The Effects of Liposomal Encapsulated Thyme Extract on the Quality of Fish Mince andEscherichia coliO157:H7 Inhibition During Refrigerated Storage

Sustainable gelatin-kappa carrageenan active packaging with Mekwiya date seeds to enhance goat meat quality and shelf life

This research aimed to elaborate a gelatin-Kappa carrageenan-based packaging with 0.22 %, 0.44 %, and 0.88 % w/v of Mekwiya date palm seeds extract (DSEMK). This extract improved the mechanical, physical, and thermal properties of the films. Moisture content, water solubility, and water vapor permeability were reduced from 17.54 ± 0.02 to 12.18 ± 0.02, from 77.61 ± 0.02 to 25.35 ± 0.29 %, and from 5.28 ± 0.29 to 1.69 ± 0.03 g s-1 m-1 Pa-1 × 10-10, respectively. During thermal degradation, DSEMK4 film had a residual weight of 27.99 %, compared to 20.67 % for the control. Despite a decline in the film's tensile strength from 24.19 to 8.94 MPa with the incorporation of DSEMK, elongation at the breaking point increased from 37.66 ± 0.16 to 46.17 ± 0.25 %. The film containing DSEMK4 displayed the highest phenolic contents and illustrated the best antioxidant effects in DPPH and FRAP assays, with IC50s of 756 and 1445 μg/mL, respectively and inhibited pathogen growth on the meat surface. Over storage at 4 °C, monitoring of pH, lipid and protein oxidation parameters, microbial spoilage, optical properties, and sensory attributes disclosed that the DSEMK-films successfully enhanced the meat quality and safety. These findings were supported by principal component analysis and heat maps.

Characterization of free radical-mediated Pleurotus ostreatus polysaccharide-EGCG conjugates for chilled minced pork preservation

To improve the functions of Pleurotus ostreatus polysaccharide (POP), POP-EGCG conjugates were prepared using free radical graft polymerization reactions and were characterized using UV-vis, FT-IR, SEM, XRD, DSC, TG, particle size and potential, three-phase contact angle, and rheological tests; The antioxidant and antibacterial ability in vitro were detected. Moreover, effects of POP-EGCG on the quality of refrigerated minced pork were investigated. The results showed the optimal preparation conditions of POP-EGCG were 1 % POP, 1.3 % EGCG, 0.25 % Vc, 16 % concentration of H2O2, and reaction 17 h. The POP-EGCG showed the characteristic peak of EGCG and was a mesh honeycomb with rough and porous surface; It had higher crystallinity, increased particle size, but decreased thermal stability, solubility, and viscosity, and significantly enhanced antioxidant and antibacterial ability. The POP-EGCG effectively improved the sensory quality and inhibited lipid oxidation of chilled minced pork, and extended the shelf life of minced pork up to 9 days at 4 °C. Specifically, the TVB-N and TBARS of minced pork in the POP-EGCG group were respectively 14.93 mg/100 g and 0.9 mg MDA/kg, which were lower than the spoilage thresholds in the national standard. This study provides a theoretical basis for further development of natural antioxidants and antimicrobial agents.

Preparation and characteristics of soy protein isolate - Sea buckthorn flavone emulsion and their effects of on quality and heterocyclic amines of roasted mutton granules

A soy protein isolate (SPI) - sea buckthorn flavonoid emulsion was developed to study its effects on roasted lamb quality and heterocyclic amine (HAAs) precursors. The emulsion was stable with uniformly dispersed, well-encapsulated droplets averaging 0.1 to 10 μm. CLSM confirmed its good physical stability, small particle size, and uniform dispersion. FTIR the existence of hydrogen bond, hydrophobic interaction and physical adhesion between SPI and sea-buckthorn flavonoids. The emulsion improved lamb pellet texture by reducing chewiness and hardness, increasing adhesion, and decreasing browning. The emulsion-treated roasted mutton showed a 47.95-53.56 % increase in DPPH scavenging activity and MDA content reduction from 60.78 to 17.80 nmol/mg, indicating strong antioxidant activity and lipid oxidation inhibition. For both precursors and HAAs, there was a significant intensity of inhibition, where creatine decreased by about 44.91-68.34 %, glucose by 84.47 %-97.74 %, and the seven HAAs, Norharman, Harman, IQ, MeIQ, MeIQx, AαC, and PhIP, were inhibited by 79.64 %, respectively, 88.76 %, 65.07 %, 87.27 %, 96.16 %, 89.30 % and 49.44 %, respectively. This study aimed to develop a novel soy protein isolate-sea buckthorn flavonoid emulsion and evaluate its potential to improve roasted lamb quality while inhibiting the formation of harmful HAAs.

Functional composite films incorporating triphala-derived carbon dots for extending chicken preservation

Triphala-based carbon dots (T-CDs) were successfully prepared using a simple one-step hydrothermal method. T-CDs were characterized by absorbance, fluorescence, Fourier-transform infrared, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. T-CDs showed bright blue fluorescence at 434 nm upon excitation at 360 nm. Functional composite films were prepared using poly(vinyl alcohol) and gelatin mixture by incorporating T-CDs and applied as a packaging film to extend the shelf life of chicken. The antibacterial activity of T-CDs against Listeria monocytogenes and Staphylococcus aureus was evaluated using well diffusion and colony count methods. T-CDs were evenly dispersed throughout the PVA/Gel solution to form a dense and uninterrupted film. They also formed strong bonds with polymer chains, which improved the tensile strength of the film from 32.44 to 42.70 MPa. Furthermore, the presence of T-CDs significantly enhanced the UV-blocking ability of the PVA/Gel films, achieving 99.7 % for UV-B and 97.2 % for UV-A. In addition, the PVA/Gel/T-CDs composite films showed excellent antioxidant, antimicrobial and UV-barrier properties, extending the shelf life of chicken. Therefore, the PVA/Gel/T-CDs composite films showed great potential as an active food packaging material to extend the shelf life and preserve the visual quality of packaged meat.

