ABSTRACT
This study aimed to evaluate the effect of nano-encapsulation of four essential amino acids (AA), threonine, methionine, tryptophan, and lysine on in vitro ruminal total gas, methane, carbon monoxide, and hydrogen sulfide production as well as the rumen fermentation profile in cattle. The highest (P < 0.001) rate and asymptotic gas production after 48 h of incubation was observed in the diets that had threonine, followed by lysine, methionine, and tryptophan. Asymptotic methane gas production decreased in the following order: threonine > lysine > tryptophan > methionine (P < 0.0001) and the rate of production per hour followed the same trend (P = 0.0259). CH4 parameters showed that in 4 h, 24 h, and 48 h of incubation the lowest methane production was obtained in the diet with methionine (P < 0.05) and the highest one in diet supplemented with threonine. Methane fractions showed that methionine-containing diets resulted in more (P < 0.05) metabolizable energy versus methane, followed by tryptophan-containing, and then lysine-containing diets. Methionine-fortified diets seem to be the most eco-friendly among those studied regarding methane output. However, based on methane, CO, and H2S output as well as the rumen fermentation profile nano-encapsulated lysine is recommended for use in ruminant nutrition.
ABSTRACT
The immunoregulatory cation channel TMEM176B plays a dual role in tumor immunity. On the one hand, TMEM176B promotes antigen cross-presentation to CD8+ T cells by regulating phagosomal pH in dendritic cells (DCs). On the other hand, it inhibits NLRP3 inflammasome activation through ionic mechanisms in DCs, monocytes and macrophages. We speculated that formulating BayK8644 in PEGylated chitosan nanoparticles (NP-PEG-BayK8644) should slowly release the compound and by that mean avoid cross-presentation inhibition (which happens with a fast 30 min kinetics) while still triggering inflammasome activation. Chitosan nanocarriers were successfully obtained, exhibiting a particle size within the range of 200 nm; they had a high positive surface charge and a 99 % encapsulation efficiency. In in vitro studies, NP-PEG-BayK8644 did not inhibit antigen cross-presentation by DCs, unlike the free compound. The NP-PEG-BayK8644 activated the inflammasome in a Tmem176b-dependent manner in DCs. We administered either empty (eNP-PEG) or NP-PEG-BayK8644 to mice with established tumors. NP-PEG-BayK8644 significantly controlled tumor growth and improved mice survival compared to both eNP-PEG and free BayK8644 in melanoma and lymphoma models. This effect was associated with enhanced inflammasome activation by DCs in the tumor-draining lymph node and infiltration of the tumor by CD8+ T cells. Thus, encapsulation of BayK8644 in chitosan NPs improves the anti-tumoral properties of the compound by avoiding inhibition of antigen cross-presentation.
Subject(s)
Adaptive Immunity , Chitosan , Dendritic Cells , Immunity, Innate , Nanoparticles , Chitosan/chemistry , Chitosan/pharmacology , Animals , Nanoparticles/chemistry , Mice , Adaptive Immunity/drug effects , Dendritic Cells/immunology , Dendritic Cells/drug effects , Immunity, Innate/drug effects , Membrane Proteins/immunology , Inflammasomes/metabolism , Cell Line, Tumor , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/drug effects , Mice, Inbred C57BL , Melanoma, Experimental/immunology , Melanoma, Experimental/pathology , Melanoma, Experimental/drug therapy , Polyethylene Glycols/chemistry , Polyethylene Glycols/pharmacologyABSTRACT
Maqui berries contain a high percentage of anthocyanins with high antioxidant and anti-inflammatory capacity but that are unstable in the colonic site. Nanocarriers based on polysaccharides and/or proteins can protect against the degradation of anthocyanins. The aim of this study was the nanoencapsulation of maqui extract (ME) in chitosan-tripolyphosphate (CTPP-ME), chenopodin (CH-ME), and chenopodin-alginate (CHA-ME). A standardised ME was prepared and then encapsulated in the nanosystems. The physicochemical properties, encapsulation parameters, and the interactions of ME with the nanovehicles were characterised. The cyanidin-3-glucoside released and ORAC activity in phosphate buffer at pH 7.4 were evaluated. The content of ME was 8-9 mg of cyanidin-3-glucoside/g of extract. CTPP with ME at 3% obtained the highest encapsulation efficiency (EE = 91%), and no significant differences were observed in size (274-362 nm), PDI (0.5-0.7), and zeta potential (+34-+41 mV) when the concentration of ME changed from 1% to 5%. CH-ME was shown to be smaller (152 nm) than CTPP-ME, and CH-ME and CHA-ME showed lower EE (79% and 54%, respectively) than CTPP-ME. FT-IR revealed a stronger interaction of ME with CTPP-ME than with CH-ME. Both systems showed a significantly lower release than free ME, and the T50 value of CTPP-ME 3% (328 min) was higher than CH-ME (197 min). Both protected the ORAC activity of ME.
