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In this study, the antimicrobial effect of Citrus aurantium essential oil on Bacillus cereus, Listeria innocua, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi and Candida albicans was evaluated. The chemical compounds, total phenol content, total flavonoids content and antioxidant potential of Citrus aurantium essential oil were determined. The results of phytochemical analysis (Ferric chloride and Shinoda) showed that, phenol, flavonoids and flavone demonstrated the presence in Citrus aurantium essential oil. Based on gas chromatography–mass spectrometry results 19 compounds identified in Citrus aurantium essential oil. Linalool (21.29 %) was the major compound in Citrus aurantium essential oil. The total phenolic content and total flavonoids content of Citrus aurantium essential oil were equal to 41.35 ± 0.46 mg GAE/g DM and 2.98 ±0.50 mg QE/g DM, respectively. The antioxidant potential based on radical Scavenging and β-carotene linoleic acid of Citrus aurantium essential oil were equal to 102.85 ± 0.60 μg/ml and 65.60% respectively. The longest and the shortest diameters of the inhibition zone at the concentration of 45 mg/ml pertained to, Listeria innocua (16.50 ±0.66 mm) and Salmonella typhi (9.80 ±0.43 mm), respectively. The minimum inhibitory concentration of the Citrus aurantium essential oil ranged from 3.125 mg/ml to 100 mg/ml, while its minimum bactericidal/fungicidal concentration ranged from 3.125 mg/ml to 200. Based on the present research, the essential oil Citrus aurantium antioxidant potential and antimicrobial activity on several food-borne pathogens tested and thus can be a good source of food industrial.

 

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     The objective of this study was to extract the essential oil of purple basil leaf, to identify its compounds and to investigate its antimicrobial effects on some food-borne pathogenic bacteria through different qualitative and quantitative methods, and eventually, to compare it with some antibiotics including vancomycin and gentamycin in vitro. The essential oil components were identified with GC/MS. The antimicrobial effect of basil essential oil was measured through well diffusion agar (WDA), and finally, the minimum inhibitory concentration (MIC) of the essential oil was determined using microdilution broth and triphenyl tetrazolium chloride. The results revealed that 28 identified compounds constituted 99.28% of the whole essential oil compounds. p-Allylanisole (51.64%) was the most abundant component of the essential oil. In addition, other main components such as n-Tricosane (24.83%) and Linalool (14.81%). In the wall in agar method, the mean free zone diameter was equal to 15.9 mm in the case of Gram-positive bacteria and 11.15 mm in the case of Gram-negative ones. The minimum MIC of purple basil essential oil ranged from 4.6 to 36.8 mg/ml in the case of pathogenic bacteria. Moreover, its minimum bactericidal concentration varied from 4.6 to 73.6. in conclusion, it can be said that purple basil essential oil was effective on Gram-positive bacteria at lower concentrations and could inhibit their growth.

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Fermentation is one of the oldest techniques in food preservation, this process is defined as the biological activity of microorganisms to improve sensory, organoleptic and nutritional properties and produce a range of metabolites that inhibit the growth of unwanted microbial flora. As a result, fermented products have a shelf life substantially higher than raw materials and also have very beneficial effects on health. In this research, ginger in 4 and 8 % levels  and yogurt whey in 0 and 3 % levels, were added to the carrots and evaluated during of 0,4, 8, 16, 24 and 32 days of fermentation. The results showed that by adding 4% ginger, pH, mold and yeast count and L* index decreased, acidity, total count, lactic acid count, a* and b* color indexes and overall acceptance increased. In contrast, the addition of 8% ginger had a negative effect on the studied parameters and decreased the overall acceptance and enumeration of lactic acid bacteria. Addition of yogurt (3%) decreased pH, mold and yeast count and L* index, but increased acidity, total count also color indices a* and b* and overall acceptance. In the non-yogurt and non-ginger sample from the beginning to the end of the storage period, pH, total count and mold and yeast counts increased steadily, and overall acidity and acceptance decreased. Whereas in the samples containing ginger and yogurt, the pH and count of mold and yeast decreased as the fermentation time increased to the 16th day and overall count increased, lactic acid bacteria, acidity and total acceptance. According to the results of this study, using 4% ginger, 3% yogurt and 16 days fermentation time to increase shelf life and lactic acid bacteria and improve the sensory characteristics of fermented carrots.

