Evaluation of Anti-Fungal Activity of Chitosan and Its Effect on the Moisture Absorption and Organoleptic Characteristics of Pistachio Nuts

Pistachio is one of the main export products of Iran and Iran is one of the largest producer and exporter of pistachio in the world. Unfavourable environmental conditions during storage, causes a sharp drop in quality of product through musty and toxin production, especially aflatoxin by Aspergillus flavus and Aspergillus parasiticus, Absorption of foreign odors and moisture, Tissue destruction of undesirable flavour. The aim of this study was to study the anti-fungal activity of chitosan and its effect on the organoleptic characteristics of pistachio nuts.  Therefore, using acetic acid 1% V / V, chitosan concentrations of 0.5%, 1% and 1.5 % V/W was prepared and pistachios were coated by these solutions. Also acetic acid at concentration 1% without chitosan was used as a treatment for coating to determine the antimicrobial effect of acetic acid. The results showed that chitosan significantly (p <0.05) inhibited the growth of the Aspergillus and its effect was increased with increased concentration. Chitosan also prevented moisture absorption and weight change in pistachio nuts, while chitosan concentration showed no significant effect on moisture absorption and weight change of pistachio nuts. Chitosan 1.5% had a significant effect (p <0.05) on the flavour of pistachio, but other concentrations had no effect. However, chitosan in general had no significant effect (p <0.05) on color, texture and acceptability of pistachio nuts

Influence of Selected Packaging Materials on Quality Aspects of High Pressure Processed Boccoli Puree

In the present study, role of packaging properties on pressure and thermal processed broccoli puree quality were investigated. Samples were packaged in two multilayer packaging pouches (PET/PA/LLLDPE and BOPP/LLDPE). Packaging type significantly influenced the product colour. PET/PA/LLLDPE package best preserved broccoli puree quality. Thermal processes at both intensity levels, had a significant effect on quality properties of broccoli puree. Tensile strength of both packaging materials were improved by severe HP and thermal pasteurization. The shape of endothermic heating curves of both packaging materials as well as Tg value of BOPP/LLDPE, compromised by conventional thermal treatments. High pressure processing at 600 MPa (holding time: 10 min/initial temperature: 10 °C) improved the colour (a* and L* values) compared to severe HP pasteurization and thermal pasteurization processes. Both packaging materials resulted in inactivation of the inoculated Listeria innocua to a level below the detection limit at HP and thermally processed broccoli pure. Keywords: Packaging material, Broccoli, Puree, Thermal processing, High pressure processing, Barrier propertie

The Combined Effect of Carum copticum (Ajwain) and Foeniculum vulgare (Fennel) Essential Oils on Escherichia coli and Clostridium sporogenes Using Checkerboard Assay

Increasing awareness of the adverse effects of chemical preservatives on health has led to an increased tendency to use natural preservatives, especially herbal essential oils in pharmaceutical and food products. Carum copticum (Ajwain) and Foeniculum vulgare (Fennel) are among the aromatic medicinal plants that can be used in this regard. In this study, the agar diffusion method was used to evaluate and compare the antimicrobial effects of the herbal essential oils in question and the dilution method in the liquid medium was also used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The checkerboard assay was used to evaluate the interaction between the herbal essential oils of Ajwain and Fennel and to determine the fractional inhibitory concentration. The results showed that the MIC of Ajwain and Fennel herbal essential oils against Escherichia coli was 1562.5 μg/ml and 12500 μg/ml, respectively, and in the case of Clostridium sporogenes this value was 1562.5 μg/ml and 50000 μg /ml, respectively. Calculation of fractional inhibitory concentration (FIC index) indicated that there was no interaction between the herbal essential oils of two plants against both bacteria in question. In general, the absence of synergistic and antagonistic interactions between the Ajwain and Fennel herbal essential oils can be related to the identically-affected sites of these essential oils in Escherichia coli and Clostridium sporogenes. Also, the results obtained through the identification of herbal essential oils composition by GC/MS showed that the main components of Ajwain were Thymol (49.96%), p-cymane (22.73%) and γ-Terpinene (15.32%) and in case of Fennel these components were Trans-anethole (63.88%), Estragole (9.97%), limonene (7.65%) and fenchone (5.72%)

