Fabrication and characterization of pectin-zein nanoparticles containing tanshinone using anti-solvent precipitation method.

Tanshinone compounds are secondary metabolites which their application in food and pharmaceutical industry is limited due to the low solubility in water and sensitivity to heat. This study aimed to develop a novel biopolymer nanocarriers system based on pectin/zein for the encapsulation of tanshinone compounds using the anti-solvent precipitation method. The concentration of pectin and mass ratio of tanshinone/zein in the final formulation of nanoparticles were optimized. According to the results, a pectin concentration of 1 g/L and a tanshinone/zein ratio of 0.1:1 g/g were considered the optimal nanoparticle formulation. The resulting nanoparticles exhibited a spherical core-shell structure, with approximate values for size, zeta potential, TSI, and encapsulation efficiency of 132 ± 0.002 nm, -38.6 ± 0.019 mV, 0.600 ± 0.084, and 79.41 ± 0.62 %, respectively. The FTIR test confirmed the presence of hydrophobic, hydrogen, and electrostatic interactions among the constituents within the nanoparticles. Additionally, XRD and DSC tests verified the amorphous nature of the nanoparticles. Morphological examination conducted through TEM, and SEM revealed the characteristics of the resulting nanoparticles. Furthermore, this carrier system significantly enhanced the solubility of tanshinone compounds in water.

Antioxidant and antimicrobial efficacy of microencapsulated mustard essential oil against Escherichia coli and Salmonella Enteritidis in mayonnaise.

The aim of this study was to investigate the effect of pure and encapsulated mustard essential oil (MEO) on the shelf life of mayonnaise and its ability to be an alternative for synthetic preservatives. Determination of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) indicated higher sensitivity of Escherichia coli O157:H7 (E. coli O157:H7) (MIC: 512 ppm, MBC: 1024 ppm) than Salmonella Enteritidis (S. enteritidis) (MIC: 1024 ppm, MBC: 2048 ppm) to MEO. Mayonnaise samples, were subsequently prepared according to the determined MIC and MBC of MEO for microbial analysis and physicochemical analysis. The antimicrobial activity of MEO in mayonnaise over 40-day storage indicated that the application of free and encapsulated MEO could inhibit the growth of target bacteria. In addition, the oxidative stability of mayonnaise samples exhibited decreasing trends over the storage time. At the end of the storage, the control sample without any preservatives revealed the highest peroxide value (3.59 meq O2 /kg of oil) whereas the sample containing 4096 ppm encapsulated MEO (2 meq O2/kg of oil) exhibited better oxidative stability, following t-butyl-hydroxyquinone (TBHQ) (1.84 meq O2 /kg of oil) as commercial antioxidant. Interestingly, the application of 2048 and 4096 ppm encapsulated essential oil had no undesirable effect on overall acceptance of mayonnaise, while the application of pure MEO at the same concentrations negatively affected the color, odor, taste and overall acceptability.

Application of natural fining agents to clarify fruit juices.

The consumption of fruit juices has been increasingly growing all over the world. The clarification process is considered as one of the most important stages in fruit juice production, which can provide the products with desired clear visual appearance. Nowadays, the tendency of consumers to use the natural-clarified fruit juices encourages the researchers to allocate much attention on utilization of natural clarifying agents to clarify different fruit juices. This review article has first introduced the most frequent causes of turbidity in fruit juices including polysaccharides (i.e., cellulose, hemicelluloses, lignin, starch, and pectic substances), proteins and polyphenols (especially tannins) as well as their removal mechanisms. After that, a comprehensive summary of research on natural fining agents, including clay minerals, polysaccharides, proteins, enzymes (free and immobilized forms), and activated carbon is provided with a focus on their application in the juice clarification process. The chemical composition of natural substances, their efficiency on reduction of turbidity-causing compounds and the changes in properties of clarified juices such as turbidity (clarity), total phenolic content, total anthocyanins, viscosity, and sensory evaluation followed by their stability during the storage have been deeply discussed.

