Seyed Amir Oleyaei; Babak Ghanbarzadeh; Ali Akbar Moayedi; Parisa Poursani; Fateme Mousavi Baygi; Mohammad Reza Bakhsh Amin
Abstract
Introduction: Biopolymers are a class of polymer, which are disintegrated by an enzymatic or bio-path and the products disseminated to the surroundings do not induce negative effects. Nowadays, non-degradable polymers are quid pro quo with biodegradable ones particularly in agricultural applications, ...
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Introduction: Biopolymers are a class of polymer, which are disintegrated by an enzymatic or bio-path and the products disseminated to the surroundings do not induce negative effects. Nowadays, non-degradable polymers are quid pro quo with biodegradable ones particularly in agricultural applications, environmental and food industry use. Starch is an example of natural biopolymers, biocompatible, which is completely biodegradable in environment. It has been considered as one of the best candidates for oil based polymer substitution due to its low cost, availability and processbility. The main disadvantages of starch based polymers are their high hydrophilic nature therefore; they have poor mechanical properties and are permeable to water vapor. However, these aspects could be considerably reclaimed by shuffling it with nanodimension materials such as itanium dioxide (TiO2) and Montmorillonite (MMT). The main reason for this improvement in comparison with conventional composites is the large surface area of these nanomaterials which results in high interactions between the nanofillers and starch. The functional behaviors of nanocomposite films have been depended to the compatibility and degree of nanoparticles dispersion in the biopolymer matrix. TiO2 is a 3D nanosphere has been perused widely because it is inexpensive, chemical inert and, has a high refractive index with visible and UV shielding potential. MMT as a 1D, platelet is the most commonly used layered silicates. The investigation of biodegradable films containing two different nanofillers simultaneously has been rarely done. TiO2 and MMT as two different inorganic nanofillers have different physical and chemical structures, so simultaneously use of TiO2 and MMT clearly had a new effect on the nanoparticle distribution and functional properties of starch films. The aim of this study was investigate the synergistic or antagonistic effect of combination of TiO2 nanoparticles and MMT platelets on the functional properties such as surface hydrophobicity, water vapor permeability (WVP), moisture uptake (MU), Water Solubility (WS) and mechanical properties of plasticized starch-MMT-TiO2 nanocomposites.
Materials and methods: 100 ml of potato starch solution with a concentration of 4% (w/v) was prepared by dispersion of starch in distilled water. It was gelatinized at 80 ºC for 15 min. Different amount of TiO2 (0.5, 1 and 2% w/w starch) and MMT (3 and 5% w/w starch) were dissolved in distilled water and added to the gelatinized starch after treatment with ultrasound for 30 min. Glycerol with concentration of 50% (w/w starch) was added to the starch-nanofillers filmogenic solution. Bionanocomposite plasticized starch (PS) films were produced by casting and were dried in an oven at 45 °C for 15 hours. The X-Ray diffraction (XRD) measurements were performed for MMT and TiO2 powder and starch-MMT and –TiO2 nanocomposite films. The methodology of WVP measurements was based on the ASTM E96-05 (ASTM, 2005). Mechanical properties of the films were determined according to ASTM standard method D882-10 (ASTM, 2010). With some modifications, the methods described by Tunc et al., (2007) and Rhim et al., (2006) were used to determine MU and WS, respectively. Water contact angle (WCA) measurements were performed by the sessile drop procedure. The statistical analyses on a completely randomized design and were carried out using analysis of variance (ANOVA). Duncan’s multiple range test (p < 0.05) was used to detect differences among the mean values of the functional properties.
Results and discussion: XRD demonstrated the change of MMT layers dispersion pattern from exfoliation in binary PS-5%MMT films to exfoliation-intercalation in ternary PS-5MMT-TiO2 films. These results showed that TiO2 agglomerates are formed in the starch matrix with MMT level more than 3% wt. This could be due to the interaction between starch and MMT tends to be more favorable than TiO2. Good dispersion of TiO2, high miscibility of with clay, and continuous phase can be obtained when the content of MMT discs is low. Due to the strong interfacial interaction between the starch and MMT, the tensile strength (TS) increased considerably from4.86 to 5.24 MPa, while the elongation at break (EB) decreased significantly from 78.23 to 71.93%, As the MMT concentration varied from 3 to 5%. The TS of nanocomposite films were further improved after the incorporation of TiO2. Suitable dispersal of TiO2, and creation of new interactions in the PS-MMT network, causes to increase the tensile strength of nanocomposites. The TS and EB values of PS-3MMT-1TiO2 nanocomposite film was higher than that of the other films. This is indicative of a synergistic effect between TiO2 and MMT which increases the tensile strength and does not decrease the EB. In the PS-5% MMT films, both mechanical characteristics were reduced. WVP shows more evidences of synergistic effect of combination of 1D MMT and 3D TiO2 on starch films. WVP reduction by MMT has been attributed to tortuous pathway which created by clay layers in the starch matrix. MMT platelets are water vapor impermeable, thus exfoliation of MMT reduce the voids in starch matrix. The PS-3MMT-2TiO2 nanocomposite showed the lowest WVP as compared to other PS films. WVP was reduced significantly from 5.84 × 10-7 g/m.h.Pa in the PS-3%MMT binary film to 3.04 × 10-7 g/m.h.Pa in the PS-3%MMT-2%TiO2 ternary film. TiO2 have low water solubility and hydrophobicity compared with starch and MMT. Thus, significant decrement of WVP in the prophase of TiO2 connoted that TiO2 was obstructing the nano- and micro-pathways in the PS films network. With addition of MMT and TiO2 content the water solubility and moisture absorption were reduced significantly. Results of water contact angle test confirmed the results of moisture absorption, solubility in water and water vapor permeability and showed that the addition of TiO2 increased the surface hydrophobicity of starch-MMT films as with addition of 2% titanium dioxide in PS-3% MMT and PS-5% MMT films, the contact angle after 60 seconds increased 4 and 15 degree respectively. As a result, 1% wt TiO2 nanoparticles (FDA maximum allowable) can be regarded as the optimum concentration and the developed starch based nanocomposite films can enable undertaking applications as appropriate candidates in food packaging systems.
Babak Ghanbarzadeh; Sahra Bashiri; Hamed Hamishekar; Jalal Dehghan nia
Abstract
Introduction : The encapsulation of nutraceuticals in lipid based carriers, such as liposomes, can lead to increasing of bio-active ingredients bioavailability and controlled release, maintaining their stability in different environmental conditions and increasing solubility of hydrophobic active ingredients ...
