Nanoemulsions: formation, stability and an account of dietary polyphenol encapsulation

Trends in polysaccharide-based hydrogels and their role in enhancing the bioavailability and bioactivity of phytocompounds

Over the years, polysaccharides such as chitosan, alginate, hyaluronic acid, k-carrageenan, xanthan gum, carboxymethyl cellulose, pectin, and starch, alone or in combination with proteins and/or synthetic polymers, have been used to engineer an extensive portfolio of hydrogels with remarkable features. The application of polysaccharide-based hydrogels has the potential to alleviate challenges related to bioavailability, solubility, stability, and targeted delivery of phytocompounds, contributing to the development of innovative and efficient drug delivery systems and functional food formulations. This review highlights the current knowledge acquired on the preparation, features and applications of polysaccharide/phytocompounds hydrogel-based hybrid systems in wound management, drug delivery, functional foods, and food industry. The structural, functional, and biological requirements of polysaccharides and phytocompounds on the overall performance of such hybrid systems, and their impact on the application domains are also discussed.

Enzyme-assisted polysaccharides extraction from Calocybe indica: Synergistic antibiofilm and oxidative stability of essential oil nanoemulsion

Recently, mushroom polysaccharides have been explored to attribute to vital biologically important functions, and several extraction techniques can be employed, therefore, polysaccharides were extracted from the edible mushroom Calocybe indica to explore its functionality. Multiple enzymes viz., cellulase, pectinase, and protease (1:1:1) at temperature 47 °C and pH 4.64 with an extraction time of 2 h yielded 7.24 % polysaccharide content. The thermograph curve of polysaccharides showed two-stage decomposition at a different temperature range and decomposition of polysaccharides initiated with an onset temperature of 226.77 °C and a maximum peak at 248.90 °C. Hydrodistillation processed Eucalyptus globulus leaf oil was characterized using the chromatography technique and eucalyptol, p-cymene, Γ-terpinene, 4-epi-cubebol, spathulenol, viridiflorol, and p-mentha-1,5-dien-8-ol was observed as major components. As well, we formulated nanoemulsion using mushroom polysaccharide and eucalyptus leaf oil with 140.8 nm and evaluated synergistic antimicrobial and antibiofilm activity. MIC and MBC values for Pseudomonas aeruginosa, E. coli, and S. typhi were 12.50-3.125 and 6.25-1.56, and for S. aureus were 6.25, 6.25, 3.125, and 3.125, 3.125, 1.56 and for C. albicans the values were 12.50,12.50, 6.250 and 6.25,6.25, and 3.125 μl/mL respectively. The polysaccharides, essential oil, and nanoemulsion showed remarkable antibiofilm activity against S.aureus with inhibition of 57.42 ± 0.19, 59.62 ± 0.15, and 69.34 ± 0.19 %, while E. coli showed the least antibiofilm activity. However, all three tested samples showed significant (p < 0.05) differences against tested pathogenic microorganisms with inhibition of biofilm formation. Therefore, it could be inferred that the synergistic properties of essential oils with mushroom polysaccharides are a promising strategy to enhance antimicrobial efficacy and control foodborne pathogens.

Nano-delivery systems for encapsulation of phenolic compounds from pomegranate peel

Pomegranate fruit is getting more attention due to its positive health effects, and pomegranate peel (PP) is its main byproduct. PP has the potential to be converted from environmentally polluting waste to wealth due to its rich phenolic compounds such as ellagitannins, proanthocyanidins, and flavonoids with antioxidant, antimicrobial, and health effects. These phenolics are susceptible to environmental conditions such as heat, light, and pH as well as in vivo conditions of gastrointestinal secretions. Some phenolics of PP, e.g., ellagitannins could interfere with food ingredients and thus reduce their beneficial effects. Also, ellagitannins could form complexes with salivary glycoproteins, then a feeling of astringency taste. In this article, nano-delivery systems such as nanoparticles, nanoemulsions, and vesicular nanocarriers, designed and fabricated for PP bioactive compounds in recent years have been reviewed. Among them, lipid-based nano carriers i.e., solid lipid nanoparticles, nanostructured lipid carriers, and vesicular nanocarriers have low toxicity, large-scale production feasibility, easy synthesis, and high biocompatibility. So, it seems that the extraction and purification of bioactives from pomegranate wastes and nanoencapsulating them with cost effective and generally recognized as safe (GRAS) materials can be a bright prospect in enhancing the quality, safety, shelf life and health benefits of pomegranate products.

