Characterization of acorn oil and its application on carnauba wax-based oleogel and chocolate spread.

This study aimed to characterize acorn oil (AO) and carnauba wax-based acorn oil oleogel (AOG) and the effect of AOG replacement on the textural and sensorial properties of chocolate spread. Oil yields from cold-pressing (Quercus longipes) were around 14%wt with a nice nutty smell. The main fatty acids of AO were included oleic, linoleic, and palmitic acid (44, 38, and 10%wt) respectively. The prepared AOG using 6%wt of carnauba wax (CW) showed high strength (G' > 100 mPa) and oil binding capacity ∼87 %. Based on microstructure assays platelet-like and ß' polymorphic triglyceride crystalline networks were formed in AOG. The Pickering AOG/water emulsions in the volumetric ratio of from 90:10 up to 40:60 were stable due to the placement of CW-based AOG particles at the interface of water/oil as Pickering stabilizer. The high physical stability of the emulgel against phase separation is considered an important advantage for using oleogel in chocolate spread formulations instead of vegetable oils, which usually have a high percentage of oil release. The spreads prepared by replacing 50%wt AOG with butter showed acceptable textural and sensorial properties.

A review of protein-phenolic acid interaction: reaction mechanisms and applications.

Phenolic acids (PA) are types of phytochemicals with health benefits. The interaction between proteins and PAs can cause minor or extensive changes in the structure of proteins and subsequently affect various protein properties. This study investigates the protein/PA (PPA) interaction and its effects on the structural, physicochemical, and functional properties of the system. This work particularly focused on the ability of PAs as a subgroup of phenolic compounds (PC) on the modification of proteins. Different aspects including the influence of structure affinity relationship and molecular weight of PA on the protein interaction have been discussed in this review. The physicochemical properties of PPA change mainly due to the change of hydrophilic/hydrophobic parts and/or the formation of some covalent and non-covalent interactions. Furthermore, PPA interactions affecting functional properties were discussed in separate sections. Due to insufficient studies on the interaction of PPAs, understanding the mechanism and also the type of binding between protein and PA can help to develop a new generation of PPA. These systems seem to have good capabilities in the formulation of low-fat foods like high internal Phase Emulsions, drug delivery systems, hydrogel structures, multifunctional fibers or packaging films, and 3 D printing in the meat processing industry.

Recent Advances of Macromolecular Hydrogels for Enzyme Immobilization in the Food Products.

Enzymes are one of the main biocatalysts with various applications in the food industry. Stabilization of enzymes on insoluble carriers is important due to the low reuse, low operational stability, and high cost in applications. The immobility and the type of carrier affect the activity of the immobile enzyme. Hydrogels are three-dimensionally cross-linked macromolecular network structures designed from various polymers. Hydrogels can provide a matrix for an immobile enzyme due to their extraordinary properties such as high water absorbing capacity, carrier of bioactive substances and enzymes, biocompatibility, safety, and biodegradability. Therefore, this study mainly focuses on some enzymes (lactase, lipases, amylases, pectinase, protease, glucose oxidase) that are of special importance in the food industry. These enzymes could be immobilized in the hydrogels constructed of macromolecules such as kappa-carrageenan, chitosan, Arabic gum, pectin, alginate, and cellulose. At last, in the preparation of these hydrogels, different enzyme immobilization methods in macromolecular hydrogels, and effect of hydrogels on enzyme activity were discussed.

Immobilization of α-amylase in ethylcellulose electrospun fibers using emulsion-electrospinning method.

