New Approach to Food Packaging: Antimicrobial and Edible Materials
In addition to adequate and balanced nutrition in the protection of human health, the reliability of consumed foods is also of great importance. When foods contact with the environment, they are undergoing many microbiological, physical and chemical changes such as moisture loss, aroma exchange, oxidation and contamination with microorganisms. So this changes reduce quality and shorten the shelf life. During cutting and processing of chicken meat, especially contamination on the surface causes deterioration of the meat starting from the surface and thus short shelf life. Though contamination of chicken meat surface is inevitable, growth of contaminant microorganisms can be inhibited and microorganisms can be killed. In recent years, increased risks of infection due to antibiotic-resistant microorganisms have forced the discovery of new and natural antibacterial materials. It is a new and advantageous approach to avoid environmental pollution caused by the use of food packaging and safety of food, prolongation of product shelf life by natural, edible, antibacterial biomolecules in packaging products. In the scope of the project, in order to produce an edible alginate gel containing the antimicrobial peptide nisin, which has an antibacterial property to prevent microbial growth on the surface of chicken meat, following steps was done; Synthesis of calcium alginate and nisin immobilized calcium alginate beads Optimization of immobilizing nisin in calcium alginate beads, Characterization of nisin immobilized calcium alginate beads by ATR-FTIR Spectrum and SEM Analysis, Determination of the antimicrobial activity of white meat product chicken which is coated by nisin immobilizing calcium alginate gel.
Phytochemical screening and evaluation of antiangiogenic properties of sapinit (Rubus fraxinifolius) fruit crude extracts
Plants are potential low-cost alternatives for cancer treatment. Rubus fraxinifolius or “sapinit” has been found to possess phytochemicals with anti-cancer potential. This project aimed to evaluate the antiangiogenic properties of methanolic R. fraxinifolius fruit crude extracts through the chick chorioallantoic membrane (CAM) assay. Through phytochemical screening, leucoanthocyanins, phenols, and tannins were detected. For the CAM assay, 10, 20, and 30 μg/μL extracts, distilled water, methanol, and retinoic acid were applied on 60 ten-day-old chicken eggs. The CAM photographs were analyzed using ImageJ Software. The mean percent inhibitions (MPI) of total length and vascular density from both analyses were subjected to One-Way Analysis of Variance (ANOVA). The ANOVA for the MPI of total length, followed by a Tukey post hoc test, show that only retinoic acid treatment has significantly higher MPI (p = 0.0010). Meanwhile, the results for the MPI of vascular density show no significant differences between all groups (p = 0.1630). It is possible that the concentrations used in the study may not be the concentrations needed to achieve optimal antiangiogenesis. The results may also be due to the absence of phytochemicals that exhibit significant antiangiogenic properties such as alkaloids. Lower concentrations and isolated phytochemicals may also be tested.
BIOINFORMATIC PREDICTION OF CORONAVIRUS (SARS-COV-2) MUTATIONS THAT INCREASE CONTAGIOUSNESS
Inhibitory effects of the secondary metabolite of actinomycete were examined on cell cycle of the yeasts of S. pombe and S. cerevisiae. The secondary metabolite was obtained from cultivation of the actinomycete isolated from the soil of Owakudani in Hakone, Japan. The fifth fraction of the secondary metabolite by ODS column separation (HK-T5), which was soluble to pure methanol, was used in the present experiments. The HK-T5 brought about the delay of forming colonies of S. pombe for about 11 days compared to that cultivated without the HK-T5. The delay of the colony formation was longer for the S. pombe cultivated with more amount of the HK-T5. The cultivation with HK-T5 also brought about the extension of the lifespan of the S. pombe for more than 10 weeks in a liquidus medium. The cell life recovered the ordinary manner by removal of the HK-T5, meaning that the activities of the HK-T5 is reversible. These facts confirm the suppression of cell cycle, and the delay of cell growth by the HK-T5. These phenomena were similarly observed for S. cerevisiae. Comparison of the action of HK-T5 with hydroxyurea, which is an anticancer drug inhibiting the cell cycle at S phase, clarified that the inhibitory action of HK-T5 worked at the phase earlier than S phase. The combined effects of HK-T5 on the cell cycle were evaluated with triamcinolone acetonide (TA), or aspirin, the former of which is a drug synchronizing cancer cells in S phase, and the latter keeping human cells in G1/G0 phases. The combined use of HK-T5 with TA synchronized the cells at the phase slightly proceeding from G1 to S phase without toxicity. On the other hand, the combined use with aspirin made the inhibitory effect of HK-T5 inactive. Hence, the HK-T5 is attractive as a drug for the extension of cell lifespan, and anticancer therapy.