جستجوی مقالات مرتبط با کلیدواژه « زمان ماندگاری » در نشریات گروه « صنایع غذایی »

Cucumber is an economically important crop, containing vitamins, minerals, antioxidants, and flavonoids. However, due to loss of weight and firmness, microbial contamination, mechanical damage, and yellowing, the storage duration of cucumber is limited to 3–5 days at room temperature. Therefore, pretreatments are crucial for prolonging its shelf life. Chitosan is a cationic polysaccharide and can interact electrostatically with anionic, partially demethylated pectin. Besides, chitosan has inhibitory effects on fungal rot and prevents weight loss in fruits. Pectin can form excellent films. Because of increasing demand to reduce synthetic chemicals as antimicrobial agents, substances derived from plants, such as essential oils, can play a significant role in the future.  Several essential oils and essential oil components have shown antimicrobial activity against spoilage and pathogenic microorganisms during fruit and vegetable storage. Essential oils of thyme and cinnamon contained phenolic groups have been found to be most consistently effective against microorganisms, however, essential oils are volatile and irritant. Therefore, forming an inclusion complex using b-cyclodextrin can improve solubility, control volatile, and induce off-flavors and unpleasant odor of the essential oils. The objectives of this study were to develop the microencapsulated thymol (thyme) and trans-cinnamaldehyde (cinnamon) essential oils to produce antimicrobial agents and subsequently evaluate the effectiveness of edible coating made of chitosan and pectin containing microencapsulated trans-cinnamaldehyde or thymol essential oils to improve qualitative and quantitative characteristics and shelf life of cucumber.

The inclusion complexes of trans-cinnamaldehyde and thymol in beta-cyclodextrin (CD) were prepared separately by freeze-drying. Each essential oil was dispersed in 1000 ml of beta-cyclodextrin aqueous solution (16 mmol/L, 18.15 g) in molecular ratio 1:1 (2.4 gr thymol, 2.11 gr trans-cinnamaldehyde) and mixed in a laboratory stirrer for 24 hour at room temperature , then frozen (-70 ºc) and freeze-dried (<20Pa, 48 h). Lyophilized samples were stored inside a freezer (-20 ºc) until further use. Cucumbers cv. Nagene with uniform size, appearance, ripeness and without mechanical damage or fungal contamination were selected. Then They were then sanitized by immersion in chlorine solution (150 mg/kg) for 1 min and air dried. Edible coatings were prepared as three immersion solutions of chitosan, pectin, and calcium chloride (CaCl2). The fruits were coated with pectin (1%) and chitosan (0-0.5%-1%) containing beta-cyclodextrin microencapsulated trans-Cinnamaldehyde or thymol each (0-0.25%-0.5%). After coating by chitosan, the fruits were immersed in 1% Calcium chloride solution to induce crosslinking reaction. After dipping step, fruits dried for 8 minutes at room temperature to remove the excess solution attached to the surface .Uncoated fruits served as control. Then fruits were preserved in cold storage (temperature: 10ºc; relative humidity: 90-95%) for 15 days. chemical (total soluble solids, titratable acidity) and physical (total color difference, Hardness, and weight loss) Characterization of fruits were measured immediately after harvest and after 5, 10 and15 days. Microbial tests (total count, mold, and yeast) were done at the end of preservation time. Analytical data were subjected to analysis of variance and factorial adopted completely randomized design and a Duncan comparison test was used. 

The results showed that weight loss, total soluble solids, and the total color difference increased and hardness and titratable acidity decreased gradually in all samples during cold storage (<0.05). Chitosan and essential oils slowed down this rising or decreasing trends. Interactive effects of chitosan, essential oil type, essential oil concentration, and storage time had positive effects on these quality attributes. The fruits coated with the highest concentration of chitosan (1%) and thymol (0.5%) essential oils showed the least weight loss, loss of hardness, and color change throughout 15 days of storage. Besides thymol in comparison with trans-Cinnamaldehyde was more efficient to prevent yeasts and molds on the surface of cucumber. By increasing chitosan and essential oil amounts, the ability of inhibiting microbial growth by coating is enhanced. 

The results of chemical, physical and microbial tests, showed that multi-layer coating solution containing chitosan 1% with thymol 0.5% was effective in extending the shelf life of cucumber. The combined usage of microencapsulated thymol essential oil and chitosan-based coating on cucumber could be considered a healthy and effective treatment that reduces microbial spoilage and preserves quality and color characteristics in cucumber and represents an innovative method for commercial application. Therefore, this coating can be used as an alternative to chemical fungicides to prevent fungal rot of cucumber and other fruits, however, it is suggested that more studies should be done in this field.