Novel Kefiran-Polyvinyl Alcohol Composite Film: Physical, Mechanical and Rheological Properties

Background and Objectives: Kefiran (Kef) is a water-soluble polysaccharide that can form transparent film; however, it is brittle. Therefore, in order to improve the mechanical properties of kefiran film, a mixture with other polymers can be offered. The expansion of mixed systems can propose kefiran and polyvinyl alcohol (PVOH) as a new composite film. Materials and Methods: Solutions of 20 gram per liter kef and 40 gram per liter of PVOH were prepared. A mixture of film-forming solutions of different ratios of Kef/PVOH (100/0, 68/32, 50/50, 32/68) was prepared. In this study, different experiments including the physical properties (thickness, moisture content, and film solubility in water), water vapor permeability, and mechanical properties (tensile strength, elongation at break, puncture strength, and puncture deformation) of composite films as well as the rheological properties of film forming solutions were investigated. Results: The results of physical properties such as thickness, moisture content, solubility in water and mechanical properties such as tensile strength, elongation at break, puncture deformation, puncture strength and water vapor permeability indicated that the mechanical properties, thickness and solubility in water increase with increase in PVOH content; however, moisture content and water vapor permeability decrease. Rheological characterization of different film forming solutions exhibited Newtonian fluid behavior. Conclusions: These results contribute to the establishment of an approach to optimize films’ composition based on the interactions between polymers, aiming at improving the properties of polysaccharide-based films. Keywords: Kefiran, Polyvinyl alcohol, Physical properties, Mechanical properties, Rheological propertie

Effect of active lipid‐based coating incorporated with nanoclay and orange peel essential oil on physicochemical properties of Citrus sinensis

The aim of this study was to evaluate the different lipid‐based coating on the physicochemical properties and shelf life of blood orange. In this study, four different carnauba wax coatings formula were used: carnauba wax, carnauba wax incorporated with orange peel essential oil (OPEO) (1%), carnauba wax with montmorillonite nanoclay (MMT) (2%), and carnauba wax combination by OPEO (0.5%) and MMT (1%). Physicochemical properties (total phenol content, antioxidant activity, °Brix, titratable acidity, vitamin C, color, firmness, and pH) of fruits were determined throughout the storage. According to the results, carnauba wax with MMT was better than the other treatments. The highest antioxidant activity was observed in carnauba wax coating containing MMT and total phenol and DDPH gained 733.00 ± 1.204 (mg gallic acid/100 g) and 78.327 ± 0/364%, respectively, at 100th day. Blood orange coated by carnauba wax with MMT had the least of deformation and dissolved solid and the highest acidity rather than other treatments. Moreover, time storage and coating had significant effect on vitamin C content in which maximum and minimum amount was observed in wax coating incorporated by MMT and combination with MMT and OPEO treatments, respectively. Fruits coating with MMT showed better brightness

Reproductive biology of the jellyfish (<i>Chrysaora</i> sp.) in the north-western coastal waters of Malaysia (Penang Island)

822-829Based on histological, microscopic and macroscopic observations, the highest gonadosomatic index (GSI) value for both sexes of Chrysaora sp. was found to be in July. Female GSI value of Chrysaora sp. was higher than male. Furthermore, this species showed an asynchronous pattern of reproduction. Spawning and the peak of the reproductive seasons were in July. Maturation in Chrysaora consisted of four stages (pre vitellogenic, early vitellogenic, mid vitellogenic and late vitellogenic) in female and three stages (spermatogonia, spermatocytes, and spermatids) in male

In Vitro Biocontrol of Escherichia coli Through the Immobilization of its Specific Lytic Bacteriophage on Cellulose Acetate Biodegradable Film

