Showing papers in "Journal of Food Measurement and Characterization in 2021"

An electrochemical strategy for toxic ractopamine sensing in pork samples; twofold amplified nano-based structure analytical tool

Abstract: Determination of food toxic compounds is one of the significant strategies for investigating food quality. The presence research introduces an electrochemical approach for toxic ractopamine sensing using a gold electrode amplified with gold nanoparticles (Au-Nps/AuME). The oxidation signal of ractopamine was investigated at the surface of Au-Nps/AuME, and results showed a 2.36-fold amplification in current and reducing 100 mV in oxidation potential compare to the pristine gold electrode. The redox reaction of ractopamine shows a pH dependence behavior with two electrons and two protons. Furthermore, the scan rate and chronoamperometric investigation showed a diffusion coefficient of 1.0 × 10−6 cm2/s to the oxidation reaction of ractopamine at the surface of Au-Nps/AuME. Analytical investigation showed a linear dynamic range of 0.1–380 µM for sensing of ractopamine using square wave voltammetric technique. Also, Au-Nps/AuME could be used to measure ractopamine in food samples such as pork samples with a recovery range of 98.3–103.9% and a detection limit of 50 nM.

Nanomaterials modified electrodes for electrochemical detection of Sudan I in food

Abstract: There is an urgent need to develop a highly sensitive detection system for detecting trace amount of food contaminants. The environmental analysis of Sudan I, a carcinogenic azo-dye, has attracted wide attention due to their increasing levels and high toxicities. Several methods have been developed to detect the presence of this compound. For example, analytical methods based on chromatography and spectroscopy has attracted significant attentions for the determination of Sudan I. However, these methods require complex separation processes, expensive equipment, toxic chemicals, long analysis times, and expert staff. Electroanalytical methods can be considered as promising alternative techniques due to their advantages such as simplicity, low cost, high sensitivity, and fast analysis speed. Electroanalytical methods have been also investigated for the determination of Sudan I. Chemically modified electrodes have been widely used to counter the problems of poor sensitivity and selectivity faced at bare electrodes. We have reviewed the materials that have been extensively used to fabricate modified electrode surfaces for detection of Sudan I. The characteristics of the materials that improve the electrocatalytic activity of the modified surfaces are discussed.

High performance of screen-printed graphite electrode modified with Ni–Mo-MOF for voltammetric determination of amaranth

Abstract: The present study introduces a novel Ni–Mo-MOF-modified screen printed electrode (Ni–Mo-MOF/SPE) to sensitively and rapidly detect amaranth. Cyclic voltammetry (CV) was also applied to evaluate the electrochemical behavior of amaranth on the surfaces of bare SPE and Ni–Mo-MOF/SPE, and differential pulse voltammetry (DPV) to calculate linearly detection range of amaranth. According to the results, various linear oxidation peak currents were obtained at different concentrations (between 0.15 ± 0.001 and 500.0 ± 0.001 µM) and the limit of detection (LOD) was estimated to be 0.05 ± 0.001 µM in the optimal conditions. Additionally, the efficacy of developed electrode was tested by real samples, the results of which were satisfactory. The proposed Ni–Mo-MOF/SPE not only had special properties such as high selectivity, high sensitivity, cost-effectiveness and rapid response, but also was shown to possess wide applications for sensitively amaranth detection in real samples.

Physicomechanical properties, release kinetics, and antimicrobial activity of activated low-density polyethylene and orientated polypropylene films by Thyme essential oil active component

Abstract: In this research active packaging based on orientated polypropylene (OPP) or low-density polyethylene (LDPE) and thymol were prepared and characterized. OPP and LDPE films were immersed in thymol for 1, 2, and 3 days. The mechanical, color, and microbial properties were examined. Film antibacterial properties were evaluated against Staphylococcus aureus ATCC 6538 bacteria as the Gram-positive model and Escherichia coli O157:H7 and Salmonella enterica ssp. enterica serovar enteritidis ATCC 13076 bacteria as the Gram-negative models. When immersion time was lengthened, the tensile strength diminished in both films, while elongation at break increased. On the other hand, as the immersion time was curtailed, the transparency (L * factor) also decreased while redness (a * factor) and yellowness (b * factor) significantly increased (p < 0.05). The results also indicated that thymol has a greater effect on the Gram-positive bacteria than on the Gram-negative bacteria. This study suggested that the effectiveness of antibacterial films depends on immersion time in the thymol.

Edible coating and films as promising packaging: a mini review

Abstract: Increasing global wastes containing various beneficial molecules such as carbohydrates, proteinous compounds, and essential oils lead scientists to design and synthesize novel materials. In this respect, agricultural wastes are among the beneficial materials that can be used as natural sources to synthesize bio-based packaging. Consequently, the use of wastes as a source of packaging material not only can reduce the costs of the food industry dramatically but also can improve the quality of packed foodstuff. Moreover, since some chemical and biological materials such as essential oils and nanoparticles cannot be implemented in food formula directly, therefore, application of such substances as a part of food packaging can be a proper solution. Therefore, this paper summarized the literature about the application of various edible coatings and films in this arena. Incorporation of various nanoparticles and essential oils in edible coatings was also discussed. Also, antimicrobial edible coating, polysaccharide, and protein-based edible coatings were discussed. In conclusion, various agricultural and food-based wastes should be considered and evaluated for their potential application in the packaging industry.

