Biotransformation of propolis phenols by L. plantarum as a strategy for reduction of allergens.

Propolis is a natural product produced by honeybees. It has antioxidant effects as well as antimicrobial, antiseptic, antibacterial, anti-inflammatory and antimutagenic properties. Except these important healthy properties some cytotoxic effects causing allergies also have been reported. In this study have been evaluated changes of phenolic compounds including allergens molecules found in propolis. Before biotransformation, propolis samples were treated with different solvent (ethanol and polyethylene glycol) to facilitate solvation of solid samples. Biotransformation was done by three different strains of Lactobacillus plantarum (10, 8014, ATCC). Results demonstrated the importance of used solvent/treatment for extraction procedure and strains of L. plantrum. The lowest values of main allergens were determined as 321 ng/mL for BCAFE, 320 ng/mL for 1.1 DMAECAFE and 8.02 ng/mL for CAPE. The study is the first work deal with evaluation of bioconversion of propolis by different L. plantarum strains and their effects on phenolic profile.

Evaluation of colour parameters and antioxidant activities of fruit wines.

The evaluation of oenological colorimetric indexes, CIELAB parameters, total phenols and antioxidant activities has been studied in different fruit wines made from black mulberry, blackberry, quince, apple, apricot, melon, red raspberry, bilberry, sour cherry and strawberry. The highest value of antioxidant activities and total phenolic contents were determined in bilberry, blackberry and black mulberry wines (61.80%, 1161 mg/l gallic acid equivalents; 60.00%, 1232 mg/l gallic acid equivalents; 58.10%, 1081 mg/l gallic acid equivalents), respectively. The highest values for A420 nm, A520 nm, A620 nm, the proportion of blue, wine colour, wine total colour of pigments, wine polymeric pigment colour and K-K values logarithmic colour intensity) were determined in bilberry fruit wine. Positive correlation was found between antioxidant activities and total phenols (r=0.958, P = 0.001). The results of grouping of different parameters in n-dimensional space with different fruit wines demonstrated the importance of bilberry, blackberry and black mulberry wines as natural antioxidants and colourants.

Protection capacity against low-density lipoprotein oxidation and antioxidant potential of some organic and non-organic wines.

Current research suggests that phenolics from wine may play a positive role against oxidation of low-density lipoprotein (LDL), which is a key step in the development of atherosclerosis. Considering the effects of different wine-making techniques on phenols and the wine consumption preference influencing the benefical effects of the product, organically and non-organically produced wines were obtained from the grapes of Vitis vinifera origin var: Carignan, Cabernet Sauvignon, Merlot, Grenache, Columbard and Semillon. Levels of total phenols [mg/l gallic acid equivalents (GAE)], antioxidant activity (%) and inhibition of LDL oxidation [%, inhibition of diene and malondialdehyde (MDA) formation] were determined. Some phenolic acids (gallic acid, p-hydroxybenzoic acid, syringic acid, 2,3-dihydroxybenzoic acid, ferulic acid, p-coumaric acid and vanillic acid) were quantified by high-performance liquid chromatography equipped with an electrochemical detection carried at +0.65 V (versus Ag/AgCl, 0.5 microA full scale). The highest concentrations of gallic, syringic and ferulic acids were found in organic Cabernet Sauvignon; 2,3-dihydroxybenzoic acid in organic Carignan and p-coumaric and vanillic acids in non-organic Merlot wine. High levels of antioxidant activity (AOA), inhibition of LDL oxidation and total phenol levels were found in non-organic Merlot (101.950% AOA; 88.570% LDL-diene; 41.000% LDL-MDA; 4700.000 mg/l GAE total phenol) and non-organic Cabernet Sauvignon (92.420% AOA; 91.430% LDL-diene; 67.000% LDL-MDA; 3500.000 mg/l GAE total phenol) grape varieties. Concentrations of some individual phenolic constituents (ferulic, p-coumaric, vanillic) are correlated with high antioxidant activity and inhibition of LDL oxidation. The best r value for all examined characteristics was determined for gallic acid, followed by 2,3-dihydroxybenzoic, syringic, ferulic and p-coumaric acids. Negative correlation of vanillic with MDA and p-hydroxybenzoic acid with LDL were confirmed by principal component analysis (PCA) analyses. Red wines display a higher antioxidant activity (81.110% AOA) than white ones (19.512% AOA). The average level of LDL inhibition capacity in red wine was determined as 87.072% and for the white as 54.867%.