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Introduction : The encapsulation of nutraceuticals in lipid based carriers, such as liposomes, can lead to increasing of bio-active ingredients bioavailability and controlled release, maintaining their stability in different environmental conditions and increasing solubility of hydrophobic active ingredients in aqueous conditions. Food grade liposomes are being increasingly used in food industry to delivery hydrophilic and hydrophobic components such as vitamin E and vitamin C, ascorbic asid, nutraceuticals, essential omega 3 fatty medium chain fatty acids-vitamine C, nisine, cartenoides, oleic acids, polyphenols include catechine, synamic acids.One of the hydrophobic nutrients with antioxidant and beneficial pro-vitamine property is beta-carotene, which its high hydrophobicity and sensitivity in different environmental conditions has limited using of it for foodstuff enrichment. In order to improve the characteristics of the lipid bilayer, cholesterol traditionally has been included in the lipid membrane. It is important in decreasing permeability and strengthening the membrane. People suffering from hyper-cholesterolaemia are encouraged to avoid foods containing cholesterol. Since the plant sterols are natural compounds found in plant cell membranes which help maintain the membrane integrity. Such as Gama oryzanol is combination of different of plant sterols that is used in the formulation of nanoliposomes in this study to improve the stability of bilayers. The principal aim of this study was to prepare beta-caroten encapsulated nano- liposome formulations as a mean to improve its aqueous dispensability and to study the effect of lecithin-phytosterol concentrations on the partical size, encapsulation efficiency (EE), zeta potential, turbibility of beta carotene loaded nano-liposomes to get the optimized formulation. Materials and methods: Preparing liposomes is being carried out using different methods one of which is a novel technique called is “Mozafari method” (based on heating method). This method is characterized by the absence of organic solvent for the solving of lipids.Non-toxicity of produced liposomes; rapid production and scalability are some of the advantages of Mozafari method over other methods of liposome production. In this study, the liposomal ingredients were added to a preheated (60 0C, 5 min) water, mixeture of beta-carotene, gamma oryzanol solution and glycerol (final concentration 3% v/v) were added. The mixtures volume increased by adding warm water until 50ml, the mixture was further heated 60 while stirring 1200 rpm for 50-60 min under nitrogen atmosphere.Results and discussion: Effect of different concentration of lecithin (20, 40, 75, 100, 150, 200 mg) on particle size and zeta potential of nano-liposomes with constant amount of beta carotene (4 mg) and gamma-oryzanol for different concentration of lecithin with ratio 1:14 w/w were evaluated. The Particle size of nano liposomes with different concentration of lecithin was obtained below 500nm andthe optimal concentration of lecithin was 100 mg that particle size was minimum (64-88 nm).The gamma-oryzanol is a natural phytostrol which is as stabilizer for liposome membrance and promoting agent of hardness of vesicles wall however, the particle size of liposomes were reduced especially in low concentration of lecithin. The using phytosterols (gamma oryzanol) for maintaining the stability of liposomal membranesystems caused to reducing of particle size from 88nm to 64nm in 200 mg concentration of lecithin.The entrapment efficiency increased by increasing concentration of lecithin for nano-liposomes. It is because increasing the lecithin concentration, more vesicles were produced which in turn increased the loading capacity of nano-liposomes. In the liposome structure, the aqueous core and bilayer are the hydrophilic and hydrophobic parts, respectively. Therefore, the phospholipid bilayers place for beta carotene, and other hydrophobic substances. The entrapment efficiency in different concentration of lecithin was between 27-98%. The entrapment efficiency of liposomes containing beta carotene that used gamma oryzanol was less than liposomes without gamma oryzanol probably because the position of capsulation of gamma oryzanol and beta carotene is same in the bilayer of liposome that’s hydrophobic source of liposomes. But Gamma oryzanol was not effective on encapsulation efficiency of beta-carotene.The zeta potential, the electric potential in the interface or particle surface charge, is used to predict the stability of colloidal systems. In general, higher zeta potential values, regardless of their positive or negativity, indicate a higher and longer-term stability of the particles. Zeta potential of liposomes, which is a measure for the electrostatic repulsion and stability, was -29 and -35 milivolt for samples with and with not containing gamma oryzanol, respectively.For turbidity of liposomes, encapsulation of bioactive compounds can change the optical appearance due to the fact that the refractive index at the interface between solvent and internal phase changes and the size of liposomes may be altered. Increasing significantly of turbidity of liposomes (16% -80%), the wave length increase from 0.116 to 0.585 cm-1 high concentration of lecithin maybe due to increasing visuals and hydrophobic interactions.
Seyed Amir Oleyaei; Babak Ghanbarzadeh; Ali Akbar Moayedi; Farhang Abbasi
Abstract
Introduction: Biodegradable films for food packaging applications have attracted an increasing amount of consideration over the last two decades, predominantly due to environmental pollution and the realization that our petroleum resources are not infinite. Starch, which is one of the natural biopolymers, ...
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Introduction: Biodegradable films for food packaging applications have attracted an increasing amount of consideration over the last two decades, predominantly due to environmental pollution and the realization that our petroleum resources are not infinite. Starch, which is one of the natural biopolymers, has been considered as one of the best candidates primarily because of its processbility, availability and price. The main disadvantages of starch films are their pronounced hydrophilic character therefore; they are permeable to water vapor and have usually poor mechanical properties. However, these features can be significantly improved by blending with nanodimension materials such as Montmorillonite (MMT) and Titanium dioxide (TiO2). The main reason for this improvement in comparison with conventional composites is the large surface area which results in high interactions between the nanofillers and polymer when these nano-materials are well dispersed. The behavior of nanocomposite films has been depended to the dispersion of the nanoparticles in the polymer matrix. MMT as a one-dimensional (1D) material is the most commonly used layered silicates. TiO2 as three-dimensional (3D) nanoparticle has been investigated most widely because it is inert, inexpensive and, has a high refractive index with UV shielding potential. The study on films with different dimensions of nanofillers simultaneously is rarely reported. MMT and TiO2 as two inorganic nanofillers have different shapes and structures, so the combination of TiO2 and MMT apparently had a synergistic effect on the starch film properties. The aim of this study was to control particle agglomeration and investigate the synergistic effect of combination of TiO2 nanoparticles and MMT layers and on the surface topography, color, and thermal properties of plasticized starch-MMT-TiO2 nanocomposites.Materials and methods:.First, 100 ml of potato starch solution with a concentration of 4% (w/v) was prepared by dispersion of the starch in distilled water and was gelatinized at 80ºC for 15 min. Different levels of MMT (3 and 5% w/w starch) and TiO2 (0.5, 1 and 2% w/w starch) were dissolved in distilled water and were added to the gelatinized starch after treatment with ultrasound for 30 min. Glycerol, as a plasticizer, with concentrations of 50% (w/w starch) were added to the filmogenic solution. The plasticized starch (PS) based filmogenic solutions were dried in an oven at 45 °C for 15 hours. The surface roughness and topography and thermal properties of the films were determined through atomic force microscopy (AFM) and differential scanning calorimetry (DSC) analysis, respectively. Fourier transforms infrared (FTIR) spectroscopy