نشریه کیفیت و ماندگاری تولیدات کشاورزی و مواد غذایی
سال سوم شماره 1 (پیاپی 9، تابستان 1402)

To investigate the effect of active composite coating carboxymethyl cellulose-based on the shelf life of rainbow trout (Oncorhynchuus mykiss) fillet during refrigerator temperature storage, an experiment for 12 days with 5 treatments including uncoated (control), carboxymethyl cellulose 1%, carboxymethyl cellulose-oleic acid 1%, carboxymethyl cellulose-oleic acid-Echinacea extract (0.5% or 1%) and 3 replications was carried out. Chemical (PV, TBARS, and TVN) and microbial (TVC and PTC) tests were performed on the fillets every 3 days. The results showed that oleic acid improved the protective effect of carboxymethyl cellulose coating. The antioxidant and antibacterial effect of Echinacea extract was concentration dependent. At the end of the storage period, the lowest values of PV (3.90±0.11 meq/kg), TBARS (1.24±0.27 mg MDA/kg), TVN (21.90±1.83 mg/100g), TVC (5.10±0.10 log cfu/g) and PTC (5.23±0.06 log cfu/g) were found in fillets containing active composite coating of carboxymethyl cellulose-oleic acid-1% Echinacea extract (P <0.05). Therefore, the composite coating of carboxymethyl cellulose-oleic acid-1% Echinacea extract can be used as an active packaging to maintain the quality and increase the shelf life of rainbow trout fillets during short-term storage at refrigerator temperature.

The increasing development of antibiotic resistance of bacteria has provided the basis for replacing antimicrobial agents with plant origin and with less side effects. This research is a type of laboratory study that was conducted with the aim of determining the antibacterial effect of Myristica fragrans on staphylococcus isolates beta lactamase producing antibiotics. The methanol extract of the plant was prepared by maceration method. The extract was filtered with Whatman No.1 paper and concentrated by rotary evaporator system. Different concentrations of 200, 100, 80, 40, 20, 10, 5, 2.5, 1.25, 0.625 of the extract were prepared in DMSO: Methanol (1:1v/v) solvent. Identification of beta-lactamase producing isolates was done by phenotypic method with cefotaxime antibiotic discs and cefotaxime / clavulanic acid combined disc. Antibacterial activity against 40 isolates of beta-lactamase-producing isolates was investigated by agar wells diffusion method. After incubation for 24 hours at 37°C, the sensitivity of bacteria was determined by measuring the diameter of the growth inhibition zone. Based on the results, out of 60 Staphylococcus aureus bacteria, 67% of isolates were beta-lactamase producers, respectively. All isolates of Staphylococcus aureus showed sensitivity to Myristica fragrans extract, and the average of minimum growth inhibition concentration to beta-lactamase-producing Staphylococcus aureus was 10 mg/ml. Due to increasing antibiotic resistance, it seems that Myristica fragrans extract can be used against beta-lactam-resistant Staphylococcus aureus strains in controlling infections, and in this regard, isolation and identification of the effective substances of the plant extract it is suggested.

This study evaluated the effects of Mycorrhiza (Rhizophagus irregularis), Trichoderma (Trichoderma harzianum) and selenium on some physiological traits of Gaviota strawberry as a factorial experiment based on a completely randomized design with three replications in the Shahed University, Faculty of Agricultural Sciences research greenhouse in 2017. The treatments included fungi (No inoculation, Mycorrhiza, Trichoderma) and selenium (0, 0.5, 1, 2 and 4 mg/kg soil). The results showed that the use of symbiotic fungi, especially Trichoderma, could significantly increase the pH, total soluble solids (TSS), antioxidant capacity and anthocyanin of the fruit, as well as increase the amount of protein, chlorophyll and carotenoid of Gaviota strawberry leaves. Furthermore, selenium treatment, especially at low concentrations (0.5 and 1 mg/kg soil), could increase the antioxidant and anthocyanin capacity of the fruit, as well as the amount of protein and chlorophyll in the leaves. Overall, it is possible to recommend the using of symbiotic fungi, especially Trichoderma, along with low concentrations of selenium (0.5 and 1 mg/kg soil) in Gaviota strawberry cultivation programs.