Gelatin-chitosan interactions in edible films and coatings doped with plant extracts for biopreservation of fresh tuna fish products: A review

The preservation of tuna fish products, which are extremely perishable seafood items, is a substantial challenge due to their instantaneous spoilage caused by microbial development and oxidative degradation. The current review explores the potential of employing chitosan-gelatin-based edible films and coatings, which are enriched with plant extracts, as a sustainable method to prolong the shelf life of tuna fish products. The article provides a comprehensive overview of the physicochemical properties of chitosan and gelatin, emphasizing the molecular interactions that underpin the formation and functionality of these biopolymer-based films and coatings. The synergistic effects of combining chitosan and gelatin are explored, particularly in terms of improving the mechanical strength, barrier properties, and bioactivity of the films. Furthermore, the application of botanical extracts, which include high levels of antioxidants and antibacterial compounds, is being investigated in terms of their capacity to augment the protective characteristics of the films. The study also emphasizes current advancements in utilizing these composite films and coatings for tuna fish products, with a specific focus on their effectiveness in preventing microbiological spoilage, decreasing lipid oxidation, and maintaining sensory qualities throughout storage. Moreover, the current investigation explores the molecular interactions associated with chitosan-gelatin packaging systems enriched with plant extracts, offering valuable insights for improving the design of edible films and coatings and suggesting future research directions to enhance their effectiveness in seafood preservation. Ultimately, the review underscores the potential of chitosan-gelatin-based films and coatings as a promising, eco-friendly alternative to conventional packaging methods, contributing to the sustainability of the seafood industry.

Fortification of cassava starch edible films with Litsea cubeba essential oil for chicken meat preservation

Chicken meat is highly perishable and mainly preserved by plastic packaging materials, whereas their widely used have increased environmental burden and threatened human health. Bioactive packaging materials fabricated by biopolymers are promising alternatives for meat preservation. Herein, cassava starch (CS)/sodium carboxymethyl cellulose (CMC) edible films fortified with Litsea cubeba essential oil (LC-EO) were fabricated and characterized. Results showed the textural, mechanical and barrier properties of the CS/CMC edible films were significantly improved after incorporating with LC-EO. Moreover, the composite edible films exhibited potent antibacterial properties, biodegradability, hydrophobicity, and thermal stability. Whereas the water solubility and moisture content was reduced up to 29.68 % and 24.37 %, respectively. The release behavior of LC-EO suggested the suitability of the composite edible films for acidic foods. Comparing with the control group, the pH values of the meat samples packaged with CS/CMC/LCEO-4 mg/mL edible films maintained at around 6.7, and weight loss rate was 15 %. The color and texture changes, and the lipid oxidation of the meat samples with CS/CMC/LCEO-4 mg/mL packaging were also markedly delayed. The microbial growth was retarded at 6.35 log CFU/g after storage for 10 days. These findings suggested the CS/CMC/LCEO-4 mg/mL edible films had great potential for chicken meat preservation.

Effect of tragacanth gum-chitin nanofiber film containing free or nano-encapsulated cumin essential oil on the quality of chilled turkey burgers packed with oxygen absorber

This research was undertaken to assess the effect of tragacanth gum-chitin nanofiber (TG-CNF) film containing free (CEO) or encapsulated cumin essential oil (CNE) combined with oxygen absorber (OA) packaging on the shelf-life of ready-to-cook (RTC) turkey breast burgers during chilled storage. The experimental groups were OA and TG-CNF as single treatments, TG-CNF + CEO, TG-CNF + CNE, and TG-CNF + OA as binary treatments, TG-CNF + CEO + OA and TG-CNF + CNE + OA as ternary treatments, and control. The samples were stored at 3°C for 20 days and analyzed for microbial, physicochemical, and sensory attributes. Binary treatments, when compared to single treatments, and ternary treatments, when compared to binary treatments, exhibited enhanced effectiveness in managing microbial growth, hindering physicochemical alterations, and decelerating sensory alterations. At day 20, TG-CNF + CNE + OA group was identified as the most effective group in inhibiting the growth of total mesophilic bacteria (TMB), total psychrophilic bacteria (TSB), and coliforms (final counts were 4.8, 4.16, and ≤1 log CFU/g, respectively), and TG-CNF + CNE + OA and TG-CNF + CEO + OA groups were known as the most effective groups in inhibiting lactic acid bacteria (LAB) (final counts were 4.71 and 5.15 log CFU/g, respectively). Furthermore, the TG-CNF + CNE + OA treatment proved to be the most effective group in reducing the total volatile nitrogen (TVN) (final level was 19.2 mg N/100 g) and thiobarbituric acid reactive substances (TBARS) (final level was 0.119 mg malondialdehyde (MDA)/kg). TG-CNF + CNE + OA and TG-CNF + CEO + OA were the most efficient groups to delay the increasing rate of cooking loss (final values were 23.3% and 24.6%) and pH (final values were 7.01 and 6.99). The sample's shelf-life was 4 days in control and TG-CNF, 8 days in OA and TG-CNF + OA, 12 days in TG-CNF + CEO, 16 days in TG-CNF + CNE and TG-CNF + CEO + OA, and at least 20 days in TG-CNF + CNE + OA. As a result, the incorporation of TG-CNF + CNE alongside OA packaging emerges as a highly effective active packaging method for preserving RTC turkey breast burgers during chilled storage.