α-Amylase encapsulated in water in oil (W/O) emulsion was prepared using poly ethylene glycol (PEG 10000) (2%w/v) as water phase and ethylcellulose (EC) in ethyl acetate as oil phase at the ratio of 10:90 v/v. Next, the electrospun fibers were prepared by mixing enzyme loaded emulsion with EC solution (20%w/v) in acetic acid/ethyl acetate (20:80 v/v) at the 2:1 ratio. The emulsion showed good physical stability. The immobilized enzyme showed high activity across a board range of pHs and temperatures. The storage stability of the immobilized enzyme was 2 fold of free enzyme activity after 45 days. The residual activity of immobilized α-amylase onto of fibers after 10 and 15 repeated cycles, was approximately 100% and 50%, respectively. The results of this study indicated that the α-amylase loaded EC fibers have acceptable activity against harsh conditions and excellent reusability.

Fabrication and characterization of novel antibacterial chitosan/dialdehyde guar gum hydrogels containing pomegranate peel extract for active food packaging application.

This study aimed to investigate synthesis and structural characteristics of the chitosan (CS) - modified dialdehyde guar gum (DAGG) hydrogel through the Schiff base reaction. The highest swelling capacity was achieved as about 12,000% of dry weight of the freeze-dried powder at CS: DAGG hydrogel with the mixing ratio of 30:70. The swelling ratio was not affected by changes in pH, which could be considered as an important property in the control of moisture in absorbent pad. The FTIR results indicated that the new amide groups have been formed at 1680 cm-1, which can be attributed to the covalent bond between the amide groups of CS and the aldehyde groups of GG. Based on a SEM image, the prepared hydrogel showed the porous structure so it verified the crosslinking formation between the two polymers. Rheological analyses confirmed that formation compact and porous structure led to some noteworthy improvements in the strength of hydrogel prepared with a high ratio of DAGG. The hydrogel loaded with 5% pomegranate peel extract (PPE) showed both good antioxidant (81.13%) and antimicrobial activities. The hydrogel was observed to have a good potential to be used as an antibacterial pad.

Advanced properties of gelatin film by incorporating modified kappa-carrageenan and zein nanoparticles for active food packaging.

Recently, the improvement of gelatin-based films for usage in food packaging has attracted more attention owing to their non-toxicity, biodegradability, availability, and renewability. In the current study, the improved gelatin-based films were produced using covalent interaction through dialdehyde kappa-carrageenan (DAK-car) and thymol-loaded zein nanoparticle content. The influences of DAK-car into the matrix of gelatin films (GEL) on the structural, total soluble matter (TSM), moisture content (MC), and water vapor permeability (WVP), and mechanical properties were investigated. After the formation of covalent crosslinking amongst the amino groups of GEL and the dialdehyde groups of DAK-car with the blending ratio of 1:2 (GEL 4% w/v): (DAK-car 1% w/v), a remarkably (p < 0.05) reduction was saw in TSM, MC, and WVP of film. The tensile strength of this film (72.26 ± 0.3 MPa) was ~20-fold higher compared with pure GEL film. It should also be noted that the presence of zein nanoparticles (ZNPs) did not have a notably effect on improving the attributes of gelatin-based film. However, the presence of thymol in concentrations of 0.25 and 0.5 mg/mL showed acceptable antioxidant and antimicrobial activities. As a result, GEL/DAK-car with blending ratio of 1:2 containing thymol-loaded ZNPs films demonstrated the valuable potential for application in active food packaging.

Fabrication of curcumin-zein-ethyl cellulose composite nanoparticles using antisolvent co-precipitation method.

The stable colloidal nano-dispersion of curcumin (CU) loaded zein-ethyl cellulose (ZN-EC) as three hydrophobic agent in water was prepared using two step antisolvent co-precipitation method. The EC coated NPs were prepared by adding EC in ethyl acetate to the ZN-CU NPs at a concentration ratio of 1: 3.5 w/v. The prepared colloidal suspension of ZN-EC showed high physical stability during storage time. The particle diameters and zeta potential values of ZN-CU and ZN-CU-EC colloidal suspensions were 140 ± 12 nm, 38 ± 2 mV and 179 ± 12 nm, 12 ± 2 mV, respectively. Based on Scanning electron microscopy (SEM) images, participation of EC on the surface of ZN-CU particles could reduce the sticky appearance of particles. Encapsulation efficiency of CU in NPs did not improve after precipitation of EC, but the stability of NPs against pH changes, increased and release rate of CU from NPs at different pH values (3-8) were significantly reduced in comparison of ZN-CU NPs. The EC coated NPs showed the excessive protection for CU antioxidant activity during storage. In conclusion, the prepared NPs, with high physical stability, have good potential for encapsulation and delivery of CU to colon region.

