QUALITY AND DURABILITY OF AGRICULTURAL PRODUCTS AND FOOD STUFFS
Year:2021 | Volume:1 | Issue:2|Papers Count:8

In many parts of the world, there is a rich tradition in the use of herbal medicine for the treatment of many infectious diseases. Because of the side effects and the resistance that pathogenic microorganisms build against the antibiotics, much recent attention has been paid to extract the biologically active compounds from plant species used in herbal medicine. The aim of this study was antibacterial activity of Salvia macrosiphon essential oil on four bacteria and identification of the chemical constituents. The essential oil was extracted using hydro-distillation method and analyzed by GC, GC/MS. The total number of compounds identified and quantified were 10 representing 92. 8 % of the total essential oil. Linalool (54. 8%) and sclareol (27. 3%) were the major compounds. The antimicrobial activity of the oil was evaluated using dilution method against standard strains of Bacillus cereus, Staphylococcus aureus. Escherichia coli and Salmonella enterica. All of the bacteria were sensitive to the oil. Minimum bactericidal concentration of the oil on S. aureus, B. cereus, Escherichia coli and S. enterica were 0. 15, 0. 15, 0. 38 and 0. 77% respectively. The obtained results confirm and suggested the justification of indigenous plant, Salvia macrosiphon essential oil used in traditional medicine as treatment for microbial infections or as preservative in food.

In this study, the effect of the magnetic field of a magnetic system on seed germination percentage was studied. The device consists of components including seed tank, device structure, 50-watt solar panel, electronic board of electromagnetic field generator with field intensity change up to 0. 1 Tesla, intelligent electronic charge control board, 14-amp battery, 2-inch inlet and outlet tube Is. To control the magnetic field, two pairs of coils are used, which are wrapped around the passage tube. By installing an intelligent electronic board, the battery charge is controlled. The current from the DC power supply to the windings will produce a non-oscillating magnetic field strength. Seed germination percentage was determined and compared before and after magnetic field formation and magnetic water production. Germination experiment showed that the water from the magnetic field did not have a significant effect on increasing the germination of wheat, canola, alfalfa, tomato and lettuce seeds. However, a significant difference was observed between the germination percentage of cucumber and pumpkin in the isolated sample and the prototype, so that the germination percentage of these seeds increased by 26 and 20. 64%, respectively, compared to the primary seeds.

Confectionery products are considered as a suitable factor for the growth of bacteria due to the presence of nutrients such as milk and egg products, and if they do not comply with proper storage conditions, they quickly become rotten and unusable. This descriptive cross-sectional study was performed to investigate the presence or absence of bacterial contamination caused by Escherichia coli and Staphylococcus aureus in creamy sweets in the west of Tehran. From 12 selected confectioneries in the west of Tehran, about 500 grams of creamy sweets equivalent to 3 pieces (solid food sample) (according to the instructions of the standard number of samples required in food sampling) were prepared using a simple random sampling method. In this study, in order to isolate and identify E. coli bacteria, lauryl sulfate tryptase (LST) culture medium was used. Due to gas production and turbidity observed in all samples (36 samples), EC Broth selective culture medium was used for complementary and confirmatory steps. Finally, peptone water culture medium was used for confirmatory tests of E. coli and differentiation from other fecal coliforms, coaxial reagent was used for final confirmation. Isolation and identification of S. aureus bacteria were done using Cooked Meat enrichment medium and due to the production of spherical or oval or spindle-shaped colonies that were created in the depth of the medium in all samples, from Baird Parker Agar culture medium as The base was used for the second stage and in continuation of coagulase test to confirm S. aureus bacteria from other staphylococci, rabbit citrate plasma was used for confirmatory tests. By reviewing the data, the rate of bacterial contamination caused by S. aureus in 36 samples was equal to 25% and the rate of bacterial contamination due to E. coli in 36 samples was equal to 5%.