In recent years, edible coatings have received much attention due to their functional properties and have been used for a number of food products including fruits. Apricot is one of the fruits with short shelf life. Therefore, this study aimed to increase the shelf life of apricots at refrigerator temperature using edible aloe vera coating and to investigate its physicochemical properties. For this purpose, aloe vera gel was first prepared, dried and powdered. Then 0, 1 and 2% solutions of aleo vera powder were prepared and apricots of Rajabali cultivar were dipped for 5 minutes in solutions. The apricots were then packed in polystyrene containers and stored in the refrigerator at 4±1°C and 60±5% relative humidity. The samples were removed from the refrigerator at 0, 5, 15 and 25 days after storage, and physicochemical characteristics including weight loss, acidity, pH, firmness, vitamin C, mold percentage and color components were evaluated. Finally, the results were analyzed using a completely randomized design based on factorial test. The results showed that aloe vera gel at 2% concentration was highly effective in increasing the shelf life of apricots up to 25 days and the control samples without aloe vera coating had a significant decrease in quality and up to 50% moldiness. Therefore, it can be concluded that the use of aloe eera edible coating increases apricot shelf life, preserves physicochemical properties and decreases moldiness in apricots. In this way Rajabali apricots could be preserved for 15 days at cold stores.

The term shrimp is used to refer to some decapod crustaceans, although the exact animals. Macrobrachium nipponense is a species of freshwater shrimp that was first described in 1849. Macrobrachium nipponense is native of Persian Gulf, Cold Temperature Northwest Pacific, East China Sea, South China Sea, Temperate Northern Pacific and Yellow Sea. This shrimp is native in Japan and Malaysia countries and introduced to China, Iran, Iraq, Philippines, Singapore and Russia. Its distribution is Southern Asia. It is introduced to Bohai Sea, Somali Sea, Sunda Shelf, Yangtze Estuary and Caspian Sea. Common names of Macrobrachium nipponense is Oriental river prawn, Bouquet Nipon, Tenaga ebi, Ho bsia and Camaron nipon. Food items reported for Macrobrachium nipponense is unspecified detritus. Macrobrachium nipponense be able to live in Benthic, freshwater, brackish and Tropical environments. This shrimp classified in Malacostraca, Decapoda and Palaemonidae. Shrimp is important types of seafood that are consumed worldwide. Shrimp is also the most popular type traded worldwide. They can be farmed domestically or caught in the wild. Shrimp as a source of protein a variety of different nutrients. It is rich in antioxidants. Shrimp's benefits include having both omega-3 and omega-6 fatty acids. The cholesterol in shrimp is fairly high, it's not bad for your health. Shrimp is low in calories yet and rich in Nutrients. Approximately 90% of the calories in shrimp come from protein, and the rest come from fat. They play important roles in the food chain and are an important food source. Macrobrachium nipponense is considered one of the most nutritious food sources in the world, which, unlike its high nutritional value, has not been considered for human consumption. Many fermented shrimp products are prepared in different parts of the world and the method of processing depends upon various factors, viz availability of raw materials, consumers preference and the climatic conditions of the region. In addition, shrimp sauce is a product that can be made cheaply from various shrimp raw materials, which are not normally used for food. Human uses of Macrobrachium nipponense is shrimp sauce. Sauces are known in different countries with different names and are commonly used as main dishes or seasonings. Sauce is a liquid condiment made from shrimp that have been coated in salt. It is used as a staple seasoning in East Asian cuisine and Southeast Asian cuisine, particularly Burma, Cambodia, China, Indonesia, Laos, Malaysia, Philippines, Taiwan, Thailand, and Vietnam. Fermentation is one of the oldest techniques in food preservation as it not only extends the shelf-life but also enhances the flavor and nutritional quality of the product. Shrimp sauce, a fermented product. It is a translucent, clear amber yellow or brown liquid, with a salty taste and shrimp flavor obtained from fermentation of a mixture of shrimp and salt, and the fermentation takes not less than 6 months. The product is intended for direct consumption as a seasoning, or condiment, or ingredient for many Asian dishes. it is the main source of protein in the diet and has become a necessity in the house, and it also contains free amino acids and other protein degradation products, essential fatty acids, considerable amount of eicosapentaenoic acid and docosahexaenoic acid that are beneficial to human health. These aroma compounds of the fish sauces were mainly from lipids, amino compounds, and sugars of the raw materials, in which lipid was the major contributor. Although fermented shrimp sauce itself may not be directly used for a physiological functional food because of its high concentration of sodium chloride, the sauce may be useful as a source of biologically active substances, traditional, food supplements in the diet, are widely used in the world as condiments, as flavoring, material, and sometimes as a substitute for the other sauce. The purpose of this study was to determine the chemical, microbial and sensory quality and shelf life of shrimp sauce produced of fresh shrimp from Anzali.

