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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. [ABSTRACT FROM AUTHOR]

In recent decades, tragacanth gum extraction from Astragalus verus has dramatically increased across Iranian rangelands. However, little information is available about the best method of gum harvest, which is economically efficient and maintains the health of the plant. This research was conducted as a factorial combination and in a completely randomized design, during spring and summer of 2018-2019, at Baraghban rangeland. Three levels of stem cuts (i.e. 1, 2, and 3 cuts on the main stem of each plant) and four frequencies of gum removals (1 to 4 times) with 10 replications were applied on 120 individual plants. Results indicated that all cut and gum removal levels significantly reduced the vigor of A. verus, but no significant relationship was detected between gum removal levels and plant vigor. There was an increase in the gum yield by increasing the number of gum harvests, but no increase was found by increasing cut numbers. Based on the ecological and economic comparisons (estimating costs and benefits), we suggest one cut and four times of gum removal as the most suitable method. [ABSTRACT FROM AUTHOR]

In order to increase the available Phosphorous (P), chemical fertilizers are applied; however, P chemical fertilizers are transformed into low available forms over time. Organic amendments could be effective in improving the efficiency of P fertilizers. The aim of this study was to investigate the effect of P fertilizers and vermicopost on the availability and fractions of P and maize (Zea Mays L.) indices in a calcareous soil. This study was performed in a factorial completely randomized design with three replicates. The experimental factors included chemical fertilizer (0 and 50 mg/kg P) and vermicopost (0 and 1 %W). After 2 months of planting in greenhouse, the shoots of maize were removed and the maize indices (P concentration, dry matter and P uptake) were determined. Then, the soil samples taken from each pot, P available, and P fractions were evaluated by a modified method developed by Hedley et al (1982). The results showed that the effect of the interaction beyween P fertilizer and vermicopost on the available P was significant. Also, the interaction of P fertilizer and vermicopost on the soluble and exchangeable P (P<0.05) and organic P (P<0.01) was significant. By applying the P fertilizer or % 1 vermicompost, all P fractions (except Ca bound P) were increased. The results, therefore, showed that the effect of the interaction between P fertilizer and vermicopost on P concentration, dry matter and P uptake was not significant (P>0.05). Vermicopost application increased the dry matter from 6.9 to 10.5 g pot-1, while application of 50 mg kg-1 P as fertilizer increased the dry matter from 7.7 to 9.7 g pot-1. Also, by adding vermicopost (11.1%), the i P uptake was increased, as compared to 50 mg kg-1. The results, therefore, indicated that the beneficial effect of vermicompost on the dry matter and P uptake in maize was more than that of the chemical fertilizer. Moreover, P fertilizer and manure could influence P fractions and P availability. [ABSTRACT FROM AUTHOR]