Gas Chromatography/Mass Spectrometry Chemical Profiling of Volatile Compounds from Cranberry Plant Byproducts as Potential Antibacterials, Antifungals, and Antioxidants.

The increasing resistance of microorganisms to currently used antimicrobials requires the urgent development of new effective treatments. Plant-based natural products can be an alternative solution. The aerial plant parts of the cranberry (Vaccinium macrocarpon) present a potential new source of antimicrobial secondary metabolites. Volatile essential oils were extracted from Stevens, Early Black, and Mullica Queen variety plants by steam distillation (SD) and the Clevenger method (CM), and their profiles were characterized by GC-MS. The extracts and two identified constituents, cinnamaldehyde and terpineol, were screened by the disc diffusion assay against Gram-positive B. cereus ATCC 11778 and S. aureus ATCC 25923 and Gram-negative bacteria E. coli ATCC 25922, P. aeruginosa ATCC 27853, and C. albicans ATCC 14053. Radical scavenging antioxidant activity was also determined using the DPPH assay. The CM extracts were rich in fatty acids, sesquiterpenes, and diterpenes, whereas the SD extracts contained more aldehydes, monoterpenes, and phenylpropanoids. All volatile extracts showed promising antioxidant activity; leaf extract activity was significantly higher than the vine (p < 0.05). The CM leaf and vine extracts exhibited antimicrobial activity against B. cereus, S. aureus, E. coli, and C. albicans compared to the SD, and the leaf extracts were more effective than the vine extracts. Individual constituents of leaf and vine extracts, cinnamaldehyde and α-terpineol, also showed antimicrobial activity against these organisms. The active constituents of the CM extracts are yet to be identified. A multivariate analysis revealed a particular pattern of inhibition of the tested organisms. Based on our results, cranberry volatile extracts have potential for future valorization as antibacterials, antifungals, and antioxidants.