Segregative phase separation of gelatin and tragacanth gum solution and Mickering stabilization of their water-in-water emulsion with microgel particles prepared by complex coacervation.

This study aimed to investigate the segregative interaction of gelatin (G) and tragacanth gum (TG) and the stabilization of their water-in-water (W/W) emulsion by G-TG complex coacervate particles. Segregation was studied at different pHs, ionic strengths and biopolymer concentrations. Results showed that incompatibility was affected by increasing the biopolymer concentrations. So, three reigns were demonstrated in the phase diagram of the salt-free samples. NaCl significantly changed the phase behavior via enhancement of self-association of polysaccharide and changing solvent quality due to the charge screening effect of ions. The W/W emulsion prepared from these two biopolymers and stabilized with G-TG complex particles was stable for at least one week. The microgel particles improved emulsion stability by adsorption to the interface and creating a physical barrier. A fibrous and network-like structure of the G-TG microgels was observed by scanning electron microscopy images suggesting the Mickering emulsion stabilization mechanism. It was confirmed that the bridging flocculation between the microgel polymers led to phase separation after the stability period. Biopolymer incompatibility investigation is a useful tool to obtain beneficial knowledge for preparation new food formulation, especially no contain oil emulsions for low- calorie diets.

Influence of fatty acid-esterified waxy maize starch type and concentration on stability and properties of oil-in-water emulsions.

In the current study, native and different fatty acid-esterified waxy maize starches (octanoate, myristoate, and stearoate), followed by an OSA-potato starch (as an industrial emulsifier) were used to prepare sunflower oil-in-water (O/W) emulsion. The effect of emulsifier type and concentration were evaluated on properties of emulsions in terms of mean droplet size, droplet size distribution, and creaming index. To prepare the emulsion, the emulsifier to oil ratios of 1.25 and 0.5 for octanoate and industrial emulsifier (control) were considered as the selected formulations based on the lowest creaming index (2.63 and 0 %, respectively). The influence of various pHs and ionic strengths on droplet size, span and zeta potential value was similar for both produced emulsions. Therefore, the fatty acid-esterified starch could be suggested as a promising environmentally friendly alternative to industrial emulsifiers for fabrication of emulsions with similar stability.

Tomato seed oil-enriched tomato juice: Effect of oil addition type and heat treatment on lycopene bioaccessibility and oxidative stability.

In this study, tomato seed oil conventional emulsion (7 µm) and nanoemulsion (0.146 µm) with desirable stability were prepared, then the effect of tomato seed oil addition (bulk and emulsified forms) and thermal treatment on properties of tomato juice was evaluated. Tomato juice without oil and heat treatment exhibited the lowest bioaccessibility of lycopene (17.8 %). Incorporation of oil and applying heat treatment significantly increased the extent of lipid digestion and bioaccessibility of lycopene. In this regard, the nanoemulsion had the highest bioaccessibility (44.85 %) compared to conventional emulsion (33.90 %) and bulk oil (27.11 %), due to the smaller oil droplets. The oxidative stability of oil in heat-treated tomato juice samples decreased during 28 days of storage at 4 °C, whereas the nanoemulsion exhibited the highest peroxide value (4.43 meq O2/kg of oil) compared to conventional emulsion and bulk oil (3.91 and 3.49 meq O2/kg of oil, respectively) at the end of the period.

Chemical modification of waxy maize starch by esterification with saturated fatty acid chlorides: Synthesis, physicochemical and emulsifying properties.