Nanoemulsions of red quinoa and ginseng extracts with chitosan wall: Investigating the antioxidant properties and its effect on the shelf life of dairy cream

The study aimed to investigate the antioxidant properties of ginseng and red quinoa extract nanoemulsion and its effect on the shelf life of dairy cream. Nanoemulsion includes dairy cream, Tween 80, chitosan, whey protein powder, chitosan/whey protein powder, red quinoa extract, ginseng extract, and a mixture of extracts (1:1). The highest total phenol content and total flavonoid content were related to ginseng extract (24,009.55 mg of gallic acid equivalent/kg, 883.16 mg quercetin/kg) with ethanol-water solvent (80:20). Most of the phenolic and flavonoid compounds of ginseng and red quinoa extracts were related to p-coumaric acid (211.3 μg/g), catechin (29.6 μg/g), ellagic acid (73.88 μg/g), and rutin (34.12 μg/g), respectively. Considerable antioxidant power in the concentration of 800 ppm of red quinoa and ginseng extracts (ethanol-water solvent (50:50), (80:20)) in 2,2-diphenyl-1-picrylhydrazyl radical scavenging (80%, 82%, 80%, and 78%), bleaching β-carotene: linoleic acid (81%, 73%, 77%, and 86%), and ferric reducing antioxidant power assays (70%, 73%, 72%, and 76%) was observed. Nanoemulsions of red quinoa extract with chitosan wall had the smallest particle size (250.67 nm), the highest encapsulation efficiency (72.79%), and the polydispersity index (0.34). Nanoemulsions containing ginseng + quinoa (1:1) with chitosan/whey protein powder wall showed the highest viscosity (5.30 mPa/s) and the mostzeta potential (-32.6 mv). Also, nanoemulsions of red quinoa extract showed the lowest amount of peroxide value and the thiobarbituric acid value (12 milliequivalent O2/kg-0.48 μg/mL) in dairy cream oil. In general, the red quinoa extract with chitosan wall was superior to other samples due to the delay in oxidation and positive effect on the shelf life of dairy cream.

Effect of cinnamaldehyde-nanoemulsion and nanostructured lipid carriers on physicochemical attributes of reduced-nitrite sausages

This study aimed to produce cinnamaldehyde (CA)-loaded nanostructured lipid carriers (NLC) and nanoemulsion (NE) to replace nitrite in sausage. The NLC and NE droplet sizes were 132 and 116 nm with encapsulation efficiency of 98 and 96 %, respectively. In in vitro antimicrobial assessment, the free CA and NE showed higher microbial activity against S. aureus and E. coli than NLC. Meanwhile, NE showed a faster release profile for CA than NLC. Among the samples, NE and NE + nitrite indicated the lowest peroxide value (3.7 ± 0.1), TVBN amount (8.6 ± 0.2), acidity (0.3 ± 0.02), microbial quality (against E. coli, C. perfringens, lactic acid bacteria, psychrophilic bacteria, total mold and yeast, and total viable counts), and sensory attribute, while the NE + nitrite sample exhibited better color properties and higher oxymyoglobin content (5-10 % higher). Therefore, NE + nitrite can be the best choice due to supporting the different quality parameters of sausage.

Fabrication and characterization of emulsion-based edible film containing cinnamon essential oil using chia seed mucilage

Chia seed mucilage (CSM) film incorporated with 2, 4, and 6 % (w/w) nanoemulsion of cinnamon essential oil (CSM-2, CSM-4, CSM-6) were developed, and their physicochemical, mechanical, antioxidant, and antimicrobial properties were determined. According to the results, cinnamon EO nanoemulsion (CEN) had droplet size 196.07 ± 1.39 nm with PDI 0.47 ± 0.04. Moreover, CSM film had higher water solubility (99.37 ± 0.05 %) and WVP (8.55 ± 1.10 g/kPa h m2) than reinforced CSM films with CENCEN. The lowest water solubility (98.02 ± 0.01 %) and WVP (3.75 ± 0.80 g/kPa h m2) was observed in CSM-6 film. Moreover, the addition of CEN improved the homogeneity and density of films and the smoothness of the surface, being observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The Fourier transform infrared (FTIR) spectroscopy also confirmed the incorporation of CEN within the film matrix. The CSM films' antioxidant (DPPH radical scavenging power) and antimicrobial (against Escherichia coli and Staphylococcus aureus) properties of CSM films were notably enhanced with the inclusion of CEN in a dose-dependent manner. The mechanical (tensile strength and elongation at break) of CSM films also was affected by the addition of CEN, TS decreased, and EAB increased (p < 0.05). The lowest TS (20.63 ± 1.39 MPa) and highest EAB (3.36 ± 0.61 %) was observed in CSM-4 film. However, CSM film was relatively dark with low opacity, and adding CEN slightly increased lightness (L*) and yellowness (b*) parameters. The superior antioxidant and barrier characteristics of the CSM edible film incorporated with CEN make it a potential candidate for product packaging and shelf-life extension.

Sodium-alginate-based indicator film containing a hydrophobic nanosilica layer for monitoring fish freshness

In this study, hydrophobic sodium alginate/anthocyanin/cellulose nanocrystal indicator films were fabricated by incorporating nanosilica (NS) as a waterproofing layer. The concentrations and formation methods (spraying (S), coating (C), and impregnation (I)) of the NS layer (denoted as NSS, NSC, NSI, respectively) were optimized. The results indicated that the optimum concentration of the NS layer was 5 % at a water contact angle (WCA) 110.5°. Further, Fourier transform infrared spectra showed the presence of SiOSi and SiCH3 groups in the NSS, NSC, and NSI films, and X-ray diffraction spectra indicated that original structures of these films were disordered. Moreover, the surface morphology, mechanical properties, and light transmission were affected by the NS layer, and the optimal layer was found to be NSI. After 10 days of storage at 100 % humidity, the NSI film exhibited low water vapor adsorption (37.22 g) and permeability (0.1484 g/m·s·Pa·10-11) and a high WCA (110.2°). In addition, the NSI film exhibited a visible color shift with an increasing pH of the buffer solution. A monitoring test of fish freshness showed that the NSI film displayed a distinctive color change corresponding to fish spoilage during 14 days of storage. This indicates that NSI has high potential in indicator film applications.

