The Effect of Different Pulsed Electric Field Treatments on Producing High Quality Red Wines

The aim of this study was to apply different Pulsed Electric Field (PEF) treatments in the pre-maceration stage of the mash which derives from ‘Pinot Noir’ and ‘Merlot’ grapes that were harvested in the Crişana-Santimreu vineyard, Romania, in 2016, in order to increase the content of total phenols, flavonoids, monomeric anthocyanin pigment and colour intensity of ‘Pinot Noir’ and ‘Merlot’ wines. The electrical and mechanical parameters that represent the variables in this experiment were: the distance between the drums, different voltages (7-8 kV), and different frequencies (178-344 Hz). The wines obtained were also analyzed in terms of the antioxidant capacity using two different methods. All PEF treatments applied in the pre-maceration stage resulted in an increase in bioactive compounds content and colour intensification. Of the five PEF treatments tested, the PEF treatment using the distance between the drums of 2.5 mm, U = 8 kV, the frequency f = 344 Hz, pulse durations of 300 s resulted in a wine with a content of total phenols 2 times and 1.5 times higher than the control sample in the case of ‘Pinot Noir’ and ‘Merlot’, respectively. Also, this type of PEF treatment also resulted in an extraction of the total flavonoids as efficiently as 1.8 times and 1.4 times, respectively, in the case of ‘Pinot Noir’ and ‘Merlot’, respectively. PEF treatment is a technology suitable for extracting phenols from grapes and so this technology can be used in the food industry to obtain wines rich in bioactive compounds with antioxidant capacity

Influence of Pasteurization on Total Phenols Content and Antioxidant Capacity of Prunus persica L. Juices

Peach and nectarine (Prunus persica ) production has an important place in the world, being the most important fruit after apple crops in the European Union. Because the fruits are perishable, it is desirable to valorize them as juice. Seven peaches and three nectarines cultivars grown in the N-W part of Romania were investigated for quality parameters, volatile profile, total phenols content and antioxidant capacity. The volatile composition of peach and nectarine cultivars was determined via the ITEX/GC-MS technique, the main volatile compounds belonging to alcohols and aldehydes. Another objective was to obtain the pasteurised juices from these fruits and to investigate the best time of pasteurisation in order to identify the most valuable cultivar from the perspective of total phenols content and its antioxidant capacity. For a better interpretation of results and a proper discrimination between cultivars, according to the total phenols content and antioxidant capacity, the multivariate analysis, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were applied. The peach cultivars showed the highest content in total phenols compared with nectarine. From peach cultivars, the highest concentration was recorded in ‘Southland’ (47.49 ± 0.14 mg GAE 100 g-1 FW) and from nectarine cultivars in ‘Romamer’ (16.28 ± 0.83 mg GAE 100 g-1 FW). The highest antioxidant capacities were recorded in ‘Southland’ peach in the case of both methods (DPPH and FRAP). The results showed that ‘Southland’ peach and ‘Romamer’ nectarine pasteurised juices are the best from the point of view of total phenolic compounds content with high antioxidant capacity

Phytochemical profile, antioxidant capacity and wound healing potential of Viscum album L. growing on Robinia pseudoacacia L.

Mistletoe (Viscum album L.), a semi-parasitic medicinal plant, continues to be of interest, due to its phytochemical composition. The leaves of mistletoe contain phenols, which have a variety of biological effects. The main goal was to characterize the mistletoe that parasitized Robinia pseudoacacia L., (called VAR) in terms of phenolic compounds and to assess the wound healing potential in vitro using the scratch method. Furthermore, the antioxidant capacity was evaluated both by spectrophotometric techniques (DPPH, FRAP, TEAC), as well as by the ability of the mistletoe extract to synthesize green selenium nanoparticles. Among the phenolic acids, dihydroxybenzoic acid is in high level (2.86±0.03 mg/g dw), whereas isorhamnetin-glucuronides dominate the flavonol class (0.593±0.03 mg/g dw). The presence of phenolic compounds in the VAR leaves provides antioxidant capacity. The reducing capacity of VAR extract was demonstrated for the first time by the biosynthesis of nanoselenium particles (NSePs) with a regular, spherical shape and a diameter of around 130 nm. The VAR concentrations of 25-200 µg/mL showed no toxic effect on normal human dermal fibroblasts (NHDF), and the concentration of 100 µg/mL exhibited the best percentage of wound surface closure in vitro (94.08%). The results show that mistletoe is a promising plant because of its phytochemical composition and antioxidant capacity, which can modulate the wound repair process in vitro