For this research, four treatments including fresh shrimp processed by salt, sorbitol, cooked rice and sucralose were considered. All treatments included 1: 1 salt, acetic acid, sodium sulfate, glutamate and sorbate potassium. Fresh shrimp processed by salt of 1: 1 was as a control sample. The experimental and control treatments were kept at refrigeration temperature for storage period of six months.

In experimental and control treatments, chemical, microbial and sensory factors showed significant changes during storage (p<0.05). Pseudomonas, Staphylococcus, Coliform, Escherichia coli, yeasts and molds were not observed in test and control treatments. The treatments processed with cooked rice showed better taste and overall acceptance compared to the others (p>0.05). Protein, fat, ash, moisture and salt absorption showed no significant difference among test and control samples (p>0.05). Sorbitol treatment has more moisture and freshness compared with the other treatments (p>0.05). The amount of sauce production in treatment processed by cooked rice has significant increase compared with the other treatments (p<0.05). But, the amount of sauce production in treatment processed by sorbitol has significant decrease compared with the other treatments (p<0.05). The control and test treatments had good quality the end of storage period in the refrigeration.

According to the results of the experiments, although the treatments processed with sorbitol were of higher freshness compared to the others, but considering the processed treatments by cooked rice had better taste than other treatments, the significant increase in the amount of sauce produced and overall acceptance of this treatment, therefore treatment processed by cooked rice is recommended for the preparation of sauce from fresh shrimp.

In this study, the effect of bilayer edible coating of gelatin-chitosan containing nanoemulsion of Perovskia abrotanoides Kar. essential oil on growth control of Aeromonas hydrophila inoculated into rainbow trout fillets over a 12-day period at 4 °C was investigated. The chemical composition of the essential oil was evaluated by GC-MS, its antibacterial properties by disk diffusion, plate well and micro-dilution broth, and its antioxidant properties by DPPH.Treatments included control, gelatin, chitosan, gelatin+essential oil, chitosan+essential oil and gelatin-chitosan+essential oil. After preparation, the treatments were packed in sterile polyethylene bags in laboratory conditions and stored for 12 days at 4 °C and their microbial, chemical and sensorial properties were evaluated every 3 days. The results of GC-MS showed that eucalyptol (24.51%) and camphor (22.02%) are the main components. The MIC and MBC of Perovskia abrotanoides Kar. essential oil nanoemulsions were reported to be 0.0625 and 0.125%, respectively. The amount of TVB-N and POV increased during the study period. According to the results of POV and pH measurements, there was a significant difference between all treatments and control treatment (P<0.05). The mean reduction log of bacteria was significantly different between all treatments and the highest antibacterial effect was observed in the gelatin-chitosan coating containing nanoemulsion of Perovskia abrotanoides Kar. essential oil. According to the results, Perovskia abrotanoides Kar. essential oil has good antioxidant and antimicrobial properties and according to the test results, it was found that chitosan-gelatin coating containing nanoemulsion of  Perovskia abrotanoides Kar. essential oil has an effective antimicrobial effect against Aeromonas hydrophila and can protect sensory properties and increase shelf life of rainbow trout fillets as well as useful coating to increase the shelf life of food products.

In food industries, nanotechnology can potentially provide solutions to food packaging with short shelf life. Nowadays, there has been an increasing interest in nanocomposites for many advantages in food packaging. Polymers have a wide range of applications in food packaging, and many studies have been conducted on the simultaneous use of nanoparticles and polymers in food packaging, which can be attributed to the synergistic effect of these nanoparticles. One of the most important goals is to increase the safety and quality of food during storage, transportation and protection against adverse factors such as chemical, moisture, light and external forces. The aim of this study was to investigate the effect of film prepared from PET containing nanoparticles of ZnO, TiO2 and TiO2 + ZnO nanoparticles in quantities 0.25, 2 and 2.25%. Weight is based on the physicochemical properties of mayonnaise.