Characterization, antioxidant and antibacterial activities of chitosan nanoparticles loaded with nettle essential oil

Abstract: In this work, essential oil was extracted from nettle leaves and encapsulated in chitosan nanoparticles by a two-stage of emulsion-ionic gelation method. An acceptable retention rate (59.5 to 68.2%) of nettle essential oil (NEO) loaded in chitosan nanoparticles was achieved. Also, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) also confirmed successful introducing and loading NEO in chitosan. The nanoparticles displayed an average size of 208.3–369.4 nm. NEO-loaded chitosan nanoparticles had greater antioxidant activity than the free form of NEO. Furthermore, the antibacterial activity of NEO-loaded chitosan nanoparticles was high against S. aureus and E. coli (inhibition zone diameter of 4.11–3.95 cm). Based on these results, the encapsulation of EOs in chitosan nanoparticles are promising candidate to be used in food and pharmaceutical products for novel applications.

Voltammetric carbon nanotubes based sensor for determination of tryptophan in the milk sample

Abstract: In this research, functionalized carbon nanotubes were employed to modify a glassy carbon electrode (F-MWCNT/GCE). Several techniques including Fourier Transform Infrared Spectroscopy, scanning electron microscopy, and transmission electron microscopy were utilized for characterization of F-MWCNT. The electrochemical activity of the developed electrode was assessed by differential pulse voltammetry, cyclic voltammetry, and electrochemical impedance spectroscopy. The electrochemical results demonstrated that oxidation of tryptophan (TRP) caused a higher anodic peak current than unmodified GCE. The F-MWCNT/GCE offered a detection limit of 3.63 nM and dynamic ranges of 0.01–0.7 µM for analysis of TRP by the differential pulse voltammetry method. Moreover, tryptophan detection was achieved successfully using F-MWCNT/GCE in milk samples. It can be stated that this method paves the way for a selective, sensitive and straightforward method to determine tryptophan in the real food sample.

A glassy carbon electrode modified based on molybdenum disulfide for determination of folic acid in the real samples

Abstract: In the present study, the electrochemical behavior of Folic acid (FA) on the glassy carbon electrode modified with 2D-MoS2 nanosheets has been investigated utilizing differential pulse voltammetry (DPV), cyclic voltammetry (CV), and chronoamperometric techniques at pH 6.0 Britton-Robinson buffer. The experimental conditions, including the pH, scan rate, were optimized. Under the optimized experimental conditions, to determine the selectivity and sensitivity of FA, the DPV procedure was conducted in the linear dynamic range from 0.06 to 1.16 to 1.16–24.3 µM with a detection limit of 32.0 nM. The 2D-MoS2 nanoparticle was synthesized and characterized by EDX and SEM methods. The proposed modified electrode offered an outstanding electrocatalytic activity towards the oxidation of FA. The FA detection successfully validated the analytical reliability of 2D-MoS2/GCE in the food samples with acceptable recoveries at the range of 97.1 and 103.1%. Based on the results, it can be speculated that 2D-MoS2/GCE can be used as an alternative analytical instrument to determine FA in real samples.

Antioxidant properties of thymol, carvacrol, and thymoquinone and its efficiencies on the stabilization of refined and stripped corn oils

Abstract: The antioxidant activities of natural phenolic compounds (thymol, carvacrol, and thymoquinone) were compared with commercial antioxidants (α-tocopherol, BHT, and BHA) using DPPH·, conjugated diene (CD) in the linoleic acid emulsion, and ferric reducing power methods. Commercial antioxidants had higher DPPH· antiradical activity than natural phenolics. Thymoquinone (TQ) at 1000 ppm showed higher inhibition (65.7%) on DPPH· radicals than other natural phenolics at 1000 ppm (25.0% for thymol, and 18.3% for carvacrol). Carvacrol and thymol showed similar antioxidant activities compared with BHT and BHA in linoleic acid emulsion test at different concentrations, while TQ and α-tocopherol exhibited lower activity among analyzed samples. The results from reducing power test showed that natural phenolics were less effective than commercial antioxidants. The impacts of natural phenolics and BHT on the oxidative stabilities of refined and stripped corn oils were investigated using the Rancimat, Schaal oven, peroxide value (PV), CD (K232) and p-anisidine value (p-AV) methods. The loss in total tocopherols in refined corn oils was recorded during storage under Schaal oven conditions (60 °C). BHT showed a higher induction period (15.01 h) than phenolic compounds added to corn oils (3.88–5.69 h) and a control sample (2.82 h). According to the results of the Schaal oven test, BHT much better protected the refined and stripped corn oils from oxidation than natural phenolic compounds. Among phenolic compounds, TQ at 250 and 500 ppm exhibited high antioxidant potential in refined and stripped corn oils.