in the range of 4000 to 400 cm-1. UV-Vis spectroscopy was employed to evaluate the absorbance and opacity behavior of the PS-MMT-TiO2 nanocomposite films in the wavelength range of 200-800 nm. The color parameters of films were measured by a portable colorimeter. Statistical analysis was performed on a completely randomized design with the analysis of variance (ANOVA) and Duncan’s multiple range tests was used to detect differences among the mean values of the films propertiesResults and discussion: Atomic force microscopy’s images demonstrated an obviously uniform dispersion of MMT and TiO2 nanomaterials in the PS-3%MMT-TiO2matrix with smoother surfaces and a lower roughness parameters than that for the corresponding binary PS-MMT nanocomposites with the MMT filler content (3 wt%). Surface roughness of starch films was changed depending on the MMT and TiO2 content. The results of the roughness parameters and topographic images were confirmed by the high frequency distribution curves. In the PS-3 and 5% MMT films, most parts have height of about 400 and 600 nm, respectively; While the height of the PS-MMT-1% TiO2 bionanocomposites film were 200 and 800 nm. FTIR revealed the hydrogen bonds and electrostatic interactions between nanofillers with starch and themselves by the peaks associated with bond C-O-H at 1142 cm-1 and 990 cm-1 and wide and high intensity IR absorption in the 500-800 cm-1.Evanescence of 3626 and 3452 cm-1 peaks assigned to OH groups of MMT in the PS-3MMT spectrum affirmed the interaction between starch and MMT.Shift in melting temperature and glass transition (Tg) towards higher temperature respectively from 295.1C to 306.3 C and from 199.1 C to 207.6 C were illustrated by DSCresults due to addition of TiO2 in the PS-3%MMT matrix.Improvement of thermal stability might be attributed much jammed and conjugated 3D MMT-TiO2 network combined together, or powerful interaction between PS and nanofillers could also slowdown the polymer chains motion and melting point during heating. These results showed a significant effect of combination of 1D MMT layers and 3D TiO2 nanoparticles on the thermal properties of PS nanobiocomposite starch based films. Montmorillonite did not affect color of nanocomposite. The transparency of a nanobiocomposite film is not significantly varied when the clay layers with about one nm thick are excellent dispersed through the polymer matrix, since such MMT platelets are less than the of visible light wavelength and do not block lights transmission. Transmittance, redness and yellowness of new ternary films decreased when TiO2 was added to PS-3%MMT matrix at 1%. In this case, color difference (ΔE) and whiteness index (WI) are increased 86.6% and 76% respectively.Starch and PS-MMT films were colorless. The presence of TiO2 imparted whiteness to the nanocomposites due to its inherent whiteness. This phenomenon can be enucleated as the large specific surface area and high refractive index of nanosized TiO2 particles were accounted or diffuse reflection of light from the interface of the materials, and consequently, transparency loss of the composite films. UV-Vis spectroscopy was employed to evaluate the absorbance and opacity behavior of the PS-MMT-TiO2 nanocomposite films in the wavelength range of 200-800 nm. Incorporation of TiO2 nanoparticles into the starch film solution caused a significant decrease of transmittance in visible, UV-A (360 nm), UV-B (300 nm), and UVC (240 nm) regions. The results of UV-Vis spectroscopy showed that this type of films could be used as a packaging material to shield against UV and visible light.
Babak Ghanbarzadeh; Akram Pezeshki; Hamed Hamishekar; Mohammad Moghaddam
Abstract
Introduction: The encapsulation of hydrophobic nutraceutical compounds such as fat soluble vitamins in nanoliposomes is a potentially effective way to protect them from from light, oxygen and chemical degradation during the maintenance. One of the potential benefits of liposomal structures is encapsulation ...
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Introduction: The encapsulation of hydrophobic nutraceutical compounds such as fat soluble vitamins in nanoliposomes is a potentially effective way to protect them from from light, oxygen and chemical degradation during the maintenance. One of the potential benefits of liposomal structures is encapsulation of three water-soluble, fat-soluble and amphiphilic compounds and use of natural food ingredients such as lecithin with beneficial effects, in their production. In this study, the effect of lecithin-cholesterol concentrations on particle size, particle size distribution, encapsulation efficiency (EE) and physical stability of vitamin A palmitate loaded nanoliposome during the storage time were explored to get the optimized formulationMaterials and method:Materials: Phospholipid (L-α-granular Lecithin) with purity of 99% was obtained from Across (USA). Cholesterol with 95% purity was supplied by Merck (Germany). Other chemicals were analytical grade and procured from Sigma (Merck Chemical Co. Darmstadt, Germany).Methods:Nanoliposomes were prepared from different concentrations of lecithin–cholesterol (60:0, 50:10, 40:20 and 30:30 mg) by thin-film hydration–sonication method. Lecithin and cholesterol were dissolved in absolute ethanol and then dried with vacuum evaporator. Prepared dried lipid film hydrated by aqueous phase. The resultant suspension was mixed for some time (Hydration-dehydration). Due to existence of water inside the lipid film, osmotic pressure runs the water into bilayer membrane and causes separation of lipid film and then liposomes were produced. In this method, mixture of Multilamellar Vesicles (MLVs) and Small Unilamellar Vesicles (SUVs) liposomes were produced. Reduction in particle sizes of prepared liposomes was done by ultra sound probe sonicator. The average diameter and span value of the particles were determined using particle size analyzer (Wing SALD 2101, Shimadzo, Japan), at 25°C and was calculated according to the DeBroukere mean in the Equation (1):The span value is an index helpful to evaluate the particle size distribution and calculated applying the following Equation: Morphology of the nano-carriers was observed using trans- mission electron microscopy (Zeiss-Leo 906 TEM (Germany). To determine the zeta potential of nano liposomes loaded vitamin A, Zeta siyzer device (Nano-ZS -Malvern England) was used at 25◦C temperature. Estimation of encapsulated vitamin in nanoliposomes (%EE) was carried out using HPLC (Knauer,Germany) equipped with a UV detector, C-18(10 mm 25mm_4.6 mm) column and acetonitrile– methanol (70:30%,v/v) as mobile phase and was calculated using the below equation%EE= (Encapsulated Vitamin A)/(Total Vitamin A) ×100The stability of vitaminA loaded-nanoliposomes was assessed by determining the average particle size at 4 °C over storage time and studying the leak out of the vitamin from the nanoliposomes after one month(1,7, 15and 30days)of storage at 4 °C by the below equation%Stability = (Remained Vitamin A)/(Initial encapsulated Vitamin A) ×100Results and Discussion: Results showed use of sonication in completion thin-film hydration method, induced production of monomodular nanoliposomes with uniform distribution The particle size was in the range of 76-115nm and particle size distribution was monomodular (span= 0.6- 0.88). In agreement with particle size results, TEM image showed that the vesicles are in the form of small unilamellar vesicles by bilayer nature. In all concentrations of lecithin-cholesterol, obtained EE was low and by increasing the lecithin concentration, loading capacity of nano liposomes increased. By increasing the lecithin concentration, more vesicles are produced which causes increase in internal volume of liposomes and bio actives concentrate, consequently loading capacity of nano liposomes increased. By tightening of the membrane by cholesterol, entrapment efficiency of hydrophobic active compounds such as vitamin A palmitate reduces. Also probably existence of cholesterol in liposome membrane inhibits of rupture and changes in liposome membrane. Overall, increasing the ratio of cholesterol /lecithin had no significant effect on particle size but decreased encapsulation efficiency of vitamin A palmitate to 10.23%. Addition of cholesterol effected on stability of the particle size of nanoliposomes and also led to reduction encapsulation efficiency of vitamin A palmitate. Incorporation of cholesterol and vitamin A palmitate into the liposome structure was increased the zeta potential from -29 to -58 mv and improved electrostatic stability. 50-10 mg ratio of lecithin-cholesterol concentration was used for preparation of optimum formulation of nanoliposome by monomodular and small size distribution (76 nm, span=0.74) and encapsulation efficiency (15.8%). Stability of vitamin A in nano liposome with 50-10 mg lecithin-cholesterol, was almost low (32% reduction during storage time), may be due to increasing fluidity of membrane. Permeability of vitamin A into phospholipid chains causes reorientation of acyl chains which leads to fluidity of membrane and exit active compound from nano carrier and more its hydrolytic degradation and oxidation. While the use of thin film hydration method using ultrasonic waves, is successful way in producing nanoscale particles of vitamin A palmitate nanoliposomes that are stable and decrease over time, but due to low efficiency and low sustainability of encapsulation, use of other nanocarriers for encapsulating of vitamin A palmitate is recommended
