METHODS: 1.5% (w/v) chitosan films with Chrysanthemum morifolium essential oil (0% to 6% (v/v)) were produced through homogenization, the casting of a film solution in a petri dish and convection drying. The edible film was evaluated in terms of its physical (color, thickness, water vapor permeability), mechanical (puncture strength, tensile strength, elongation at break) and chemical properties (antioxidant assay, Fourier Transform Infrared Spectroscopy (FTIR)).
RESULTS: With an increasing concentration of Chrysanthemum morifolium in the chitosan film, the test values of physical properties such as tensile strength, puncture force, and elongation at break declined significantly. However, the thickness, water permeability, and color profile (L*, a*, b*) values of the chitosan film increased. Similarly, the scavenging effect of antioxidant assay increased (from 4.97% to 18.63%) with a rise in Chrysanthemum morifolium concentration. 2%, 3%, and 4% of Chrysanthemum morifolium in the chitosan film showed a significant inhibition zone ranging from 2.67 mm to 3.82 mm against Staphylococcus aureus, a spoilage bacterium that is commonly found in chicken and beef products. The storage and pH tests showed that 4% of Chrysanthemum morifolium in the film maintained pH level (safe to consume), and the shelf life was extended from 3 days to 5 days of meat storage.
CONCLUSIONS: This study demonstrated that the incorporation of 4% (v/v) Chrysanthemum morifolium extract into 1.5% (w/v) chitosan film extends the storage duration of raw meat products noticeably by reducing Staphylococcus aureus activity. Therefore, it increases the quality of the edible film as an environmentally friendly food packaging material so that it can act as a substitute for the use of plastic bags. Future studies will be conducted on improving the tensile strength of the edible film to increase the feasibility of using it in the food industry. In addition, the microstructure and surface morphology of the edible film can be further determined.
MATERIAL AND METHODS: Nine electronic databases and manual search were applied to detect available publications. A meta-analysis using a fixed- or random-effect model was performed to measure standardized mean difference (SMD) with 95% confidence interval (CI). The National Institute of Health (NIH) tools for observational cohort, cross-sectional, and case-control studies were used to examine the risk of bias. The protocol was recorded in PROSPERO with CRD42017060230.
RESULTS: A total of 38 articles were found including 19 case-control, 11 cross-sectional and 8 prospective cohort studies. We indicated that Th2 cytokines (IL-4, IL-6, IL-8) and Th17 cytokine (IL-17) in dengue patients were notably higher than in a healthy control group in acute phase (SMD = 1.59, 95% CI [0.68, 2.51], p = 0.001; SMD = 1.24, 95% CI [0.41, 2.06], p = 0.003; SMD = 1.13, 95% CI [0.61, 1.66], p<0.0001; SMD = 1.74, 95% CI [0.87, 2.61], p<0.0001), respectively.
CONCLUSIONS: This study provides evidence of the significant roles of IL-4, IL-6, IL-8, IL-10 and IL-17 in the pathogenesis of developing a severe reaction in dengue fever. However, to fully determine the association of Th cytokines with dengue, it is necessary to perform further studies to assess kinetic levels during the duration of the illness.