Chitosan coating incorporated with grape seed extract and Origanum vulgare essential oil: an active packaging for turkey meat preservation

Abstract: This work was carried out to evaluate the microbial and chemical attributes as well as sensory characteristics of turkey breast meat coated with chitosan incorporated with 1% of Origanum vulgare essential oils (oregano EOs) and 1 or 2% of grape seed extract (GSE) stored at refrigerator for 20 days. Gas chromatography–mass spectrometry (GC–MS) assay represented that oregano EO is rich in phenolic compounds mainly carvacrol and thymol. Lipid oxidation, as showed by thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVBN) values were significantly (P < 0.05) lower in combined treatments containing both oregano EO and GSE which were 0.71 MDA/kg and 10.04 mg N/100 g, respectively in the chitosan containing 2% GSE and 1% oregano EO treatments. The minimum count of total viable count (TVC), Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria (LAB) and yeast-mold were also determined in these treatments which determined 3.54–4.51 Log CFU/mL on day 20 of cold storage. These combined treatments also obtained the highest sensory scores (the overall acceptability was about 7) due to effective delaying microbial and oxidation activities. Therefore, chitosan-based coating containing GSE and oregano EOs can enhance microbial, chemical and organoleptic properties of fish turkey meat under refrigerated storage.

Active barrier chitosan films containing gallic acid based oxygen scavenger

Abstract: Active oxygen barrier films of chitosan/gallic acid/sodium carbonate (CH/GA/SC) were prepared by solution casting method. The effect of gallic acid on physical, mechanical, structural, and oxygen scavenging properties of films was investigated. As compared with neat CH film, CH/GA/SC films displayed higher thicknesses and water solubility. Tensile strength and elongation at break were affected by the addition of gallic acid and sodium carbonate. The chemical interaction evaluated by Fourier-transform infrared spectroscopy and morphology evaluated by scanning electron microscopy, and it is noticed that sodium carbonate and gallic acid were distributed homogeneously in the film structure. The X-ray diffraction confirmed that gallic acid, sodium carbonate, and chitosan had excellent compatibility. The addition of gallic acid in the chitosan matrix caused low water and oxygen permeability. The lowest oxygen transmission rate of the film was 4.10 ± 1.07 cm3/μm/m2 day kpa. The CH/GA/SC 20 film displayed the maximum oxygen-absorbing rate and capacity of 2.66 mL O2/g. day and 19.55 mL O2/g respectively, at 23 ± 2 °C. Moisture inside the package was utilized as a catalyst to begin the oxygen scavenging reaction. The results suggest that the combination of gallic acid and the sodium carbonate in chitosan film is a promising oxygen scavenging material for active oxygen barrier films.

Impact of Aloe vera gel coating enriched with basil ( Ocimum basilicum L.) essential oil on postharvest quality of strawberry fruit

Abstract: Strawberries are very perishable and decay rapidly after harvest. Among the several preservation techniques, application of edible coating is found to be an effective way to extend the fruits shelf life and has gained lots of attentions in the recent years. In the present study, the effect of Aloe vera gel coating alone and combined with basil essential oil in 500 and 1000 µL L− 1 concentrations on the postharvest qualities of strawberry fruit was investigated. After treatment, the fruit were stored at 4 °C and 85% relative humidity for 12 days. The surface morphology of samples was also studied by using a scanning electron microscope (SEM). The results showed that the coating treatments had a significant effect on the respiration rate of the fruit, delayed weight loss, softening, and fungal growth. Besides, the treatments led to maintain the total acidity, flavor index, L*, and hue° color values and sensory attributes without affecting total soluble solids, and pH of strawberries during storage. The efficacy of treatments enhanced in the samples where Aloe vera gel was combined with basil oil specially at 1000 µL L− 1 of basil oil. Thus, the edible coating prepared from the combination of Aloe vera gel and basil oil could be a promising postharvest treatment for maintaining the quality of strawberry fruit during cold storage.

Application of sepiolite/FeS2 nanocomposite for highly selective detection of mercury(II) based on stripping voltammetric analysis

Abstract: In this work, a novel electrochemical sensor for trace detection of Hg(II) is fabricated using sepiolite/pyrite (Sep/FeS2) nanocomposite. A mixture of the synthesized Sep/FeS2, graphite powder and paraffin oil was packed into a glass tube to fabricate modified carbon paste electrode for detection of Hg(II). The square wave anodic stripping voltammetry (SWASV) method was used for the determination of target metal ions after open-circuit mode. The effects of experimental conditions, such as the pre-concentration solution pH, pre-concentration time, and deposition potential and deposition time were investigated to optimize the conditions for maximum electrochemical signal. At optimal conditions, a linear range from 10 to 120 nM with a detection limit of 4.12 nM was obtained for the proposed electrochemical method. The selectivity investigations showed that the several heavy metal ions did not interfere with the quantitative Hg(II) determination. Moreover, the stability and reproducibility of the presented modified electrode was also evaluated with satisfactory results. Finally, the sensor was used to analyze the Hg(II) concentration in real water samples.

