فهرست مطالب b. ghanbarzadeh

Deinking waste paper is done in various ways, and research on newer methods is also being done. Traditional deinking methods to remove ink from waste printing papers have a relatively high efficiency compared to contact methods, but in non-contact printing such as electrophotographic printing (LaserJet printers and photocopiers) due to Mixing of the ink with the paper texture during the stabilization of the ink with the help of high heat, the traditional deinking methods are less efficient and it is necessary to use newer methods. In this research, enzymatic deinking of office waste paper was done by a commercial cellulase enzyme in a neutral environment. 15 tests were conducted, and optical and printing properties including the paper were investigated. By measuring the reflection before and after printing and measuring the print density after printing, it was determined that the printability of deinked paper is within the desired range. Eric's number was 128 ppm for sample number 8 and 138 ppm for sample number 12, which has decreased compared to the control sample with an Eric number of 571 ppm. Measuring the reflection before and after printing and measuring the print density after printing, show that the printability of decomposed ink paper is in the desired range. </em>

Several reports are available on species diversity of yeasts on grape berries in different grapevine producing countries, including Iran. However, there is a paucity of knowledge on species diversity of yeasts on post-harvest table grapes worldwide. Hence, this study was performed to explore the species diversity of epiphytic yeasts on post-harvest table grapes in markets of Tabriz, northwest Iran. Towards this aim, 120 grape samples, mostly Keshmesh, Shahani, Gezeluzum and Shast-arous cultivars, were purchased from selected main markets in Tabriz and subjected to yeast isolation. Total number of 180 epiphytic yeast isolates were recovered. The isolates were preliminary grouped based on the morphological characteristics and DNA fingerprinting profiles using MSP-PCR fingerprinting technique. The D1/D2 domain of the 26S rDNA was amplified and sequenced for one or two isolates representing each fingerprinting group. Totally, 20 isolates were sequenced and the phylogeny inferred from sequence data of D1/D2 region revealed a rich diversity of yeast species on post-harvest table grape berries. Sixteen yeast species belonging to both ascomycetes and basidiomycetes were identified. The majority of identified yeast species (75%) belonged to ascomycetes. Aureobasidium pullulans, Hanseniaspora uvarum and Metschnikowia sinensis are reported as the most frequently isolated yeasts. In this study, Clavispora lusitaniae and Cyberlindnera fabianii are newly reported on grape berries worldwide and C. lusitaniae, C. fabianii, Wickerhamomyces anomalus and Yamadazyma mexicana represent new records for the mycobiota of Iran.

is the evaluation of the effect of gelatin/Hydroxypropyl-β-cyclodextrin coating containing nanoemulsion of nettle (Urtica dioica L. ( on chemical, microbial and sensory properties of turkey meat during storage.

Chemical compositions of nettle essential oil were detected using Gas Chromatography-Mass Spectrometry. Samples of turkey meat coated with 1.5% (V/V) nanoemulsion of nettle, coated with gelatin/hydroxypropyl-β-cyclodextrin (HPBC) containing nanoemulsion of nettle, packed in cellophane and without coating (Control) were stored at 4°C. Their physical and chemical (weight loss, total volatile basic nitrogen, and thiobarbituric acid reactive substances), microbial and sensory properties were evaluated at different intervals (0, 5, 10, 15, 20 days) of storage.

The results of Gas Chromatography-Mass Spectrometry showed the presence of effective compounds with antimicrobial and antioxidant activities especially Carvacrol (51.71%). According to the results, lower amounts of weight loss, total volatile basic nitrogen, mesophilic, psychrophilic bacteria, molds, and yeasts were observed in turkey meat samples treated with nanoemulsion of nettle essential oil in comparison to the control during storage (p˂0.05) and the highest sensory scores were gained.

Application of gelatin/HPBC coating containing nanoemulsion of nettle essential oil had a desirable effect on the control of chemical and microbial spoilage, therefore it can be used for increasing the shelf life of turkey meat in the food industry.

