Encapsulation of Pomegranate Peel Extract (Punica granatum L.) by Double Emulsions: Effect of the Encapsulation Method and Oil Phase

Encapsulation of Indicaxanthin-Rich Opuntia Green Extracts by Double Emulsions for Improved Stability and Bioaccessibility

Opuntia ficus-indica var. Colorada fruit is an important source of indicaxanthin, a betalain with antioxidant, anti-inflammatory, and neuromodulatory potential, proven in both in vitro and in vivo models. Other betalains and phenolic compounds with bioactive activities have also been identified in Colorada fruit extracts. These compounds may degrade by their exposure to different environmental factors, so in the present research, two double emulsion systems (W1/O/W2) were elaborated using Tween 20 (TW) and sodium caseinate (SC) as surfactants to encapsulate Colorada fruit pulp extracts, with the aim of enhancing their stability during storage. Encapsulation efficiencies of up to 97.3 ± 2.7%, particle sizes between 236 ± 4 and 3373 ± 64 nm, and zeta potential values of up to ∣46.2∣ ± 0.3 mV were obtained. In addition, the evaluation of the in vitro gastro-intestinal stability and bioaccessibility of the main individual bioactives was carried out by standardized INFOGEST© protocol, obtaining the highest values for the encapsulated extract bioactives in comparison with the non-encapsulated extract (control). Especially, TW double emulsion showed bioaccessibility values of up to 82.8 ± 1.5% for the main bioactives (indicaxanthin, piscidic acid, and isorhamnetin glucoxyl-rhamnosyl-pentoside 2 (IG2)), indicating a promising potential for its use as a functional natural colorant ingredient.

Designing and fabrication of colloidal nano-phytosomes with gamma-oryzanol and phosphatidylcholine for encapsulation and delivery of polyphenol-rich extract from pomegranate peel

Nano-carriers are well-known delivery systems to encapsulate different bioactive compounds and extracts. Such nano-systems are used in various food and drug areas to protect active ingredients, increase bioavailability, control the release, and deliver bioactive substances. This study aimed to design and fabricate a stable colloidal nano-delivery system to better preserve the antioxidant properties of pomegranate peel extract (PPE) and protect its sustained release in a gastrointestinal model. To achieve this goal, a nano-phytosomal system was fabricated with plant-based, cost-effective, and food-grade compounds, i.e., phosphatidylcholine (PC) and gamma-oryzanol (GO) for encapsulation of PPE. To fabricate the nano-phytosomes, thin film hydration/sonication method was used. The parameters of particle size, zeta potential, polydispersity index (PDI), loading capacity (LC), and encapsulation efficiency (EE) were investigated to evaluate the efficiency of the produced nano-system. In summary, the size, zeta potential, PDI, LC, and EE of homogenous spherical PC-GO-PPE nano-phytosomes (NPs) in the ratio of 8:2:2 % w/w were achieved as 60.61 ± 0.81 nm, -32.24 ± 0.84 mV, 0.19 ± 0.01, 19.13 ± 0.30 %, and 95.66 ± 1.52 %, respectively. Also, the structure of NPs was approved by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). The optimized NPs were stable during one month of storage at 4 °C, and changes in the size of particles and PPE retention rate were insignificant (p > 0.05). The nano-encapsulation of PPE significantly decreased the loss of its antioxidant activity during one month of storage at 4 °C. The optimized NPs exhibited prolonged and sustained release of PPE in a gastrointestinal model, so that after 2 h in simulated gastric fluid (SGF) and 4 h in simulated intestinal fluid (SIF), 22.66 ± 2.51 % and 69.33 ± 4.50 % of initially loaded PPE was released, respectively. Optimized NPs had considerable cytotoxicity against the Michigan Cancer Foundation-7 cell line (MCF7) (IC50 = 103 μg/ml), but not against Human Foreskin Fibroblast cell line (HFF-2) (IC50 = 453 μg/ml). In conclusion, spherical PC-GO-PPE NPs were identified as a promising delivery system to efficiently encapsulate PPE, as well as protect and preserve its bioactivity, including antioxidant and cytotoxicity against cancer cell line.

Biopolymer- and Lipid-Based Carriers for the Delivery of Plant-Based Ingredients

Natural ingredients are gaining increasing attention from manufacturers following consumers’ concerns about the excessive use of synthetic ingredients. However, the use of natural extracts or molecules to achieve desirable qualities throughout the shelf life of foodstuff and, upon consumption, in the relevant biological environment is severely limited by their poor performance, especially with respect to solubility, stability against environmental conditions during product manufacturing, storage, and bioavailability upon consumption. Nanoencapsulation can be seen as an attractive approach with which to overcome these challenges. Among the different nanoencapsulation systems, lipids and biopolymer-based nanocarriers have emerged as the most effective ones because of their intrinsic low toxicity following their formulation with biocompatible and biodegradable materials. The present review aims to provide a survey of the recent advances in nanoscale carriers, formulated with biopolymers or lipids, for the encapsulation of natural compounds and plant extracts.

