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In this research, a dual encapsulation system was developed for loading niosomes into electrospun nanofibers of soy protein isolate (SPI)-polyvinyl alcohol (PVA); high hydrostatic pressure (HHP) was also applied to reinforce the nanofibers. For this purpose, different samples with various levels of HHP-treated SPI, PVA, and iron niosomes were prepared. Encapsulation efficiency as well as the bioavailability of iron increased in HHP-treated samples because HHP was able to disassemble the structure of the base polymers (SPI-PVA), allowing the iron to load into the skeleton of the base polymer and, consequently, encapsulated it in the structure strictly and suitably. HHP resulted in a higher transformation and bioavailability of SPI:PVA fibers, which is due to the destruction effect of this pretreatment on SPI and neutralizing its inhibitory effect. HHP eventuated lower Atomic Force Microscopy (AFM) indices in nanofibers because it can cause denaturation and aggregation of proteins, resulting in a more compact and homogeneous protein network. The results of this study are useful as a practical guide on how to prepare niosome-embedded SPI nanofibers (especially for the enrichment of plant-based nanofibers), what their properties are, and how to improve their characteristics through HHP pretreatment. [Display omitted] • A dual carrier for the iron encapsulation was developed for the first time. • Iron-loaded niosomes were encapsulated within electrospun nanofibers. • Dual encapsulation system resulted in the higher encapsulation efficiency of iron. • High hydrostatic pressure (HHP) improved electrical conductivity of feed solutions. • HHP enhanced iron bioavailability of niosome-embedded nanofibers. [ABSTRACT FROM AUTHOR]

One of the main conventional problems with the storage of goose meat is its high susceptibility to microbial spoilage as well as oxidation during its shelf-life. Researchers have paid less attention to this issue, with modified atmosphere packaging being the main recommendation for solving this problem despite that this type of packaging brings about some quality issues. Thus, our chief objective, in this research, was to enhance goose meat shelf-life by fabrication of a blend film comprising soy protein isolate (SPI)-Alyssum homolocarpum seed gum (AHSG) based film having carrot seed extract (CSE)-pomegranate peel extract (PPE) mixture as CSE and PPE possess antioxidant and antimicrobial properties. For this purpose, first, different concentrations (1%, 5%, 10%, and 20% w/w) of the mixture of the extracts were inserted in the based film. Next, structural (SEM and XRD), nutritional (total phenolic content), and antimicrobial properties (through disc diffusion method against Listeria monocytes and Escherichia coli) of films were investigated. Besides, shelf-life parameters including microbial indices (total bacterial count, coliforms and S. aureus), chemical parameters (pH and TBA) as well as organoleptic analysis of goose meat packaged with the optimum film during 14 days storage period were studied. The results showed that application of the fabricated films increased the shelf-life of goose meat from 7 days to 14 days successfully if ignoring inappropriate TBA index of the meat after this period. Rigter-Peppas model fitted the release profiles of CSE and PPE from SPI/AHSG films appropriately. [ABSTRACT FROM AUTHOR]

We hypothesized that incorporation of carrot seed extract (CSE) and pomegranate peel extract (PPE) might prompt some intermolecular bonds which improve physical and mechanical characteristics of our base films including soy protein isolate (SPI) and Alyssum homolocarpum seed gum (AHSG). To test this hypothesis, composite films based on SPI and AHSG were enriched with various levels (1%, 5%, 10%, and 20% w/w) of CSE/PPE mixture (50 to 50 ratio) and were characterized through physical, mechanical as well as structural experiments. Results showed that with enhancing the concentration of the extracts, thickness, density, contact angle, flexibility and tensile strength of the films increased, but their water solubility, moisture content as well as water vapor permeability (WVP) decreased, resulting in impeccable films. FTIR analyses showed that hydrogen bonds were formed in the structure of SPI/AHSG films after incorporation of the extracts. According to the scanning electron microscope (SEM) images, the addition of the extract changed the structure of the films. X-ray diffraction patterns show that the addition of the extract altered the crystal structure of SPI/AHSG. Results showed that the WVP of the films was decreased (2.01 g mm m−2 d−1 kPa−1 for the control film) with increasing the concentration of the extracts (0.61 g mm m−2 d−1 kPa−1 for the films containing 20% of extract) while tensile strength and elongation at break increased from 4.85 MPa and 84.72% for control film to 7.21 MPa and 176.31% for the films containing 20% extract. It is concluded that the blend film having 10% mixture of plant extracts results in the best film considering all physical and mechanical properties. [ABSTRACT FROM AUTHOR]