In recent years, the tendency to use biodegradable polymers in food packaging has been increased due to enhanced awareness on the ecological and environmental problems and the contaminations of natural resources caused by non-degradable petrochemical-based polymers. In this regard, two types of biodegradable polymers have been investigated: edible and non-edible biopolymers. Carbohydrates and proteins or their combination with lipids usually are used for producing edible biopolymers (Noshirvani et al., 2018). Cinnamon essential oil (CEO) is a mixture of aldehyde, phenol and terpene active compounds, exhibiting antioxidant and wide spectrum antimicrobial properties against fungal spoilage. CEO is granted by the world health organization (WHO) expert committee as a non-toxic additive and flavoring agent, meanwhile CEO is widely applied in many food formulations thus it fits desirable taste (Ojagh et al., 2010). Mostly, synthetic antimicrobial and antioxidant compounds are directly added into the food products to control the microbial growth. This method may lead to the inactivation or evaporation of active agents and rapid migration into the bulk of the foods. Hence, the antimicrobial activity may be quickly lost by dilution below active concentration and also the flavor of the food may be changed. The incorporation of an antimicrobial compound in a polymer matrix and the production of active packaging potentially cause to gradual release of active agents, which may be promising approach to inhibit the microbial growth. Carboxymethyl cellulose (CMC) is a biodegradable semi-synthetic biopolymer. It is a linear anionic charge polysaccharide due to having many hydrophilic carboxyl groups. CMC produces high viscosity solution and transparent films with favorable properties from consumer point of view. The CMC-based films show good barrier properties against gases and lipophilic compounds, while showing poor inhibition against water vapor permeation, similar to other polysaccharide and protein-based films. In order to fix these defects and improve packaging properties, a number of approaches have been studied such as combination with other compatible biopolymers, using hydrophobic compounds (such as lipid and essential oil), cross linking agents and nanofillers. To our knowledge, there is no study on comparing the effects of nano and macro emulsion of cinnamon essential oil (CEO) on the physicochemical and antifungal properties of the active biopolymer based films. Therefore, the objectives of this work were (i) to produce the emulsified CMC-based films from CEO macroemulsions (ME) and nanoemulsions (NE) prepared by using Ultra-Turrax and Ultrasonication (ii) to compare the effects of these two types of the emulsified films on some physical features of the resulted films (iii) and to study the in-vitroefficiency of these films against Aspergillus niger and mucor racemous.

Macroemulsions (ME) were formed by adding different amounts (0.125, 0.25 or 0.5 gr) of Tween 80 equation with 50% W/W surfactant oil ratio (SOR) to 20 ml of double distilled water and followed by homogenization by Ultra-Turrax (JANKE & KUNKEL, Germany), at 20000 rpm for 1 min. Then, CEO was added at (0.25, 0.50 or 1 gr) equation with 0.25, 0.50 and 1% W/V (CEO/Emulsion) to each solution and mixed again for 2 min. Prepared ME were sonicated at the condition of 20 kHz frequency, 400 W input power and 70S amplitude for 10min by Ultrasonicator (FAPAN, Iran) to obtain nanoemulsions. In order to prevent the increase of emulsions temperature during sonication, the solutions were keeping in ice-water bath. Films were prepared as described by Dashipour et al. (2015), with slight modifications. First, 80 ml of double distilled water was heated in a water bath until temperature increased to about 85 , then, 1.5 g of CMC powder was added to hot water and mixed by magnetic stirrer(800 rpm) at 85 for 60 min. After that, glycerol was added at 0.75 w/w of CMC as a plasticizer and mixing continued for 10 min. Then, the solution temperature reduced to 60  in order to prevent the destruction of CEO active compounds. Having done that, the solution was mixed with 20 ml of macro and nano emulsions solution prepared in the previous section and agitated with magnetic stirrer (500 rpm) at 60  for 30 min to obtain homogeneous solutions. The film forming solutions were degassed with vacuum pump(DV-3E 250, JB,USA), at ambient condition for 5 min, then, 100 ml of the emulsified film forming solutions were poured into an even surface Teflon plates (PTFE) in the dimension of 15 15 cm and dried at 40  for 18 h in cold incubator to cast the films.