ABSTRACT
Anthocyanins (ACNs) are natural compounds with potential applications due to their colorimetric response to pH. Due to their sensitivity to various environmental factors, nanoencapsulation with biopolymers is a successful strategy for stabilizing ACNs. In this work ACNs were extracted from grape skins and encapsulated into chitosan (CS) nanoparticles by ionic gelation using sodium tripolyphosphate (TPP) as a cross-linking agent. CS nanoparticles loaded with ACNs had particle sizes between 291 and 324 nm and polydispersity index around 0.3. The encapsulation efficiency of ACNs was approximately 60 %; and encapsulated anthocyanins (ACN-NPs) exhibited color change properties under different pH conditions. pH-sensitive labels based on polyvinyl alcohol (PVA) were prepared by the casting method. The effect of incorporating ACN-NPs on the physical, structural, and pH-sensitive properties of PVA labels was evaluated, and its application as shrimp freshness indicator was studied. The nanoencapsulation protected ACNs against heat and light treatments, preserving the original purple color. When applying the label, visible changes from red to blue until reaching yellow were observed with the change in the quality of the shrimp at the refrigeration temperature. The results suggest that PVA labels containing ACNs encapsulated in C-NPs can be used as smart packaging labels in the food industry.
Subject(s)
Chitosan , Nanoparticles , Vitis , Chitosan/chemistry , Polyvinyl Alcohol/chemistry , Anthocyanins/chemistry , Nanoparticles/chemistry , Plant Extracts/chemistry , Food Packaging/methods , Hydrogen-Ion ConcentrationABSTRACT
This study aimed to evaluate the antibacterial and inhibitory action of NorA, Tet(K), MsrA and MepA efflux pumps in S. aureus strains using the sesquiterpenes named trans-caryophyllene and caryophyllene oxide, both isolated and encapsulated in liposomes. The antibacterial and inhibitory action of these efflux pumps was evaluated through the serial microdilution test in 96-well microplates. Each sesquiterpene and liposome/sesquiterpene was combined with antibiotics and ethidium bromide (EtBr). The antibiotics named norfloxacin, tetracycline and erythromycin were used. The 1199 B, IS-58, RN4220 and K2068 S. aureus strains carrying NorA, Tet(K), MsrA and MepA, respectively, were tested. In the fluorescence measurement test, K2068 S. aureus was incubated with the sesquiterpenes and EtBr, and the fluorescence emission by EtBr was measured. The tested substances did not show direct antibacterial activity, with MIC >1024 µg/mL. Nonetheless, the isolated trans-caryophyllene and caryophyllene oxide reduced the MIC of antibiotics and EtBr, indicating inhibition of NorA, Tet(K) and MsrA. In the fluorescence test, these same sesquiterpenes increased fluorescence emission, indicating inhibition of MepA. Therefore, the sesquiterpenes named trans-caryophyllene and caryophyllene oxide did not show direct antibacterial action; however, in their isolated form, they showed possible inhibitory action on NorA, Tet(K), MsrA and MepA efflux pumps. They may also act in antibiotic potentiation. Further studies are needed to identify the mechanisms involved in antibiotic potentiation and efflux pump inhibitory action.