Multicomponent system for development of antimicrobial PLA-based films with enhanced physical characteristics

This study aims to develop polylactic acid (PLA)-based packaging films with imparted antimicrobial properties and enhanced physical characteristics by evaluating the likely interaction among multiple film components. For this purpose; epoxidized soybean oil (ES) (20 %) serves as a plasticizer, spruce resin (SR) (15 %) functions as both a plasticizer and antimicrobial agent, ZnO (0.1 %) acts as a nanofiller and antimicrobial, and finally thyme and clove essential oil mixture (5 % and 10 %) serves as an antimicrobial agent were incorporated to PLA film formulation. Composite materials were prepared by the solvent casting method using methylene chloride as the solvent. The developed films were characterized in terms of physical, mechanical, thermal, and antimicrobial properties. Tensile strength (59 MPa) and elastic modulus (2625 MPa) of the neat PLA film gradually decreased to 8.99 MPa and 725.4 MPa, respectively, with the sequential addition of all components, indicating enhanced flexibility. SR, ZnO, and EOs significantly imparted antimicrobial property to the PLA film as demonstrated by the inhibition zone of 13.83 mm and 15.67 mm observed for E. coli and S. aureus, respectively. The barrier properties of the films were enhanced by the addition of SR and ZnO; however, EOs increased the water vapor permeability from 0.080 to 0.090 g.mm/m2.day.kPa compared to the neat PLA film. Principal component and hierarchical cluster analysis enabled the successful discrimination of the films, demonstrating how the film properties are affected by the film components. Therefore, this study suggests that selection of a proper combination is essential to highly benefit from the multicomponent film systems for designing alternative food packaging materials with desired properties.

Volatile compounds produced in smoked bacon inoculated with potential spoilage bacteria

BACKGROUND

Volatile organic compounds (VOCs) produced during meat storage are mainly derived from the decomposition of meat components and the metabolism of spoilage bacteria. VOCs produced in sterile bacon model substrate inoculated or un-inoculated with spoilage bacteria, Staphylococcus xylosus (P2), Leuconostoc mesenteroides (P6), Carnobacterium maltaromaticum (P9), Leuconostoc gelidum (P16) and Serratia liquefaciens (P20), previously isolated, were identified by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Furthermore, combinations of the strains (Pm) were also obtained.

RESULTS

In total, 54 volatile compounds, including aldehydes, alcohols, phenols, ketones, alkanes, alkanes, organic acids, esters and so forth, were determined after 45 days of storage in bacon inoculated with potential spoilage bacteria using the HS-SPME/GC-MS method. VOC concentrations of alcohols and organic acids in groups inoculated with bacteria were remarkably higher (P < 0.05) compared to that in control samples. Specifically, some VOCs are closely related to the metabolic activity of the inoculated bacterial strains; for example, 2,3-butanediol was associated with P2, P16 and P20, and acetic acid was mainly related to P6 and P9.

CONCLUSION

The results of partial least squares regression indicated that there was a high correlation between the electronic nose sensors and VOCs of smoked inoculated potential spoilage bacteria. These compounds are potentially important for predicting deterioration of smoked bacon. © 2023 Society of Chemical Industry.

Investigating the possibility of increasing the microbial and oxidative stability of silver carp burgers using hydrolyzed protein of watermelon seeds

In this study, watermelon seeds (Citrullus lanatus) protein hydrolyzed (WSPH) was produced using microbial enzymes Alcalase and Protamex. Then, the effect of different concentrations of WSPH (0, 1, 2, and 3%) on the quality of the silver carp (Hypophthalmichthys molitrix) burger during refrigerated storage (4 ± 1 °C) was investigated. According to the results, WSPH by alcalase had significantly higher degree of hydrolysis and antioxidant activity (p < 0.05) and it was used for burger tests. The results showed that, the addition of WSPH was able to reduce the microbial, chemical spoilage and sensory score during 16 days compared to the control, and with increasing the concentration of WSPH, better results were observed (p < 0.05). According to the chemical, microbial and sensory indicators, WSPH at 3% could increase the shelf life of fish burgers up to 8 days compared to the control, and this treatment was within the permissible quality limit until the end of the refrigerated storage.

Graphical abstract

Enhanced physical properties, antioxidant and antibacterial activity of bio-composite films composed from carboxymethyl cellulose and polyvinyl alcohol incorporated with broccoli sprout seed extract for butter packaging

This study investigated the development of biodegradable films made from a combination of carboxymethyl cellulose (CMC), Polyvinyl alcohol (PVA), and purified extract of broccoli sprout seed (BSSE). The films were characterized for their color, physical properties, surface morphology, crystallinity, mechanical properties, and thermal properties. The addition of BSSE up to 1.4 % to the film matrix imparted opaque color and increased opacity up to 3.652. The films also became less moisture-absorbent 8.21 %, soluble 19.16 %, and permeable to water vapor 1.531 (× 10-10 g.m-1 s-1 pa-1). By utilizing 0.7 % from BSSE inside films, the surface of the films became smoother but became rough with higher concentrations 2.1 % of BSSE. Fourier transform infrared (FT-IR) analysis showed that there was physical interaction between the BSSE extract and the PV/CM matrix. The films showed good thermal stability, and the incorporation of BSSE improved their ability to preserve the acidity, TBARS, peroxide value, and total color differences of butter during cold storage.