Ladan Rahimi; Babak Ghanbarzadeh; Jalal Dehghan nia
Abstract
Introduction:Polyethylene terphthalate (PET) is one of the materials that are widely used for packaging of beverages and edible oils. In this study, the migration of di(2- ethylhexyl) phthalate (DEHP), dimethyl phthalate (DMP), diethyl phthalate (DEP), di-iso-butylphthalate (DIBP) and di-n-butylphthalate ...
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Introduction:Polyethylene terphthalate (PET) is one of the materials that are widely used for packaging of beverages and edible oils. In this study, the migration of di(2- ethylhexyl) phthalate (DEHP), dimethyl phthalate (DMP), diethyl phthalate (DEP), di-iso-butylphthalate (DIBP) and di-n-butylphthalate (DBP) from PET bottles into the lemon juice was investigated. Material and methods:According to European Commission regulations, 3% acetic acid (w/v) was chosen as simulant. The acetic acid samples were stored at 5, 25, and 40°C for three months and analyzed periodically by gas chromatography. Results and discussion: It was concluded that the storage temperature and time had a large effect on the migration of phthalet ester. The concentrations of migrating substance were more than its specific migration limit. The release kinetics of phthalet ester from PET bottle was described using Fick’s second law of diffusion coefficient, and crank model. The diffusion coefficients (D) determined for DEHP have most migration than other, were 0.084, 0.109, and 0.159 ×10-9 cm2/s at 5, 25, and 40°C, respectively. The diffusion coefficients (D) determined for DBP have most migration than other, were 0.084, 0.105, and 0.138 ×10-9 cm2/s at 5, 25, and 40°C, respectively. The diffusion coefficients (D) determined for DIBP have most migration than other, were 0.084, 0.177, and 0.125 ×10-9 cm2/s at 25, and 40°C, respectively. The temperature dependence of D, Arrhenius equation giving values of activation energy (Ea) for DIBP, DBP and DEHP are 2.82, 2.06 and 1.302 J mol-1 respectively.
Jalal Dehghan nia; Hamed Bagheri-Darvish-Mohammad; Babak Ghanbarzadeh
Abstract
Introduction: Deep-fat frying is a process of cooking foods through immersing them in edible oils at temperatures above the boiling point of water (150-200°C). During this complex unit operation, heat and mass transfer occur simultaneously.During frying, heat is transferred from edible oil to surface ...
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Introduction: Deep-fat frying is a process of cooking foods through immersing them in edible oils at temperatures above the boiling point of water (150-200°C). During this complex unit operation, heat and mass transfer occur simultaneously.During frying, heat is transferred from edible oil to surface of the food and then transferred into it and at the same time, moisture is transferred from inside the food to outside.As a result of these phenomena and by continuing the process, food temperature increases and its moisture content decreases. This, in turn, creates favorable characteristics such as color, texture and taste of the product.Moisture content is one of the important features in the quality of fried products.In the frying process, moisture loss from food occurs by the mechanisms of molecular diffusion, capillary flow and pressure driven flow.The driving force of moisture loss is the partial water vapor pressure difference between the inside and the surface of the food product due to turning the water into vapor.Rate of moisture loss from the food during the frying process decreases exponentially with frying time and increases with increasing temperature.For information about therelationshipsbetweenvarious variables during the frying process, moisture loss kinetics modelingcan bea suitable steptowards improving thequality offried products.To our knowledge, there has been no study in literature associated with the effect of ultrasound and microwave on moisture loss during deep-fat frying of foods. This study aimed to evaluate the effect of these waves on moisture loss kinetics during frying of potato strips.Materials and Methods: Potatoes (Agria variety) were purchased from a local market and kept in a cold room at 0°C. A mixture of sunflower, soy and cottonseed oil (Behshahr Industrial company), was used for frying potato strips.Inthis study, effect ofultrasound pretreatment at frequencies of 28 and 40 kHz for 15 min and microwave pretreatment at powers of 3 and 6 W/g for 10 min on moisture content of the fried potato slices at 150, 170 and 190°C for 60, 120, 180 and 240 s was investigated.The moisture content of the samples was measured by drying them in a convection oven at 105°C until the weight was constant.Moisture loss experimental data during frying were fitted with six empirical models proposed in this study as well as the Fick’s law of diffusion.The effective moisture diffusion coefficient was calculated based on the Fick's law. To calculate the effect of temperature on the effective moisture diffusion coefficient, the Arrhenius equation was used.Results and Discussion: By increasing frying temperature, moisture content of the potato slices decreased; however the decrease was not significant at a probability level of 5 percent. The positive effect of oil temperature on moisture loss during deep-fat frying of potato strips has been well documented. This is due to the high kinetic energy of water molecules at higher temperatures, leading to a rapid loss of moisture. The moisture loss by diffusion of water molecules as well as the oil uptake during the frying process lead to the formation of cracks in the structure of the solid food. This, in turn, leads to structural damages and significant changes in terms of structural characteristics including porosity.On the other hand, moisture content of the samples significantly decreased in an exponential manner by increasing the process time. Rapid moisture loss in the first moments of frying is associated with the removal of surface moisture. By decreasing surface moisture over time, the rate of moisture loss was reduced accordingly.Results also showed that both the ultrasound and microwave pretreatments at all the studied levels significantly reduced the final moisture content of the samples at a probability level of 5 percent. The difference between the samples pretreated with two ultrasound frequencies of 28 and 40 kHz was not significant (P > 0.05), but with increasing frequency of the pretreatment, the moisture content decreased to a greater extent. Lower final moisture contents of the samples pretreated with ultrasound were probably due to the creation of microscopic channels in the food structure, which may facilitate moisture loss during frying. On the other hand, application of microwave pretreatment at powers of 3 and 6 watts per gram, decreased initial moisture content of the samples by 38 and 80%, respectively. This resulted in significant (P < 0.05) reduction of the final moisture contents of the samples pretreated with microwave. More moisture loss at higher microwave power is probably due to the high intensity of electromagnetic energy as a result of microwave volumetric heating.In addition, the applied modelswerewell fitted toexperimentaldata having high R2 and low RMSE. The effective moisture diffusion coefficient ranged between 3.57×10-8 to 11.08×10-8 m2/s. Results also demonstrated that the effective moisture diffusion coefficient is increased and the activation energy is decreased by implementing the ultrasound and microwave pretreatments.