Subject(s)
Liposomes , Staphylococcus aureus , Staphylococcus aureus/metabolism , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology , Polycyclic Sesquiterpenes , Ethidium , Bacterial Proteins/metabolism , Multidrug Resistance-Associated ProteinsABSTRACT
The challenge of low water solubility in pharmaceutical science profoundly impacts drug absorption and therapeutic effectiveness. Nanocrystals (NC), consisting of drug molecules and stabilizing agents, offer a promising solution to enhance solubility and control release rates. In the pharmaceutical industry, top-down techniques are favored for their flexibility and cost-effectiveness. However, increased solubility can lead to premature drug dissolution in the stomach, which is problematic due to the acidic pH or enzymes. Researchers are exploring encapsulating agents that facilitate drug release at customized pH levels as a valuable strategy to address this. This study employed wet milling and spray drying techniques to create encapsulated NC for delivering the drug to the intestinal tract using the model drug ivermectin (IVM). Nanosuspensions (NS) were efficiently produced within 2 h using NanoDisp®, with a particle size of 198.4 ± 0.6 nm and a low polydispersity index (PDI) of 0.184, ensuring uniformity. Stability tests over 100 days at 4 °C and 25 °C demonstrated practical viability, with no precipitation or significant changes observed. Cytotoxicity evaluations indicated less harm to Caco-2 cells compared to the pure drug. Furthermore, the solubility of the NC increased by 47-fold in water and 4.8-fold in simulated intestinal fluid compared to the pure active compound. Finally, dissolution tests showed less than 10% release in acidic conditions and significant improvement in simulated intestinal conditions, promising enhanced drug solubility and bioavailability. This addresses a long-standing pharmaceutical challenge in a cost-effective and scalable manner.
Subject(s)
Chemistry, Pharmaceutical , Nanoparticles , Humans , Chemistry, Pharmaceutical/methods , Caco-2 Cells , Pharmaceutical Preparations/chemistry , Solubility , Biological Availability , Nanoparticles/chemistry , Water , Hydrogen-Ion Concentration , Particle SizeABSTRACT
The substitution of synthetic food dyes with natural colorants continues to be assiduously pursued. The current list of natural carotenoid colorants consists of plant-derived annatto (bixin and norbixin), paprika (capsanthin and capsorubin), saffron (crocin), tomato and gac fruit lycopene, marigold lutein, and red palm oil (α- and ß-carotene), along with microalgal Dunaliella ß-carotene and Haematococcus astaxanthin and fungal Blakeslea trispora ß-carotene and lycopene. Potential microalgal sources are being sought, especially in relation to lutein, for which commercial plant sources are lacking. Research efforts, manifested in numerous reviews and research papers published in the last decade, have been directed to green extraction, microencapsulation/nanoencapsulation, and valorization of processing by-products. Extraction is shifting from conventional extraction with organic solvents to supercritical CO2 extraction and different types of assisted extraction. Initially intended for the stabilization of the highly degradable carotenoids, additional benefits of encapsulation have been demonstrated, especially the improvement of carotenoid solubility and bioavailability. Instead of searching for new higher plant sources, enormous effort has been directed to the utilization of by-products of the fruit and vegetable processing industry, with the application of biorefinery and circular economy concepts. Amidst enormous research activities, however, the gap between research and industrial implementation remains wide.
ABSTRACT
Cantaloupe melon is known for its carotenoid-rich orange pulp. However, carotenoids are sensitive to oxygen, light, and heat, potentially reducing their benefits. Nanoencapsulation can preserve these benefits but raises concerns about toxicity. We aimed to assess the safety and bioactive potential of crude extract-rich carotenoids (CE) and nanoparticles based on gelatin loaded with CE (EPG) by investigating parameters such as cardio or neurotoxicity, especially acute toxicity. EPG was obtained by O/W emulsification and characterized by different methods. Zebrafish embryos were exposed to CE and EPG at 12.5 mg/L and 50 mg/L for 96h and were investigated for survival, hatching, malformations, and seven days post fertilization (dpf) larvae's visual motor response. Adult fish underwent behavioral tests after acute exposure of 96h. CE and EPG showed no acute toxicity in zebrafish embryos, and both improved the visual motor response in 7dpf larvae (p = 0.01), suggesting the potential antioxidant and provitamin A effect of carotenoids in cognitive function and response in the evaluated model. Adult fish behavior remained with no signs of anxiety, stress, swimming pattern changes, or sociability that would indicate toxicity. This study highlights the safety and potential benefits of carotenoids in zebrafish. Further research is needed to explore underlying mechanisms and long-term effects.