The PET-based nanocomposites containing 2% by weight of TiO2 nanoparticles and 0.25% by weight of ZnO nanoparticles were prepared by melt mixing using an extruder. Mixtures of PET nanoparticles were dried in the oven at 170 ° C before loading in the extruder and fed simultaneously from the feeder to the extruder. The material was melted and thoroughly mixed as it passed through the extruder. The melt from the extruder was cooled by passing through a pool of cold water and entered the granule mill to make granules. Pure PET samples were molded as control and PET-based preforms containing nanoparticles. At the end of the molding stage, chillers were used to cool the preforms. PET-based bottles containing nanoparticles were produced by blowing preforms at appropriate temperatures and pressures for 120 to 140 seconds. The morphology and particle size of the bottle layers were investigated using FE-SEM. Then physicochemical properties including colorimetry, pH and acidity of mayonnaise, oxidative and peroxide stability, acidity of the extracted oil and migration of Zn +2 and Ti +2 ions from mayonnaise during 90 days at room temperature (22 ± 2 ° C) Celsius) was examined.

Based on FE-SEM images, the films of polymer bottles containing ZnO and TiO2 nanoparticles showed a smoother surface than the films of polymer bottles of ZnO + TiO2 nanoparticles. Moreover, the results of physicochemical properties showed that the reduction of brightness index as well as pH, acidity number, peroxide number and oxidative stability of mayonnaise sample during 90 days of storage in a bottle containing nanoparticles had a significant decrease compared to the control sample. According to the results of the present study, mayonnaise shelf life indices can be increased.

Due to the importance of food emulsions such as mayonnaise, it is necessary to pay attention to the quality characteristics and shelf life of this popular condiment. The use of these nanocomposites could be a promising approach to creating new active packaging in the food industry.

Due to the importance of consuming meat and meat products especially sausage and bologna and the adverse effects of using synthetic preservatives used in them, this study aimed to investigate the effect of natural preservative on shelf-life of cooked beefbologna and comparison with sodium nitrite as synthetic preservative. the effect of chitosan (0, 0.5 and 1%) added individually or in combination with CCEO nanoemulsion (0, 1, 2 and 3%) as an alternative for sodium nitrite on microbiological (Total Viable Counts, Coliforms, Lactic acid bacteria (LAB), molds and yeasts), pH and water holding capacity (WHC), of beef bologna stored at 4 °C for 30 days was investigated. The experiment was performed in completely randomized based on factorial in 3 replication. Duncans test at 5% probability level was used to determine the significant difference mean between the data. Results indicated that chitosan addition resulted in significant (p< 0.05) inhibition of microbial growth, so that the lowest microbial counts were obtained in the samples containing both chitosan and CCEO nanoemulsion indicating a possible synergistic effect. Chitosan also improved the WHC and reduced the synersis of the samples during shelf-life respect to the control, while CCEO nanoemulsion had no significant effect on these parameters (p>0.05). The combination of chitosan (1%) with CCEO nanoemulsion (2-3%), which showed the best results, could have a valuable potential for commercial use in order to improve preservation of meat products without the use of nitrites or other synthetic additives.

Ultraviolet radiation was used in the present study to process lemon juice. The designed UV system had five UV-C lamps and irradiation was performed based on the distance of the lamps (10, 20, and 30 cm) from the fluid layer and the circulation time (10, 20, and 30 minutes) of lemon juice in the system. Non-irradiated sample was also considered as a control treatment. The control and irradiated samples were filled in dark polyethylene bottles and stored at ambient temperature for 90 days. Immediately after irradiation and during the storage period, parameters such as pH, titratable acidity, total soluble solids, ascorbic acid content, color indices (L*, a*, and b*), browning index, as well as sensory attributes were evaluated. The pH, acidity, and total soluble solids did not show a definite trend. The results showed that among the color indices, L* decreased significantly, but a* and b* increased significantly during the storage period. The rate of color changes in irradiated samples from a distance of 10 cm was higher than other treatments. Irradiation also significantly reduced the ascorbic acid content of irradiated samples from a distance of 10 cm compared to other samples and control. However, the browning of irradiated samples from 10 cm distance was significantly less than that of irradiated samples from 20 and 30 cm distance. The score of the panelists indicated that irradiation and storage time altered the quality characteristics of lemon juice. The panelistschr(chr('39')39chr('39')) scores showed more acceptance of irradiated samples from 20 and 30 cm distance compared to irradiated samples from 10 cm distance. In general, the designed system in this study is not recommended for lemon juice processing due to the destructive effect of UV-C radiation on the content of ascorbic acid.

