Green Synthesis of Silver Nanoparticles Using Cirsium Congestum Extract Modified by Chitosan/Alginate: Bactericidal Activity against Pathogenic Bacteria and Cytotoxicity Analysis in Normal Cell Line.

AIM: The study aimed to determine in vitro pharmacological effects of modified Ag nanoparticles (AgNPs). BACKGROUND: AgNPs are considered antimicrobial agents. However, the cytotoxicity of chemically synthesized AgNPs (cAgNPs) has raised challenges that limit their use. OBJECTIVE: The purpose of the study was to examine the antimicrobial and cytotoxicity effects of AgNPs synthesized using Cirsium congestum extract modified by chitosan/alginate AgNPS (Ch/ALG-gAgNPs). METHODS: Nanoparticles were characterized using TEM, DLS, XRD, and FTIR. Resistant strains of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were used for the antimicrobial analysis of Ch/ALG-gAgNPs using disc diffusion and microdilution methods. The effects of NPs on cell viability and apoptosis in L929 normal cells were determined using MTT assay and annexin/PI staining, respectively. RESULTS: Physicochemical characterizations confirmed Ch/ALG-gAgNPs to be spherical and uniformly dispersed, and their size ranged from 50 to 500 nm. Ch/ALG-gAgNPs inhibited the growth of microbial strains in a dose-dependent manner. The antibacterial effect of Ch/ALG-gAgNPs was significantly higher than cAgNPs. The Ch/ALG-gAgNPs showed little cytotoxicity against normal cells at concentrations less than 50 µg/ml. Cytotoxicity effects of Ch/ALG-gAgNP were less than cAgNPs. Flow cytometry and real-time PCR results showed a decrease in apoptosis percentage and BAX marker in the presence of Ch/ALG-gAgNPs relative to when the cell was treated with cAgNPs. CONCLUSION: Current findings introduce novel gAgNPs modified with chitosan/alginate for use in medicine.

Evaluation of physicochemical, antioxidant, antibacterial activity, and sensory properties of watermelon rind candy.

Watermelon (Citrullus lanatus) is consumed all over the world that contains a large number of seeds and rind, which is discarded. These by-products contain phytochemical compounds with great nutritional potential. This study aims to evaluate physicochemical properties and sensory values of watermelon rind candy. In this study in order to make the waste of watermelon a more sustainable and value-added food product, the watermelon rind was dried using an osmotic dehydration technique which comprises gradual impregnation of syrup (50 and 70% w/w - 1 to 5 h) before drying at 40 and 60 °C in 8 and 10 h. Various variables such as moisture content, chemical composition, water loss, solid gain, rehydration water, acidity, pH, antioxidant activity, antibacterial activity, residual toxins, phenolic and flavonoid contents during osmotic dehydration of watermelon were investigated. Results showed by rising temperatures, dehydration becomes more severe. Increasing the temperature in both osmotic samples in a concentrated solution (70%) and in osmotic samples with a dilute solution (50%) can enhance the mass transfer, water loss, solid absorption, as well as dehydration intensity. However, antioxidant activity, phenolic and flavonoid content significantly decreased after osmotic dehydration. TPC decreased from 35.83 mg/100 g to 27.45 mg/100 g and TFC of the watermelon rind (8.71 ± 0.01 mg/100 g) decreased to 2.63 ± 0.02 mg/100 g and also antioxidant activity after the osmotic process decreased from 61% to 40%. Also, osmotic dehydration had no significant impact on acidity and pH. The watermelon rind dehydrated sample (osmosis temperature: 40 °C, osmotic solution concentration: 70%, immersion duration: 5 h) was the best choice of panelists due to the highest score in the sensory evaluation including taste, texture, and overall acceptability. By determining the hardness of the watermelon rind candy and comparing it with the results of texture analysis of other dried products, it can be concluded that this product can be used as a healthy snack with longer shelf life properties.

Evaluation of the effect of basil seed gum, tragacanth gum, pectin, and coating formulation with corn flour on oil absorption and sensory properties of watermelon rind chips.