Subject(s)
Cucumis melo , Nanoparticles , Water Pollutants, Chemical , Animals , Carotenoids/pharmacology , Zebrafish , Gelatin/pharmacology , Larva , Water Pollutants, Chemical/toxicity , Embryo, NonmammalianABSTRACT
The application of oils in the food industry is challenging, owing to their inherent factors such as oxidation. Therefore, new technologies, such as nanoencapsulation, are being developed. Among the nanoencapsulated oils, essential oils (EO) and edible oils stand out for their high consumer demand. This review analyzes the production, characterization, stability, and market scenario of edible and EO nanoparticles applied in foods. Homogenization was found to be the most common technique for producing oil nanoparticles. Different encapsulants were used, and Tween 80 was the main emulsifier. Approximately 80% of the nanoparticles were smaller than 200 nm, and the polydispersibility index and zeta potential values were satisfactory, mainly for nanoparticles containing EO, whereas encapsulation efficiency varied based on the technique and the type of oil used. Oil nanoparticles were mainly applied on meat products. The temperatures and times used in the stability tests of foods containing oil nanoparticles varied depending on the food matrix, especially in microbiological and physicochemical analyses. Only one product with nanoencapsulated oil in its composition was found in the market. Oil nanoparticles have great potential in the development of innovative, economically viable, and sustainable techniques for producing new food products that are high in nutrition value.
ABSTRACT
In vitro and in vivo studies have demonstrated the bioactivity of rutin, a dietary flavonol naturally found in several plant species. Despite widespread knowledge of its numerous health benefits, such as anti-inflammatory, antidiabetic, hepatoprotective and cardiovascular effects, industrial use of rutin is still limited due to its low solubility in aqueous media, the characteristic bitter and astringent taste of phenolic compounds and its susceptibility to degradation during processing. To expand its applications and preserve its biological activity, novel encapsulation systems have been developed. This review presents updated research on the extraction sources and methodologies of rutin from fruit and vegetable products commonly found in a regular diet and grown using family farming approaches. Additionally, this review covers quantitative analysis techniques, encapsulation methods utilizing nanoparticles, colloidal and heterodisperse systems, as well as industrial applications of rutin.
Subject(s)
Antioxidants , Rutin , Rutin/pharmacology , Antioxidants/pharmacology , Antioxidants/analysis , Phenols/analysis , Fruit/chemistry , Plant Extracts/pharmacology , AgricultureABSTRACT
Plant-derived polyphenols are naturally occurring compounds widely distributed in plants. They have received greater attention in the food and pharmaceutical industries due to their potential health benefits, reducing the risk of some chronic diseases due to their antioxidant, anti-inflammatory, anticancer, cardioprotective, and neuro-action properties. Polyphenolic compounds orally administered can be used as adjuvants in several treatments but with restricted uses due to chemical instability. The review discusses the different structural compositions of polyphenols and their influence on chemical stability. Despite the potential and wide applications, there is a need to improve the delivery of polyphenolics to target the human intestine without massive chemical modifications. Oral administration of polyphenols is unfeasible due to instability, low bioaccessibility, and limited bioavailability. Nano-delivery systems based on polysaccharides (starch, pectin, chitosan, and cellulose) have been identified as a viable option for oral ingestion, potentiate biological effects, and direct-controlled delivery in specific tissues. The time and dose can be individualized for specific diseases, such as intestinal cancer. This review will address the mechanisms by which polysaccharides-based nanostructured systems can protect against degradation and enhance intestinal permeation, oral bioavailability, and the potential application of polysaccharides as nanocarriers for the controlled and targeted delivery of polyphenolic compounds.