Encapsulation of Dicranopteris linearis extract using cellulose microparticles for antiulcer medication

Dicranopteris linearis (DL) is a fern in the Gleicheniaceae family, locally known as resam by the Malay community. It has numerous pharmacological benefits, with antiulcer and gastroprotective properties. Peptic ulcer is a chronic and recurring disease that significantly impacts morbidity and mortality, affecting nearly 20 % of the world's population. Despite the effectiveness of peptic ulcer drugs, there is no perfect treatment for the ailment. Encapsulation is an advanced technique that can treat peptic ulcers by incorporating natural sources. This work aims to encapsulate DL extract using different types of cellulose particles by the solvent displacement technique for peptic ulcer medication. The extract was encapsulated using methyl cellulose (MC), ethyl cellulose (EC), and a blend of ethyl methyl cellulose through a dialysis cellulose membrane tube and freeze-dried to yield a suspension of the encapsulated DL extracts. The microencapsulated methyl cellulose chloroform extract (MCCH) has a considerably greater level of total phenolic (84.53 ± 6.44 mg GAE/g), total flavonoid (84.53 ± 0.54 mg GAE/g), and antioxidant activity (86.40 ± 0.63 %). MCCH has the highest percentage of antimicrobial activity against Escherichia coli (2.42 ± 107 × 0.70 CFU/mL), Bacillus subtilis (5.21 ± 107 × 0.90 CFU/mL), and Shigella flexneri (1.25 ± 107 × 0.66 CFU/mL), as well as the highest urease inhibitory activity (50.0 ± 0.21 %). The MCCH particle size was estimated to be 3.347 ± 0.078 μm in diameter. It has been proven that DL elements were successfully encapsulated in the methyl cellulose polymer in the presence of calcium (Ca). Fourier transform infrared (FTIR) analysis indicated significant results, where the peak belonging to the CO stretch of the carbonyl groups of methyl cellulose (MC) shifted from 1638.46 cm-1 in the spectrum of pure MC to 1639.10 cm-1 in the spectrum of the MCCH extract. The shift in the wavenumbers was due to the interactions between the phytochemicals in the chloroform extract and the MC matrix in the microcapsules. Dissolution studies in simulated gastric fluid (SGF) and model fitting of encapsulated chloroform extracts showed that MCCH has the highest EC50 of 6.73 ± 0.27 mg/mL with R2 = 0.971 fitted by the Korsmeyer-Peppas model, indicating diffusion as the mechanism of release.

Inhibition of Staphylococcus aureus biofilms by poly-L-aspartic acid nanoparticles loaded with Litsea cubeba essential oil

Staphylococcus aureus (S. aureus) biofilms contamination on various food-contacting surfaces is considered a significant threat in the field of food. Poly-L-aspartic acid (PASP) was proven to damage biofilm by affecting bacterial adhesion, metabolic activity, and extracellular polymeric substances in this study. Especially for eDNA, its generation was reduced by 49.4 %. After treatment with 5 mg/mL of PASP, the number of S. aureus in the biofilm at different growth stages decreased by 1.20-1.68 log CFU/mL. The nanoparticles prepared by PASP and hydroxypropyl trimethyl ammonium chloride chitosan were used to embed LC-EO (EO@PASP/HACCNPs). The results indicated that the particle size of the optimized nanoparticles was 209.84 nm with an encapsulation rate of 70.28 %. Compared to LC-EO alone, EO@PASP/HACCNPs had more significant permeation and dispersion effects on biofilms and possessed long-lasting anti-biofilm activity. For the biofilm grown for 72 h, the population of S. aureus in the EO@PASP/HACCNPs-treated biofilm was additionally reduced by 0.63 log CFU/mL compared with the LC-EO-treated group. EO@PASP/HACCNPs were also applied to different food-contacting materials. The lowest inhibition rate of EO@PASP/HACCNPs on S. aureus biofilm still reached 97.35 %. The sensory properties of the chicken breast were not affected by EO@PASP/HACCNPs.

Encapsulation of Nepeta hormozganica and Nepeta dschuprensis essential oils in shrimp chitosan NPs: Enhanced antifungal activity

This study investigated the encapsulation of Nepeta hormozganica (NHEO) and Nepeta Dschuprensis (NDEO) essential oils into chitosan nanoparticles (CSN) via a simple ionic gelation method with tripolyphosphate (TPP). Chitosan (CS) is prepared by demineralizing, deproteinizing, and deacetylating shrimp shells waste in high yield (70.2 %). SEM, TEM, FT-IR, TGA, and XRD techniques were employed to characterize the encapsulated essential oils ((NHEO-CSN) and (NDEO-CSN)). The prepared EOs-CSN and CSN are found with particle sizes of 100-150 nm and 400-500 nm, respectively, and regular distribution. The encapsulation efficiency of encapsulated Nepeta hormozganica and Dschuprensis essential oils were found to be 73.64 % and 75.91 %, respectively. The synthesized nanocapsules were evaluated for antifungal activity against Fusarium oxysporium, Sclerotinia sclerotiorum, Pythium aphanidermatum, Alternaria alternata, Rhizactonia Solani, and Botrytis cinerea. Antifungal studies show that encapsulated essential oils increased antifungal efficiency by up to 100 %.

