## 3 Results  
This study provides a comprehensive evaluation of GSE and BE from Romania-grown black grapes' skin and blackberries including extraction methods and characterization. Solvent extraction of phenolic compounds from fresh, dried, or freeze-dried fruit materials has been the most common method in fruit sample preparation. The solvents generally used were methanol, ethanol, acetone, water, and their mixtures. To obtain high yield of anthocyanins in the extract, solvents were usually mildly acidified to facilitate the liberation and solubilisation of anthocyanins from the fruit tissue and to stabilize anthocyanins as well. The relative recovery efficiency between solvents varied with different plant materials. For example, it was found that methanol was 20% more effective than ethanol and 73% more effective than water in recovering anthocyanins from grape pomace [34]. However, water was more effective in recovering anthocyanins from purple corn waste than acidified water or ethanol [32]. In addition to the solvent system, other factors such as temperature and time are important. It has been reported that elevated temperature improves extraction efficiency due to enhanced solubility and the diffusion rate of compounds into the solvent. However, high temperature accelerates anthocyanin degradation in the extraction process. A few extraction technologies, such as pressurized liquid extraction, have been developed to enable the rapid extraction of anthocyanins and other phenolics at high temperatures (>50 \({}^{\circ}\)C) [35], and they were found to be successful in retarding anthocyanin degradation during processing. It was also found that ultrasound-assisted solvent extraction was more efficient for extracting anthocyanin than conventional solvent extraction due to the strong disruption of the fruit tissue under ultrasonic acoustic cavitation [36]. An ultrasound-assisted acidified ethanol and methanol extraction method was used for grape skin and blackberry extracts preparation. Total anthocyanin (TA) and phenolic content (TC), polymeric colour (PC), and the total antioxidant activity (TAC) of the grape skin and blackberry extracts are shown in Table 1.  
Using the same extraction method, it was found that the total anthocyanin and phenolic content, polymeric colour, and total antioxidant activity were comparable between grape skin and blackberry extracts. It was found that blackberries had a higher content of both polyphenols and anthocyanins and significantly increased polymeric colour, both for extraction with ethanol and methanol, but the TAC values were higher for ethanol extracts than the methanol extracts. In addition, the percentage of polymeric colour was about 45% higher for blackberries and about 35% for ethanolic extracts, indicating that more polymeric browning products were extracted from blackberry than grape skin. To investigate the effect of the extraction solvents with different ethanol to water ratios on the properties of the extracts, a series of GSE and BE were prepared from grape skin puree and blackberry puree using a solvent system with 0 to 100% ethanol content and two (one for grape skin and one for blackberry) extracts with 80% methanol content. As shown in Figure 3, the GSE and BE obtained using solvents with 25-70% ethanol contained about the same content in total polyphenols, the largest amount being obtained when 50% ethanol was used, while the same amount was obtained when 80% methanol was used for blackberries. For both blackberries and grapes, 80% methanol was the most effective, but in order to further study biological effects (such as anti-tumour effect), it is indicated to use ethanol, methanol being toxic for living beings.