Preparation and characterization of carnauba wax/adipic acid oleogel: A new reinforced oleogel for application in cake and beef burger.

In this study, the reinforced carnauba wax (CW)-based oleogel with adipic acid (AA) was prepared and its potential for application in the cake and the beef burger was evaluated. As a result, the addition of AA in CW-based oleogels caused to form new intramolecular or intermolecular hydrogen bonding, and improve the thermal behavior and crystallinity of oleogels. Additionally, the increase of AA concentration higher than 3% of oleogel formulation significantly increased the strength of oleogels. The formulated food models (cake and beef burger) with partial substitution CW2%/AA4% oleogel as the optimized sample showed an acceptable texture profile, color, and organoleptic characteristics. Consequently, reinforced oleogel with carnauba wax/adipic acid in bakery and meat products can provide considerable promise to develop food products with lower saturated and trans-fatty acid.

Latest developments in the detection and separation of bovine serum albumin using molecularly imprinted polymers.

Recently, enormous attention has been focused on the development of protein-molecularly imprinted polymers (MIPs). In this sense, bovine serum albumin (BSA) is well regarded as a favorite template in various MIPs-based biochemical/analytical assays mainly due to its low price, easy availability, and high structural homology to human serum albumin (HSA). Equally, the implications of BSA in the pathology of different human-related disorders necessitate the development of methods for its precise detection in biological samples. Accordingly, the current review seeks to provide an update on the design, synthesis, and characterization of the developed MIPs which have used BSA as template protein. Also, the recognition and quantification of BSA in different real samples using the prepared MIPs are discussed. Additionally, main strategies, such as surface imprinting, epitope-MIPs, microcontact imprinting and other methods to overcome the problems associated with the molecular printing of BSA are discussed here. The final discussion provides a comparative exploration of different approaches developed, emphasizing their relative advantages and disadvantages and underlining developments and possible future directions.

Development of behenic acid-ethyl cellulose oleogel stabilized Pickering emulsions as low calorie fat replacer.

This study investigated the optimization of thermal, functional and rheological properties of Ethyl Cellulose (EC)-based oleogel considering different concentrations of Behenic Acid (BA) and stability of water in oleogel (w/og) emulsions. The results showed that the combination of EC and BA improved the oleogel properties at specific ratios (2:4 and 1:5 wt%). High strength (G' > 1000 mPa) with good thermo-responsive and viscoelastic behavior in the range of 45-60 °C and low loss of oil (<0.2%) were observed in these oleogel formulations. Polarized light microscopy images and XRD results showed the presence of crystals and high proportion of crystalline regions in the mentioned formulations. There were no significant differences among solid fat content (SFC) of EC contained oleogels. The FTIR results indicated new hydrogen bonds formation. The w/og stabilized emulsions with EC: BA (1:5 wt%) oleogel showed high physical stability even at high ratios of disperse phase (5 to 45 wt% of water). The particle size and polydispersity index (PDI) of emulsions were reduced significantly to 250 nm and 0.19, respectively by increasing the ratio of water phase to 45:55 w/og. The oleogel and developed Pickering w/og emulsion has good potential in the formulation of low calorie food products.

Recent advances in the use of walnut (Juglans regia L.) shell as a valuable plant-based bio-sorbent for the removal of hazardous materials.