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Gamma Aminobutyric Acid (GABA) is a bioactive molecule with different physiological roles in the body that inhibits neuronal stimulation and inhibits the delivery of stress-containing messages, has a calming effect and is used to treat diseases. Different has an effective role. In the present study, the possibility of producing this amino acid by Lactococcus lactis NZ1330 was investigated. In order to optimize the fermentation process three levels of dairy sludge (5,10,15%), monosodium glutamate (0, 0.5 and 1%) were selected at 24, 48 and 72 hours after fermentation. The presence of GABA in the culture medium was investigated by thin layer chromatography. Spectrophotometric method was used to quantify the bands present in thin-layer chromatography. Optimization results at 95% significance level showed that the optimum treatment consisted of medium containing 11.2% dairy sludge, 0.7% monosodium glutamate and 70 hours fermentation at 32 ° C and under these conditions, GABA production was ppm. It's 400. Therefore, this combination of media can be used as a suitable substrate for the production of valuable GABA drug and bioactive compounds

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Cold plasma is a dry, non-thermal technology with no chemicals capable of working continuously at atmospheric pressur. In the present study, plasma discharge of atmospheric pressure dielectric barrier with gases (air, nitrogen, and argon) was applied to the plasma for (0,5,15,25) min at the surface of curcuma longa samples to reduce total microbial, coliform, yeast and mold, Clostridium perfringens was performed. Results of microbial tests showed that irradiation of plasma with nitrogen gas for 15 minutes reduced curcuma longa microbial load with minimal effect on physicochemical properties.Control samples lacked coliform and Clostridium perfringens. The results of physicochemical properties of the samples (color and antioxidant activity) showed that the effect of gas type on any of the curcuma longa color indices was not significant, while with increasing plasma duration the mean of all three color indices decreased, which decreased in There were significant differences between 15 and 25 minutes.(p<0.05). nvestigation of the effect of gas type and duration of plasma application on the inhibitory index of curcuma longa samples showed that the type of gas used had no effect on this index(p>0.05), while the effect of time was significant for this index and their antioxidant properties compared to the control sample Decreased(p<0.05). The results of sensory characteristics (color, odor, appearance and taste) of the samples showed that the type of gas used did not differ significantly on the sensory parameters of the samples, while with increasing plasma duration the mean values ( Except for the taste index of the samples which decreased significantly between 15 and 25 minutes(p<0.05). In general, cold plasma is a novel method of food processing that, given its non-thermal nature, can be a good alternative to other methods used for food sterilization and pasteurization.

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Ostrich fillets is highly edible and one of most healthy and the least fat red meat samples. Due to carcass contamination along the slaughter chain, it becomes corrupted by the growth of meat microorganisms during storage. Being biodegradable, edible and efficient have caused edible films to be widely investigated and used as a good replacement for synthetic materials in packaging of food products. In this study a gelatin/frankincense (G/F) bilayer film was produced from gelatin and frankincense monolayers using the casting method in two phases. This research investigated antimicrobial activity of various concentrations of acid ascorbic (0, 1%,2%) and Hyssopus officinalis oil (0, 0.75%, 1.5%) in edible bilayer gelatin/frankincense against S.aureus, B.cereus, E.coli and P.aeroginosa. on the other hand, effect of edible film was evaluated on microbial and chemical properties of ostrich meat for 12 day at refrigerator temperature. Diameter of inhibition zone showed that S.aureus and P.aeroginosa were most sensitive and resistant bacteria respectively. Compared with control sample, two treatments (G/F+2%AA+0.75%HO and G/F+2%AA+1.5%HO) decreased total viable count, psychrophilic and lactic acid bacteria significantly (p<0.05). The result also showed with addition Hyssop oil and ascorbic acid, pH and peroxide values notably reduced compared with pure edible film (without oil and acid)( (p<0.05). The gelatin/frankincense films enriched with essential oil and vitamin C delayed tissue breakdown, and increases the pH by reducing the bacterial growth. Therefore, antimicrobial edible film containing Hyssop oil and vitamin C as an economical and biodegradable coating has a good potential for increasing the shelf-life of ostrich meat at the refrigerator temperature.

