Comprehensive study of phenolic profile and biochemical activity of monovarietal red and white wines from Fruska Gora region, Serbia.

This paper presents a comprehensive study of commercially available monovarietal red and white wines from Fruska Gora mountain in Serbia, conducted to characterize their chemical and biochemical properties. Namely, 72 wines of 18 different Vitis vinifera varieties, including international, domestic and autochthonous ones, were assessed. Phenolic profile of wines was determined qualitatively, using spectrophotometric methods, and quantitatively, using LC-MS/MS and HPLC-UV/VIS methods. Quantified phenolic compounds pointed out differences between red and white wines, where some compounds stood out as distinctive characteristic of analyzed varieties, while others served as chemotaxonomic markers of the Fruska Gora region. Antioxidant and inhibitory properties towards acetylcholinesterase were evaluated for all wines and their relation to phenolic composition was investigated. This study is valuable since chemical and biochemical properties of domestic and autochthonous Fruska Gora varieties are reported for the first time. Also, international varieties studied herein gave distinctive information about the terroir of Fruska Gora region, which is scarce in scientific literature.

Advance diversity of enzymatically modified arabinoxylan from wheat chaff.

Hydrolysates of arabinoxylan extracted from wheat chaff were prepared using different enzymatic treatments with an emphasis on improvements in their anti-diabetic, antioxidant and functional characteristics. The extracted arabinoxylan was subjected to enzymatic hydrolysis using individual xylanase, arabinofuranosidase, and feruloyl esterase, and their combinations. In all obtained hydrolysates, peaks corresponding to molecular weight lower than 38 kDa were noticed, while non-hydrolysed arabinoxylan had only peaks corresponding to 580 and 38 kDa. Results indicated that applied enzymes could hydrolyse polymeric arabinoxylan while their synergistic actions successfully modified its structure reflecting in lowered viscosity. Besides, it has been observed that the synergistic actions of enzymes improved the biological activities of arabinoxylan more than twice. Chemometric classification analysis showed that synergistic enzymes' actions were predominantly responsible for the improvement of biological activities. It indicated that they might be a useful tool for diversification and enhancement of biological activities of arabinoxylan from wheat chaff.

Environmental-friendly technologies for the production of antioxidant xylooligosaccharides from wheat chaff.

Ultrasound irradiation and enzymatic hydrolysis were applied for the production of antioxidant xylooligosaccharides from wheat chaff. To facilitate enzyme action, 3% (w/w) suspension of raw material was pretreated by ultrasound at 25Hz, 540W for 10min. Ultrasound treatment released xylooligosaccharides with predominant xylotriose into liquid fraction which expressed 1.03±0.01 (µmolAAE/g) ABTS radicals-scavenging activity. Endo-xylanase action on pretreated wheat chaff released 21.76±1.42 and 32.3±0.75mg reducing sugars equivalents/g after 24h when applied at dosages 0.15 and 0.3U/g. respectively. With increase in reaction time portion of xylotriose and xylotetraose in hydrolysates was increase relatively to xylopentose as well as quantities of xylose and glucose. Extremely significant inverse correlation between monosaccharides/oligosaccharides ratio and ABTS radical-scavenging activity was determined. Results indicated potential of environmental friendly ultrasound and enzymatic technologies for the production of xylooligosaccharides from wheat chaff for potential food application.