Application of inulin for the formulation and delivery of bioactive molecules and live cells.

Inulin is a fructan biosynthesized mainly in plants of the Asteraceae family. It is also found in edible vegetables and fruits such as onion, garlic, leek, and banana. For the industrial production of inulin, chicory and Jerusalem artichoke are the main raw material. Inulin is used in the food, pharmaceutical, cosmetic as well biotechnological industries. It has a GRAS status and exhibits prebiotic properties. Inulin can be used as a wall material in the encapsulation process of drugs and other bioactive compounds and the development of their delivery systems. In the review, the use of inulin for the encapsulation of probiotics, essential and fatty oils, antioxidant compounds, natural colorant and other bioactive compounds is presented. The encapsulation techniques, materials and the properties of final products suitable for the delivery into food are discussed. Research limitations are also highlighted.

An Optimization Procedure for Preparing Aqueous CAR/HP-CD Aggregate Dispersions.

ß-Carotene is a very important molecule for human health. It finds a large application in the food industry, especially for the development of functional foods and dietary supplements. However, ß-carotene is an unstable compound and is sensitive to light, temperature, and oxygen. To overcome those limitations, various delivery systems were developed. The inclusion of ß-carotene by cyclodextrin aggregates is attractive due to non-toxicity, low hygroscopicity, stability, and the inexpensiveness of cyclodextrins. In this study, ß-carotene/2-hydroxypropyl-ß-cyclodextrin aggregates were prepared based on the procedure of the addition of ß-carotene in an organic solvent to the hot water dispersion of 2-hydroxypropyl-ß-cyclodextrin and the following instant evaporation of the organic solvent. The best conditions for the aggregate preparation were found to be as follows: 25% concentration of 2-hydroxypropyl-ß-cyclodextrin in water, 65 °C temperature, and acetone for ß-carotene dissolution. The efficiency of entrapping was equal to 88%. The procedure is attractive due to the short time of the aggregate preparation.

Microencapsulation of Bioactive Ingredients for Their Delivery into Fermented Milk Products: A Review.

The popularity and consumption of fermented milk products are growing. On the other hand, consumers are interested in health-promoting and functional foods. Fermented milk products are an excellent matrix for the incorporation of bioactive ingredients, making them functional foods. To overcome the instability or low solubility of many bioactive ingredients under various environmental conditions, the encapsulation approach was developed. This review analyzes the fortification of three fermented milk products, i.e., yogurt, cheese, and kefir with bioactive ingredients. The encapsulation methods and techniques alongside the encapsulant materials for carotenoids, phenolic compounds, omega-3, probiotics, and other micronutrients are discussed. The effect of encapsulation on the properties of bioactive ingredients themselves and on textural and sensory properties of fermented milk products is also presented.

Nisin-Loaded Ulvan Particles: Preparation and Characterization.

Nisin is an attractive alternative to chemical preservatives in the food industry. It is a cationic peptide of 34 amino acid residues that exhibits antimicrobial activity against Gram-positive bacteria. To ensure nisin stability in food matrices, new nisin-loaded ulvan particles were developed by the complexation method. The interaction of nisin with ulvan was demonstrated by FT-IR spectroscopy and differential scanning calorimetry. The encapsulation efficiency was calculated at different pH values within the range of 4.0-7.0 and was found to have the highest value at pH 7.0. The size and surface charge of particles fabricated at different concentrations of nisin and pH values were determined. Nisin-loaded ulvan particles exhibited antimicrobial activity against Gram-positive bacteria comparable to that of free nisin. Therefore, the developed complexes have the potential for application as biopreservatives in the food industry. For the first time, the potential of ulvan as a carrier of antimicrobial agent nisin was demonstrated.

Inactivation of Bacteria Using Bioactive Nanoparticles and Alternating Magnetic Fields.

Foodborne pathogens are frequently associated with risks and outbreaks of many diseases; therefore, food safety and processing remain a priority to control and minimize these risks. In this work, nisin-loaded magnetic nanoparticles were used and activated by alternating 10 and 125 mT (peak to peak) magnetic fields (AMFs) for biocontrol of bacteria Listeria innocua, a suitable model to study the inactivation of common foodborne pathogen L. monocytogenes. It was shown that L. innocua features high resistance to nisin-based bioactive nanoparticles, however, application of AMFs (15 and 30 min exposure) significantly potentiates the treatment resulting in considerable log reduction of viable cells. The morphological changes and the resulting cellular damage, which was induced by the synergistic treatment, was confirmed using scanning electron microscopy. The thermal effects were also estimated in the study. The results are useful for the development of new methods for treatment of the drug-resistant foodborne pathogens to minimize the risks of invasive infections. The proposed methodology is a contactless alternative to the currently established pulsed-electric field-based treatment in food processing.