Nowadays, the food industry is looking for new technologies to increase the shelf life of various products. Furthermore, as consumerchr  s demand for more “healthier” meals (free of conventional chemical preservatives) has increased in the last decade. In this study, edible sago starch coating containing leave extract of Withania Somnifera (0.125 and 0.25 mg/ml, 1 and 2 times MIC, respectively) was applied onto chicken fillet to extend its shelf life at 4 ˚C. Examination of coated chicken fillets showed that active film of sago starch inhibited the microbial load (aerobic bacteria, coliform and Staphylococcus aureus bacteria) of chicken fillets. The results of chemical analysis of chicken fillet also showed that the coated samples had less volatile nitrogen compounds, thiobarbituric acid index and peroxide value than control. In general, the results of this study showed that the edible film produced from sago starch containing Withania Somnifera extract increases the shelf life of chicken fillets.

In this study, some preservative solutions were used as an alternative to sulphur fumigation. For this purpose, sodium metabisulfite, calcium chloride, sodium acetate, and sodium carbonate solutions at concentrations of 0.5, 1 and 2 percent were applied. Grapes (Sorkh-e-Fakhri var.) were dipped in different concentrations of each solution for 2 minutes. After dipping, the surface water of grapes was dried by natural air blowing and then, put in conventional baskets and stored at 0.5-1°C at 85-95% RH for 6 months. The percentage of moldiness, soluble solids, reducing sugar, acidity, and pH of the samples were determined after 2, 4, and 6 months of storage. The results of this study showed that the effect of type of preservative used and the storage time, on the percentage of moldiness and pH and acidity of all samples were significant at 1% level. Sodium metabisulfite had the highest inhibitory effect on mold growth. Calcium chloride had the greatest effect on moisture retention. In addition, the highest pH was observed in samples immersed in sodium carbonate solution. In the case of interactions, the effect of type of preservative and storage time on moldiness, moisture content, brix, sugar content, and acidity, and also the type of preservative and its concentration on moldiness and acidity of samples were significant. According to the obtained results, it was shown that the grapes could be stored for 6 months by dipping them in 0.5% sodium metabisulfite for 2 minutes before cold storage.

Rainbow trout (Oncorhynchus mykiss) is a species with high commercial value and much appreciated by consumers. This study was carried out to determine proximate analysis, amino acids composition and their changes in rainbow trout fillets during 9 months storage at -18°C. The results revealed that 17 amino acids were obtained in rainbow trout fillet,10 essential and 7non essential amino acids. In this research, Aspartic acid, Glutamic acid, Arginine, Leucine and Lysine were the main amino acids of rainbow trout fillets. The results of proximate analysis and its changes shown that moisture content of fillet s gradually reduced, protein content was decreased significantly, and fat and ash content were continually increased during frozen storage time (p<0.05). Primary and secondary lipid oxidation compounds measure by PV and TBA. PV was raised from 0.84±0.005 to 5±0.05meq O2/Kg and TBA from 0.65±0.03 to 1.92±0.05mg ma/Kg. In this research the increase was observed in FFA from 0.46±0.008 to 1.3±0.05g of Oleic acid/Kg. The TVB-N value raising from 10±0.1 to 40.5±0.02mg/Kg after 9 months (p<0.05). The results shown that the reduction of protein content related to breakdown of protein and all of essential and nonessential amino acids were changes. This changes, specially, shown after3 months and affected to the quality and nutrition value of fish fillets.