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Wheat is one of the most important food products around the world. That's why there is a need to produce it all year round. The process of reaching the new wheat during the storage period will bring about changes that will improve its characteristics. The effect of time storage wheat for 90 days (0, 45 and 90) at the Temperature 30 ° C and relative humidity 45% on the chemical and rheological properties flour by farinograph test were analyzed. A completely randomized design was used to perform the tests. The comparison of the averages was done by Duncan’s multiple-range test at a probability level of 95%. The results of this study showed that wheat dormancy for 90 days increased wheat quality indices such as gluten index and Zeleny sedimentation volume, but pH decreased and acidity increased (p <0.05) . Percentage of gluten, moisture and ash did not change significantly during storage. storage time was effective on enzymatic activity, so that the activity of α-amylase decreased significantly (p <0.05) . Wheat also held significant improvement in the farinograph dough properties such as Water Absorption, Dough Stability, Degree of Softening and Farinograph Quality Number (FQN).
According To improve properties quality and rheological flour, freshly harvested grain storage for 90 days is suggested.

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Gamma-aminobutyric acid (GABA) is a non-protein amino acid existing in bacteria, plants, and vertebrates. GABA is especially well-known because of its physiological role in the neurotransmission, induction of hypotension, diuresis, and tranquility. GABA is biologically synthesized by GABA-producing lactic acid bacteria (GLAB) which are widely used as starters in the fermented foods. In this study, GABA-producing strain were chosen to be microencapsulated by soy protein isolate (SPI)-alginate using emulsion method. Encapsulation efficiency and entrapment of GLAB into soy protein-alginate microcapsules (SAE) was confirmed by scanning electron microscope. The GABA-producing ability and survivability of the microencapsulated GLABs were investigated in the human gastro-intestinal simulant. For screening of GLAB strains, the isolates from Tarkhineh and fermented carrot were separately cultivated in MRS broth supplemented with 1% (w/v) monosodium glutamate (MSG). The GABA production efficiency was studied by thin layer chromatography (TLC) and High performance liquid chromatography (HPLC). According to the recorded chromatograms, Lactobacillus brevis PML1 isolated from Tarkhineh and Lactobacillus brevis G42 from fermented carrot showed GABA producing ability of 304 mg/L and 2511 mg/L, after 30 h at 30 °C, respectively. The results indicated that survival and GABA production improved upon microencapsulating the bacteria due to the good cell protection provided by soy protein isolate-alginate coating. In long with previous reports, this study proves the potential of microencapsulation toward increased efficiency of GABA production in functional foods.
 

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The impact of a_w (0.65-0.9), temperature (15-30°C) and their interaction on the germination and radius growth of Aspergillus fumigatus isolated from cake was surveyed on Yeast Extract Glucose Chloramphenicol Agar (YGC-Agar) during 60 days as well as the capabilities of Gompertz and Logistic models for fitting data were explored. Rising a_w (from 0.65 to 0.9) and temperature (from 15 to 25°C) caused significant enhancing of germination and growth rate of A. fumigatus (P < 0.05). However, in constant a_ws, further increasing of temperature (up to 30°C) led to meaningful decreasing of these parameters (P < 0.05). A. fumigatus did not germinate at a_w 0.65. In addition, germination was observed at a_w 0.7 and 0.75 only when the temperature was 15 and 25°C while the mycelium growth was not occurred at these conditions. Although the germination rate was relatively high at a_w 0.8, the mycelium growth was very limited. The most amount of germination and radius growth was for a_w 0.85 -0.9 and temperature 15-25°C (P < 0.05). Consequently, the optimum growth of A. fumigatus was seen at a_w 0.9 and temperature 25°C and the best shelf life of cake proved at a_w < 0.7. Furthermore, fitting the growth curves demonstrated the more accuracy of Logistic model rather than Gomperts model.