In this investigation, the essential oil chemical composition of healthy and infected Bakraei with Candidatus Phytoplasma aurantifolia from Rigan-Bam area has been studied. The branches of flower and roots of this species were collected in spring 2014 and dried in shade (at room temperature) and subjected to volatile fraction were isolated by hydrodistillation using an all-glass Clevenger-type apparatus. The analysis of the essential oils was performed by using GC-MS. In the aerial organs, 39 components of essential oil of healthy bakraei were identified including linalool-L (22. 7%), n-octane (11. 4%), E-caryophyllene (9. 8%), citronellal (8. 7%), limonene (5. 3%), β-bisabolene (5. 3%) while, 44 components were identified in the essential oil of infected bakraei with major components including linalool-L (14. 0%), n-octane (12. 4%), E-caryophyllene (11. 5%), citronellal (7. 4%), β-bisabolene (6. 9%), α-sinensal (6. 0%) and limonene (5. 3%). In the essential oil of underground organs in healthy bakraei, 9 components (including major component: elemol (34. 3%), geijerene (11. 3%), n-decane (8. 0%), dictamnol (7. 5 %), pregeijerene (6. 0%), β-eudesmol (5. 2%) and in infected bakraie 12 components (including major component: elemol (39. 5%), geijerene (16. 9%), dictamnol (7. 8 %), pregeijerene (5. 0%). The comparison of the essential oil chemical compositions was showed that α-sinensal compound as one of the major components in infected aerial organs does not exist in healthy bakraei. Also, n-dodecane, α-santalane and seselinee as identified partial components in underground organs do not find in it, s healthy type.

Hazelnut fruit or kernel has nutritional and medicinal value and is consumed raw or roasted. Used hazelnut was Gerd-e-Eshkevarat. To determine the best drying temperature for hazelnuts, a factorial experiment in a completely randomized design with two factors; dryer air temperature in three levels (40, 50 and 60˚ C) and fruit type in two levels (with and without skin) in three replications was applied. Fruits were dried in a thin layer with a laboratory dryer. To determine the specialized energy required for drying hazelnut in each treatment, an electrical work equation in the dryer (heater work + fan work) was used. Peroxide and acidity of hazelnut oil were measured by the standard institute and Iran industrial research methods. The results showed that the interaction effect of fruit type and the temperature was not significant on fruit oil percentage, but other traits were influenced by the interaction effect of treatments. The highest percentage of protein (13. 62%) was obtained in roasted hazelnuts with 60˚ C and with skin. The highest and lowest percentages of oil acidity (0. 28 and 0. 11%) were recorded in roasted hazelnuts with 50˚ C with and without skin, respectively. Peroxide numeral value (8. 25 and 1. 30) was obtained in roasted hazelnuts with 40 and 60˚ C with skin, respectively. Overall, 60˚ C was the most suitable temperature for drying hazelnut fruit which resulted to enhance most physiologic and taste traits.

Any change in food that reduces its quality value or reduces its popularity and marketing is called food spoilage. Ethylene gas is one of the gases produced from ripe fruits that causes high ripening and spoilage of the fruit during storage. Solutions have been suggested to absorb this gas during fruit storage. The aim of this study was to apply bio-filters to remove ethylene gas to increase the life of banana fruit after harvest during storage. Various samples prepared from agricultural wastes containing natural environmental microorganisms were evaluated in biological filters designed to remove ethylene gas and prevent spoilage of banana fruit compared to control samples. The gas chromatograph showed that the amount of gas passing through column 4, which contained peat soil substrates, poplar wood chips, enriched organic substrate, leaf soil, straw and creamy organic fertilizer was equal to 0. 6528 ml of ethylene per liter of air. It had the highest ability to remove ethylene gas compared to other columns and showed a significant difference with the control sample. In addition, this filter was observationally effective in terms of shelf life of immature bananas compared to control samples, and biological filters containing Pseudomonas putida have the highest amount of ethylene gas absorption. Based on the findings, the use of biological filters is recommended to increase the shelf life of fruits in storage.

In this study, a composite coating of polypyrrole/modified multiwalled carbon nanotubes/modified activated carbon prepared from hazelnut shells (PPy/MWCNTs/AC), was electrochemically synthesized and used for analyzing a group of volatile aromatic hydrocarbons in tea and vegetable samples. In order to obtain an adherent and stable composite coating, the effective parameters on electrodeposition process were optimized using the one-variable-at-a-time procedure, as well as the effective parameters in the desorption step of analytes was performed by this method. Based on the results, the deposition potential of 1 V, the deposition time of 1000 seconds, the desorption temperature of 280 ° C and the desorption time of 5 minutes were considered as the optimal values. To optimize the effective parameters in the extraction stage, the experimental design was used. Finally, the extraction temperature was 25 ° C, the extraction time was 30 minutes and the amount of salt was 10%. The calibration curve for each analyte in a range was linear as follows: 2 ̶ 15 μ g ̸ L (fluorene and phenanthrene), 2 ̶ 10 μ g ̸ L (anthracene and pyrene) and 0. 5-8 μ g ̸ L (naphthalene). Under the optimized conditions, the amounts of the detection limits (LODs) calculated at S ̸ N proportion of 3, were varied from 0. 06 to 0. 9 μ g ̸ L. The RSDs% of the peak areas ranged between 0. 5 and 8. 6%.