Meat is prone to contamination and spoilage due to its composition and production. Therefore, in order to extend its shelf life, the use of antioxidant and antimicrobial compounds has always been the focus of researchers' attention.The present study was conducted to evaluate effects of edible chitosan (2%) coating containing Cuminum cyminum essential oil (1%) on the shelf-life of meat in modified atmosphere packaging at refrigerated storage. The meat samples were separated into three groups uncoated (control), treated with chitosan coated without Cuminum cyminum essential oil and immersed in chitosan coated with Cuminum cyminum essential oil.  Then Samples were packed in MAP (80% O2 and 20% CO2) conditions and stored at 4°C up to 21 days and evaluated periodically (on days 0, 3, 6, 9, 12, 15, 18 and 21) for microbiological (Total microbial counts, lactic acid bacteria, Enterobacteriaceae and Pseudomonas spp.) and chemical (pH, TBA and TVN) characteristics. Microbial analysis indicated that coating had significant influence (p<0.001) on reduction of increasing trends of Total microbial counts, lactic acid bacteria, Enterobacteriaceae and Pseudomonas spp.bacteria. From the aspects of chemical factors, the containing chitosan coating groups showed lower pH, TBA and TVN than those without coating. According to the results, chitosan coating significantly improved (P<0.05) quality of samples. This study also indicated that the effect of chitosan containing Cuminum cyminum essential oil on samples was to retain their good quality characteristics and extend the shelf life during refrigerated storage, which was supported by the results of microbiological, chemical, and sensorial properties.

The effect of 500 ppm mixed plant extracts (green tea, stinging nettle and olive leaves extract in the same rates) in combination with nisin (200 ppm) and nisin nanoparticles (200 ppm) was studied to produce nitrite free frankfurter sausage. Nitrite free frankfurter sausages in three treatments containing 500 ppm plant extract + 200 ppm of nisin, 500 ppm plant extract + 200 ppm nisin nanoparticles with control sample (120 ppm sodium nitrite) were produced, then packaged in polyethylene bags in vacuum condition and physicochemical, quality, microbiological and sensory properties were evaluated during 45 days of storage. The results showed that the use of nisin and nisin nanoparticles had no significant effect (P>0.05) on moisture, fat, protein and ash content. Nisin nanoparticles, due to the presence of chitosan in the capsule structure, prevented the lipid oxidation and the sausages containing these compounds had the lowest TBARS at the end of the storage. Total viable count, molds and yeasts counts increased significantly (P<0.05) during storage. At the end of 45 days, sausages containing sodium nitrite and nisin nanoparticles had the lowest total viable bacterial and molds and yeasts counts, respectively. The count of Staphylococcus aureus (2.5 Log CFU/g) and Escherichia coli (2 Log CFU/g) decreased significantly during storage (P<0.05). It was found that sausage containing nisin nanoparticles had high sensory scores compared to other treatments. The results showed that the use of 200 ppm nisin nanoparticles in combination with 500 ppm of mixed extracts could be a novel step in the production of nitrite free frankfurter sausage with good quality characteristics and extended shelf life.

Chitosan is one of the natural preservers and an active coating that due to nontoxic nature, antioxidant activity, antimicrobial, and film producing properties, biocompatibility and biodegradability has been considered as one of the natural additives. This material singly or in combination and along with the other biological materials such as extracts and or essence of different herbs is used as a nanocomposite. In this study, the effect of chitosan coating was assessed on the sensory, tissue and physical changes of roostertail grape. 1 and 1.5% solutions of chitosan with median molecular weight were prepared in 1% acetic acid wherein glycerol and Tween 80 were used as the softeners and an emulsifier.After the selection of different treatments, the samples were suspended in the considered chitosan solution for 3 minutes and after extrusion of excess dripping were introduced in the disposable containers and were experimented on 1, 5 and 12 days. For tissue analysis the texture analyzer having a cylindrical steel probe TA39 with a 2mm diameter and 20mm width and for acidity measurement the pH meter was used. The results showed that the acidity rate in 1.5% chitosan had a significant reduction in comparison to 1% chitosan treatment. The results of sensory changes viz. juiciness, crack and rupture, spoilage, color change, smell in the 1 and 1.5 % chitosan treatment at different time periods were more desirable in relation to the control. The results of conducted experiments exhibited that chitosan can be considered as a biological preserver that is able to increase the shelf-life of different fruits viz. grapes besides the qualitative changes of the fruit with increased preservation time does not get exposed to significant changes.