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Mechanical injuries in to the tissue of ready-to-eat fresh-cut ​​lettuce usually cause stresses which leads to increasing respiration rate. The shelf life of this product depends on the processing and packaging steps, the type of packaging film and the environmental conditions during storage. The purpose of this study was to evaluate the effect of storage time, storage temperature, immersion pretreatment and the number of perforations of packing film on the crispness coefficient and sensory evaluation (total acceptance) of fresh-cut packaged lettuce stored under modified atmospheric condition and also development of shelf-life kinetic model of this product. For this purpose, 250 g of the lettuce strips were washed and immersed into two different concentrations (1.5/0.5 and 1.5/0.1) of CaL/Cys, then packed and sealed in low-density polyethylene packaging films (LDPE, 42 μm thickness) with no perforation (N-MAP: 21% O2, 0% CO2) and 20 and 40 perforations per m², respectively. The study was carried out at two temperatures of 5 and 10 °C, for a storage time of 12 days. Indices of quality maintenance, i.e., crispness coefficient and sensory evaluation (total acceptance) were investigated. Furthermore, a mathematical model was developed to describe the kinetics of changes in crispness coefficient and sensory evaluation. Then, the shelf life of the samples was predicted based on sensory evaluation. The results showed that changes in selected targeted parameters could be best described by a zero-order. The prediction of shelf life of fresh-cut lettuce samples showed that samples treated with 1.5%CaL/0.1% Cys packed in 20-PM-MAP, stored at 5°C and 10 °C and samples treated with 1.5%CaL/0.5% Cys packed in 20-PM-MAP stored at 5°C, had a shelf life of 12.62, 12.59 and 11.59 days (with no significant difference at p < 0.05), respectively.
 

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Microbial quality of raw milk is very important in two respects. First, milk consumption itself plays a very significant role in people's food tables and its high microbial load endangers consumer health. Second, if the microbial quality of milk is not suitable, from a technology point of view, milk-derived products will not have a good quality. In this project, which has been carried out in collaboration with Pegah Golestan Company, the separation process (with separators) and double bactofugation was used to reduce microbial load with the aim of reducing milk heating (in order to reduce the nutritional value as a result of heat). Milk samples used for lactic cheese production in Golestan province were examined in 2020 and 2021. After the process, total microbial counting, aerobic and anaerobic spores were counted. The results showed that by using this method, the total microbial load, aerobic and anaerobic spores of the collected milks were reduced to an acceptable level throughout the year without decreasing the microbial quality of the produced cheese during the storage period. On the other hand, the process of separation and bactofugation produces dairy sludge. Normally, dairy sludge is removed every 20 minutes, which was performed in separator and bactofuge1 to 21 minutes to reduce dairy sludge.

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L-glutamate is one of the most abundant amino acids in the body, which plays an important role in various cellular processes and also acts as a precursor of bioactive molecules, which has received much attention due to its medicinal and food applications today, and as an important amino acid. Industrial is produced commercially. L-glutamate is one of the metabolites produced by these bacteria, which is also biologically active. In this research, the production of L-glutamate by three autochthonous lactic acid bacteria (Lactobacillus brevis PML1, Lactobacillus plantarum 1058 and Lactobacillus fermentum 4-17) at three percentage levels of dairy sludge (0, 10, 20%), three levels of soybean meal (0, 2.5, 5%) and three levels of fermentation time (48, 84, 120 hr) were optimized using RSM. TLC was used for qualitative evaluation and HPLC was used for quantitative estimation of L-glutamate production, and then the antimicrobial and antioxidant properties of the fermentation extract were evaluated and compared with the control sample.
 