Background and Aims: Bacteriophages are mandatory bacterial parasites that are harmless to human and animal, which are used by dipping or spraying in food as natural antimicrobial agents. The use of these methods leads to wasting or trapping of phage in food, but its immobilization on the polymer surface facilitates the contact of phage with the host cell at the food surface. Therefore, the aim of this study was to immobilize the lytic phage of Escherichia coli on the cellulose acetate film and investigate of its antimicrobial effect. Materials and Methods: Escherichia.coli bacteria was incubated at 37°C for 24 hours, and the antimicrobial effect of phages was evaluated through plaque forming. The cellulose acetate film was prepared by casting, then modificated by plasma, and immersed in a suspension of phage (1010 PFU/ml) and incubated at 37 °C for 24 hours with slow shaking, then the number of immobilized phages was estimated. To confirm the immobilization, FESEM was done. The antimicrobial effect of the active film was evaluated by disk diffusion and the release rate and antimicrobial activity of immobilized phages were investigated in 14 days. Results: Phages formed clear plaques against E.coli. Modification of film by plasma resulted in uniform immobilization (108 PFU/ml) that FESEM revealed it. The active film (with zone diameter 12 mm) showed stronger antimicrobial effect than the antibiotic ampicillin (positive control sample with zone diameter 8 mm). 11 days after the immobilization, the number of immobilized phages decreased from 108 to 106 (PFU/ml) and released from the film surface, afterwards did not release. The antimicrobial activity of active film was decreased due to the absence of host bacteria continuously in 15 days, so that the host bacteria population increased from 3 to 5.3 LOG CFU/ml.  Conclusions: In spite of reducing the antimicrobial activity of cellulose acetate active film over the time, due to the presence of host bacteria at food surface and its high potential in destroying the host bacteria, it can be used to increase of food safety in food packaging

Investigation on the Changes in Color Parameters and Turbidity of Cornelian Cherry (cornus mass L) Produced by Microwave and Conventional Heating

Background and Objectives: Red colored fruits such as cornelian cherry (Cornus mas L) are recognized as being healthy. The color of these fruits is an important sensory property in assessment of product quality therefore, minimizing the loss of color in the process is very important. Materials and Methods: In this study, comparison of the color, turbidity, degradation rate of anthocyanin, and rate of evaporation in cornelian cherry (cornus mass L) juice produced from microwave and conventional heating at different operational pressures (12, 38.5 and 100 K Pa) was investigated. Results: The final brix juice 42  was obtained in 137, 125, and 93 min by conventional heating at 100, 38.5 and 12 K Pa, respectively. Applying microwave energy decreased the required times to 115, 90 and 75 min at 100, 38.5 and 12 K Pa, respectively. In both methods, the heating temperature at pressures of 12, 38 and 100 K Pa was 50, 75 and 100 ° C, respectively. The results also showed that hunter lab values (L, a, and b) were decreased with increasing the time of process, turbidity, and degradation rate of anthocyanin. Conclusions: The heating method affects the color, degradation rate of anthocyanins and evaporation rate of cornelian cherry concentrate. Also the results indicated that temperature and time of process are higher in conventional heating than in microwave. Degradation of anthocyanins and color of cornelian cherry juice was more evident in rotary evaporation as compared to microwave heating method. Thus according to the results, microwave energy could be successfully used in production of cornelian cherry juice concentrate

Occurrence of Bacillus cereus in raw milk receiving from UF-Feta Cheese Plants

Background and Objective: Milk and milk products are very suitable medium for growing microorganisms (e.g. Bacillus cereus). B. cereus is spore former bacilli, which easily survives during pasteurization and makes several problems in dairy industries. The aim of this study was to investigate aerobic spore and B. cereus of receiving raw milk from three UF plants. Materials and Methods: Samples were gathered from raw milk transport tankers arrived to plants during 30 days in winter. Also, the swab test was used for detection of B.cereus residual on milk contact surfaces. Results: High contamination level of aerobic spores (AeSC) and especially B.cereus were found in most samples compared with the criteria established by national and international standards. Although total viable count (TVC) in samples from industrial farms (IF) was lower than those from traditional farms (TFs) and milk collection centers (MCCs), considerable AeSC and B.cereus were transmitted to the UF plants from IFs. The highest and lowest TVC and B.cereus were found in samples from IFs and MCCs, respectively. In addition, our investigation in IFs revealed that teats contamination to soil and feces, as well as contaminated bedding might were the most important sources of B. cereus and AeSC of raw milk. Moreover, the results of swab tests confirmed that the “cleaning in place” system may not remove B.cereus effectively. Conclusion: It seems that for classifying raw milk quality, AeSC might be used as a more effective quality factor than TVC. Management commitment is effective to improve quality by balance between the amount and quality of receiving raw milk. This leads to the lower contamination in dairy plants and final products