The effective use of agricultural by-products is definitely a major challenge in waste management. In the walnut fruit processing industry, large amounts of shells are produced as agricultural by-products and discarded or burned produced as fuel. Walnut (Juglans regia L.) is a valuable tree nut in the Juglandaceae family. The fruit is composed of four main parts: the kernel, the skin, the shell, and the husk. The importance of walnuts is mostly related to theirs valuable kernels. However, their shells are currently experiencing as much interest as their kernels due to the beneficial effects of the shells. In the past several years, walnut shell (WS) has been widely explored as a naturally inert plant-based biosorbent. In this review, we first highlight recent scientific literature regarding the development of adsorbents from WS in the form of carbon-based materials including unmodified/modified WS, and activated carbons (ACs). Next, we discuss the potential applications of WS-derived by-products as natural yet effective adsorbents for the removal of various hazardous materials including heavy metals (HMs), synthetic industrial dyes, and harmful chemicals.

Zein-CMC-PEG Multiple Nanocolloidal Systems as a Novel Approach for Nutra-Pharmaceutical Applications.

Purpose: Hydrophobic nutraceuticals are suffering from water solubility and physicochemical stabilities once administered to the body or food matrixes. The present study depicts the successful formulation of a zein-carboxymethyl cellulose (CMC) complex to stabilize a water in oil (W/O) emulsion to protect them from environmental and gastrointestinal conditions. The formulated water in oil in water (W/O/W) system was used for nanoencapsulating of hydrophobic nutraceutical, rutin, via protein-polysaccharide complexes. Methods: Zein nano particles smaller than 100 nm were produced using poly ethylene glycol (PEG 400) and Tween 80, which eliminates the use of ethanolic solutions in preparation of zein nanoparticles (ZN). CMC was then added to the ZN under magnetic stirrer to provide zein-CMC complex. A concentration of 20% CMC showed the smallest particle size (<100 nm). Rutin was dispersed in water in oil in water (W/O/W) emulsion stabilized by zein-CMC complex. A set of experiments such as encapsulation efficiency (EE%), encapsulation stability (ES%), and releasing rate of rutin were measured during 30 days of storage at 4°C. Results: Results showed that, produced multiple emulsion prepared with lower concentrations of Tween 80 (0.5%), ethanol: PEG: water ratio of 0:80:20 showed smaller size (89.8±4.2 nm). ES% at pH values of 1.2, 6.8, and 7.4 were 86.63±6.19, 91.54±3.89, and 97.13±2.39 respectively, indicating high pH tolerability of formulated W/O/W emulsions. Conclusion: These findings could pave a new approach in stabilizing W/O/W emulsions for encapsulating and controlling the release of water insoluble nutraceuticals/drugs.

A Comprehensive Review on the Chemical Constituents and Functional Uses of Walnut (Juglans spp.) Husk.

The walnut (Juglans spp.) is an appreciated nut that belongs to the Juglandaceae family. The fruit includes four main parts: the kernel, the skin, the shell, and the green husk. It is widely cultivated due to its edible kernel. In walnut production centers, high amounts of the husk as an agro-forest waste product are produced and discarded away. Recently, it has been demonstrated that the walnut green husk could be valued as a source of different natural bioactive compounds with excellent antioxidant and antimicrobial properties. Regarding this respect, in this contribution, the current scientific knowledge on the antioxidant and antiradical activities, various identified and isolated individual chemical constituents, as well as the functional applications of the walnut husk with more emphasis on the Persian walnut (Juglans regia L.) are reviewed.

Recent developments in the detection of bovine serum albumin.

Albumin is a globular protein which plays a pivotal role in maintaining plasma pressure and the nutritional balance. Different compounds are transported by binding to albumin in the blood. Also, human health is closely related to the serum albumin concentration in blood plasma or other biological fluids. Due to the high structural similarity with human serum albumin (HSA), bovine serum albumin (BSA) has been widely investigated as a model protein in different fields. Importantly, albumin detection has recently gained huge interest, as this protein serves as an important indicator of cow health, and its milk and meat quality. Also, it is also known as an allergenic and a carrier protein. As a result, it is highly essential to determine bovine albumin in various industries, such as medicine, pharmaceutical, clinical and food. Therefore, the development of new, efficient, fast and straightforward methods for selective detection of BSA is critical. This review seeks to highlight different characteristics of BSA and its importance. Then, by focusing on recent developments made in the last two decades in BSA biosensing and determination methods, the use of different biomaterials/nanomaterials is discussed.

