Phytochemical characterization and antimicrobial evaluation of young leaf/shoot and press cake extracts from Hippophae rhamnoides L

摘要

The chemical components, as well as antioxidant and antimicrobial activities of extracts derived from the young leaves/shoots and press cake of sea buckthorn (SBT) (Hippophae rhamnoides L.) were studied. The chemical analysis of the ethanolic extracts by liquid chromatography-mass spectrometry (LC-DAD-ESI-MS/MS) led to the identification and quantification of 20 individual hydrophilic compounds including phenolic acids, flavonols, flavan-3-ols, and proanthocyanidins. The results of this study imply that DPPH. radical scavenging of each polyphenol acts independently. The relative speed of the reaction depends predominantly on each compound's chemical structure rather than its concentration. The extracts from SBT leaves/shoots and press cake, dissolved in water after the removal of ethanol, showed a significant antimicrobial activity against Gram-positive aerobic or facultative anaerobic and Gram-negative pathogenic bacteria, which included Bacillus spp. and the Enterobacteriaceae family (Salmonella spp., Escherichia coli, Yersinia pestis, Klebsiella, and Shigella). The study confirmed that SBT extracts obtained using 20% EtOH are promising antimicrobial agents, their preparation is cost efficient, and uses neither toxic reagents nor any expensive extraction techniques. The analysis of microbiological contamination of chicken and pork meat showed that these samples could be stored for 72 h using accelerated spoilage conditions at 22 degrees C, and relative air humidity of 39%, and only slightly exceed limits for Enterobacteriaceae.