Hojatollah Bodaghi; Younes Mostofi; Abdulrasoul Oromiehie; Zabihollah Zamani; Babak Ghanbarzadeh; Ziba Ghasimi Hagh
Abstract
Introduction: Active and intelligent packaging devices and systems represent emerging technologies that may have profound implications on the quality, safety and integrity of packaged food and beverage products. It is well known that the photocatalyst titanium dioxide (TiO2), being a wide band gap (3.2 ...
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Introduction: Active and intelligent packaging devices and systems represent emerging technologies that may have profound implications on the quality, safety and integrity of packaged food and beverage products. It is well known that the photocatalyst titanium dioxide (TiO2), being a wide band gap (3.2 eV) semiconductor under UV illumination, generates energy-rich electron-hole pairs that can be transferred to the surface of TiO2, and promotes reactivity with the surface-absorbed molecules leading to the production of active radicals. These active radicals oxidize C-H bonds resulting in degradation of the organic molecules TiO2 photocatalyst has been used to degrade organic pollutants and inactivate a wide spectrum of microorganisms. To the best of our knowledge, there is no report on the photocatalytic disinfection properties of low density polyethylene (LDPE)-TiO2 nanocomposite produced by extrusion. Therefore, in this study LDPE-TiO2 nanocomposite film was prepared by a film blowing machine. The antimicrobial activity of the new packaging film against Pseudomonas spp. and Rhodotorula mucilaginosa, representing the main microorganisms on fruit and vegetable crops, was examined in vitro under UVA light. The antimicrobial property of the developed active film was also tested in a food application Materials and methods: LDPE -TiO2 nanocomposite was prepared by the melt blending method. Modified TiO2 (M-TiO2) powder obtained by mixing modified anatase and rutile phases in a weight ratio of 7:3 (total of 30 g), LDPE granules (935 g), PE-MA (30 g) and glycerol (5 g) were blended for 1 h using a mixer. The mixture was extruded by a Brabender twin-screw compounder (model DSE 20, Germany) for incorporating nanoparticles into the LDPE matrix. For LDPE and its nanocompounds, a constant temperature of 130 °C was used in all the zones of the extruder and the speed of the central screw was set to 120 rpm. The extrudate was cooled down in air at 23 ± 3 °C and pelletized. A composite LDPE-TiO2 film with a thickness of 30 ± 3 µm was finally obtained by a film-blowing machine. The resulting film had a milky whitish appearance. In vitro and in vivo antimicrobial activity test of film Each test film (6 cm diameter) was placed in sterilized petri dishes under aseptic conditions. One mL of each microorganism stock solution (containing approximately 108 and 107 CFU/mL for Pseudomonas spp. and R. mucilaginosa, respectively) was pipetted onto each test piece in its petri dish. Test samples were placed at a distance of 25 cm from six 8-WUVA black light bulbs Samples were taken in three replicates at 60 min intervals for 3 h. Then, 9 mL of sterile saline solution was added to the petri dishes containing the test and polyethylene films and shaken for 180 s on a universal small shaker (IKA MS 3 digital, Germany). One milliliter of solution was withdrawn at each sampling event and diluted to 1/10, 1/100, 1/1000, and 1/10,000 with sterile saline solution. A volume of 0.1 mL of the undiluted and diluted solutions was plated over appropriate media. Pseudomonas agar base (PAB) was incubated at 25 °C for 48 h for Pseudomonas spp. and Sabouraud dextrose agar for R. mucilaginosa and the colony-forming units (CFU) were counted. For in vivo test, every 6 days, approximately 20 g of packed apricot pieces with nanocompsite films, were collected randomly and placed into 180 mL of saline solution and agitated in a stomacher bag for 120 s. Decimal dilutions were made in sterile saline solution and 0.1 mL of the undiluted and diluted solutions were plated. Results and discussion: This work describes a TiO2 nanocomposite thin film with biocidal capacity for food packaging that was prepared by the extrusion method. The film caused inactivation of Pseudomonas spp., R. mucilaginosa and mesophilic bacteria in saline solution and on apricot when exposed to UVA light. The number of microorganisms on LDPE-TiO2 nanocomposite film plus UVA light was lower than that on LDPE-TiO2 nanocomposite film without UVA light and LDPE film exposed to UVA light. These results suggest that the TiO2 nanoparticles were responsible for the antimicrobial effect when exposed to UVA light illumination. The higher antimicrobial activity of the composite films under UV light is due to the photocatalytic reaction of the TiO2 nanoparticles in the matrix. Thus, the prepared TiO2 nanocomposite films are effective in diminishing live microorganisms and are promising as antimicrobial packages.
Ronak Gholami; Jalal Dehghan nia; Babak Ghanbarzadeh
Abstract
Introduction: In recent years, demand for edible and biodegradable films has increased. One reason for this increase is the pollution caused by synthetic polymers. Edible films are produced from different biopolymers such as lipids, polysaccharides and proteins. Starch is a common polysaccharide in the ...