Technological strategies for the use of plant-derived compounds in the preservation of fish products

New approaches to reducing synthetic preservatives in the preservation of foods draw the attention of plant-derived bioactive compounds, especially for application in foods highly susceptible to spoilage, such as fish products. The review presents relevant data from procurement, application, and methodological research trends to investigate the potential effects of plant-derived bioactive compounds on shelf life extension in fish products. The systematization of data allowed observation that the different methods of extraction and application of bioactive plant compounds result in different effects, such as the reduction of lipid oxidation, antimicrobial effects, and maintenance of sensory characteristics, benefiting the extension of shelf life. In general, plant-derived bioactive compounds are an alternative for the preservation of fish products; however, approaches to the composition of the compounds can contribute to the optimization and efficiency of the process from a technical point of view and industrial viability.

A Review of Regulatory Standards and Advances in Essential Oils as Antimicrobials in Foods

As essential oils (EOs) possess GRAS status, there is a strong interest in their application to food preservation. Trends in the food industry suggest consumers are drawn to environmentally friendly alternatives and less synthetic chemical preservatives. Although the use of EOs has increased over the years, adverse effects have limited their use. This review aims to address the regulatory standards for EO usage in food, techniques for delivery of EOs, essential oils commonly used to control pathogens and molds, and advances with new active compounds that overcome sensory effects for meat products, fresh fruits and vegetables, fruit and vegetable juices, seafood, dairy products, and other products. This review will show adverse sensory effects can be overcome in various products by the use of edible coatings containing encapsulated EOs to facilitate the controlled release of EOs. Depending on the method of cooking, the food product has been shown to mask flavors associated with EOs. In addition, using active packaging materials can decrease the diffusion rate of the EOs, thus controlling undesirable flavor characteristics while still preserving or prolonging the shelf life of food. The use of encapsulation in packaging film can control the release of volatile or active ingredients. Further, use of EOs in the vapor phase allows for contact indirectly, and use of nanoemulsion, coating, and film wrap allows for the controlled release of the EOs. Research has also shown that combining EOs can prevent adverse sensory effects. Essential oils continue to serve as a very beneficial way of controlling undesirable microorganisms in food systems.

Effect of extraction methods on the efficiency of sumac (Rhus coriaria L.) fruit extract in soybean oil quality during accelerated conditions

Herbal extracts containing natural bioactive substances with numerous beneficial effects have been recently noticed as appropriate alternatives for synthetic food preservatives. In this study, we aimed to optimize the effects of different sumac (Rhus coriaria) fruit extracts (SFE) on oxidative stability of soybean oil under accelerated conditions compared to a synthetic antioxidant. Hydro-ethanolic extracts (70%) of sumac fruits were prepared by three methods of immersion (I-SFE), ultrasound (U-SFE), and microwave (M-SFE). According to the response surface methodology (RSM), 13 runs were considered in the concentrations of 0, 500, and 1000 ppm of each extract that were added to the soybean oil and stored at 60°C for a 20-day period. All of the treatments were significantly (p < .05) efficient in preventing the chemical and sensory changes of soybean oil compared to the control in the dose-dependent manner during storage period. I-SFE treatment showed the lowest peroxide value (PV) (0.000063 meq (milliequivalents) O2/kg oil), thiobarbituric acid reactive substances (TBARS) (115.06 MDA (malondialdehyde)/kg oil), and acid value (0.0169 mg KOH (potassium hydroxide)/kg oil) among the other extracts at the end of the storage period. Furthermore, I-SFE treatment earned the highest sensory scores (flavor, color, odor, and overall acceptability) of soybean oil in the range of 4-5 in comparison to the other treatments and synthetic antioxidant during storage time. According to the analysis of RSM, I-SFE in the concentration of 999.998 ppm could optimally enhance the shelf life of soybean oil for 11.3614 days under accelerated conditions. It was concluded that I-SFE with the same efficiency as synthetic antioxidants can be considered as a suitable alternative in soybean oil with various health benefits.

The Impact of Thyme, Rosemary and Basil Extracts on the Chemical, Sensory and Microbiological Quality of Vacuumed Packed Mackerel Balls

The effect of natural extracts (0.05%) and vacuum packaging on the sensory, chemical, and microbiological quality of mackerel balls were evaluated at refrigerated (4 ± 2 °C) storage. Natural extracts thyme (38.13 mg GAE/g), rosemary (81.85 mg GAE/g) and basil (21.08 mg GAE/g) were evaluated. Natural extracts imparted stability to lipids (TBA, FFA, and PV), and the ability was further improved by vacuum packaging. Biochemical changes (TVB-N, pH) and microbiological quality (total viable count) were also retained. Control samples packed under vacuum were found to cross over acceptable limits on day 28. Based on sensory quality evaluation, samples treated with rosemary and thyme extracts showed superior sensory quality over control, whilebasil-treated samples were not found acceptable at day 28. Consequently, the inclusion of thyme and rosemary extracts exhibits preservative quality when combined with vacuum packaging, retaining biochemical, microbial, and sensory quality.

Combined effects of calcium-alginate coating and Artemisia fragrance essential oil on chicken breast meat quality

The objective of the present study was to evaluate the effects of calcium-alginate (CA) containing Artemisia fragrance essential oils (AFEOs) as a potential antioxidant and antimicrobial coating on quality attributes and shelf life of chicken meat throughout keeping period (4°C). Five treatments were produced as follows: T1 (distilled water as control), T2 (2% CA), T3 (2% CA +500 ppm AFEOs), T4 (2% CA +1000 ppm AFEOs), and T5 (2% CA +1500 ppm AFEOs). The chicken meats packaged in polyethylene bags at atmospheric condition and physicochemical, microbiological, and organoleptic properties were assessed at days 1, 4, 8, and 12. There was no remarkable difference in proximate composition (moisture, ash, protein, and fat) of meat samples by treating with CA or AFEOs. The results revealed that CA +AFEOs coating reduced significantly the pH, total volatile base nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) values and also displayed higher contents of the total phenolic content (TPC) and redness value when compared with control. According to results, 2% CA +1500 ppm AFEOs reduced 58.3 (mg MDA (malondialdehyde)/kg) and 0.63 (mg/100 g) of TBARS and TVB-N values when compared to control, respectively. The microbiological count showed that CA +AFEOs had a significantly higher inhibitory impact on the total viable count (TVC), coliforms, molds and yeasts. At day 12, 6.89 Log CFU (colony-forming units)/g was recorded for TVC in 2% CA +1500 ppm AFEOs, which was the lowest overall. This treatment also displayed the reduction of 2.97 Log CFU/g in coliforms and 3.3 Log CFU/g in molds and yeasts in comparison with uncoated samples. The outcomes of pH, TBARS, TPC, color values, microbiological count, and organoleptic properties suggested 2% CA +1500 ppm AFEOs as an efficient coating for quality stability and improving the shelf life of chicken breast meat without negative impact on organoleptic properties.

