The Acute Effect of a Novel Miso-Type Sauce, Enhanced with a Carotenoid-Rich Extract from Fruit By-Products, on Postprandial Biomarkers of Oxidative Stress and Inflammation.

Several fruit by-products may exert a beneficial role on oxidative stress and inflammation modulation, providing essential bioactive components, such as polyphenols and carotenoids. Recently, the potential bioactivity of miso has been reported. The aim of this dietary intervention−clinical study was to evaluate the acute effect of a novel, functional miso-type sauce based on legumes, on postprandial biomarkers of oxidative stress and inflammation. In this randomized, cross-over design, intervention−clinical trial, 14 healthy volunteers, aged 20−30 years old, consumed a rice meal rich in fat and carbohydrates (258 g), containing a legume-based sauce. After a 1-week washout period, the same subjects consumed the same meal, containing the novel fermented miso-type sauce, enhanced with 50% carotenoid-rich, fruit peel extract. Differences in postprandial total plasma antioxidant capacity according to the FRAP method, serum lipids, glucose, uric acid levels, and antithrombotic activity in platelet-rich plasma were evaluated before, 30 min, 1.5 h, and 3 h after consumption. The results showed that, in comparison to the control group, consumption of the novel sauce resulted in a significantly increased total plasma antioxidant capacity 3 h after consumption (p < 0.05). In addition, we observed a significant attenuation of triglycerides concentration increase in the last 1.5 h in the functional group (p < 0.05). A significant decrease in serum aggregation was found at 30 min and 3 h after functional sauce intake in comparison with the baseline (p < 0.05). Finally, LDL-cholesterol concentrations were significantly reduced 3 h after the functional meal consumption, in comparison with baseline values (p < 0.05). The remaining biomarkers did not show statistically significant differences (p > 0.05). Further investigation is needed in order to validate the current results.

Postprandial Bioactivity of a Spread Cheese Enriched with Mountain Tea and Orange Peel Extract in Plasma Oxidative Stress Status, Serum Lipids and Glucose Levels: An Interventional Study in Healthy Adults.

Postprandial lipemia, glycemia and oxidative stress may affect the occurrence of cardiovascular disease. The purpose of the present intervention study was to investigate the effect of a spread cheese enriched with mountain tea (Sideritis sp.) and orange peel (Citrus sinensis) extract on postprandial metabolic biomarkers in healthy volunteers. In a cross-over design, 14 healthy subjects 20-30 years old were consumed either a meal rich in fat and carbohydrates (80 g white bread, 40 g butter and 30 g full fat spread cheese) or a meal with the spread cheese enriched with 6% mountain tea-orange peel extract. Differences in postprandial total plasma antioxidant capacity, resistance of plasma to oxidation, serum lipids, glucose and uric acid levels were evaluated at 0, 1.5 and 3 h after consumption. Plasma total antioxidant capacity was significantly increased 3 h after the consumption of the meal in the presence of the extract-enriched cheese, compared to the conventional cheese (p = 0.05). Plasma resistance to oxidation was increased at 30 min in the Functional meal compared with the Control meal. A tendency to decrease the postprandial rise in glucose and triglyceride levels, 1.5 h and 3 h, respectively, after the intake of the meal with the extract-enriched cheese was observed (p = 0.062). No significant changes in the concentrations of the remaining biomarkers studied were observed (p > 0.05). Further studies with a larger sample are needed in both healthy adults and patients with cardiovascular disease to draw safer conclusions about the postprandial effect of the extracts on metabolic biomarkers that predict cardiovascular risk.

Optimization of Silver Nanoparticle Synthesis by Banana Peel Extract Using Statistical Experimental Design, and Testing of their Antibacterial and Antioxidant Properties.

BACKGROUND: In this study, silver nanoparticles (AgNPs) were synthesized using Banana Peel Extract (BPE), and characterized using UV- Vis absorbance spectroscopy, X-Ray Powder Diffraction (XRD), Atomic Force Microscopy (AFM), and Fourier Transform Infrared Spectroscopy (FTIR). UV-Vis absorbance spectroscopy showed the characteristic plasmon resonance of AgNPs at 433 nm. The synthesized AgNPs were tested for their antibacterial and antioxidant properties. METHODS: Nanoparticle size (between 5 and 9 nm) was measured using AFM, whereas their crystallinity was shown by XRD. FTIR identified the ligands that surround the nanoparticle surface. The synthesis conditions were optimised using Central Composite Design (CCD) under Response Surface Methodology (RSM). Silver nitrate (AgNO3) and BPE concentrations (0.25-2.25 mM, 0.2-1.96 % v/v respectively), incubation period (24-120 h) and pH level (2.3-10.1) were chosen as the four independent factors. The fitting parameters (i.e. the wavelength at peak maximum, the peak area, and the peak width) of a Voigt function of the UV- Vis spectra were chosen as the responses. The antibacterial properties of the AgNPs were tested against Escherichia coli and Staphylococcus aureus using the tube dilution test. The synthesized nanoparticles were tested for total phenolic composition (TPC) using the Folin - Ciocalteau method, whereas their radical scavenging activity using the 1,1-diphenyl-2- picrylhydrazyl (DPPH) free radical assay. RESULTS: An optimum combination of all independent factors was identified (BPE concentration 1.7 % v/v, AgNO3 concentration 1.75 mM, incubation period 48 h, pH level 4.3), giving minimum peak wavelength and peak width. The nanoparticles inhibited the growth of E. coli, whereas S. aureus growth was not affected. However, no superiority of AgNPs compared to AgNO3 used for their fabrication (1.75 mM), with respect to antibacterial action, could be here demonstrated. AgNPs were found to present moderate antioxidant activity (44.71± 3.01%), as measured using DPPH assay, while the BPE (used for their fabrication) presented alone (100%) an antioxidant action equal to 86±1%, something expected due to its higher total phenolic content (TPC) compared to that of nanoparticles. CONCLUSION: Altogether, the results of this study highlight the potential of an eco-friendly method to synthesize nanoparticles and its promising optimization through statistical experimental design. Future research on the potential influence of other synthesis parameters on nanoparticles yield and properties could further promote their useful biological activities towards their successful application in the food industry and other settings.