Preparation and characterization of geraniol nanoemulsions and its antibacterial activity

Geraniol nanoemulsions (G-NE) based on Tween 80 and medium chain triglyceride (MCT) as surfactant and co-surfactant, respectively, has been prepared by the spontaneous emulsification method. Its physical and chemical properties such as mean particle size, zeta potential, PDI, pH, viscosity, contact angle, appearance morphology, and stability (storage stability, thermal stability, centrifugal properties, acid-base stability, and freeze-thaw properties) of the droplet were analyzed. The results showed that the mean particle size of G-NE was 90.33 ± 5.23 nm, the PDI was 0.058 ± 0.0007, the zeta potential was -17.95 ± 5.85 mV and the encapsulation efficiency was >90%. The produced G-NE has been demonstrated to be fairly stable in long-term storage at 4°C, pH = 5 and high-speed centrifuges. Moreover, G-NE had a significant inhibition effect on Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Listeria monocytogenes (p < 0.05). The bacterial inhibition rates of G-NE at a concentration of 1 MIC were 48, 99, 71.73, and 99% after 12 h of action against these four foodborne pathogenic bacteria, respectively. Therefore, the results obtained indicated that nanoemulsification enhanced the stability and antibacterial activity of geraniol to some extent, which will promote the utilization of geraniol in food preservation.

Dietary Polyphenols Alleviate Autoimmune Liver Disease by Mediating the Intestinal Microenvironment: Challenges and Hopes

Autoimmune liver disease is a chronic liver disease caused by an overactive immune response in the liver that imposes a significant health and economic cost on society. Due to the side effects of existing medicinal medications, there is a trend toward seeking natural bioactive compounds as dietary supplements. Currently, dietary polyphenols have been proven to have the ability to mediate gut-liver immunity and control autoimmune liver disease through modulating the intestinal microenvironment. Based on the preceding, this Review covers the many forms of autoimmune liver illnesses, their pathophysiology, and the modulatory effects of polyphenols on immune disorders. Finally, we focus on how polyphenols interact with the intestinal milieu to improve autoimmune liver disease. In conclusion, we suggest that dietary polyphenols have the potential as gut-targeted modulators for the prevention and treatment of autoimmune liver disease and highlight new perspectives and critical issues for future pharmacological applications.

Nano-Strategies for Enhancing the Bioavailability of Tea Polyphenols: Preparation, Applications, and Challenges

Tea polyphenols (TPs) are among the most abundant functional compounds in tea. They exhibit strong antioxidant, anti-inflammatory, and anti-cancer effects. However, their instability and low bioavailability limits their applications. Nanotechnology, which involves the use of nanoscale substances (sizes ranging from 1 to 100 nm) to improve the properties of substances, provides a solution for enhancing the stability and bioavailability of TPs. We reviewed the preparation, performance, effects, and applications of different types of TPs nanocarriers. First, we introduced the preparation of different nanocarriers, including nanoparticles, nanoemulsions, nanomicelles, and nanolipids. Then, we discussed various applications of tea polyphenol-loaded nanocarriers in functional ingredient delivery, food quality improvement, and active food packaging. Finally, the challenges and future development directions of TPs nanocarriers were elucidated. In conclusion, a nano-strategy may be the “key” to break the application barriers of TPs. Therefore, the use of nano-strategies for the safe, stable, and efficient release of TPs is the direction of future research.