Fabrication and characterization of ZnO nanofilms using extracted pectin of Premna microphylla Turcz leaves and carboxymethyl cellulose

The current study sought to fabricate pectin nano-films from Premna microphylla Turcz (PMTP) leaves using a combination of ZnO-carboxymethyl cellulose. The rheological and physical properties of fabricated nano-ZnO films were studied. Spectroscopy FT-IR, microscopic study (SEM), thermogravimetry (TG), and XRD were applied to characterize the fabricated film. The antibacterial activity of the nanofilm was determined using the antibacterial circle method. The findings showed that the addition of PMTP can reduce the nanofilm color, water solubility/hydrophilicity, air permeability, and ultraviolet light permeability of the nanofilm. Treatment CPN0.5 achieved the optimized Tensile strength (TS) of 4.50 Mpa, significant differences compared to CPN2 (3.99 Mpa) and CPN1 (3.65 Mpa). In addition, treatment CPN1 achieved the lowest WVP value (29.35) compared to the highest value (41.62) achieved by CPN0.5 treatment with no significant differences with CPN3 (29.7) and CPN1 (30.98) treatments. Elongation (E%) at break was the best for each CP10 (74.9) and CPN0.5 (73.03). Moreover, ZnO can enhance the nanofilm activity and the nanofilm water swelling ratio. Furthermore, adding ZnO to the nano-formula improved the antibacterial activity of the fabricated film against Staphylococcus aureus. In sum, nanofilms fabricated of PMTP and ZnO possess promising prospects as antibacterial agents in packaging applications.

Oxidative stability of soybean and corn oils enriched with Pluchea quitoc hydroalcoholic extract

Soybean and corn oils are among the most popular vegetable oils, and are ingredients which are widely used in cooking and in the food industry. These oils contain many unsaturated fatty acids such as oleic, linoleic and linolenic acids, which makes them easily oxidized by oxygen. Extensive efforts are being made to prevent or minimize vegetable oil oxidation through the development of antioxidants. Phenolic antioxidants which are present in some extracts can be used as food additives to prevent lipid oxidation. In this study chromatographic analyses (HPLC and GC) of the Pluchea quitoc hydroalcoholic extract were performed. The content of phenolic compounds by the Folin-Ciocalteau method and the antioxidant properties against radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) were also evaluated. The effect of samples prepared with soybean and corn oils enriched with Pluchea quitoc hydroalcoholic extract was determined and compared with samples of these oils which were free of antioxidants and with samples containing the synthetic antioxidant BHT. The results showed potential for application of the extract. A high content of phenolic compounds (314 milligrams of gallic acid equivalents (GAE)/g of extract) and good IC50 values were detected for the inhibition of the radicals DPPH and ABTS (13.2 µg·mL-1 and 5.6 µg·mL-1). In the evaluation of the oxidative stability of the oils enriched with this extract, it was found that at 1% concentration it was possible to obtain values of induction period (IP) close to the samples with added BHT.

Biocontrol Approaches against Escherichia coli O157:H7 in Foods

Shiga-toxin-producing Escherichia coli O157:H7 is a well-known water- and food-borne zoonotic pathogen that can cause gastroenteritis in humans. It threatens the health of millions of people each year; several outbreaks of E. coli O157:H7 infections have been linked to the consumption of contaminated plant foods (e.g., lettuce, spinach, tomato, and fresh fruits) and beef-based products. To control E. coli O157:H7 in foods, several physical (e.g., irradiation, pasteurization, pulsed electric field, and high-pressure processing) and chemical (e.g., using peroxyacetic acid; chlorine dioxide; sodium hypochlorite; and organic acids, such as acetic, lactic, and citric) methods have been widely used. Although the methods are quite effective, they are not applicable to all foods and carry intrinsic disadvantages (alteration of sensory properties, toxicity, etc.). Therefore, the development of safe and effective alternative methods has gained increased attention recently. Biocontrol agents, including bacteriophages, probiotics, antagonistic bacteria, plant-derived natural compounds, bacteriocins, endolysins, and enzymes, are rapidly emerging as effective, selective, relatively safe for human consumption, and environmentally friendly alternatives. This paper summarizes advances in the application of biocontrol agents for E. coli O157:H7 control in foods.