Corn seed variety classification based on hyperspectral reflectance imaging and deep convolutional neural network

Abstract: Variety purity is an important indicator in seed quality detection. Different varieties of corn seeds may be mixed in the growth and development process, which affects the growth and yield of the seeds. Thus, it is necessary to find a fast and non-destructively method to detect the purity. In this paper, the feasibility of combining hyperspectral imaging with deep convolutional neural network (DCNN) was studied to classify four corn seed varieties. Firstly, the average spectra from the region of seed in endosperm side hyperspectral images over the wavelength range of 450–979 nm were extracted. Secondly, the performances of three models were compared, including DCNN, K nearest neighbors (KNN) and support vector machine (SVM). DCNN model has the 100% training accuracy rate, 94.4% testing accuracy rate and 93.3% validation accuracy rate, and outperforms KNN and SVM models in most cases. DCNN model also had the best performance in evaluation indexes (sensitivity, specificity and precision). Finally, the visual classification map was generated according to the results of DCNN. Results show that DCNN can be adopted in spectral data analysis for the variety classification of corn seed; and the classification performance can be improved effectively.

Chemical composition and antifungal activity of essential oils and their combinations against Botrytis cinerea in strawberries

Abstract: Strawberry has a short postharvest shelf life, mainly because of the gray mold caused by Botrytis cinerea. The chemical composition and antifungal activities of essential oils from Mentha piperita, Cymbopogon martinii, Cinnamomum camphora, Mentha spicata, and their binary mixtures against B. cinerea were evaluated by different in vitro methods, and also in vivo in vapor-phase on inoculated strawberries. The major components present in M. piperita essential oil were menthol (45.37%), menthone (20.13%), isomenthone (16.94%), menthyl acetate (3.81%), pulegone (1.89%), α-terpinene (1.88%), isopulegol (1.83%), neoisomenthol (1.19%), and α-terpineol (1.08%), in C. martinii essential oil were geraniol (83.82%), geranyl acetate (7.49%), linalool (2.48%), and caryophyllene (1.33%), in C. camphora essential oil were linalool (98.39%), and M. spicata essential oil were carvone (61.71%), limonene (20.22%), 1,8-cineole (5%), sabinene (2.28%), cis-dihydrocarvone (1.63%), and α-thujene (1.4%). The highest antifungal activity in vitro was presented by M. spicata and C. martinii essential oils by the direct contact, vapor contact, spore germination, and micro-well dilution methods. In vivo, strawberries treated with the vapor of M. spicata and C. martinii essential oils showed a reduction in disease incidence and severity. At a 10% concentration, M. spicata and C. martinii showed a reduction of 100% and 83% in the disease incidence, respectively. Thus, the M. spicata and C. martinii essential oils may be potential alternatives for the control of B. cinerea in postharvest fresh strawberries.

A new electrochemical method for the detection of quercetin in onion, honey and green tea using Co3O4 modified GCE

Abstract: Quercetin (Qu) is a most active biological flavonoid and it has a very wide spectrum of potential applications. Herein, we have synthesized ionic liquid assisted Co3O4 nanostructures through an aqueous chemical growth method and fabricated a Co3O4 modified GCE as an electrochemical sensor for the sensitive detection and determination of Qu. The proposed electrochemical sensor was not only prepared with a very easy, simple and cheap method but it was also found to be very selective, sensitive and highly stable for the detection of Qu in standard solutions as well as in real food samples like onion, honey and green tea. The prepared electrochemical sensor has shown an excellent electrochemical response for Qu with a wide range of detection from 0.01 to 3 µM. The oxidation current response of Qu on Co3O4 modified GCE was found 4 times higher than the response of bare GCE which is due to the high conductivity, tremendous catalytic ability and large surface area of Co3O4 nanostructures. The limit of detection (LOD) and the limit of quantification (LOQ) for Co3O4/GCE sensor was calculated and found to be 0.0002 µM and 0.0007 µM respectively. While, the amount of Qu in real samples was found to be 5.367 µg/mL in honey, 15.58 µg/g in onion and 3.473 mg/g in green tea respectively. In comparison to the previously reported sensors, the prepared Co3O4/GCE sensor has shown a higher electrocatalytic capability, remarkable stability, super sensitivity and adequate selectivity for the determination of Qu in standard solutions as well as in real samples.