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Today various sweeteners are competing with sucrose in food market. They are creating acceptable sweetness and preserving technological and sensory properties of the product. In this study enzymatic sorghum malt use as sucrose replacer in gluten-free rice cake production. For this purpose, moisture, specific volume, porosity, crust color values, firmness and sensory properties were evaluated. The results showed that with increasing substitution of sucrose by enzymatic sorghum malt, moisture content and a* increased. However, falling the moisture content in sample containing malt flour were lower than control during the storage (1week) was with the lapse of time a week after bake a cake, malt flour contains less moisture loss in samples from the control samples. The results also showed enzymatic sorghum malt increased the softness of texture and able to prevent hardening of the texture during storage. In addition, the results indicated that the sample that 40% sucrose had been replaced with malt flour had the highest porosity, specific volume and L* value. Also this sample was equal in sweetness to control and the judges taste the sample was superior in other features. Thus, according to the results we can say that an enzymatic sorghum malt can be used as a natural sweetener, especially in celiac disease is needed products.
 

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Recently, special attention has been paid to enterococci for use as probiotics in dairy products. All these desirable features are a stimulus for the producers of dairy products to use enterococci isolated from dairy products such as Liqvan cheese. Despite having all these features, enterococci are not recognized as GRAS and their presence in food products is a sign of fecal contamination. The purpose of this research is to investigate enterococci isolated from Liqvan and Koze cheese in terms of having pathogenic indicators in order to confirm that they are safe for consumers and finally to investigate the possibility of using them as starters or starter aids in dairy products. Especially cheeses. Based on this, 57 isolates of Enterococcus faecium from traditional Iranian cheeses were examined for the presence of pathogenic genes, and finally 23 isolates did not have any pathogenic genes. Then the technological properties of these isolates such as acidification, proteolytic, lipolytic, autolytic, heat and acid resistance and exopolysaccharide production were investigated. The results showed that among the 23 investigated strains, 19 isolates had antimicrobial activity against pathogenic bacteria, 16 strains were able to produce exopolysaccharide and 20 isolates had moderate acidification properties. The highest proteolytic and lipolytic activity was related to strains c18 and c16, respectively, and strain LR78 showed the highest acid and heat resistance.

 

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Tooth decay is one of the most common problems in the world, which is caused by the growth of biofilm and acid production by them. Many solutions have been used to solve this problem. However, due to the increase in antibiotic resistance of microorganisms and the increasing need for antimicrobial substances, efforts are being made to use natural antimicrobial substances. Lactoferrin is a protein in milk and saliva with antimicrobial and anti-biofilm properties. In this research, lactoferrin was encapsulated by nanoliposomes to increase its antimicrobial properties. In order to measure the effect of lactoferrin on the number of bacteria in the polymicrobial biofilm and acid production, each of the free substances or nanoliposomes in 4 concentrations (0, 1.5, 3, 6 mg/ml) in the Active Attachment biofilm model with saliva and culture medium was incubated.
The results showed that lactoferrin nanocoating increased the ability to inhibit biofilm and acid production by this bacterium due to the slow release of lactoferrin from liposomes. When increasing the concentration of free and nanoliposomal lactoferrin to a concentration of 3 mg/ml, a significant decrease in the number of bacteria in the biofilm was observed compared to the control sample (P<0.01). However, increasing the concentration of free lactoferrin again increased the number of bacteria in the biofilm. Meanwhile, nanoliposomal lactoferrin at a concentration of 6 mg/ml still caused a decrease in bacteria in the biofilm, which was insignificant compared to the concentration of 3 mg/ml (P>0.01). From the obtained results, it can be concluded that nanoliposomal lactoferrin can be used to design products related to oral and dental health.
 