The current study aims to produce coated watermelon rind chips with the approach of reducing oil absorption and optimal use of waste and investigating its physicochemical, textural, and sensory characteristics. The effect of coating with basil seed gum, Tragacanth gum, pectin, and coating formulation with corn flour on oil absorption rate, moisture loss, and color of white skin slices of fried watermelon was studied. The results indicated that due to the controlling role of water in the amount of oil absorption, the amount of oil in all the samples coated with gum and corn flour was decreased compared to the samples coated with gum and the samples without coating. The pretreatment of osmotic dehydration reduces oil absorption in compared to fresh and blanched samples. The color changes in the sample with two pre-treatments of osmosis and blanching were less than other samples, as a result, the brightness of this sample was also higher than others. The lowest amount of oil absorption was observed in samples coated with basil gum and 0.5% and 1% corn flour (0.33 and 0.29, respectively). The highest amount of moisture loss during frying was related to the coated samples was observed with the combination of basil gum and corn flour (0.5%) and pectin and corn flour (2%). The highest level of antioxidant activity of the fried samples was related to the sample coated with 0.5% basil gum. Significant color changes were also observed in the coated samples.

Sodium metabisulfite in dried plum and its cytotoxic effects on K-562 and L-929 normal cell lines.

In the present study, the concentration of sodium metabisulfite (SMB) in dried plums and its toxicity effects on the cell lines of K-562 (human leukemia cell line) and L-929 (normal fibroblast cell line) were measured. Samples of dried plums were randomly collected from the shops located in Neyshabur and Mashhad (Iran). SMB residue was measured using iodometric titration and high-performance liquid chromatography. To analyze the cytotoxicity, the cells were treated with various concentrations of SMB, and cell viability was determined by the MTT and LDH methods. The average concentration of SMB in the samples of dried plums was selected to evaluate the apoptosis/necrosis by flow cytometer. The expression analysis of apoptosis marker genes (BAX, Bcl-2, and P53) was also assessed. Results indicated that the average concentration of SMB residue in 12 samples of dried plum was 516 ± 285.39 mg/kg. When K-562 cells were treated with 500 mg/L of SMB, apoptosis increased significantly (p < 0.01). The IC50 of SMB for K-562 and L-929 cells after a 48-h exposure was 200.31 and 257.82 mg/L, respectively. SMB-treated cells showed that cell viability in both cell lines decreased in a dose-dependent manner after 72 h (p < 0.01). The percentage of apoptotic but not necrotic cells was 69.49% for K-562 and 77.32% for L-929 cells, whereas apoptosis of untreated control cells was 0.17%. Our findings also showed an opposite mRNA expression of Bcl-2 (anti-apoptotic marker) and Bax2 (pro-apoptotic marker) when k-562 cells were treated with SMB. The results indicated that the concentration of sulfite residue in some dried plums poses a cell toxicity risk for normal cells. PRACTICAL APPLICATION: The results of current study provide important information concerning the toxicological effects of SMB, and give a warning that it needs to be replaced by natural products for fruit drying processes.

Pomegranate seed clustering by machine vision.

Application of new procedures for reliable and fast recognition and classification of seeds in the agricultural industry is very important. Recent advances in computer image analysis made applicable the approach of automated quantitative analysis in order to group cultivars according to minor differences in seed traits that would be indiscernible in ocular inspection. In this work, in order to cluster 20 cultivars of pomegranate seed, nine image features and 21 physicochemical properties of them were extracted. The aim of this study was to evaluate if the information extracted from image of pomegranate seeds could be used instead of time-consuming and partly expensive experiments of measuring their physicochemical properties. After data reduction with principal component analysis (PCA), different kinds of overlapping between these two types of data were controlled. The results showed that clustering base on all variables of image features contain more similar cultivars with clustering base on physicochemical properties (66.67% for cluster 1, 75% for cluster 2, and 50% for cluster 3). Therefore, by applying image analysis technique, the seeds almost were placed in different pomegranate clusters without spending time and additional costs.

Applying an intelligent model and sensitivity analysis to inspect mass transfer kinetics, shrinkage and crust color changes of deep-fat fried ostrich meat cubes.

The objectives of this study were to use image analysis and artificial neural network (ANN) to predict mass transfer kinetics as well as color changes and shrinkage of deep-fat fried ostrich meat cubes. Two generalized feedforward networks were separately developed by using the operation conditions as inputs. Results based on the highest numerical quantities of the correlation coefficients between the experimental versus predicted values, showed proper fitting. Sensitivity analysis results of selected ANNs showed that among the input variables, frying temperature was the most sensitive to moisture content (MC) and fat content (FC) compared to other variables. Sensitivity analysis results of selected ANNs showed that MC and FC were the most sensitive to frying temperature compared to other input variables. Similarly, for the second ANN architecture, microwave power density was the most impressive variable having the maximum influence on both shrinkage percentage and color changes.