Extract of Ellagitannins starting with Strawberries (Fragaria sp.) and Blackberries (Rubus sp.)

Abstract Characterize the content of phytochemical compounds present in samples of extracts of strawberry (Fragaria sp.) and blackberry (Rubus sp.). The extraction of said compounds was carried out with solutions of polar solvents, such as acetone, ethanol and methanol, using an experimental design with three factors: state of maturity, resting time and temperature. The characterization of these fruits is the beginning of the utilization mainly of ellagitannins to produce ellagic acid. Total phytochemical content was determined by spectrophotometric techniques, for phenolic content it was used Folin-Ciocalteu, for flavonoids it was determined with aluminium chloride, the antioxidant activity was evaluated by the methods of DPPH and ABTS+, the bactericidal effect of the extracts was shown for strains of E. coli and S. aureus. The determination of ellagitannins was performed by spectrometry. The influence of the state of maturity on the response variable was evaluated; it was observed that concentration of phytochemicals increases proportionally to maturity stage. The antioxidant activity was evaluated, determining that extracts obtained exhibit 94% - 95% inhibition. The determination of ellagitannins, finding that the highest concentration of ellagitannins was found in a state of green maturity, for strawberries as well as blackberries.

摘要 本研究旨在表征草莓（*Fragaria* sp.）与黑莓（*Rubus* sp.）提取物样品中含有的植物化学物质含量。本研究以丙酮、乙醇、甲醇等极性溶剂提取目标化合物，实验设计涵盖三个影响因子：成熟度、静置时间与提取温度。对该类果实的化学表征工作，是后续以其鞣花单宁（ellagitannins）为主要原料制备鞣花酸（ellagic acid）的前置基础。总植物化学物含量采用分光光度法测定；酚类物质含量采用福林-酚（Folin-Ciocalteu）法测定，黄酮类物质含量以氯化铝显色法测定；抗氧化活性通过DPPH与ABTS+法评估；提取物对大肠杆菌（*E. coli*）与金黄色葡萄球菌（*S. aureus*）菌株具有杀菌活性。鞣花单宁的含量采用光谱法测定。本研究评估了成熟度对响应变量的影响，结果显示植物化学物浓度随成熟度提升呈线性递增趋势。抗氧化活性测试结果表明，所制备的提取物抑制率可达94%~95%。鞣花单宁含量测定结果显示，草莓与黑莓的鞣花单宁最高浓度均出现在青绿成熟阶段。