ABSTRACT
In the last decades, evidence has indicated the beneficial properties of dietary polyphenols. In vitro and in vivo studies support that the regular intake of these compounds may be a strategy to reduce the risks of some chronic non-communicable diseases. Despite their beneficial properties, they are poorly bioavailable compounds. Thus, the main objective of this review is to explore how nanotechnology improves human health while reducing environmental impacts with the sustainable use of vegetable residues, from extraction to the development of functional foods and supplements. This extensive literature review discusses different studies based on the application of nanotechnology to stabilize polyphenolic compounds and maintain their physical-chemical stability. Food industries commonly generate a significant amount of solid waste. Exploring the bioactive compounds of solid waste has been considered a sustainable strategy in line with emerging global sustainability needs. Nanotechnology can be an efficient tool to overcome the challenge of molecular instability, especially using polysaccharides such as pectin as assembling material. Complex polysaccharides are biomaterials that can be extracted from citrus and apple peels (from the juice industries) and constitute promising wall material stabilizing chemically sensitive compounds. Pectin is an excellent biomaterial to form nanostructures, as it has low toxicity, is biocompatible, and is resistant to human enzymes. The potential extraction of polyphenols and polysaccharides from residues and their inclusion in food supplements may be a possible application to reduce environmental impacts and constitutes an approach for effectively including bioactive compounds in the human diet. Extracting polyphenolics from industrial waste and using nanotechnology may be feasible to add value to food by-products, reduce impacts on nature and preserve the properties of these compounds.
ABSTRACT
Liposomes have been used for several decades for the encapsulation of drugs and bioactives in cosmetics and cosmeceuticals. On the other hand, the use of these phospholipid vesicles in food applications is more recent and is increasing significantly in the last ten years. Although in different stages of technological maturity-in the case of cosmetics, many products are on the market-processes to obtain liposomes suitable for the encapsulation and delivery of bioactives are highly expensive, especially those aiming at scaling up. Among the bioactives proposed for cosmetics and food applications, vitamins are the most frequently used. Despite the differences between the administration routes (oral for food and mainly dermal for cosmetics), some challenges are very similar (e.g., stability, bioactive load, average size, increase in drug bioaccessibility and bioavailability). In the present work, a systematic review of the technological advancements in the nanoencapsulation of vitamins using liposomes and related processes was performed; challenges and future perspectives were also discussed in order to underline the advantages of these drug-loaded biocompatible nanocarriers for cosmetics and food applications.
ABSTRACT
Curcumin and vitamin D3 are bioactive molecules of great importance for the food industry. However, their low stability in several processing conditions hampers their proper incorporation into powdered food formulations. This study proposes the enrichment of a common raw material (cornstarch) with curcumin and vitamin D3 by using high-shear wet agglomeration. The bioactives were initially encapsulated into liposome dispersions and then subjected to lyophilization. The resulting dried vesicles were later incorporated into cornstarch by wet agglomeration using maltodextrin as the binder solution. The phospholipid content and the amount of added liposomes were evaluated to characterize the enriched cornstarch samples. The lyophilized vesicles showed a high retention rate of 99 % for curcumin and vitamin D3, while the enriched cornstarch samples retained above 96 % (curcumin) and 98 % (vitamin D3) after 30 days of controlled storage. All in all, the presence of dried liposomes improved the flowability and delayed retrogradation phenomenon in agglomerated cornstarch. Therefore, this study introduced a novel and reliable method of incorporating hydrophobic and thermosensitive molecules into powdered food formulations by using readily available materials and a straightforward high-shear wet agglomeration process.