In the current study, the physicochemical and emulsifying properties of modified waxy maize starch obtained through a new environmentally friendly method of esterification were evaluated. The starch modification was carried out in NaOH solution with different levels of octanoyl, myristoyl, and stearoyl chlorides. Increasing the fatty acid chlorides concentration led to the degree of substitution increment, while reaction efficiency and yield decreased. Based on fourier transform infrared spectroscopy results, the presence of two new bands of carbonyl (1740-1750 cm-1) and carboxyl (1570 cm-1) groups in the ester bond confirmed the successful starch esterification process. The level of 0.1 mL fatty acid chlorides/g of starch demonstrated the highest emulsifying properties. Upon esterification, the crystalline structure of amylopectin was destroyed, indicating no gelatinization features. Therefore, using the fatty acid chlorides in an alkaline condition could be suggested as a feasible way to modify waxy maize starch toward hydrophobicity increment with desirable properties.

Effect of biopolymers concentration and drying methods on physicochemical properties of emulsion-templated oleogel.

In current study, oleogel containing surface-active (sodium caseinate) and non-surface active biopolymers (xanthan gum) prepared in different concentrations through emulsion template (containing 60% canola oil) and dried by freeze-drying. Results showed that biopolymer content affects the oleogel structure: applying the biopolymer combination with increased concentration mainly sodium caseinate, resulted in lower droplet size in emulsions and obtained oleogels with higher firmness and less oil loss. Therefore, samples containing 4% sodium caseinate with 0.2% and 0.4% xanthan were selected as the superior formulas for examining deeply the drying methods' effects (freeze and vacuum-oven drying) on oleogel's physicochemical properties such as hardness, rheology, XRD, color, and oxidative stability. Freeze-drying with higher content of xanthan (0.4% w/w) generated a high mechanical strength oleogel. However, reducing xanthan concentration (0.2% w/w) reduced the gel strength, probably due to not enough viscoelasticity in oil droplets interface. Nevertheless, the charm of freeze-drying method is high-quality dried products in optimized biopolymer concentration due to the water removal by sublimation of ice crystals. Contrariwise, vacuum-oven revealed soft-discolored materials even in high biopolymers concentrations due to the higher temperature and structural collapse. Independence of biopolymer concentration and drying method, no significant difference in XRD patterns, and oxidative stability was observed. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05214-1.

Fabrication of edible solid lipid nanoparticle from beeswax/propolis wax by spontaneous emulsification: Optimization, characterization and stability.

In the current study, the production and characterization of novel solid lipid nanoparticles (SLNs) using safe/low-cost natural beeswax (BW) and propolis wax (PW) and by the simple and inexpensive assay of spontaneous emulsification were studied. To fabricate SLNs, the optimum levels of surfactant/oil ratio (SOR), stirring speed, and time were obtained based on minimum particle size (PS) and polydispersity index (PDI). Therefore, the optimal conditions to produce PW and BW nanoparticles were SOR of 1.26 and 2 under stirring speed of 1050 rpm for 20 min, leading to PS of 21.9 and 23.2 nm, respectively. The contact angle of 73.7° and 62.9° for BW and PW SLNs respectively, showed suitable hydrophilicity to stabilize oil-in-water (O/W) Pickering emulsions. Temperatures over 70 °C led to a drastic increment of PS in both types of SLNs. Upon nanoparticles drying, the utilization of cryoprotectants could cause less aggregation and better reconstitution.

Thermodynamic compatibility of gelatin and tragacanth gum in aqueous systems.

The influence of total concentration, biopolymer mixing ratio, and ionic strength on the association of tragacanth gum (TG) and gelatin (G) in the aqueous system during acidification was investigated. The onset of soluble complex formation appeared at pHc, where both biopolymers carried a negative charge. Insoluble complexes were formed at pHφ1 by a further pH decrease, owing to increased interactions between the polymers. The complexes formed at pHφ1 still had partly high negative surface charge. Complex coacervation was observed at pHopt due to the growing size and number of insoluble complexes. The ζ value of the G- TG significantly decreased at pHopt, which was subjected to phase separation. Turbidity decreased at pHφ2 as a result of complex decomposition. The maximum efficiency of complex formation was at the salt-free samples. NaCl reduced critical pHs and complex formation efficiency by screening the ionized groups on the biopolymers.

