Essential oils as antimicrobials in food systems – A review

Antibacterial and antifungal activities of thymol: A brief review of the literature

Essential oil nanoemulsions as antimicrobial agents in food.

Core-shell biopolymer nanoparticle delivery systems: synthesis and characterization of curcumin fortified zein-pectin nanoparticles.

Today, there is an ever-growing interest on natural food ingredients both by consumers and producers in the food industry. In fact, people are looking for those products in the market which are free from artificial and synthetic additives and can promote their health. These food bioactive ingredients should be formulated in such a way that protects them against harsh process and environmental conditions and safely could be delivered to the target organs and cells. Nanoencapsulation is a perfect strategy for this situation and there have been many studies in recent years for nanoencapsulation of food components and nutraceuticals by different technologies. In this review paper, our main goal is firstly to have an overview of nanoencapsulation techniques applicable to food ingredients in a systematic classification, i.e., lipid-based nanocarriers, nature-inspired nanocarriers, special-equipment-based nanocarriers, biopolymer nanocarriers, and other miscellaneous nanocarriers. Then, application of these cutting-edge nanocarriers for different nutraceuticals including phenolic compounds and antioxidants, natural food colorants, antimicrobial agents and essential oils, vitamins, minerals, flavors, fish oils and essential fatty acids will be discussed along with presenting some examples in each field.

A systematic review on nanoencapsulation of food bioactive ingredients and nutraceuticals by various nanocarriers

In this work, a novel encapsulation method was studied by spray-drying a warm aqueous ethanol solution with codissolved sodium caseinate (NaCas) and lipophilic food components, using curcumin as a model compound. The encapsulation caused the loss of crystallinity of curcumin. After hydration of spray-dried powder and centrifugation, 137 μg/mL curcumin was dispersed in the transparent dispersion, which was 4 decades higher than its water solubility. Dynamic light scattering and atomic force microscopy results showed that curcumin-loaded casein nanoparticles were bigger than those of NaCas processed at encapsulation conditions but were smaller than those of the native NaCas. The increased nanoparticle dimension, together with fluorescence and FTIR spectroscopy results, suggested that curcumin was entrapped in the nanoparticle core through hydrophobic interactions. The curcumin encapsulated in casein nanoparticles had higher biological activity, as assessed by antioxidant and cell proliferation assays, than pristine curcumin, likely due to the improved dispersibility. This simple approach may be applied to encapsulate various lipophilic bioactive compounds.

Enhanced Dispersibility and Bioactivity of Curcumin by Encapsulation in Casein Nanocapsules

The poor water solubility and bioactivity of lipophilic phytochemicals can be potentially improved by delivery systems. In this study, a low-cost, low-energy, and organic solvent-free encapsulation technology was studied by utilizing the pH-dependent solubility properties of curcumin and self-assembly properties of sodium caseinate (NaCas). Curcumin was deprotonated and dissolved, while NaCas was dissociated at pH 12 and 21 °C for 30 min. The subsequent neutralization enabled the encapsulation of curcumin in self-assembled casein nanoparticles. The degradation of curcumin under encapsulation conditions was negligible based on visible light and nuclear magnetic resonance spectroscopy. The dissociation of NaCas at pH 12 and reassociation after neutralization were confirmed using dynamic light scattering and analytical ultracentrifugation. The curcumin encapsulated in casein nanoparticles showed significantly improved anti-proliferation activity against human colorectal and pancreatic cancer cells. The studied encapsulation method is promising to utilize lipophilic compounds in food or pharmaceutical industries.

pH-driven encapsulation of curcumin in self-assembled casein nanoparticles for enhanced dispersibility and bioactivity.

In this work, thymol was encapsulated in sodium caseinate using high shear homogenization. The transparent dispersion at neutral pH was stable for 30 days at room temperature as determined by dynamic light scattering and atomic force microscopy, which agreed with high ζ potential of nanoparticles. The slightly decreased particle dimension during storage indicates the absence of Ostwald ripening. When molecular binding was studied by fluorescence spectroscopy, thymol was observed to bind with tyrosine and possibly other amino acid residues away from tryptophan of caseins. At pH 4.6 (isoelectric point of caseins), the stabilization of thymol nanoparticles against aggregation was enabled by soluble soybean polysaccharide, resulting from the combined electrostatic and steric repulsions. The encapsulated thymol showed the significantly improved antilisterial activity in milk with different fat levels when compared to thymol crystals, resulting from the quicker mixing and increased solubility in the milk serum....

Kang Pan

Papers

Enhanced Dispersibility and Bioactivity of Curcumin by Encapsulation in Casein Nanocapsules

pH-driven encapsulation of curcumin in self-assembled casein nanoparticles for enhanced dispersibility and bioactivity.

Thymol Nanoencapsulated by Sodium Caseinate: Physical and Antilisterial Properties

Casein/pectin nanocomplexes as potential oral delivery vehicles.

Low energy, organic solvent-free co-assembly of zein and caseinate to prepare stable dispersions