The emulsified films based on carboxymethyl cellulose (CMC) containing macroemulsion (ME) and nanoemulsion (NE) of cinnamon essential oil (CEO) were prepared. The atomic force microscopy (AFM) images showed different morphology in the ME and NE films and more compact and uniform microstructure in the NE films than the ME one. Adding CEO led to more flexible films with lower glass transition temperature (Tg) and storage modulus (E'). Low droplet size in NE than ME led to brighter and yellowish films. Antifungal index against A. niger and M.racemous were 14.16% and 20.82 % in the ME films and 18.81% and 25 % in the NE ones. The antifungal activities of cinnamon essential oil (CEO) is related to their major phenolic or aldehyde such as eugenol and cinnamaldehyde constituents, respectively. Eugenol caused to killed microbial cells probably by two important mechanisms; leached out cell content by increasing the permeability of cellular membranes and released proton of hydroxyl groups causing to reduce proton gradient that resulted depletion energy polls in microbial cells. Another effective mechanism of cinnamaldehyde in microbial growth is its reaction with nucleophilic compound in microorganism's structure by higher electrophilic compounds such as carbonyl groups in cinnamaldehyde structure. The disruption of cytoplasmic membranes, the cytoplasm depletion, thedeformation of hyphal tips, the formation of short branches and the collapse of entire hyphaewere the major effect of essential oil on fungus, observed by transmission electron microscopy.

Comparing different physicochemical and antifungal properties of CMC films containing ME and NE of CEO showed significant differences. The decrease of droplet size by sonicator caused to better diffusion of CEO NE from cell membrane of microorganisms, resulting in improved antifungal efficiency. Microscopic images showed smooth and homogenous appearance with lower Sa and Sq of NE films. More interruption among biopolymer chains by nano droplets caused to the production of the films more extensible than ME films. Thermomechanical analysis confirmed more decrease in glass transition temperature (Tg) and storage modulus (Eʹ). This study introduced a new nano active packaging film with some improved functional characteristics.

Coating of fresh-cut fruits by biopolymer coatings containing bioactive materials are one of the methods and effective ways to prevent undesirable quality changes during storage. Enzymatic browning is an important factor in reducing the shelf-life of freshly squeezed apples, which is due to the release of the enzyme and its contact with the substrate (phenolic matter) through the cutting. Formulation and production of active carboxymethylcellulose-pectin-based active coatings containing citric acid and ascorbic acid and their effectiveness in improving the qualitative characteristics of apple peelings, which have been peeled during storage. In the present study, natural substances found in fruits were used for coatings formulations and a mixture of pectin-carboxy methyl cellulose polysaccharides as based biopolymers and ascorbic acid and citric acid were used as materials inhibited enzymatic browning. Measured tests include determination of weight loss Samples were weighed after 9 days of storage in cold storage. Also, tissue texture determination and determination of tissue firmness using a manual pentometer, soluble solids content (Bx) with refractometer, titreable acidity in malic acid in 100 ml of juice, colorimetry of samples using a device The colorimetric method was evaluated based on Hunterlab's parameters and Photoshop software and Sensory Hedonic test (consumerism) by 10 randomized (from female students 22 to 25 years old) and 5-point method. At first, optimization of active-blend edible coating formulation was investigated by response surface methodology (RSM) based on the minimum a * (red - green) in fresh-cut apples and for this purpose, central composite design with three variables (concentration of carboxymethyl cellulose-pectin, ascorbic acid and citric acid) three replicate and 18 treatments were used. In this way, the coating solution of containing 3.14% carboxymethyl cellulose-pectin, 1.17% ascorbic acid and 1.17% citric acid (%w/v) was determined as best coating solution. Then effects of optimized coating on quality of fresh-cut apples were studied. Although there is no significant difference among coated and uncoated apples after 9 days (P<0.05) but the results of firmness test showed that coated fresh- cut apples maintain initial texture better than control. The acidity values were higher in coated apples compared to un coated apples (0.41 and 0.17, respectively). Coating caused to decrease in overall color change of fresh-cut apples after 9 days. The use of coating resulted to better flavor, texture, color, aroma and appearance acceptability in comparison to the control sample and there is a significant difference at the 5% level between the samples. Comparison of the data on the content of soluble solids in coated and uncoated peelable apples showed that the difference was not significant at 5% level. Hunter's colorimetric parameters were compared to the coated peelable apples and uncoated samples at day 1 and ninth of storage. ∆E in fact, the degree of color difference shows the samples of the ninth day with the first day. The values of ∆E for the coated sample are lower, the values of the color parameters (a, b and L) are less pronounced in the coated sample than in the first day. Edible coatings can delay the progress of this reaction by reducing the contact of oxygen with fruit tissue, as well as the presence of anti-browning agents such as ascorbic acid and citric acid in active coatings, exacerbating the inhibitory effect. Which can reduce the pH and hence decrease the activity of the enzyme in the phenolase and make the copper cofactor chelate. The results of the Hedonic evaluation of peeled apples showed that there was a significant difference in the level of 5% between the final color absorbance of coated samples and uncoated samples. Sensory evaluators significantly increased the scoring of the samples and more accurately recognized it. The results of analysis of variance showed that the final aromas of freshly squeezed apples were affected by the coating and prevented the decrease in aroma. After 9 days of storage, the taste of the coated samples was score higher.