The effects of nanosilver and nanoclay nanocomposites on shrimp (Penaeus semisulcatus) samples inoculated to food pathogens

Abstract: Today, antibacterial packaging plays a major role in enhancing shelf life of food products. Application of nanoclay and nanosilver as antimicrobial agents has been glorified recently in the food industry due to their ability to enhance mechanical properties of food packaging. As vibrio parahaemolyticus, Staphylococcus aureus and Escherichia Coli are among of the most usual bacteria affecting fisheries, the aim of this study was to evaluate effects of nanoclay and nanosilver packaging on the growth of pathogens within 6 days of shrimp shelf life at 4 °C. Silver and clay nanoparticles (NPs) were analyzed using AFM, SEM, FESEM, EDX, FTIR, DLS and TEM as well. The size of clay and silver nanoparticles were 15 nm and 35 nm respectively. 21 packaging samples containing 1 to 7 percent of NPs were produced using melt mixing method. Shrimps samples were inoculated with pathogens using a 0.5 McFarland standard and hot sealed using nanopackaging treatments. Result showed that nanopackaging could decrease colony counts more than one logarithmic cycle which was a significant reduction (P < 0.05). Also, a synergistic effect was observed for packaging containing both nanoclay and nanosilver particles. Results of the current study shows that application of silver and clay NPs in nanocomposites could be a promising method to reduce microbial load and increasing shelf life of perishable food products.

Optimization of ultrasound assisted extraction of polyphenols from Meghalayan cherry fruit (Prunus nepalensis) using response surface methodology (RSM) and artificial neural network (ANN) approach

Abstract: In this work, polyphenols have been recovered from Meghalayan cherry using ultrasound assisted extraction (UAE). The RSM and ANN were used to analyse the effect of solvent concentration (40–80%), solvent-solid ratio (10–30 ml/g), extraction time (15–45 min) and amplitude (20–40%) on yield and total phenol content (TPC) of fruit extract. The yield (41.30%), TPC (117.80 mgGAE/g), DPPH (85.11 ± 0.40%) and FRAP (0.92 ± 0.46 mg AAE/g) of Meghalayan cherry extracts were obtained under optimal extraction conditions (solvent concentration (58%); solvent-solid ratio (26 ml/g); time (31 min); amplitude (28%)). Results indicated that RSM and ANN could be effectively applied to describe the experimental data, but ANN showed better prediction accuracy as compared to RSM due to higher R2 and lesser MSE. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the presence of polyphenols and Liquid chromatography mass spectroscopy quadrupole time-of-flight (LC-MS-Q-TOF) identified sixteen polyphenols compounds, out of which ten were proposed for the first time in Meghalayan cherry fruit. Scanning electron microscopy showed that ultrasound processing caused disruptions in the cell wall of fruit powder which leads to higher extraction of polyphenolic compounds. Thus, the extract obtained from UAE has higher antioxidant activity and would be used in pharmaceuticals and food products as a source of bioactive compounds. Furthermore, ANN found to be an efficient tool for predicting extraction efficiency of Meghalayan cherry polyphenols.

An experimental study on characteristics of sago starch film treated with methanol extract from Artemisia sieberi Besser

Abstract: The present study aimed at investigation of the influence of methanol extract from Artemisia sieberi on some important physical and mechanical properties as well as antibacterial activity of sago starch film. Experiments were performed using various concentrations (0, 1, 3, 5 and 10%) of the extract incorporated with the films. The obtained results revealed that the physical properties of the films were significantly (P < 0.05) enhanced by increasing concentration of the extract. The water solubility, water absorption capacity and water vapor permeability of the films changed from 21.31 to 26.47%, from 1.98 to 3.93 g water/g dry matter and from 1.63 to 2.93 g/m.s.Pa, respectively. In comparison with the control films, both the tensile strength and Young’s modulus of the incorporated films were meaningfully (P < 0.05) lower and varied in the range of 4.91‒6.43 MPa and 87.04‒118.55 MPa, respectively. The elasticity of the films was continually increased with the increasing concentration of the extract. Good antimicrobial activity against both the Gram-positive and Gram-negative bacteria was observed for the films.

Improving antioxidant effect of phenolic extract of Mentha piperita using nanoencapsulation process

Abstract: In the present investigation, effect of chitosan, Alyssum homolocarpum gum (AHG) and complex (1:1) of chitosan and AHG (CCA) on the properties of nanoencapsulated Mentha piperita phenolic extract (polydispersity index (PDI), particle size, ζ-potential, encapsulation efficiency, release of phenolic compounds and evaluating effect of nanoencapsulation process on the antioxidant activity of phenolic extract of M. piperita in the soybean oil) was studied. The use of a high-pressure homogenizer, at pressure of 11,000 psi, reduced the particle size of W/O/W nanoemulsions coated with chitosan, CCA, and AHG, with a diameter of 108.66, 65.18, and 70.81 nm, respectively. Moreover, the PDI of nanoemulsions in AHG and CCA in all conditions was lower than 0.5, indicating the uniform size distribution and thus the success of the nanoparticle production process. The Intensity curve also showed that the emulsion generated by CCA had better emulsion droplets than the others due to its lower curve width and therefore greater uniformity. Also, the amount of ζ-potential of droplets of emulsions coated with chitosan, CCA and AHG were 28.69, 20.16 and − 37.4 mV, respectively. The results of the peroxide and p-anisidine test revealed that CCA extract caused the best oxidative stability in soybean oil, followed by AHG and chitosan, respectively, which were consistent with the results of the phenolic release test. Gradual and more release of phenolic compounds over time in the CCA-coated sample was superior to other samples.