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Introduction: In recent years, demand for edible and biodegradable films has increased. One reason for this increase is the pollution caused by synthetic polymers. Edible films are produced from different biopolymers such as lipids, polysaccharides and proteins. Starch is a common polysaccharide in the preparation of edible films which is taken into consideration because of its low price and easy access. Structure and composition of starch-based films affects the resulting film properties such as moisture sorption, gas permeability, plasticizer crystallization, glass transition temperature and its mechanical properties. Starch films have usually poor mechanical properties and are permeable to water vapor. The use of nanofillers such as cellulose nanocrystal (CNC) in the structure of starch films and production of nanocomposite films is one way to modify properties of the films. The most important purpose of the application of edible films is to prevent moisture or other compounds such as carbon dioxide or volatile components transfer between the product and the environment or between different layers of the product. Modeling mass transfer and moisture permeability of edible films can be effective in predicting film properties and packaged product during storage. For example, it can be predicted that at a certain temperature, relative humidity and time, how much moisture packaging material will absorb. Therefore, before using edible film as a protective coating for food, calculation of the amount of moisture sorption and permeability to water vapor is essential. The purpose of this study was to investigate mass transfer in starch - CNC nanocomposite films. The effect of adding different percentages of CNC on the water vapor permeability and moisture sorption kinetics of nanocomposite films was studiedMaterials and Methods: First, 100 ml of potato starch solution with a concentration of 4% (w/v) was prepared by dispersion of the starch in distilled water and was gelatinized at 90ºC for 5 min. Different levels of CNC (0, 3, 5, 7 and 9% w/w) were dissolved in distilled water and were added to the gelatinized starch after treatment with ultrasound for 10 min. Then, glycerol, as a plasticizer, with concentrations of 0.2, 0.3 and 0.4% (w/w) were added to the solution. The film solutions were distributed on polystyrene surfaces and the resulting films were dried in an oven at 40°C for 24 hours. The Fickʹs second law and four empirical equations were used for moisture sorption modeling of samples. The effect of glycerol concentration on water vapor permeability was investigated and the experimental data were fitted with an exponential model.Results and Discussion: By increasing the concentration of CNC, moisture content of the nanocomposite films declined. Effective moisture diffusion coefficient values for nanocomposite samples were higher than the pure starch film. The coefficient increased from 0.293×10-13 to 0.547×10-13 m2/s by increasing CNC concentration from 0 to 9%. This result can be attributed to the influence of cellulose nanofibers on the polymer matrix and gaps creation in the polymer amorphous regions. This, in turn, would facilitate moisture diffusivity into the polymer structure. It should be noted that plasticizer presence in the nanocomposite structure can be an important factor. Regarding that plasticizer lead to increase in polymer chain mobility, simultaneous presence of CNC and plasticizer could lead to create gaps in the structure of nonocompositefim. As expected, in the absence of plasticizer, the effective moisture diffusion coefficient in nanocomposite samples decreased by increasing the concentration of nanoparticles due to high immobility of polymer chains. In addition, the initial stages of moisture sorption were well described by the Fickʹs law but due to the polymer relaxation between 2.5 - 9 h interval, its behavior was deviated from this law. Finally, after about 9 hours, it was observed that the equilibrium moisture content of the nanocomposite samples were consistent with the values predicted by the Fickʹs model. Equilibrium moisture content depends on the hydrophilic locations of the nanocomposite structure. These locations have the ability to absorb moisture and this ability is not influenced by changes in the structure of the polymer during the moisture sorption process. Despite higher levels of effective moisture diffusion coefficients in starch-nanocrystalline cellulose nanocomposites compared to pure starch film, moisture content was lower in nanocomposite films. These results are probably due to the nature of nanocrystalline cellulose which is resistant to water and is compatible with the starch polymer. Nanocrystalline cellulose has the ability to make many hydrogen bonds with the hydrophilic polymer matrix. This results in decreasing hydrophilic property of starch. On the other hand, in all samples, the permeability to water vapor reduced with increasing nanoparticles concentration. For example, in the starch film which contained 0.4% glycerol, water vapor permeability was 2.62×10-7g.m/m2.h.Pa; with the addition of nanocrystalline cellulose to 9%, its value was decreased to 1.8×10-7g.m/m2.h.Pa. Moreover, the permeability to water vapor in all cases increased by increasing the concentration of plasticizer. Results also showed that there is an exponential relationship between the water vapor permeability and plasticizer content.Conclusion: By increasing the concentration of CNC, moisture content of the nanocomposite films declined. Effective moisture diffusion coefficient values for nanocomposite samples were higher than the pure starch film. The coefficient increased by increasing CNC concentration. The initial stages of moisture sorption were well described by the Fickʹs law but due to the polymer relaxation, its behavior was deviated from this law. Finally, after about 9 hours, it was observed that the equilibrium moisture content of the nanocomposite samples were consistent with the values predicted by the Fickʹs model. In addition, in all samples, the permeability to water vapor reduced with increasing nanoparticles concentration. However, the permeability to water vapor increased by increasing the concentration of plasticizer. Results also showed that there is an exponential relationship between the water vapor permeability and plasticizer content
Hadi Almasi; Babak Ghanbarzadeh; Jalal Dehghan nia; Ali Akbar Entezami; Asghar Khosrowshahi Asl
Abstract
Fatty acid modified cellulose nanofibers (MCNFs) and TBHQ antioxidant were added to poly(lactic acid) (PLA) film. The combined effects of the MCNFs and TBHQ on the morphological, thermal, mechanical and barrier properties of PLA film were analyzed. The morphology of fracture surfaces evaluated by field ...
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Fatty acid modified cellulose nanofibers (MCNFs) and TBHQ antioxidant were added to poly(lactic acid) (PLA) film. The combined effects of the MCNFs and TBHQ on the morphological, thermal, mechanical and barrier properties of PLA film were analyzed. The morphology of fracture surfaces evaluated by field emission scanning electron microscopy (FE-SEM). XRD results showed that the crystallinity of the PLA film with added MCNFs was substantially higher than that of pure PLA and antioxidant active PLA films. Glass transition and melting temperatures changed with the addition of these two components. The addition of 3wt% of TBHQ to PLA films leads to a significant reduction (p
Mahdi Barmour; Jalal Dehghan nia; Babak Ghanbarzadeh
Abstract
The objective of this study was to evaluate the effect of process conditions and different pretreatments including ultrasound, microwave and osmotic dehydration on mass transfer and oil uptake during deep fat frying of potato slices. Ultrasound pretreatment was performed at frequency of 40 KHz for 10 ...
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The objective of this study was to evaluate the effect of process conditions and different pretreatments including ultrasound, microwave and osmotic dehydration on mass transfer and oil uptake during deep fat frying of potato slices. Ultrasound pretreatment was performed at frequency of 40 KHz for 10 and 30 minutes, microwave pretreatment was conducted at 5 W/g power and osmotic dehydration pretreatment was done in NaCl solutions with concentrations of 1 and 3 percent. Potato slices were then fried at 150, 170 and 190°C for 90, 180, 270 and 360 seconds. The results showed that ultrasound pretreatment for 10 minutes increases oil uptake of samples as compared with control sample, but when samples were exposed to ultrasound for 30 minutes, oil uptake was decreased. In addition, microwave pretreatment reduced oil uptake of potato slices insignificantly. Furthermore, osmotic dehydration pretreatment reduced oil uptake. In order to model oil uptake, experimental data were fitted with 6 models. The aforementioned models had the highest R2 and a minimum value of RMSE.