Polystyrene nanocomposites were prepared with varying amounts of nanotitanium dioxide and nanosilver by melt mixing process at 190°C. The nanocomposites structure was characterised by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). The mechanical properties were obtained with tensile test. The influence of nanoparticles on the thermal properties of polystyrene matrix was examined using differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). The results of the SEM showed that both nanoparticles were present in nanocomposite, and the distribution of nanoparticles in the polymer was relatively good, despite the fact that in some places aggregation (with maximum size of 55 nm) were observed. The EDS spectrum showed that the nanocomposite was non-impure and contained three elements of carbon, titanium and silver, and the amount of nanotitanium was about 10 times that of silver. The augment of nanoparticles leading to decrease Young’s modules and stress at break point slightly. But, a point of view yield at break had not seen significantly different (P˃0.05). The investigating of the thermal properties of the samplesshowed they did not differ significantly from the point of view of glass temperature and thermal stability of the polystyrene and nanocomposites.

Thin-layer drying of grapes pretreated with ultrasound and carboxymethyl cellulose (CMC) was investigated in a tunnel dryer at 65°C and 1.5 m/s air velocity. The results showed that with increasing ultrasound treatment time from 10 to 30 minutes, drying time is reduced and the effective moisture diffusivity is increased. Also, with increasing carboxymethyl cellulose concentration from 0.1 to 0.2 percent, drying time increased and from 0.2 to 0.3 percent, drying time decreased. Furthermore, in order to precioucely predict the drying process, data from experiments were fitted by the models such as Newton, Page, Henderson and Pabis, logarithmic, Midili, Wang and Singh, Seiiedlou and Aghbashlou and as well some new proposed models in this study. Multiple regression analysis was used to find the relations between the coefficients of the models with the defined variables. Thereafter, one of the proposed models was selected as the best model to describe the drying process of grapes under the selected experimental conditions.