The effect of hydrolyzed sesame meal protein on the quality and shelf life of hamburgers during refrigerated storage

In this study, to improve the quality and shelf life of hamburgers, sesame meal protein hydrolysates (SPH) were produced using two enzymes of alcalase and flavourzyme and then four hamburger treatments: T1: control (10% soybean), T2: 1% SPH + soybean 9%, T3: 2% SPH + soybean 8%, and T4: 3% SPH + soybean 7% were prepared. Physicochemical properties were analyzed at the beginning of the storage period; microbial and chemical quality was evaluated at intervals of 0, 4, 8, 12, and 16 days. The results of SPH showed that alcalase enzyme can produce a SPH with a higher antioxidant properties (DPPH, FRAP, and beta-carotene-linoleic acid) (P < 0.05); therefore, this SPH was used for hamburger properties. According to the results, with the addition of SPH, moisture, fat, texture firmness decreased, protein, and brightness increased (P < 0.05), and all treatments had the allowable range. SPH replacement with soybean slowed down the increasing trend of oxidation and microbial spoilage (P < 0.05). In general, better results were observed in T3 and T4, which had a permissible range chemical and microbial index until the end of the storage period, as well as these treatments inhibited the growth of Staphylococcus aureus and Escherichia coli. Only T3 was approved by the evaluators.

Use composite coating of chitosan-chia seed gum enriched with microliposomes of Bay laurel essential oil to increase the shelf life of quail fillets

In this study, the effect of composite chitosan-chia seed coating (CH-CG) with Bay laurel (Laurus nobilis) essential oil (BE) in two forms including free and nanocapsulated on the shelf life of quail fillets during the 16-day refrigeration (4 ± 1℃) period was investigated. For this purpose, first, BE was extracted by Clevenger apparatus. Then, nanoliposomes BE were produced, and the properties of BE and nanoliposomes BE were investigated. In order to investigate the shelf life of quail, 6 treatments were produced including 1: control (C), 2: CH-CG, CH-CG+BE at 800 ppm, 3: CH-CG+BE at 1600 ppm, 4: CH-CG+nano BE at 800 ppm, 5: CH-CG+nano BE at 1600 ppm, and periodically chemical parameters (peroxide value, free fatty acid, total volatile basic nitrogen, texture firmness, and chewing ability) and microbial (total viable bacteria (TVC) and psychrotrophic bacteria), and the effect of different treatments on control in Escherichia coli and Staphylococcus aureus inoculated populations in quail was also investigated. The BE had high antioxidant and antimicrobial properties. The particle size and microencapsulation efficiency of BE nanoliposome were 98.3 nm and 75.95%, respectively. The results of chemical and microbial analysis showed that in general, the coating with essential oil slowed down the increasing trend of oxidation and microbial indices compared to the control treatment and nanocapsulation of essential oil has increased its antimicrobial and antioxidant properties (p < .05). At the end of storage period, in all tests, treatments of 3, 4, and 5 had the allowed microbial and chemical range and they also inhibited the growth of these bacteria (p < .05). Overall, considering the higher sensory score of treatment 4 and economic efficiency, it seems that this treatment can be used as a natural preservative in the meat industry.

Fortifying of probiotic yogurt with free and microencapsulated extract of Tragopogon Collinus and its effect on the viability of Lactobacillus casei and Lactobacillus plantarum

In this study, the effect of free and microencapsulation of Tragopogon Collins extract (TPE) on the properties of probiotic yogurt was investigated. For this purpose, first, TPE was extracted by ultrasound method. The amounts of phenolic and flavonoid compounds in TPE were 890.04 mg/g gallic acid and 512.76 mg/g extract (respectively), and it had high antioxidant and antimicrobial properties. Then, the extract was encapsulated by maltodextrin-whey protein concentrate. The results related to the particle size, zeta-potential, and microencapsulation efficiency of the TPE microencapsulation were 93.87 nm, 18.99 MV, and 64.35% respectively. In order to investigate the effect of nano- and free TPE on the properties of yogurt during a 15-day storage period of 5 treatments including control, nano- and free TPE at 750 and 1,000 ppm were provided and the physicochemical properties, probiotic bacteria viability, and sensory properties were investigated. The results showed that adding TPE to yogurt affects the physicochemical properties, probiotic bacterial viability, and sensory properties were investigated. The results showed that adding TPE to yogurt affects the physicochemical properties. TPE samples had lower pH, less syneresis, and more acidity, viscosity, and antioxidant properties compared to the control sample (p < .05). Furthermore, in these samples, the viability of probiotic bacteria during storage was higher than the control treatment and the sensory properties were acceptable. In most cases, better results were observed in nano-TPE treatment. Therefore, by industrial production of probiotic yogurt containing nano-TPE as a functional food, a new choice will be provided for consumers of dairy products that would have more desirable nutritional value and sensory properties.

Effects of cinnamon essential oil and Persian gum on preservation of pomegranate arils

Given the high perishability of pomegranate arils, edible antimicrobial coating will enhance their shelf life and maintain their marketability. An antimicrobial coating was prepared using 1% (w/v) soluble part of Persian gum (PG) and different concentrations (0.25%, 0.50%, and 0.75% (v/v)) of cinnamon essential oil (CEO) to extend the shelf life of pomegranate arils. Microbiological, chemical, physical, and sensorial characteristics of coated and uncoated samples were evaluated at 7-day intervals. Total anthocyanin (TAN), titrable acidity (TA), and ascorbic acid showed a decreasing trend, during the whole period of the storage. TAN, TA, and ascorbic acid decreased from 119.8 to 44.5 mg/L, 1.6% to 1.37%, and 682 to 140 mg/L, respectively. Firmness increased during the storage time, while total soluble solids (TSS, around 17.4 °Brix) and total phenolic compounds (TP, around 14.21 mg/100 ml) showed no significant changes with CEO concentrations. Coatings containing 0.5% and 0.75% CEO significantly prevented fungal growth on the samples at least for 3 weeks and 3 months, respectively. Optimization proved that 1-week cold storage and 0.43% CEO could dramatically meet 80% of the research targets including maximum nutritional quality and freshness, as well preventing microbial spoilage. It was concluded that coating the pomegranate arils by PG and selecting an appropriate concentration of the CEO could considerably increase shelf life, marketability, and nutritional quality of pomegranate arils at a suitable and acceptable level.