Nowadays chemical preservatives are commonly used in foodstuffs to increase their shelf life and maintain the quality. Due to their probable risk of continuous use in foodstuffs, natural preservatives are increasingly used. In this study, oak powder has been used as a natural preservative with antimicrobial properties and desired sensory effects on ready-to-cook chicken.Treated samples containing 5, 10, and 20 percent of powder in 0, 1, 2, 3, 7, and 14 days of storage periods in fridge temperature using chemical tests (including peroxide number, thiobarbituric acid, and volatile nitrous bases) and microbial tests (including total bacteria count, Staphylococcus aureus count, coliform count; Also the effect of oak powder on sensory features of chicken was oak powder examined. The results of the present study show that oak powder could appropriately postpone microbial spoilage and peroxidation of lipids in chicken fillets. It was proved that the use of appropriate concentrations of oak powder (5 and 20 percent) in the ready-to-cook chicken, significantly (P<0.05), could result in chicken microbial Fluorine decrease and oak powder of 10 and 20 percent concentrations showed more positive effects on treatments`oreganoliptic properties. Therefore, as a natural preservative,the oak powder can be used in ready-to-cook chicken production process with positive effects on the product`s sensory properties and longer shelf life.

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.

Demand for the production and consumption of fresh meat has led to the use of various methods to improve the quality characteristics and increase its shelf life. In this study, stinging nettle extract (SNE) in combination with epsilon (ɛ-PL) were used for the production of fresh, functional, and extended shelf life of beef fillets. After drying of stinging nettle leaves under favorable conditions, aqueous extraction was performed at concentrations of 3, 6 and 9% (w/v) of leaves. A solution of ɛ-PL at 0.5% (w/v) concentration was prepared and mixed with 3, 6 and 9% of SNE. Beef fillets (4 treatments) were prepared in 2×2×2 sizes and treated for 1 h at 4 ° C with a ratio of 1 to 1 (meat fillets to SNE). Distillation water was used to treat the control. Finally, beef fillets were packed in polyethylene bags and quality properties were performed at days 1, 3, 6, 9 and 12. During storage, pH, phenolic compounds, redness value (a) and sensory scores decreased significantly (P < 0.05), and in contrast to lipid oxidation, total volatile nitrogen, lightness (L) and yellowness (b) increased significantly (P < 0.05). It was found that the treatment of beef fillets using SNE (6%) in combination with ɛ-PL (0.5%) resulted in a significant reduction (P < 0.05) in the amount of lipid oxidation and total volatile nitrogen compounds of about 50% compared to the control sample. The color and sensory characteristics of processed beef fillets showed that SNE in combination with ɛ-PL could increase the sensory scores of the samples. Based on the results, SNE had synergistic effects with ɛ-PL in reducing lipid oxidation and total volatile nitrogen compounds, therefore it could be used to produce fresh and functional beef.

In recent years, edible coatings have been extensively used for extension shelf life of fruits and vegetables. In this research, the effect of washing with citric acid (1%w/v) followed by coating with different concentrations of carboxymethyl cellulose (CMC;1, 1.5 and 2% (w/v)) in combination with ascorbic acid (AA; 1, 2 and 3% (w/v)) on postharvest quality of button mushrooms when stored at 4  for up to 15 days was studied. After treatment, mushrooms weight loss, soluble solid content, firmness, color, microbial and sensory quality were evaluated at 1, 4, 8, 12 and 15 days of storage. The result indicated that coating reduced weight loss and delayed changes of soluble solid content and color compared to uncoated control mushroom. Coatings had not remarkable effect on firmness of mushrooms. Sensory evaluation showed that the shelf life of mushrooms increased from 8 to 15 days. Washing with citric acid reduced total bacteria, yeast and mold counts. Among different coatings the combination of CMC 2% and AA 3% was more effective.