Subject(s)
Curcumin , Liposomes , Liposomes/chemistry , Starch , Cholecalciferol/chemistry , Curcumin/chemistry , Phospholipids/chemistryABSTRACT
Nanoencapsulation can increase the stability of bioactive compounds, ensuring protection against physical, chemical, or biological degradations, and allows to control of the release of these biocompounds. Chia oil is rich in polyunsaturated fatty acids-8% corresponds to omega 3 and 19% to omega 6-resulting in high susceptibility to oxidation. Encapsulation techniques allow the addition of chia oil to food to maintain its functionality. In this sense, one strategy is to use the nanoemulsion technique to protect chia oil from degradation. Therefore, this review aims to present the state-of-the-art use of nanoemulsion as a new encapsulation approach to chia oil. Furthermore, the chia mucilage-another chia seed product-is an excellent material for encapsulation due to its good emulsification properties (capacity and stability), solubility, and water and oil retention capacities. Currently, most studies of chia oil focus on microencapsulation, with few studies involving nanoencapsulation. Chia oil nanoemulsion using chia mucilage presents itself as a strategy for adding chia oil to foods, guaranteeing the functionality and oxidative stability of this oil.
Subject(s)
Plant Oils , Salvia , Plant Oils/chemistry , Salvia/chemistry , Polysaccharides/analysis , Plant Extracts/analysis , Seeds/chemistryABSTRACT
Beehive derivatives, including honeybee pollen (HBP), have been extensively studied for their beneficial health properties and potential therapeutic use. Its high polyphenol content gives it excellent antioxidant and antibacterial properties. Today its use is limited due to poor organoleptic properties, low solubility, stability, and permeability under physiological conditions. A novel edible multiple W/O/W nanoemulsion (BP-MNE) to encapsulate the HBP extract was designed and optimized to overcome these limitations. The new BP-MNE has a small size (â¼100 nm), a zeta potential greater than +30 mV, and efficiently encapsulated phenolic compounds (â¼82%). BP-MNE stability was measured under simulated physiological conditions and storage conditions (4 months); in both cases, stability was promoted. The formulation's antioxidant and antibacterial (Streptococcus pyogenes) activity was analyzed, obtaining a higher effect than the non-encapsulated compounds in both cases. In vitro permeability was tested, observing a high permeability of the phenolic compounds when they are nanoencapsulated. With these results, we propose our BP-MNE as an innovative solution to encapsulate complex matrices, such as HBP extract, as a platform to develop functional foods.
Subject(s)
Antioxidants , Phenols , Bees , Animals , Antioxidants/pharmacology , Chile , Anti-Bacterial Agents/pharmacology , Permeability , PollenABSTRACT
Essential oils (EO) are compounds synthesized by plants as secondary products and are a complex mixture of volatile molecules. Studies have demonstrated their pharmacological activity in the prevention and treatment of metabolic syndrome (MetS). Moreover, they have been used as antimicrobial and antioxidant food additives. The first part of this review discusses the role of EO as nutraceuticals to prevent metabolic syndrome-related disorders (i.e., obesity, diabetes, and neurodegenerative diseases), showing results from in vitro and in vivo studies. Likewise, the second part describes the bioavailability and mechanisms of action of EO in preventing chronic diseases. The third part presents the application of EO as food additives, pointing out their antimicrobial and antioxidant activity in food formulations. Finally, the last part explains the stability and methods for encapsulating EO. In conclusion, EO dual role as nutraceuticals and food additives makes them excellent candidates to formulate dietary supplements and functional foods. However, further investigation is needed to understand EO interaction mechanisms with human metabolic pathways and to develop novel technological approaches to enhance EO stability in food systems to scale up these processes and, in this way, to overcome current health problems.