Nasrin Jamshidi; Babak Ghanbarzadeh; Jalal Dehghan nia; Mahood Sowti Khiabani; Ali Akbar Entezami
Abstract
Cellulose nanocrystal (CNC) is a type of nanomaterial which is produced by partial hydrolysis of cellulose and elimination of its amorphous regions. CNC has several advantages such biodegradability and safety toward human health. In this study, CNC was produced from cotton linters and methods such transmission ...
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Cellulose nanocrystal (CNC) is a type of nanomaterial which is produced by partial hydrolysis of cellulose and elimination of its amorphous regions. CNC has several advantages such biodegradability and safety toward human health. In this study, CNC was produced from cotton linters and methods such transmission electron microscopy which were used for confirmation of nanoscale size production of cellulose crystals. Due to the disadvantages of pure starch films, in the present research, for improving the properties of plasticized starch-PVOH films, from nanoparticles CNC and TiO2 are used together, then effects of nanoparticles and glycerol determined on physical properties by response surface methodology (RSM). CNC and GLY showed significant linear effects on ultimate tensile strength (UTS) of nanocomposit and there were significant interaction effects between TiO2 and CNC, and also between GLY and TiO2. The optimum levels of TiO2, CNC and GLY for obtaining maximum UTS were as 0.118, 0.6 g and 1.06 ml, respectively. In addition, the TiO2 concentration had linear and quadratic effect on the contact angles of bionanocomposites and optimum levels of TiO2, CNC and GLY for obtaining maximum contact angles were 0.112, 0.299 g and 1.06 ml, respectively. UV-visible spectroscopy studies in the wavelength range 200–800 nm showed that adding of CNC and TiO2 decrease the light transmission and increase the opacity, adding of glycerol increase the light transmission and decrease the opacity.
Zahra Mohammad Hassani; Babak Ghanbarzadeh; Hamed Hamishekar; Reza Rezaeemokaram
Abstract
Utilization of non-food-grade organic solvents and high shear forces in conventional liposome formation techniques has limited their applications as carriers of nutrecuticals in food industry. The objective of this research is the production of gamma-oryzanol bearing nanoliposome by using modified thermal ...
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Utilization of non-food-grade organic solvents and high shear forces in conventional liposome formation techniques has limited their applications as carriers of nutrecuticals in food industry. The objective of this research is the production of gamma-oryzanol bearing nanoliposome by using modified thermal method. Nanoliposomes were produced by a suitable concentration of lecithin and gamma-oryzanol solution. Size and zetapotential of nanoliposomes was determined using laser light scattering method and Infrared spectroscopy (FTIR) was employed for detection of interaction type between the nanoliposome and gamma-oryzanol. Then, the prepared samples were tested in terms of turbidity, stability, and rheological properties. The FTIR results demonstrate that interactions between lecithin and gama-oryzanol are weak physical type. The results of particle size showed that size distribution (span) were in the range of 90-110 nm and 0.69- 0.90, respectively. The negative zeta potential and loading capacity were reported 20.4 mV and 15.7% (±0.07), respectively. The results indicated that the prepared samples were stable in the 4 ˚C temperature. Increase of lecithin concentration increased turbidity. It was observed that the viscosity not changed by increasing the shear rate (Newtonian behavior), suggesting a nonflocculated system with very small particle size pointing toward the stability of the system.
Arezu Salmanpour; Babak Ghanbarzadeh; Mahood Sowti Khiabani; Seyed Hossein Jalali
Abstract
In this research, the effects of three variables, whey protein concentrate, WPC (0.7- 2.8%), sodium Ceinate, SC (0.7-208%) as a substitute for egg and carboxymethyl cellulose, CMC (0.66-0.234 % w/w) as thickening agent on sensory (taste and texture) and rheological (Complex viscosity, η* , Storage modulus, ...
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In this research, the effects of three variables, whey protein concentrate, WPC (0.7- 2.8%), sodium Ceinate, SC (0.7-208%) as a substitute for egg and carboxymethyl cellulose, CMC (0.66-0.234 % w/w) as thickening agent on sensory (taste and texture) and rheological (Complex viscosity, η* , Storage modulus, G´ and Loss modulus, G˝ ) properties of salad dressing were investigated. The central composite experimental design (CCD) was used and the data were analyzed using response surface methodology (RSM). The results of analysis of variance (ANOVA) showed that P values of all models were significant and lack of fit P values was no significant at the level of 95%. Therefore, the adequacy of models was acceptable. The results showed that the optimum level of hydrocolloids for producing salad dressing with highest rheological properties were 2.27% WPC, 2.27% SC and 0.2341% CMC. The sensory evaluation of six treatments with improved physicochemical properties and stability of salad dressing (data not shown) and control sample (prepared with eggs) was carried out. The results suggest that there is no significant difference in the overall acceptability between control samples and samples prepared with the alternatives. So milk proteins can be used as a suitable substitute for egg in the salad dressing.
Mina Akbarian; Babak Ghanbarzadeh; Jalal Dehghan nia; Mahood Sowti Khiabani
Abstract
In this study, the optimization of osmotic solutions (containing fructose, calcium chloride and citric acid) were investigated based on maximum water loss (WL) in the osmotic dehydration of quince. The response surface methodology (RSM) and central composite design, with 18 treatment and 3 replicate, ...
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In this study, the optimization of osmotic solutions (containing fructose, calcium chloride and citric acid) were investigated based on maximum water loss (WL) in the osmotic dehydration of quince. The response surface methodology (RSM) and central composite design, with 18 treatment and 3 replicate, was used for optimizing. The results showed that fructose and calcium chloride had linear and quadratic significant effects (p
Sajedeh Bahrani; Babak Ghanbarzadeh; Hamed Hamishekar; Mahood Sowti Khiabani
Abstract
Encapsulation of bioactive ingredient and production of nano carriers in order to food enrichment and production of functional food is one of the applications of nano technology in food science and pharmaceutical. Nano carriers are produced using biopolymers (proteins and polysaccharids) or lipid based ...
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Encapsulation of bioactive ingredient and production of nano carriers in order to food enrichment and production of functional food is one of the applications of nano technology in food science and pharmaceutical. Nano carriers are produced using biopolymers (proteins and polysaccharids) or lipid based materials. In this research, production and characterization of pectin-casein nanocomplexes as a potential nanocarrier were investigated by Fourier Transform Infrared Spectroscopy (FTIR) and measurement of particle size and distribution. FTIR results showed electrostatic interactions between pectin and casein. Transmission Electron Microscopy, zeta potential and particle size showed stable dispersion with 86 nm at pH = 1.4, casein %1 and pectin 0.45. Nanocomplex solutions compared to pure pectin and sodium caseinate solutions have higher shear stress and viscosity in constant shear rate and rheological behavior of biopolymer solutions were altered from Newtonian to non Newtonian in complexes includes casein and pectin.
