Ina Jasutienė

Biosynthesis of silver nanoparticles using lingonberry and cranberry juices and their antimicrobial activity

In this study lingonberry and cranberry juices were used for silver nanoparticle synthesis. The berry juices were characterized by total phenolics, total anthocyanins and benzoic acid content, respectively 1.9-2.7mg/ml, 55.2-83.4mg/l and 590.8-889.2mg/l. The synthesis of silver nanoparticles was performed at room temperature assisting in solutions irradiated by ultraviolet for 30min. Ultraviolet-visible (UV-vis) spectroscopy and microscopy confirmed the formation of nanoparticles as well as the dark red color of colloid of silver samples showed the formation of stable nanoparticles. Broad localized surface plasmon resonance (LSPR) peaks in UV-vis spectra indicated the formation of polydispersive silver nanoparticles and LSPR was observed at 485nm and 520nm for the silver nanoparticles synthesis using lingonberry and cranberry juices, respectively. The antimicrobial activity of silver nanoparticles was determined against the reference strains of microorganisms that could be found in food products: Staphylococcus aureus ATCC 25923, Salmonella typhimurium ATCC 13076, Listeria monocytogenes ATCC 19111, Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633, Candida albicans ATCC 10231 and foodborne B. cereus producing and non-producing enterotoxins. Silver nanoparticles showed a broad spectrum of antimicrobial activity and were most active against S. aureus ATCC 25923, B. subtilis ATCC 6633 and B. cereus ATCC 11778 reference cultures, and less active against C. albicans ATCC 10231 and foodborne B. cereus. It can be concluded that lingonberry and cranberry juices could be used as bioreductants for silver ions.

Investigations of anthocyanins, organic acids, and sugars show great variability in nutritional value of European cranberry ( Vaccinium oxycoccos ) fruit

Increased consumer interest in nutraceutical-rich foods in relation to human health has resulted in the increased use of cranberries in the modern diet. Berries of wild European cranberry clones and cultivars show great variation in yield, colour and quantities of biologically active compounds. In the present study, we estimate the production of different phytochemical components in 40 genotypes of Vaccinium oxycoccos. Our main goal was to identify genotypes that have superior economic attributes, such as high levels of anthocyanins, organic acids and easily digestible carbohydrates. As a result, two wild clones of Lithuanian origin (98-C-17 and 98-C-15), and the Estonian cultivar ‘Maima’ were selected as the most valuable in terms of TAC, organic acid, fructose and glucose concentrations.