Assessment of nanochitosan packaging containing silver NPs on improving the shelf life of caviar (Acipenser persicus) and evaluation of nanoparticles migration

Abstract: Nano packaging plays a major role in reducing microbial load and preserving proper quality. The aim of this study was to evaluate antimicrobial characteristics of nanochitosan-silver packaging against both Gram positive and negative microorganism. The total count test was used to measure the antimicrobial effects. Additionally, the minimal inhibitory concentration and minimum fungicidal concentration of nano chitosan were both measured. Finally, the antimicrobial effects of the silver and chitosan nanoparticles were evaluated. Caviar samples were inoculated to Coagulase-positive Staphylococcus aureus, Escherichia coli using 0/5 McFarland standard. Also, Fusarium solani was inoculated to caviar samples using 105 CFU/mL. Samples were checked out in the 1st, 15th, 30th, 60th, and 70th days, respectively. To determine the size and distribution of nanoparticles) NPs), scanning and transmission electron microscopy (SEM&TEM), dynamic light scattering (DLS), and atomic force microscopy (AFM) analyses were used. The images from SEM and TEM were indicative of spherical silver nanoparticles (AgNPs), and the average size of the AgNPs was lower than 100 nm. The average size of chitosan particles was 60–100 nm as revealed by DLS and Zeta potential analyses, and the chitosan nanoparticles were completely homogenous. The results showed that silver and chitosan NPs had significant antibacterial effects compared to blank low-density polyethylene samples (P < 0.05), and reduced the bacterial and fungal loads more than one logarithmic cycle. Migration of nanoparticles was measured using the atomic absorption spectroscopy (AAS), inductively coupled plasma mass spectrometry (ICP-MS). AAS results showed no migration of nanoparticles although, the ICP-MS showed 0/165 ppm from nanopackaging.

Incorporation effect of inulin and microbial transglutaminase on the gel properties of silver carp (Hypophthalmichthys molitrix) surimi

Abstract: Surimi-based products with elasticity and specific shapes have received considerable notice in recent years. To ascertain the effects of inulin, microbial transglutaminase (MTGase) and the combination of inulin/MTGase on gel formation of silver carp surimi, the gel strength, textural properties, water-holding capacity (WHC), dynamic rheological measurements, Raman spectroscopy, light microscopy of gel structure and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of gels from different groups were analyzed. The results showed that addition of inulin, MTGase and MTGase + inulin improved gel strength (increased by 7.7%, 26.8% and 38.56% compared with control group), textural properties and WHC. Raman spectroscopy proven that MTGase + inulin promoted the conversion of α-helixes to β-sheets and β-turns compared with other experimental and control groups. Pure surimi gelation contained a loose and non-heterogeneous network via light microscopy. With the addition of MTGase and inulin, the microstructure of surimi gelation became more compact and homogeneous, particularly the MTGase + inulin groups. Moreover, The SDS-PAGE pattern further disclosed that the MTGase + inulin had a weakened myosin heavy chain band, indicating that inulin could enhance the cross-linking effects of MTGase on myosin heavy chains. These data demonstrated inulin incorporating with MTGase may be a new and effective strategy to improve the gel properties of fish surimi.

Physicochemical and antibacterial effect of Soy Protein Isolate/Gelatin electrospun nanofibres incorporated with Zataria multiflora and Cinnamon zeylanicum essential oils

Abstract: Recently, combination of nanotechnology and active food packaging provided new horizon to extend the shelf life of food. This study aimed to fabricate natural nanofibrous film incorporated with essential oils using the nanospinning technique and examine its antimicrobial activity. Constituents of Zataria multiflora and Cinnamon zeylanicum essential oils (EOs) were investigated by Gas Chromatography–Mass Spectrometry and their antimicrobial properties were examined. Subsequently, electrospun Soy Protein Isolate (SPI)/Gelatin was embedded with Zataria multiflora and Cinnamon zeylanicum EOs. Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectrometry (FTIR), and Thermogravimetric analysis (TGA) were done to evaluate the properties of electrospun fibers. The antimicrobial activity of nanofibrous films was evaluated. SEM revealed that the addition of 30% gelatin neutralized SPI charge, representing a significant increase in the diameter of nanofibers by 314.08 nm. Furthermore, TGA showed stability for Soy/Gel nanofibers. The fabricated nanofibrous film exhibited exquisite antimicrobial activity against Gram-negative and Gram-positive pathogens. For example, SPI-gelatin nanofibrous film incorporated with 20% Z. multiflora reduced 100% of S. aureus, B. cereus, and L.monocytogenes. The reduction for E. coli and S. typhimurium were 70% and 63%, respectively. We suggest that incorporating EOs with nanofibrous films can be a promising method to extend the shelf life of food and can be used in production for active food packaging.