Carotenoids: Considerations for Their Use in Functional Foods, Nutraceuticals, Nutricosmetics, Supplements, Botanicals, and Novel Foods in the Context of Sustainability, Circular Economy, and Climate Change.

Carotenoids are versatile isoprenoids that are important in food quality and health promotion. There is a need to establish recommended dietary intakes/nutritional reference values for carotenoids. Research on carotenoids in agro-food and health is being propelled by the two multidisciplinary international networks, the Ibero-American Network for the Study of Carotenoids as Functional Foods Ingredients (IBERCAROT; http://www.cyted.org) and the European Network to Advance Carotenoid Research and Applications in Agro-Food and Health (EUROCAROTEN; http://www.eurocaroten.eu). In this review, considerations for their safe and sustainable use in products mostly intended for health promotion are provided. Specifically, information about sources, intakes, and factors affecting bioavailability is summarized. Furthermore, their health-promoting actions and importance in public health in relation to the contribution of reducing the risk of diverse ailments are synthesized. Definitions and regulatory and safety information for carotenoid-containing products are provided. Lastly, recent trends in research in the context of sustainable healthy diets are summarized.

Preparation and characterization of iron oxide magnetic nanoparticles functionalized by nisin.

Nisin is a known bacteriocin approved as a food additive for food preservation. It exhibits a wide spectrum antimicrobial activity against Gram-positive bacteria. Iron oxide magnetic nanoparticles were synthesized and characterized by X-ray diffraction method. A main part of iron oxide nanoparticles was found to be maghemite though a small quantity of magnetite could also be present. Magnetic nanoparticles were stabilized by citric, ascorbic, gallic or glucuronic acid coating. Stable iron oxide magnetic nanoparticles were functionalized by nisin using a simple and low cost adsorption method. Nisin loading was confirmed by FT-IR spectra, thermogravimetric analysis, dynamic light scattering and atomic force microscopy methods. Nisin-loaded iron oxide magnetic nanoparticles were stable at least six weeks as judged by the measurements of zeta-potential and hydrodynamic diameter. The antimicrobial activity of nisin-loaded iron oxide magnetic nanoparticles was demonstrated toward Gram-positive bacteria. Functionalized nanoparticles could therefore find the application as antimicrobials in innovative and emerging technologies based on the magnetic field.

Inactivation of Escherichia coli Using Nanosecond Electric Fields and Nisin Nanoparticles: A Kinetics Study.

Nisin is a recognized bacteriocin widely used in food processing, however, being ineffective against gram-negative bacteria and in complex food systems. As a result, the research of methods that have cell wall-permeabilizing activity is required. In this study, electroporation to trigger sensitization of gram-negative bacteria to nisin-loaded pectin nanoparticles was used. As a model microorganism, bioluminescent strain of E. coli was introduced. Inactivation kinetics using nanosecond pulsed electric fields (PEFs) and nisin nanoparticles have been studied in a broad range (100-900 ns, 10-30 kV/cm) of pulse parameters. As a reference, the microsecond range protocols (100 µs × 8) have been applied. It was determined that the 20-30 kV/cm electric field with pulse duration ranging from 500 to 900 ns was sufficient to cause significant permeabilization of E. coli to trigger a synergistic response with the nisin treatment. The kinetics of the inactivation was studied with a time resolution of 2.5 min, which provided experimental evidence that the efficacy of nisin-based treatment can be effectively controlled in time using PEF. The results and the proposed methodology for rapid detection of bacteria inactivation rate based on bioluminescence may be useful in the development and optimization of protocols for PEF-based treatments.

Overcoming Antimicrobial Resistance in Bacteria Using Bioactive Magnetic Nanoparticles and Pulsed Electromagnetic Fields.

Nisin is a known bacteriocin, which exhibits a wide spectrum of antimicrobial activity, while commonly being inefficient against Gram-negative bacteria. In this work, we present a proof of concept of novel antimicrobial methodology using targeted magnetic nisin-loaded nano-carriers [iron oxide nanoparticles (NPs) (11-13 nm) capped with citric, ascorbic, and gallic acids], which are activated by high pulsed electric and electromagnetic fields allowing to overcome the nisin-resistance of bacteria. As a cell model the Gram-positive bacteria Bacillus subtilis and Gram-negative Escherichia coli were used. We have applied 10 and 30 kV cm-1 electric field pulses (100 µs × 8) separately and in combination with two pulsed magnetic field protocols: (1) high dB/dt 3.3 T × 50 and (2) 10 mT, 100 kHz, 2 min protocol to induce additional permeabilization and local magnetic hyperthermia. We have shown that the high dB/dt pulsed magnetic fields increase the antimicrobial efficiency of nisin NPs similar to electroporation or magnetic hyperthermia methods and a synergistic treatment is also possible. The results of our work are promising for the development of new methods for treatment of the drug-resistant foodborne pathogens to minimize the risks of invasive infections.