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.

Cellulose Nanofibers/Pectin/Pomegranate Extract Nanocomposite as Antibacterial and Antioxidant Films and Coating for Paper

Bio-based polymer composites find increasing research and industrial interest in different areas of our life. In this study, cellulose nanofibers (CNFs) isolated from sugar beet pulp and nanoemulsion prepared from sugar beet pectin and pomegranate extract (PGE) were used for making films and used as coating with antioxidant and antimicrobial activities for paper. For Pectin/PGE nanoemulsion preparation, different ratios of PGE were mixed with pectin using ultrasonic treatment; the antibacterial properties were evaluated to choose the formula with the adequate antibacterial activity. The antioxidant activity of the nanoemulsion with the highest antimicrobial activity was also evaluated. The nanoemulsion with the optimum antibacterial activity was mixed with different ratios of CNFs. Mechanical, greaseproof, antioxidant activity, and antibacterial properties of the CNFs/Pectin/PGE films were evaluated. Finally, the CNFs/Pectin/PGE formulation with the highest antibacterial activity was tested as a coating material for paper. Mechanical, greaseproof, and air porosity properties, as well as water vapor permeability and migration of the coated layer from paper sheets in different media were evaluated. The results showed promising applicability of the CNFs/Pectin/PGE as films and coating material with antibacterial and antioxidant activities, as well as good stability for packaging aqueous, fatty, and acidic food products.

From Pomegranate Byproducts Waste to Worth: A Review of Extraction Techniques and Potential Applications for Their Revalorization

The food industry is quite interested in the use of (techno)-functional bioactive compounds from byproducts to develop ‘clean label’ foods in a circular economy. The aim of this review is to evaluate the state of the knowledge and scientific evidence on the use of green extraction technologies (ultrasound-, microwave-, and enzymatic-assisted) of bioactive compounds from pomegranate peel byproducts, and their potential application via the supplementation/fortification of vegetal matrixes to improve their quality, functional properties, and safety. Most studies are mainly focused on ultrasound extraction, which has been widely developed compared to microwave or enzymatic extractions, which should be studied in depth, including their combinations. After extraction, pomegranate peel byproducts (in the form of powders, liquid extracts, and/or encapsulated, among others) have been incorporated into several food matrixes, as a good tool to preserve ‘clean label’ foods without altering their composition and improving their functional properties. Future studies must clearly evaluate the energy efficiency/consumption, the cost, and the environmental impact leading to the sustainable extraction of the key bio-compounds. Moreover, predictive models are needed to optimize the phytochemical extraction and to help in decision-making along the supply chain.

Ecological Synthesis of CuO Nanoparticles Using Punica granatum L. Peel Extract for the Retention of Methyl Green

The aqueous extract from the bark of Punica granatum L. was invested to generate CuO nanoparticles from CuSO4 using a green, economical, ecological, and clean method. The synthesized nanoparticles were characterized and were successfully used as adsorbents for methyl green retention of an absorptive capacity amounting to 28.7 mg g−1. Methyl green equilibrium adsorption data were correlated to the Langmuir model following the pseudo-second order kinetics model. This study clearly corroborates that copper nanoparticles exhibit a high potential for use in wastewater treatment.

Regulation Effects of Beeswax in the Intermediate Oil Phase on the Stability, Oral Sensation and Flavor Release Properties of Pickering Double Emulsions

Double emulsions (W/O/W) with compartmentalized structures have attracted a lot of research interests due to their diverse applications in the food industry. Herein, oil phase of double emulsions was gelled with beeswax (BW), and the effects of BW mass ratios (0-8.0%) on the stability, oral sensation, and flavor release profile of the emulsions were investigated. Rheological tests revealed that the mechanical properties of double emulsions were dependent on the mass ratio of BW. With the increase in BW content, double emulsions showed a higher resistance against deformation, and lower friction coefficient with a smoother mouthfeel. Turbiscan analysis showed that the addition of BW improved the stability of double emulsions during a 14 days' storage, under freeze-thawed, and osmotic pressure conditions, but it did not improve the heating stability of double emulsions. The addition of BW contributed to lower air-emulsion partition coefficients of flavor (2,3-diacetyl) compared to those without the addition of BW at 20 °C and 37 °C, respectively. Furthermore, the addition of BW and its mass ratio significantly altered the flavor release behavior during the open-bottle storage of double emulsions. The response value of 0% BW dropped sharply on the first day of opening storage, showing a burst release behavior. While a slow and sustained release behavior was observed in double emulsions with 8.0% BW. In conclusion, gelation of the intermediate oil phase of double emulsions significantly enhanced the stability of double emulsions with tunable oral sensation and flavor release by varying the mass ratio of beeswax.