Leila Abolghasemi Fakhri; Babak Ghanbarzadeh; Jalal Dehghan nia; Ali Akbar Entezami
Abstract
The high hydrophilic property of biopolymer based plastics is one of the most important defects of them. Blending biopolymers with compatible synthetic polymers and using nano particles such as nanoclay as nanofiller are improving methods that have been extensively considered in recent years. Carboxymethyl ...
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The high hydrophilic property of biopolymer based plastics is one of the most important defects of them. Blending biopolymers with compatible synthetic polymers and using nano particles such as nanoclay as nanofiller are improving methods that have been extensively considered in recent years. Carboxymethyl cellulose (CMC) is one of the lowest cost biopolymers that have enormous applications in different industries and polyvinyl alcohol (PVA) is a synthetic polymer which has a high compatibility with biopolymers. In this research, CMC-PVA nanocomposites containing 3-10% Montmorillonite (W/W CMC) were prepared by casting method. The X-ray diffraction (XRD) results indicated the formation of an exfoliated nanostructure in all MMT content samples. Nanocomposites containing 10% MMT exhibited 29.06% reduction in water vapor permeability (WVP) compared to the blend film without nanoclay. Samples with 10% MMT, showed the lowest surface hydrophilisity (contact angle = 65.1o). The differential scanning calorimetry (DSC) results indicate that by increasing of MMT contents, the glass transition disappeared gradually and no glass transition was observed in the thermograms of the films containing 5, 7 and 10% MMT.
Azam Seraji; Babak Ghanbarzadeh; Mahood Sowti Khiabani; Sara Movahhed
Abstract
In this study, the effect of edible coating and osmotic dehydration, as pre-treatments before drying of cucurbit, were investigated. Cucurbit samples were cut spirally and coated by carboxy methyl cellulose (CMC) 1% and ascorbic acid 0.1% solutions and then processed by osmotic dehydration. Proportion ...
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In this study, the effect of edible coating and osmotic dehydration, as pre-treatments before drying of cucurbit, were investigated. Cucurbit samples were cut spirally and coated by carboxy methyl cellulose (CMC) 1% and ascorbic acid 0.1% solutions and then processed by osmotic dehydration. Proportion of sample to solution was 1:10 and the solution containing sucrose %45, salt%25 and citric acid %1 (W/W) was selected as the best osmotic solution. Finally, the cucurbit samples were dried by oven (at 80 ˚C for 3 hours). The effects of CMC based coating on water loss (WL), solid gain (SG), immersion time, amount of salt, sucrose, citric acid absorption and color and sensory acceptability of samples were evaluated. The results showed that CMC based coating decreased SG without decreasing effect on WL which in turn decreased drying time of osmotic dehydrated samples in oven. Furthermore, the coated, osmotic dehydrated samples showed higher color quality and sensory acceptability in comparison to the control samples.
Shahram Mohammadi; Babak Ghanbarzadeh; Mahood Sowti Khiabani; Shiva Ghiyasifar; Seyed Hossein Jalali
Abstract
During storage of eggs, unfavorable changes occur due to exertion of CO2 and water vapor from through of crust pinholes. One of the practical methods for preventing or reducing these changes is to use biopolymer-based coatings. In this research, five coating solutions based on carboxymethyl cellulose ...
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During storage of eggs, unfavorable changes occur due to exertion of CO2 and water vapor from through of crust pinholes. One of the practical methods for preventing or reducing these changes is to use biopolymer-based coatings. In this research, five coating solutions based on carboxymethyl cellulose (CMC) and glycerol as plasticizer, oleic acid (1 and 2% V/V) and antimicrobial agents (potassium sorbate, natamycin and butylated hydroxyanisole) were prepared and their effects on physicochemical properties of the eggs (weight loss, pH, Haugh unit (HU) and yolk index (YI)) were evaluated at room temperature (25 ) during 5 weeks storage. The results showed that CMC- based coatings have considerable effects on quality of eggs and shelf life of them increased 1-3 weeks (depending on coating type). As well as, adding oleic acid to the CMC- based coating had positive significant effects (P < 0.05) on quality parameters of eggs during 5 week storage. Adding antimicrobial compounds also caused significant difference in all parameters, except yolk index, in comparison to CMC coating without antimicrobial compounds.
Babak Ghanbarzadeh; Ali Akbar Entezami
Abstract
The starch based films have some disadvantages such as weak mechanical and poor water barrier properties that restrict their applications in food packaging. In the present research, the polyvinyl alcohol (POVH), as a compatible polymer, and montmorillonite (MMT) nanoclay, as a nanofiller, were added ...
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The starch based films have some disadvantages such as weak mechanical and poor water barrier properties that restrict their applications in food packaging. In the present research, the polyvinyl alcohol (POVH), as a compatible polymer, and montmorillonite (MMT) nanoclay, as a nanofiller, were added to plasticized starch film (PS) to improve its properties and also to produce PS-MMT-PVOH nanocomposits with different MMT content (3,5,7%). The results of X-ray diffraction (XRD) villustrated that the nanostructure of investigated starch based nanocomposites films has an exfoliated structure which can be attributed to the good dispersing of filler in polymer matrix. DSC results showed that with adding MMT and increasing its content from 0 to 7%, melting point and Tg increased from 242ᵒC to 262ᵒC and 148ᵒC to 188ᵒC. The results of tensile test showed that addition of PVOH and MMT increased the ultimate tensile strength (UTS) and decreased the water vapor permeability (WVP) of nanocomposite films.
Younes Zahedi; Nasser Sedaghat; Babak Ghanbarzadeh
Abstract
Novel edible emulsified films were made using pistachio globulin protein (PGP) and palmitic fatty acid at concentrations of 2, 4, and 6 % w/w protein by Tween-80 and homogenization technique. Addition of palmitic acid to the PGP filmogenic solution resulted in great reduction of WVP in the emulsified ...
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Novel edible emulsified films were made using pistachio globulin protein (PGP) and palmitic fatty acid at concentrations of 2, 4, and 6 % w/w protein by Tween-80 and homogenization technique. Addition of palmitic acid to the PGP filmogenic solution resulted in great reduction of WVP in the emulsified films (37-40 %). Concentration of palmitic acid did not create significant difference (P>0.05) among WVP of the emulsified films. The WVP decreased as function of palmitic acid concentration. Water solubility of PGP films was 44.8 % and slightly decreased in the emulsified films. Oxygen permeability of the emulsified films were lower than the PGP films, but the differences were not significant (P>0.05). Tensile strength and elongation at break of the emulsified films were diminished as a result of palmitic acid addition. Incorporation of palmitic acid led to produce the opaque films, which opacity increased as function of palmitic acid concentration. Glass transition temperature (Tg) was determined by differential scanning calorimetry. The Tg of the PGP film revealed at 127.19 °C and was not affected by palmitic acid.
Keywords: Pistachio globulin protein, Palmitic acid, Gas permeability, Elongation, Tensile strength