Thermal treatment is the primary method of food preservation and pasteurization; nevertheless, it impairs food quality. High hydrostatic pressure (HHP) could be complementary, or alternative to thermal processing. Compared with thermal treatment, HHP has no significant impact on thermo-sensitive and small molecules including flavor compounds, amino acids and vitamins. In this review article, the effects of HHP treatment on functional and intrinsic (protein solubility, free sulfhydryl content, surface hydrophobicity, and water holding capacity), colloidal (turbidity, zeta potential, particle size distribution, and surface pressure isotherms), emulsifying (emulsifying activity and protein adsorption), rheological, spectroscopic (ultraviolet absorbance and fluorescence), and structural, as well as nutritional properties of legume proteins (LPs) are comprehensively reviewed. It not only mentions the measurement detail of each described technique but also explains the effect of HHP treatment on the structural properties, colloidal stability as well as spectroscopic properties of legume proteins. Since most articles regarding the effect of HHP on legume proteins are devoted to the soybean; hence, the coverage of this article is mostly related to the soy proteins. HHP might improve the protein unfolding and the exposure of its hydrophobic groups which subsequently may increase the emulsion activity index. However, it may principally decrease the emulsion stability index. The comprehensive review of the relevant studies confirms the appropriate potential of HHP compared to other methods of protein modification. This method not only improves the functional properties of the LPs, but also reduces their allergenicity and antigenicity. [Display omitted] • Changes in techno-functional properties of legume proteins after HHP were studied. • Effects of HHP on structural properties of legume proteins were addressed. • 300/400 MPa pressure leads to the highest increase in solubility of legume proteins. • HHP at 400 MPa gives the highest emulsion activity index of legume proteins. • After applying HHP, the enthalpy of the thermal peaks decreases sharply. [ABSTRACT FROM AUTHOR]

In this research, the characteristics of the high hydrostatic pressure (HHP)-treated soy protein isolate (SPI) solutions as well as HHP-treated SPI (HSPI) electrospun fibers were comprehensively studied for the first time. For this purpose, surface tension, electrical conductivity, viscosity, zeta potential, and secondary structure of HSPI solutions at different ratios were investigated. Also, differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM) of HHP-treated and non-treated SPI: PVA nanofibers were thoroughly compared. HHP denaturation reduced the size of nanofibers by 50–100 nm, diminished ordered structures and crystallinity of nanofibers, increased their melting point and induced hydrogen bonding between amino groups of denatured SPI and hydroxyl groups of PVA. These findings open a new horizon in the successful application of non-thermal energies in the electrospinning process to achieve appropriate fibers at nanoscale. [Display omitted] [ABSTRACT FROM AUTHOR]

A common problem of electrospinning of plant proteins is that these kinds of proteins, including soy protein isolate (SPI), should be highly soluble and preferably in a random coil structure rather than the globular conformation. The current solution is to apply thermal treatment; however, it results in extensive organoleptic consequences (e.g. color degradation and off-flavor) and loss of nutrients. Thus, if a non-thermal technology such as high hydrostatic pressure (HHP) increases the disordered structure of the protein, it could facilitate the electrospinning of the protein and eliminate the barriers of thermal treatment, forming our hypothesis in this research. To this end, initially, extensive experiments including protein solubility, sulfhydryl content, turbidity, surface hydrophobicity, circular dichroism, and viscosity tests were carried out on HHP (200, 400 and 600 MPa) and thermally treated SPI samples (3.5% and 7% w/w). The results of sulfhydryl content revealed that disulfide bonds decreased at 400 MPa more intensely than other pressures while surface hydrophobic forces were promoted at this pressure. The circular dichroism test results showed that HHP treatment resulted in higher disordered structures and lower ordered ones, which is particularly helpful for the electrospinning process; besides, lower β-sheet content achieved by HHP treatment is especially useful for attaining defect-free fibers. For the first time, in this research, ideal electrospun fibers with average diameters of 300–400 nm were achieved through HHP processing, without using any thermal energy. [Display omitted] • Efficiency of HHP denaturation on SPI was compared with thermal denaturation. • Structural properties of SPI denatured by HHP were studied extensively. • HHP denaturation at 400 MPa resembled thermal denaturation of SPI sufficiently. • For the first time, HHP denaturation of SPI was followed by its electrospinning. [ABSTRACT FROM AUTHOR]

Natural antioxidant and antimicrobial agents are innovative alternatives to commercial preservatives. In the present study, phycocyanin (PC), as a strong antioxidant and antimicrobial agent, was encapsulated into nanoliposomes. Then, PC-loaded nanoliposomes (PCNL) were incorporated into the soy protein films (SPI) at four concentrations (1, 5, 10 and 20 g/100g) to improve the shelf-life of pacific white shrimp (Litopenaeus vannamei) during 15 days of cold storage. Thus, our novelty in this research was to include a nanoliposome in an edible/biodegradable film to enhance the shelf life of a sea product. This innovative approach demonstrated significant improvements in film properties, including enhanced barrier characteristics, optical qualities, and mechanical strength. Furthermore, PCNL-incorporated SPI films exhibited remarkable antioxidant activity when compared to control films. The encapsulation process extended the release of PC into water, reaching 210 min. Importantly, the results revealed that SPI films containing PCNL effectively inhibited the growth of total aerobic plate count, total volatile basic nitrogen content, and pH changes in white shrimp, providing a promising solution to extend the shelf life of seafood products while reducing the reliance on commercial preservatives. This research showcases the potential of nanoliposome-embedded edible films as an effective means of food preservation in seafoods. [Display omitted] • Phycocyanin-loaded nanoliposomes were distributed uniformly in SPI films. • Phycocyanin and lecithin in nanoliposome interacted physically. • Shrimp freshness indices were kept exclusively through successful encapsulation. [ABSTRACT FROM AUTHOR]