A Comparative Review on the Extraction, Antioxidant Content and Antioxidant Potential of Different Parts of Walnut (Juglans regia L.) Fruit and Tree.

As a valuable tree nut, walnut is a well-known member of the Juglandaceae family. The fruit is made up of an outer green shell cover or husk, the middle shell which must be cracked to release the kernel, a thin layer known as skin or the seed coat, and finally, the kernel or meat. The nutritional importance of walnut fruit is ascribed to its kernel. The shell and husk are burned as fuel or discarded away as waste products. In the past two decades, the evaluation of the phenolic content and antioxidant activity of different parts of walnut has received great interest. In this contribution, the recent reports on the extraction and quantification of phenolic content from each part of the walnut tree and fruit using different solvents were highlighted and comparatively reviewed. The current review paper also tries to describe the antioxidant content of phenolic extracts obtained from different parts of the walnut tree and fruit. Additionally, the antioxidant and antiradical activities of the prepared extracts have also been discussed.

Development of resveratrol loaded chitosan-gellan nanofiber as a novel gastrointestinal delivery system.

Resveratrol loaded chitosan:gellan (CS:Gel) nanofibers (NFs) were prepared for the first time using electrospinning technique. The NFs were prepared with CS (9% w/v) in trifloroacetic acid and Gel (2.5% w/v) at a concentration ratio of 95:5% w/v. Based on the scanning electron microscopy (SEM) images, the diameters of CS-Gel fibers at a ratio of 95:5 and 90:10% w/v were 166 ±â€¯37 and 291 ±â€¯41 nm, respectively. Resveratrol (0.05% w/v) was loaded in NFs of CS-Gel at a ratio of 95:5. Encapsulation efficiency (EE) of resveratrol in NFs of CS-Gel were 86 ±â€¯6%. The amount of resveratrol delivered in intestine region was in the range of 43-51% of the total encapsulated resveratrol (equivalent to ~840 µM). Antioxidant activities of resveratrol loaded NFs were significantly higher than that of free resveratrol. Furthermore, the resveratrol releasing ability of the NFs was proved through the MTT assay and revealed that the resveratrol NFs have almost the same cytotoxicity against HT29 cancer cells compared to free resveratrol. Based on the obtained results, the prepared NFs hold great potential as drug delivery carriers for resveratrol delivery.

Pectin modification assisted by nitrogen glow discharge plasma.

This study is concerned with modification of high methoxy pectin (HMP) assisted by nitrogen AC glow discharge plasma. Intrinsic viscosity of plasma treated pectin (PTP) was measured as primary index for structural changes in pectin molecules at different plasma conditions. The intrinsic viscosity of pectin increased within 7 min of exposure to plasma treatment and then remained constant. According to Fourier Transform Infrared Spectrometry (FT-IR) analysis, the intensity of carboxylate peaks increased in PTP samples due to de-esterification of pectin. Moreover, by decreasing the degree of esterification (DE) in PTP samples, the results of FT-IR were confirmed. Based on high performance size-exclusion chromatography (HPSEC) analysis, the molecular weight of PTP reduced. PTP gel had higher storage and loss modulus and shorter linear viscoelastic region. Moreover, X-ray diffraction (XRD) studies indicated an increase of crystallinity in PTP due to the formation of hydrogen bonds. Results revealed that nitrogen AC glow discharge plasma had significant influence on physicochemical and functional properties of pectin. The result of this study showed AC glow discharge plasma has promising potential towards modification of pectin.