ABSTRACT
ß-carotene-loaded nanoparticles improves absorption by increasing bioavailability. The Drosophila melanogaster model of Parkinson's disease must be helpful in investigating potential neuroprotective effects. Four groups of four-day-old flies were exposed to: (1) control; (2) diet containing rotenone (500 µM); (3) ß-carotene-loaded nanoparticles (20 µM); (4) ß-carotene-loaded nanoparticles and rotenone for 7 days. Then, the percentage of survival, geotaxis tests, open field, aversive phototaxis and food consumption were evaluated. At the end of the behaviors, the analyses of the levels of reactive species (ROS), thiobarbituric acid reactive substances (TBARS), catalase (CAT) and superoxide dismutase (SOD) activity was carried out, as well as an evaluation of the levels of dopamine and acetylcholinesterase (AChE) activity, in the head of flies. Nanoparticles loaded with ß-carotene were able to improve motor function, memory, survival and also restored the oxidative stress indicators (CAT, SOD, ROS and TBARS), dopamine levels, AChE activity after exposure to rotenone. Overall, nanoparticles loaded with ß-carotene showed significant neuroprotective effect against damage induced by the Parkinson-like disease model, emerging as a possible treatment. Overall, ß-carotene-loaded nanoparticles presented significant neuroprotective effect against damage induced by model of Parkinson-like disease, emerging as a possible treatment.
Subject(s)
Nanoparticles , Neuroprotective Agents , Parkinson Disease , Animals , Parkinson Disease/drug therapy , Parkinson Disease/prevention & control , Drosophila melanogaster , beta Carotene/pharmacology , Antioxidants/pharmacology , Antioxidants/metabolism , Dopamine , Rotenone , Reactive Oxygen Species , Neuroprotective Agents/pharmacology , Thiobarbituric Acid Reactive Substances , Acetylcholinesterase/metabolism , Oxidative Stress , Superoxide Dismutase/metabolism , Disease Models, AnimalABSTRACT
Chitosan nanocapsules containing polyunsaturated fatty acid (PUFA) concentrates from tuna oil, with EPA + DHA contents around 57% (w w-1), were developed by emulsification process, using different chitosan concentration (1.0%, 1.5%, 2.0%, w v-1) and stirring speed (10,000, 15,000, 20,000â rpm). The effects of these parameters on particle size and zeta potential were evaluated. The physical and oxidative stabilities were used to measure the product quality during storage. Chitosan concentration, stirring speed and its interaction significantly affected (p < 0.05) the particle size. In addition, chitosan concentration significantly affected (p < 0.05) the zeta potential of nanocapsules emulsion. Based on the results of physical and oxidative stabilities, the nanocapsules were stable for 30 days under refrigeration temperature (7â °C), and with 1.5-2% chitosan resulted in improved protection against oil oxidation. The nanocapsules produced with 2% chitosan and 10,000â rpm showed the lowest variations of polydispersity index and nanocapsules size after 30 days of storage (221.8 ± 3.0â nm). These conditions can be considered the most suitable to produce nanocapsules of PUFA concentrates from tuna oil using chitosan as wall material. These nanocapsules showed physical characteristics and oxidative stability, which could enable their application in the food industry, representing an important source of EPA and DHA fatty acids.
ABSTRACT
Liposomes are among the most studied nanostructures. They are effective carriers of active substances both in the clinical field, such as delivering genes and drugs, and in the food industry, such as promoting the controlled release of bioactive substances, including food preservatives. However, toxicological screenings must be performed to ensure the safety of nanoformulations. In this study, the nematode Caenorhabditis elegans was used as an alternative model to investigate the potential in vivo toxicity of nanoliposomes encapsulating the antimicrobial peptide nisin. The effects of liposomes containing nisin, control liposomes, and free nisin were evaluated through the survival rate, lethal dose (LD50), nematode development rate, and oxidative stress status by performing mutant strain, TBARS, and ROS analyses. Due to its low toxicity, it was not possible to experimentally determine the LD50 of liposomes. The survival rates of control liposomes and nisin-loaded liposomes were 94.3 and 73.6%, respectively. The LD50 of free nisin was calculated as 0.239 mg mL-1. Free nisin at a concentration of 0.2 mg mL-1 significantly affected the development of C. elegans, which was 25% smaller than the control and liposome-treated samples. A significant increase in ROS levels was observed after exposure to the highest concentrations of liposomes and free nisin, coinciding with a significant increase in catalase levels. The treatments induced lipid peroxidation as evaluated by TBARS assay. Liposome encapsulation reduces the deleterious effect on C. elegans and can be considered a nontoxic delivery system for nisin.