The present study used a constant level of citric acid and polyvinyl alcohol and different amounts of nanocrystalline cellulose (CNC) and TiO2 nanoparticles to improve the properties of starch film. The effect of different amounts of glycerol was also examined. The results of differential scanning colorimetry demonstrated that the addition of CNC increased the melting and glass transition temperatures and the addition of high levels of TiO2 decreased the melting temperature and increased the glass transition temperature. The effects of these three compounds on the hydrophobicity and color of bionanocomposite plasticized starch were studied and their optimum values determined using a central composite design in response surface methodology. Water uptake data showed that the quadratic effect of TiO2 concentration and the linear and quadratic effects of CNC and GLY concentrations were significant. The optimum levels for TiO2, CNC and GLY for minimum water uptake were 0.118, 0.3 g and 1.36 ml, respectively. Quadratic CNC concentrations and linear glycerol concentrations were significant for water solubility. The optimum levels of TiO2, CNC and GLY for minimum water solubility were 0.235, 0.30 g and 1.36 ml, respectively. The CNC concentration had linear and quadratic effects on the yellowness index (YI) of the bionanocomposite. There was a significant interaction between TiO2 and GLY. The optimum levels of TiO2, CNC and GLY for minimum YI were as 0.235, 0 g and 1.06 ml, respectively.

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.

Starch-based biopolymer films have disadvantages such as poor mechanical and barrier properties against water vapour that restrict their application in packaging. To improve the properties of starch-based films, different methods such as blending with other polymers and adding nanofillers have been suggested. Cellulose nanocrystals (NCC) are a suitable candidate for reinforcing starch biopolymers due to their biodegradability, nontoxicity, abundance in nature, low price, and renewability. The objectives of the current research were to investigate the effects of NCC and polyvinyl alcohol (PVA) on the properties of starch-based films to improve their mechanical and barrier properties.

NCC was produced from cotton linter and added to the starch-PVA film-forming blend. Tests used to determine the properties of the films thus produced included mechanical, water- vapour permeability, thermal property, X-ray diffraction (XRD), and transmittance electron microscopy (TEM) tests.

Addition of PVA and NCC to film-forming solutions caused an increase in the maximum tensile stress (UTS) and a decrease in water-vapour permeability and solubility of the nanobiocomposit films. In addition, the XRD test showed that the 2 components − polymer matrix and nanofiller – were well dispersed in the blend. The optimum structure was observed at a concentration of 10% NCC.

Polyvinyl alcohol has OH groups and, hence, it can form hydrogen bonds with the starch OH groups, resulting in enhanced mechanical strength of polymer and improved mechanical and barrier properties of the biocomposite produced. Due to their high crystalline structure (as a result, high rigidity and elastic modulus) and their ability to form strong hydrogen bonds with starch and PVA, cellulose nanocrystals can potentially improve the mechanical and barrier properties of starch-based bionanicomposite films. The starch-based nanocomposites showed the highest UTS at a concentration of 10% NCC. At higher concentrations the UTS decreased, which could be attributed to aggregation of NCC in the polymer matrix. Aggregation of NCC at a level of 15% or 20% was observed as shown by XRD pattern peaks.

Tofu (soybean curd) is one of the most important soya protein products. It has a low-energy content and is a very suitable replacer for cheese and meat for persons who are sensitive to lactose, cholesterol and saturated fatty acids contained in these animal products. In this research, the effects of a hydrocolloid, namely, carrageenan, at a concentration of 0.1% and 0.2% (w/w of soya milk) and two coagulants, namely, glucono-Delta-lactone (GDL) and calcium chloride (CaCl2), on the quality characteristics of Tofu were investigated.

Soya milk, carageenan and the 2 coagulants, GDL and CaCl2, were used in the formulation of Tofu. Soya milk samples were heated at 100C and then carageenan and coagulants were added and mixed to obtain soya curd. This was followed by removing the serum phase of the soya curd specimens and measuring the quality parameters (yield, color, texture and sensory properties) of the final product..

Addition of carageenan brought about increases in the yield, lightness (L*- hunter parameter), softness and flexibility of the Tofu produced by using GDL and CaCl2. The CaCl2-Tofu specimens showed more hardness (fracture force) than the GDL-Tofu samples. The results of sensory evaluation showed that addition of carageenan caused decreases in hardness and elasticity and increases in freshness and moisture of the samples, the effects being more pronounced in the GDL-Tofu specimens.

The types and amounts of hydrocolloids and coagulants, as well as interaction between them, in making Tofu can have important effects on its yield and quality parameters. In this study, carageenan (at a level of 0.1%) and GDL showed the best results.