Molecular interactions of thymol with bovine serum albumin: Spectroscopic and molecular docking studies.

Thymol is the main monoterpene phenol present in the essential oils which is used in the food industry as flavoring and preservative agent. In this study, the interaction of thymol with the concentration range of 1 to 6 µM and bovine serum albumin (BSA) at fixed concentration of 1 µM was investigated by fluorescence, UV-vis, and molecular docking methods under physiological-like condition. Fluorescence experiments were performed at 5 different temperatures, and the results showed that the fluorescence quenching of BSA by thymol was because of a static quenching mechanism. The obtained binding parameters, K, were in the order of 104  M-1 , and the binding number, n, was approximately equal to unity indicating that there is 1 binding site for thymol on BSA. Calculated thermodynamic parameters for enthalpy (ΔH), entropy (ΔS), and Gibb's free energy (ΔG) showed that the reaction was spontaneous and hydrophobic interactions were the main forces in the binding of thymol to BSA. The results of UV-vis spectroscopy and Arrhenius' theory showed the complex formation in the interaction of thymol and BSA. Negligible conformational changes in BSA by thymol were observed in fluorescence experiments, and the same results were also obtained from UV-vis studies. Results of molecular docking indicated that the subdomain IA of BSA was the binding site for thymol.

Hepatoprotective and free radical scavenging actions of quercetin nanoparticles on aflatoxin B1-induced liver damage: in vitro/in vivo studies.

The objective of present study was in vitro and in vivo evaluation of hepatoprotective and antioxidant activity of Quercetin nanoparticles (Q NPs) against toxicity induced by aflatoxin B1. The Q NPs were prepared using precipitation method. Hepatocytes were prepared by the method of collagenase enzyme perfusion via portal vein. The NPs were characterized in terms of size and morphology using dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The level of parameters, such as cell death, ROS formation, lipid peroxidation, mitochondrial membrane potential and cellular glutathione (GSH) content, in the aflatoxin B1-treated and non-treated hepatocytes were determined and the mentioned markers were assessed in the presence of Q NPs. The prepared NPs showed particle size of 52.70 nm with polydispersity index (PDI) of 0.18. In contrast to free Q, the administration of Q NPs more efficiently decreased the rate of ROS formation, lipid peroxidation and improved cell viability, mitochondrial membrane potential and glutathione level and showed a significant hepatoprotective efiect by reducing levels of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase. It is suggested that the Q NPs is a promising candidate for drug delivery, which enhances the hepatoprotective effect of Q against the cytotoxic effects of aflatoxin B1.

Pectin-zinc-chitosan-polyethylene glycol colloidal nano-suspension as a food grade carrier for colon targeted delivery of resveratrol.

The aim of the present study was to develop chitosan-zinc-pectinate-polyethylene glycol (PEG) nanoparticles (NPs) for colon-targeted delivery of resveratrol. The effects of pectin:ZnCl2:chitosan (PZnC) % w/v, pH and ionic strength of media, and addition of PEG on the colloidal stability and release behavior of resveratrol from NPs were examined by Zeta potential, particle size analyzer, scanning electron microscopy (SEM), and Fourier transform-infrared (FTIR) methods. The particle size and Zeta potential of PZnC NPs in the ratio of 10:1:3% w/v were 399±18nm and +25±1mV, respectively. The addition of PEG to PZnC as a solvent for resveratrol (10% w/v) noticeably decreased the size of NPs to approximately 83±4nm. More than 63% of the resveratrol was encapsulated into the developed NPs; furthermore, a low amount of resveratrol was released during one month, using simulated juice model (pH=4) as investigated by High Performance Liquid Chromatography (HPLC) analysis of resveratrol.The remaining resveratrol in NPs (∼49%) was released in simulated colon fluid in the presence of pectinase. These NPs can be introduced as a novel platform for successful colon delivery of resveratrol in fruit juice matrix.