The increase in the production of food waste and their entry into the environment through urban waste has created many problems for biological resources. Therefore, it is very important to present new methods in the elimination and optimal use of food waste. Preparation of polymer nanocomposites from food waste is one of the methods of optimal use of these materials. In this research work, chitosan polymer nanocomposite containing iron oxide nanoparticles was prepared using shrimp skin waste and pistachio green skin extract. Also, the effectiveness of this composite as a filter in removing malathion poison from water sources was investigated in different conditions of poison concentration, amount of adsorbent and pH. The results of examining the morphology and surface characteristics of the prepared nanocomposite using electron microscope images show that the average diameter of nanofibers in this structure is about 40 nm. Also, the presence of iron oxide nanometer particles with an average size of 47 nm can be seen in the structure. Also, the results of absorption test by nano adsorbent showed that the maximum amount of absorption of malathion poison is 90% at pH=7 and with 0.7 grams of adsorbent.

Amino acids are biological stimulants that has an effective role in improving the metabolism, growth and performance of plants. In this research, the effect of amino acids alanine, proline and glutamine on some growth, physiological and enzymatic characteristics of coriander (Coriandrum sativum L.) was investigated. this experiment was carried out as a completely random statistical design in three replications in a greenhouse located in Garmsar city. The foliar application of alanine, proline and glutamine with concentrations of zero, 50 and 100 mg l-1 were applied in two stages of 2 to 4 leaves and 4 to 6 leaves. The results showed that the treatments significantly increased the evaluated traits compared to the control, so that the highest percentage of cell membrane stability index and protein amount, the activity of superoxide dismutase, catalase and peroxidase enzymes were in 100 mg l-1 proline treatment, the highest amount of fresh and dry weight shoots and roots and the amount of nitrogen were in 100 mg l-1 glutamine treatment, and the highest total chlorophyll content of leaf were in 100 mg l-1 alanine treatment. Therefore, according to the results of this research, foliar application of alanine, proline and glutamine, especially with a concentration of 100 mg l-1, can be recommended to improve the morphophysiological and enzymatic properties of coriander.

Meat products are very prone to Oxidative spoilage. Lipid oxidation is one of main factors that are responsible for bad flavor and reducing quality of meat products. This oxidation would takes place due to the destruction of fat-soluble vitamins and fatty acids. This study has been conducted to investigate the effect of sesamol and propyl gallate as antioxidant agent on lipids oxidation in sausage. The details of the samples in this research is following, control sample without any Antioxidant material, T1 contains 600 ppm sesamol and without propyl gallate antioxidant, T2 contains 450 ppm sesamol and 150 propyl gallate, T3 contains 300 ppm sesame and 300 ppm propyl gallate, T4 contains 150 ppm sesamol and 450 propyl gallate and T5 contains 600 ppm propyl gallate without sesamol anti-oxidant. Tests were conducted with 3 times replication in all steps. Evaluated characteristics have been contained results of peroxide, TBA and pH in day 0, 15, 30, 45, 60respectively.Sensory evaluation was also conducted at the end of the tests. Levels of Peroxide and TBA were increased with increasing time, however, this increase was higher in control sample and it was determined that pH. Levels of chosen samples have not been changed in comparison with control sample but after passing of time, levels of this character decreased in all samples and control one. It can be concluded that 600 ppm anti-oxidant propyl gallate, have shown the best results on most evaluated characters.

The health benefits of omega-3 polyunsaturated fatty acids (n-3 PUFA) are generally recognized. Unfortunately, in most countries, the recommended daily intake of these compounds is rarely met. Therefore, the enrichment of commonly occurring foods and the production of functional foods can increase intake of these fatty acids. From this point of view, eggs are an interesting target due to their superior nutritional value and low cost, because they form an integral part of the diet. Their n-3 PUFA profile can be modified through dietary supplements. For this purpose, the oilseeds such as flaxseed, rapeseed, camelina, plant sources rich in alpha-linolenic acid and fish oil, which is rich in long-chain n-3 PUFA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been used. A more recent trend is feed supplementation with microalgae as a source of EPA and/or DHA. On the other hand, it seems necessary to use effective approaches to increase people's awareness of consuming functional foods. In this paper, recent scientific literature concerning n−3 PUFA enrichment in eggs is reviewed, giving an overview of advantages and disadvantages of the different approaches and the effect of consuming enriched eggs on human health was presented.