Instant soup is a type of convenience food which is commercially produced for ease of consumption, portable and has a long shelf life. According to quick preparation and inexpensive, it becomes quite popular for people too short on time in the modern world. Instant dried soup powder is meat or vegetable-based product and generally constituted mixture of dehydrated cereals, vegetables and spices. However, interesting in consuming convenience foods has been received criticism due to lack of nutritive value and other health concerns. On the other hand, seafood industry generates great amount of edible wastes or by-products which can be highly perishable and needed to process in various value added products. Beluga or great sturgeon (Huso huso) is an endemic fish species of the Caspian Sea and extremely cultured for meat and caviar purposes in many countries in particular Iran. According to big size of farmed sturgeon, the fish fillet is commonly raw material for consumers, but unfortunately the wastes from the fillet producing and trimming are usually discarded or used for relatively low commercial value products (e.g. fishmeal and oil production). Treated fish waste described as an edible offal or edible by-product which can also be used for various value added products instead of being discarded and causes potential adverse environmental impacts. Fisheries products are highly perishable, while dried fish soup powder can be stored for a long time due to lower water activity. On the other hand, protein deficiency in some countries or low per capita consumption of seafood can be compensated by the production of a variety of fish products. The production of ready-to-eat soups from fish due to their high nutritional value can be considered as a healthy food among other instant foods. This study aimed to use farm-raised beluga sturgeon by-products in instant soup powder, as well as its shelf-life at ambient temperature for 120 days. At first, the fresh beluga fish wastes were processed and dried till lower 10% moisture. Then, the beluga fish powder at 0% (control; vegetable soup), 20%, 35%, 50%, and 65% was used in instant soup formulas to specify the best formula. Then, some physical properties (i.e. color, water activity, and water holding capacity) and chemical properties (i.e. proximate composition, pH, TVN, PV, TBARS, FFA, and fatty acids profile) were compared among the best formula fish soup and control. The highest overall acceptance score (4.70) was obtained in 50% beluga fish formula and selected as a best formula. After 4 months of storage, free fatty acid (8.87%), peroxide value (7.30 meq. O2/kg), thiobarbituric acid-reactive substances (0.1 mg of malondialdehyde in kg), and total volatile basic nitrogen (2.87 mg/100 g) was within the permitted ranges. Also, pH of vegetable soup (7.57) was lower than fish soup (7.82). Water activity was lower than 0.5 in both types of soup samples during storage. The amount of E in fish soup was changed from 1.21 at the begging of the experiment to 2.83 after 120 days. The results showed that fish soup is a good source of high unsaturated fatty acids, and their amounts were decreased during the storage time, especially eicosapentaenoic acid and dicosas hexanoic acid were decreased to 2.01% and 4.14%, respectively. The results of this study showed that the use of 50% of dried beluga sturgeon fish meat in the instant soup formulation received the highest sensory evaluation points compared to other formulas and was selected as the best formula. Study of changes in chemical indices showed that all the measured factors were in the allowed range after 4 months of storage under ambition condition. Also, water activity was lower than the critical level for the growth and activity of spoilage microorganisms. Increasing in the storage time led to a decrease in water holding capacity and whiteness of the fish soup. In addition, unsaturated fatty acids including oleic acid, linoleic acid, and linolenic acid were more susceptible to oxidation during storage, and decreased over the shelf-life. Therefore, fish soup with high protein content (55% in dry weight) and high unsaturated fatty acids has a high nutritional value and can provide an enriched instant soup with a high nutritional value and appropriate shelf life up to four months.

Walnuts contain many nutritional compounds, including omega-3, various vitamins, especially vitamin E and types of minerals. Therefore, the development of foods based on walnut and studies on chemical and microbial stability during storage, is very important. In this research, the effects of various concentrations of BHT (three levels 100, 150 and 200 mg/L) on changes in peroxide value and acid value of walnut butter, as well as the effect of two types of preservatives of benzoic acid and sorbic acid, each in two levels (400 and 800 mg/kg) were separately and mixed, on the total count of microorganisms and the count of mold and yeast of walnut samples during 75 days of storage at ambient temperature is investigated. The results of this study showed that by adding BHT at 200 mg/L, the peroxide value decreased significantly compared to the control sample. After production, acidic value was 0.3% and it rose to 0.4-0.5% after 75 days of storage. Also, benzoic acid was more effective in reducing total bacterial count and counting mold as well as yeast during storage in comparison with sulfuric acid.

Using the natural-based coating and natural preservatives has became a novel method in food packaging. Accordingly, the use of natural preservatives for prevention of spoilage and extend the shelf life of perishable foods like as fish burger has gained more attention. The aim of this paper was studying the effect of edible g on physiochemical, microbial and sensory characteristics of rainbow trout fish burger during 14 refrigerated storage. In this study, the effect of 2% gelatin coating containing different concentration of alga essential oil (0.3, 0.6, 0.9) on physiochemical (TBA, pH PV, TVB-N), microbial (PTC, TVC) and sensory properties were analyzed periodically during storage. According to the results, the combination effect of gelatin and alga essential oil on improvement the physiochemical and microbial values of treated samples were significantly higher than untreated samples (p<0.05), and this antimicrobial coating has significant effect to decrease the microbial spoilage and to extened the shelf life of rainbow trout fish burger during refrigerated storage.resulted in significant shelf life gelatin coating Dunaliealla salina alge essential oil 0.9% as compared to control sample (p<0.05).