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Dairy sludge is one of the main and inexpensive wastes of the dairy industry, which contains the nutrients necessary for the growth of lactic acid bacteria (LAB) to produce microbial metabolites, and for its efficient use, optimization of fermentation conditions is critical. In order to optimize the production of dry biomass, three independent variables of dairy sludge concentration (5, 12.5 and 20%), pH (6, 7 and 8) and the inoculation rate of Lactobacillus fermentum strain 4-17 (1, 3 and 5%) were used. Before fermentation, the cell growth and morphology of this bacterium were examined in order to determine the function of the growth rate and confirm the presence of bacteria in this medium. The independent variables were optimized using response surface method (RSM) with central composite design (CCD) in order to maximize dry biomass production by this bacterium. The optimization results showed that the maximum amount of dry biomass production related to the optimal treatment included 20% dairy sludge concentration, 1% inoculation rate and pH 8. Also, according to the results, the dairy sludge substrate is suitable for the fermentation of this bacterium. As a result, the effect of dairy sludge bed concentration and pH on dry biomass production by this bacteria was very significant.

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Dairy factories produce high volume of sludge from bactofuge and separator. Meantime, global demand for the proteases is increasing. Recently, utilization and conversion of the waste materials into value added product is a sustainable process. The objective of this study was to investigate the potential of bactofuge and separator sludge to produce alkaline protease enzymes. Total viable aerobic and anaerobic counts were determined on Plate Count Agar at 37 and 50^ºC for both types of sludge. Lactobacillus count in MRS Agar plates corresponded to 3.12±0.25 log CFU mL^-1 for sludge of bactofuge and 3.085±0.2 log CFU mL^-1 for sludge of separator. Mold and yeast had population levels of 2.3±0.1 log CFU mL^-1 for bactofuge and 2.08±0.1 log CFU mL^-1 for separator. Proteolytic bacteria were isolated from dairy sludge using Skim Milk Agar media. A clear zone of Skim Milk hydrolysis indicated protease-producing organisms. Different cultural parameters (temperature, pH, thermal shock, and kind of sludge) were optimized for maximal enzyme production. Maximum proteolytic activity was observed at 37^◦C (P< 0.05). Isolated alkaline protease producing Bacilli were identified by Polymerase Chain Reaction (PCR). The species were identified as Bacillus cereus strain zk2, Bacillus sp. cp-h71, Bacillus thuringiensis strain ILBB224, and Bacillus sp. Bac6D₂.
 

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Escherichia coli and Staphylococcus aureus are pathogens that have the ability to form biofilms and cause disease in food products. Due to the fact that the enterotoxins produced by these two pathogens remain in a wide range of temperature, pH and saline conditions, they cause severe infections in humans. Melittin is a natural peptide derived from bee venom that can show its antimicrobial and anti-biofilm potential through disrupting the membrane of bacterial cells. For this purpose, in this study, the antimicrobial effect of this peptide on Gram positive and negative bacteria was investigated and its minimum inhibitory concentration (MIC) was determined as 100 µg/mL and 300 µg/mL, respectively. Also, the scanning electron microscope images confirmed the antimicrobial effect of the peptide on these two bacteria. Peptide melittin caused wrinkling, deformation and creation of holes in the cell membrane of treated bacteria, compared to the control sample. On the other hand, the results of the biofilm inhibition test showed that the addition of the peptide at a concentration of 2MIC completely prevented the biofilm formation of S. aureus prevented, while this value was equal to 91.00 ± 2.82 in E. coli bacteria. Also, the increase in peptide concentration caused an increase in the destruction of adult biofilms of both bacteria. On the other hand, this peptide decreased the invasion and adhesion of these two bacteria to HT-29 and Caco-2 cells by reducing the mobility of pathogens. Therefore, according to the obtained results, melittin peptide can be a suitable alternative to chemical disinfectants that are harmful to the environment.