage bioactive nanoparticles and provide a critical analysis of the reported nanoparticle formation. Overall, through the investigation of microalgae from biomass to bioactive nanoparticles, we aim to facilitate microalgae nutraceuticals incorporation as high value-added ingredients in more functional food that can improve human health.

Mucilages: sources, extraction methods, and characteristics for their use as encapsulation agents

The increasing interest in the use of natural ingredients has driven keen research and commercial interest in the use of mucilages for a range of applications. Typically, mucilages are polysaccharide hydrocolloids with distinct physicochemical and structural diversity, possessing characteristic functional and health benefits. Apart from their role as binding, thickening, stabilizing, and humidifying agents, they are valued for their antimicrobial, antihypertensive, antioxidant, antiasthmatic, hypoglycemic, and hypolipidemic activities. The focus of this review is to present the range of mucilages that have been explored as encapsulating agents. Encapsulation of food ingredients, nutraceutical, and pharmaceutical ingredients is an attractive technique to enhance the stability of targeted compounds, apart from providing benefits on delivery characteristics. The most widely adopted conventional and emerging extraction and purification methods are explained and supplemented with information on the key criteria involved in characterizing the physicochemical and functional properties of mucilages. The unique traits and benefits of using mucilages as encapsulation agents are detailed with the different methods used by researchers to encapsulate different food and bioactive compounds.