Physicochemical properties of beef burger after partial incorporation of ethylcellulose oleogel instead of animal fat.

The aim of this study was to evaluate the physicochemical properties of beef burger after substitution of animal fat with the ethylcellulose (EC) oleogel. Therefore, sesame oil oleogels were prepared using EC in concentrations of 10%, and cooled at 25 °C. The fatty acid profile of EC oleogel compared with animal fat. Then, the EC oleogel was incorporated to hamburger at the 0, 25 and 50% instead of animal fat and color and textural properties as well as cooking loss, cooking shrinkage, fat absorption, and lipid oxidation of the beef burgers were evaluated. As an outcome, the EC oleogel contained high levels of linoleic and linolenic acids, while the palmitic and stearic acids were lower than the animal fats, and myristic acid was not detectable. Replacement of animal fat with EC oleogel upgraded the quality of final product by reducing cooking loss and fat absorption. Production of beef burger with EC oleogel decreased the oxidation process during frozen storage as well as cooking loss and fat absorption, and enhanced textural properties including chewiness and hardness. Improvement of nutritional and technological properties of hamburgers contained EC oleogel makes it a desirable candidate for animal fat substitution. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at(10.1007/s13197-021-04970-4).

Pomegranate seed oil nanoemulsion enriched by α-tocopherol; the effect of environmental stresses and long-term storage on its physicochemical properties and oxidation stability.

In this study, pomegranate seed oil (PSO) nanoemulsions loading different amounts of α-tocopherol (0-40%) were produced. The nanoemulsions were fabricated by ultra-sonication method and the influence of thermal treatment (20-90 °C), pH (2-8) and ionic strength (0-500 mM NaCl) were investigated on physicochemical properties of all treatments. Moreover, the oxidative stability and α-tocopherol degradation were also assessed on optimal enriched nanoemulsion formulation during 50-day storage. The droplet diameter, viscosity, antioxidant activity, encapsulation efficiency and loading capacity of optimal formulation were 37.5 nm, 514 cp, 92%, 3.45% and 92.5%, respectively. The peroxide value changed in the range of 4.5-5.3 and 6.7-10.5 meq O2/kg in loaded and unloaded nanoemulsions, respectively. Transmission electron microscopy demonstrated spherical morphology of nanoemulsion droplets with diameter average of 40 nm. This study suggested that PSO nanoemulsion loading α-tocopherol could be introduced as delivery system with favorable features under severe environmental conditions.

Wax-based delivery systems: Preparation, characterization, and food applications.

The development of lipid-based delivery systems has attracted much attention over the last years and a wide variety of strategies and formulations are currently available to encapsulate, protect, and target delivery of bioactive and functional lipophilic constituents within the food and pharmaceutical industries. Waxes are crystalline lipid material, consisting of a complex mixture of long-chain fatty acids and fatty alcohols, hydrocarbons, aldehydes, and ketones and show great promises as constituents of carrier systems. Most of waxes are classified under food-grade category and show high availability at a low cost. This review article has provided a comprehensive summary of research on major carriers containing wax as one of the main constituents, including solid lipid nanoparticles, nanostructured lipid carriers, oleogels, and Pickering emulsions, with a focus on their food applications. The physical and chemical nature of natural waxes are described in the first while the second part deals with the structure, formulation, main methods of preparation, characterization, and finally utilization of each type of wax-based delivery system for specific food applications.

ß-Sitosterol Loaded Nanostructured Lipid Carrier: Physical and Oxidative Stability, In Vitro Simulated Digestion and Hypocholesterolemic Activity.

