Iron-encapsulated cold-set whey protein isolate gel powder - Part 1: Optimisation of preparation conditions andin vitroevaluation

Recent advances in iron encapsulation and its application in food fortification

Iron (Fe) is an important element for our body since it takes part in a huge variety of metabolic processes. However, the direct incorporation of Fe into food fortification causes a number of problems along with undesirable organoleptic properties. Thus, encapsulation has been suggested to alleviate this problem. This study first sheds more light on the Fe encapsulation strategies and comprehensively explains the results of Fe encapsulation studies in the last decade. Then, the latest attempts to use Fe (in free or encapsulated forms) to fortify foods such as bakery products, dairy products, rice, lipid-containing foods, salt, fruit/vegetable-based products, and infant formula are presented. Double emulsions are highly effective at keeping their Fe content and display encapsulation efficiency (EE) > 88% although it decreases upon storage. The encapsulation by gel beads possesses several advantages including high EE, as well as reduced and great Fe release in gastric and duodenal conditions, respectively. Cereals, particularly bread and wheat, are common staple foods globally; they are very suitable for food fortification by Fe derivatives. Nevertheless, the majority of Fe in flour is available as salts of phytic acid (IP6) and phytates, reducing Fe bioavailability in the human body. The sourdough process degrades IP6 completely while Chorleywood Bread Making Process and conventional processes decrease it by 75% in comparison with whole meal flour.

Nanofood Process Technology: Insights on How Sustainability Informs Process Design

Nanostructured products are an actively growing area for food research, but there is little information on the sustainability of processes used to make these products. In this Review, we advocate for selection of sustainable process technologies during initial stages of laboratory-scale developments of nanofoods. We show that selection is assisted by predictive sustainability assessment(s) based on conventional technologies, including exploratory ex ante and "anticipatory" life-cycle assessment. We demonstrate that sustainability assessments for conventional food process technologies can be leveraged to design nanofood process concepts and technologies. We critically review emerging nanostructured food products including encapsulated bioactive molecules and processes used to structure these foods at laboratory, pilot, and industrial scales. We apply a rational method via learning lessons from sustainability of unit operations in conventional food processing and critically apportioned lessons between emerging and conventional approaches. We conclude that this method provides a quantitative means to incorporate sustainability during process design for nanostructured foods. Findings will be of interest and benefit to a range of food researchers, engineers, and manufacturers of process equipment.

Development of iron-vitamin multilayer encapsulates using 3 fluid nozzle spray drying

Considering the growing concern of iron and folic acid deficiency, encapsulation of these nutrients and fortification into foods is emerging as an effective counter-strategy. The present work focuses on a scalable approach for the production of iron, ascorbic acid, and folic acid core-shell encapsulates using novel 3-fluid nozzle (3FN) spray drying with whey protein as core and either pectin or hydroxypropyl methylcellulose (HPMC) as shell polymers. The effect of shell formation was observed by comparing core-shell encapsulates with conventional 2-fluid nozzle (2FN) encapsulates. Also, the effect of pH of whey protein on the color of encapsulates is noteworthy; reducing the pH to 4.0 significantly improved the lightness value (52.91 ± 0.13) when compared with the encapsulates with native pH (38.91 ± 0.58). Furthermore, sample with pectin as shell polymer exhibited fair flowability with lowest values of Hausner ratio (1.25 ± 0.04) and Carr's index (20.06 ± 2.71) and highest encapsulation efficiency for folic acid (86.07 ± 5.24%). Whereas, encapsulates having HPMC as shell polymer showed highest lightness value (60.80 ± 0.32) and highest encapsulation efficiency for iron (87.28 ± 4.15%). The formation of core-shell structure was confirmed by evaluation of the surface composition which showed reduced amine bonds and increased aliphatic and carbonyl bonds in the encapsulates prepared by 3FN spray drying. The encapsulates prepared without adjusting whey protein pH showed the least release (∼51 % in 24 h) and bioaccessibility (∼56%) of iron indicating the iron-whey protein complex formation. Based on appearance, smooth surface morphology, flowability, and release behavior, a combination of whey protein and pectin is recommended for co-encapsulation of iron, folic acid and ascorbic acid.

Synthesis and characterization of cellulose nanocrystal-Fe composite nanoparticles and their digestion behavior in simulated gastric fluid

Cellulose nanocrystals (CNC) exhibit great potential as a food emulsifier or functional material template. Herein, CNC-Fe nanoparticles were successfully prepared via an in situ chemical reduction approach. Zeta potential measurements, low-field nuclear magnetic resonance spectroscopy, and atomic force microscopy showed that Fe(III) ions were adsorbed onto CNC when FeCl₃ was added to a CNC dispersion. Micromorphological analysis revealed small (diameter = 10.0 ± 2.4 nm) spherical nanoparticles synthesized on the surface of aggregated CNC after the reduction of the Fe(III) ions. Fourier transform infrared spectroscopy revealed an intense peak at 779 cm^-1 in the CNC-Fe nanoparticles, which was attributed to FeO stretching vibrations. X-ray photoelectron spectroscopy indicated that the valence state of Fe in CNC-Fe nanoparticles was predominantly ferrous. The synthesized CNC-Fe nanoparticles demonstrated excellent colloidal stability in a dispersion for 21 d and complete, rapid, and spontaneous dissolution in vitro simulated gastric fluid. Our results highlight the potential use of CNC as a template for loading Fe into nanoparticles for Fe fortification in food.

Milk Protein-Based Nanohydrogels: Current Status and Applications

Milk proteins are excellent biomaterials for the modification and formulation of food structures as they have good nutritional value; are biodegradable and biocompatible; are regarded as safe for human consumption; possess valuable physical, chemical, and biological functionalities. Hydrogels are three-dimensional, cross-linked networks of polymers capable of absorbing large amounts of water and biological fluids without dissolving and have attained great attraction from researchers due to their small size and high efficiency. Gelation is the primary technique used to synthesize milk protein nanohydrogels, whereas the denaturation, aggregation, and gelation of proteins are of specific significance toward assembling novel nanostructures such as nanohydrogels with various possible applications. These are synthesized by either chemical cross-linking achieved through covalent bonds or physical cross-linking via noncovalent bonds. Milk-protein-based gelling systems can play a variety of functions such as in food nutrition and health, food engineering and processing, and food safety. Therefore, this review highlights the method to prepare milk protein nanohydrogel and its diverse applications in the food industry.