Antioxidant and cytotoxic activities of sulfated polysaccharides from five different edible seaweeds

Abstract: In recent times, there has been a growing interest in the exploration of antioxidants and global trend toward the usage of seaweeds in the food industries. The low molecular weight up to 14 kDa sulfated polysaccharides of seaweeds (Portieria hornemannii, Spyridia hypnoides, Asparagopsis taxiformis, Centroceras clavulatum and Padina pavonica) were evaluated for in vitro antioxidant activities and cytotoxic assay using HeLa cell line and also characterized by FTIR. The high yield (7.74% alga dry wt.) of sulfated polysaccharide was observed in P. hornemannii followed by S. hypnoides (0.69%), C. clavulaum (0.55%) and A. taxiformis (0.17%). In the brown seaweed P. pavonica, the sulfated polysaccharide yield was 2.07%. High amount of sulfate was recorded in the polysaccharide of A. taxiformis followed by C. clavulaum, P. pavonica, S. hypnoides and P. hornemannii as indicative for bioactivity. The FTIR spectroscopic analysis supports the sulfated polysaccharides of S. hypnoides, C. clavulatum and A. taxiformis are similar to agar polymer whereas the spectral characteristics of P. hornemannii have similarities to carrageenan. The higher DPPH activity and reducing power were recorded in the polysaccharide of brown seaweed P. pavonica than the red seaweeds as follows: DPPH activities: S. hypnoides > A. taxiformis > C. clavulatum > P. hornimanii; Reducing power: A. taxiformis > P. hornimanii > S. hypnoides > C. clavulatum. The polysaccharide fractions contain up to 14 kDa from red seaweeds P. hornemannii and S. hypnoides followed by brown seaweed P. pavonica exhibit cytotoxic activity in HeLa cancer cell line (and are similar to structural properties of carrageenan extracted from P. hornemannii). The low molecular weight agar like polymer of S. hypnoides and alginate like brown seaweed P. pavonica showing better in vitro antioxidant activities that are capable of exhibiting cytotoxicity against HeLa cell line can be taken up further in-depth investigation for nutraceutical study.

Active packaging technologies for clean label food products: a review

Abstract: Consumers in developed countries are highly interested in facts about the production techniques and ingredients of the food they consume. Some production techniques are apparent as less “natural,” whereas some food ingredients/additives are perceived as “unhealthy.” Such terms, referred to as the “clean label” trend, have driven the food processing industries to connect whether some ingredients/additives are not existing or if the food has been produced using a “natural” production method. With customers motivating the modernization, the food processing industries have moved toward no or fewer ingredients using active packaging solutions. The food manufacturer is responding by integrating active packaging. Here we review active packaging techniques which support clean label trends with focus on driving the clean labels market. We present active packaging technologies antimicrobial packaging; antioxidant releaser; ethylene absorber; oxygen scavenger, carbon dioxide emitters. We discuss the various challenges in implementing clean label foods technology and its future in the modern society

Microencapsulation of basil essential oil: utilization of gum arabic/whey protein isolate/maltodextrin combinations for encapsulation efficiency and in vitro release

Abstract: Basil (Ocimum basilicum L.) essential oil (BEO) draws attention for its phenolic acid content which causes it to be used as a medicinal agent and food additive. However, its vulnerability to environmental and technological factors can be an obstacle to its implementation in industry and, at this point, encapsulation technology is utilized. The objective of this study was to encapsulate BEO using a spray drying technique to extend its shelf life, and to evaluate the influence of different wall material formulations on the properties of the BEO microcapsules. Gum Arabic (GA), maltodextrin (MD), and whey protein isolate (WPI) were used as wall materials and four different formulations were studied: GA, GA:WPI (1:1, w/w), GA:WPI:MD (1:1:1, w/w), and WPI:MD (1:1, w/w). The GA, GA:WPI, and GA:WPI:MD emulsions displayed shear thinning behavior (pseudoplastic, n < 1) while the WPI:MD emulsion behaved as a Newtonian fluid (n = 1). The GA (0.21 µm) and WPI:MD (0.25 µm) emulsions, having smaller droplets, exhibited no creaming. Powder recovery values of the BEO microcapsules ranged from 65.92% to 76.39%. The encapsulation efficiency of the microcapsules varied between 82.34% and 87.19%; the highest value was determined for the GA:WPI:MD microcapsules. Optimal thermal stability and higher Tg values were obtained for the GA:WPI and GA:WPI:MD formulations. The ternary combination also had the highest in vitro eugenol release (58.97%) in ethanol. Finally, the GA:WPI:MD formulation demonstrated a high product yield and encapsulation efficiency with better physicochemical properties for encapsulation of BEO.