The objective of the present study was to explore the potential of nanostructured lipid carriers (NLCs) for improving the oral delivery of ß-sitosterol, a poorly water-soluble bioactive component with hypocholesterolemic activity. Two ß-sitosterol formulations with different solid lipid compositions were prepared by melt emulsification, followed by the sonication technique, and the effect of storage conditions and simulated digestion on the physical, chemical and oxidative stability, bioaccessibility and release were extensively studied. Both NLC preparations remained relatively stable during the four weeks of storage at different conditions (4, 25 and 40 °C), with more superior stability at lower temperatures. The in vitro digestion experiment indicated a high physical stability after exposure to the simulated mouth and stomach stages and an improved overall ß-sitosterol bioaccessibility at the end of the digestion. The NLCs presented an increased solubility and gradual release which could be justified by the remarkable affinity of ß-sitosterol to the complex lipid mixture. An in vivo study demonstrated an improved reduction in the total cholesterol and low-density lipoprotein cholesterol plasma levels in mice compared with the drug suspension. These investigations evidenced the potential of the developed NLC formulations for the enhancement of solubility and in vivo performance of ß-sitosterol.

Characterization and enhanced functionality of nanoparticles based on linseed protein and linseed gum biocomplexes.

The formation, characterization, and functionality of hybrid nanoparticles based on linseed bio-macromolecules extracted as linseed protein (LP) and linseed gum (LG) from the remaining meal after oil extraction were investigated. The assembly of bioparticles at different protein to polysaccharide ratios as a function of pH was characterized in terms of absorbance measurements, dynamic light scattering and surface charge. The wettability of the assembled particles as well as the plain LP and LG was also determined. By increasing the LG proportion in the bioparticles, both the size of the particles and their contact angle tended to decrease, whereas their zeta potential became more negative over the whole studied pH range. The formed negatively charged particles at pH 3 with a 50:50 LP to LG ratio and a size of approximately 300 nm were selected and their functional properties (solubility, emulsifying and foaming properties) were compared to the individual biopolymers. The interaction between LG and LP was found to modify the functional properties of native LP especially at and around its isoelectric point. The LP-LG particles could be useful for stabilizing plant-based emulsions and foams.

Maillard conjugation of whey protein isolate with water-soluble fraction of almond gum or flaxseed mucilage by dry heat treatment.

The Maillard conjugation of whey protein isolate (WPI) by dry heat treatment (74% relative humidity at 60 °C) to either the water-soluble fraction of almond gum (SFAG) or flaxseed mucilage (SFM) was compared. Depending on the protein to polysaccharide ratio, carbohydrate type, and incubation time, different degrees of substitutions of the amino groups were obtained. The characterization of the conjugates by TNBS, SDS-PAGE, size exclusion chromatography, and circular dichroism analysis confirmed the formation of conjugates. SFAG was found to have less tendency for the formation of grafted WPI than SFM, which could be attributed to both the polysaccharide composition and/or a higher molecular weight. Ultimately, the emulsions stabilized by conjugates (pH 5.0 and 6.5) remained homogenous with no droplet size variation after heating, indicating that the conjugation of WPI to SFAG and SFM substantially improved its heat stability.

Data on environmental analysis of natural antioxidant production from walnut husk by a solar photovoltaic-driven system as a replacement for potentially carcinogenic synthetic antioxidants.

In order to develop a product sustainably, multiple analyses, including comprehensive environmental assessment, are required. Solar-assisted production of walnut husk methanolic extract (WHME) as a natural antioxidant for biodiesel was scrutinized by using the life cycle assessment (LCA) approach. More specifically, the environmental sustainability of WHME antioxidant was evaluated and compared to that of propyl gallate (PG), the most widely used synthetic biodiesel antioxidant, under two scenarios. Additionally, supplementary files including the inventory data consisting of raw data as well as elementary flows, mid-point, and end-point categories are presented. The analysis of scenarios revealed that the use of the natural antioxidant and the avoidance of the chemical antioxidant in biodiesel fuel could be regarded as an eco-friendly approach substantially enhancing the environmental friendliness of biodiesel in particular in terms of human health. Furthermore, given the waste-oriented nature of WHME, the scenario involved its application could serve as a promising strategy to simultaneously valorize the agro-waste and generate a value-added product; a move toward implementing the circular economy approach in the biodiesel industry.

Effect of thymol and Pickering stabilization on in-vitro digestion fate and oxidation stability of plant-derived flaxseed oil emulsions.

The aim of this study was to evaluate the effect of Pickering stabilization by biopolymer-based particles (bioparticles), consisting of flaxseed protein and polysaccharides, and of the addition of thymol to the oil phase on the oxidation stability, and digestion fate of flaxseed oil (FO) emulsions, compared to bulk FO and conventional emulsions stabilized by polysorbate 80 (PS80). Applying Pickering stabilization and thymol simultaneously was a successful approach to retard FO oxidation. Moreover, lipid digestion was slower in bioparticle-stabilized emulsions compared to PS80 stabilized emulsions. The thymol bioaccessibility increased after incorporation into FO Pickering emulsions in comparison to the bulk oil. The results suggested that the combination of Pickering stabilization and thymol addition to the oil phase can be used as a promising way of protecting highly unsaturated oils such as FO against oxidation. These emulsions are also applicable for designing functional foods with controlled lipid digestion.

Bioparticles of flaxseed protein and mucilage enhance the physical and oxidative stability of flaxseed oil emulsions as a potential natural alternative for synthetic surfactants.

Flaxseed protein (FP) and mucilage (FM) complex bioparticles as sustainable ingredients were assembled by electrostatic interaction for plant-based Pickering stabilization of flaxseed oil (FO)-in-water emulsions. The effect of FO content (1-5 wt%) on droplet size and accelerated creaming stability of the emulsions was evaluated, from which it was found that 2.5 wt% FO emulsion had the smallest initial droplet size (i.e. D[4,3] = 8 µm) and creaming velocity (2.9 µm/s). The microstructure of the emulsions was observed using Cryo-SEM, confocal and optical microscopy, showing a thick layer of the particles on the oil surface responsible for the stabilization. The physical stability of FO emulsions stabilized by complex bioparticles against various environmental stress conditions (pH, salt and temperature) was higher compared to plain FP- and polysorbate 80-stabilized emulsions. Thus, the droplet size of FP-stabilized emulsions (pH 3) increased from 21 to 38 µm after thermal treatment (80 °C), whereas the size distribution of particle-stabilized emulsions hardly changed. The latter emulsions also remained stable during 28 days of storage and displayed good stability against a wide range of pH conditions (2-9) and salt concentrations (0-500 mM) with no sign of oiling-off. The complex particles as Pickering emulsifiers were successful to depress the FO oxidation at 4 °C and 50 °C. This study could open a promising pathway for producing natural and surfactant-free emulsions through Pickering stabilization using plant-based biopolymer particles for protecting lipophilic bioactive components.

Encapsulation of flaxseed oil in the tertiary conjugate of oxidized tannic acid-gelatin and flaxseed (Linum usitatissimum) mucilage.

Flaxseed oil, due to high amount of unsaturation, is susceptible to oxidation which could reduce oil nutritional value and cause off-flavor. In this study, flaxseed oil was encapsulated in new wall materials of tertiary conjugate of gelatin-flaxseed mucilage (FM)-oxidized tannic acid (OTA) which are available and food grade with nutritional value, controlled-release ability. The effect of different percentages of oil (15, 30 and 50% w/w concentration of total dry matter) on encapsulation efficiency (EE) and loading (EL) was investigated. Then, the microcapsules were evaluated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), oxidative stability and release profile of flaxseed oil. The data showed that the treatment containing 50% (w/w) oil had the highest oil loading. The oil was surrounded by physical link into the complex and the final powder was fine with low porosity. Also, oxidative test exhibited an improved stability of the oil encapsulated in triple complex. During storage, the peroxide value of encapsulated oil increased from 3.0 to 5.3 meq O2/kg while in free oil, higher oxidation rate was recorded. According to the results, this tertiary complex can be used as wall material in encapsulation and delivery system of functional and sensitive oils.