Comparison of coating and nano-coating of chitosan- Lepidium sativum seed gum composites on quality and shelf life of beef

Abstract: Due to the side effects of artificial preservatives in meat products, the use of natural preservatives has increased. The aim of this study was investigated the effect of coating and nano-coating of chitosan (C)- Cress (Lepidium sativum) seed gum (CSG) on the shelf life of beef during 18-day at cold temperature. For this purpose, composite coatings including 33% C:6% CSG, 50% C:50% CSG, 66% C:33% CSG were prepared. The nano-coating was also constructed using ultrasound method. Antioxidant and antibacterial properties were measured and the results showed that the antioxidant and antimicrobial activity of the coatings incremented with increasing C content (66% C:33% CSG) and the antimicrobial and antioxidant activity of nano-coating was significantly higher than the coating (p < 0.05). In order to study the effect of coatings on the shelf life, four treatments including control, coating (66% C:33% CSG), nano coating (66% C:33% CSG) and sodium nitrite were prepared and chemical (peroxide value and total volatile nitrogen) and microbial parameters (total viable count, psychrotrophic count, Pseudomonas aeruginosa and Staphylococcus aureus) were studied at − 2, 4, and 8 °C for 18 days. Synthetic and natural preservatives delayed lipid oxidation and improved the chemical properties in beef. Also, microbial spoilage was significantly reduced compared to the control (p < 0.05). The nano-coating performed better than other treatments in all experiments (p < 0.05), and reduced the growth of pathogenic bacteria from the third day to the end of the period to below the permissible limit. Therefore, it seems that the nano 66% C:33% CSG can be used as a safe preservative in the active packaging of beef during refrigerator and freezer storages.

Comprehensive study on the antioxidant capacity and phenolic profiles of black seed and other spices and herbs: effect of solvent and time of extraction

Abstract: The effects of solvent and time of extraction on the antioxidant properties and phenolic profiles of 13 herbs and spices used for food seasoning and preservation were investigated. The profiles of phenolics in plant material were analysed by UPLC, and the chemometric approach was used for the deeper evaluation of relationships between phenolic compounds and the antioxidant properties of the samples. The best extraction conditions enabling to obtain the highest total phenolics and the antioxidant activity were: long time extraction (24 h) with 50% aqueous ethanol. The most potent antioxidant was clove with the ABTS—2495.85 µmol/g, DPPH—1443.35 µmol/g and FRAP—1310.91 µmol/g, which resulted from the high total phenolic content (TPC—167.22 mg GAE/g) and total flavonoid content (TFC—26.22 mg QE/g). Wide variations in the antioxidant activity (ABTS: 7.31—2495.85 µmol/g) and TPC (0.87–167.22 mg GAE/g) were observed with black seed extract showing one of the lowest values of the parameters studied. High linear correlation (above 0.95) calculated for the parameters showed significant contribution of phenolics to the antioxidant activity of spices. UPLC analysis together with PCA (principal component analysis) confirmed this relation and ABTS, FRAP, DPPH, TFC, TPC, total phenolic acids, protocatechuic acid, t-cinnamic acid, p-hydroxybenzoic acid determined sample distribution along PC1 (principal component 1), whereas total flavonoids determined by UPLC, kaempferol, catechin and luteolin along PC2. All samples were discriminated with 100% classification’s propriety according to GDA (general discrimination analysis) which proved huge diversity among phenolic profiles and the antioxidant properties of tested samples.

Physicochemical properties, total phenolic content, and antioxidant activity of chestnut, rhododendron, acacia and multifloral honey

Abstract: The aim of this study is to investigate the physicochemical properties, antioxidant activities, and total phenolic contents of the plateau (multifloral), chestnut, rhododendron, and acacia honey collected from Ordu province in Turkey. The rhododendron honey had the highest acidity (p < 0.05) while the chestnut honey showed the highest conductivity (1.13 ± 0.25 mS/cm) among all (p < 0.05). The highest diastase activities and the lowest HMF contents were determined in the multifloral and chestnut honey. Considering the DPPH and FRAP assays, the multifloral honey showed the highest antioxidant activity. Accordingly, the highest total phenolic content was determined in the multifloral honey followed by rhododendron, chestnut, and acacia honey. A moderate correlation was determined between the total phenolic content and antioxidant activities (r = 0.575 for FRAP and r = 0.697 for DPPH). Consequently, the plateau honey could be recommended for nutritional and health purposes due to its relatively higher antioxidant activity and total phenolic content together with relatively lower HMF content and higher diastase activity. Considering that Ordu is the largest honey producer city in Turkey, the second top honey producer country, this work could shed light for future studies and be taken as a reference providing insights on the characteristics of different types of honey for both local and worldwide producers.