Investigation of Free and Bound Phenolic Profiles in Walnut Male Flowers during Ripening and Their Contribution to Antibacterial and Antioxidant Activities.

This study examined the dynamic changes in free and bound phenolic compounds in young and mature walnut male flowers (WMF, Juglans regia L.) during ripening alongside the total phenolic content, antioxidant potential, and antibacterial activity. Phenolic profiles were identified using LC-MS/MS. Distinct variations were observed between maturation and phenolic forms. Free phenolics were significantly dominant in young WMF; their levels decreased during maturation, with bound phenolics becoming predominant in the mature fraction. Bound fractions showed higher antioxidant activity (DPPH IC50: 34.33 μg/mL; ABTS IC50: 4.51 μg/mL), consistent with their higher total phenolic content. The bound fraction of mature flowers exhibited the strongest antibacterial activity against Bacillus cereus and Escherichia coli (MIC: 256 μg/mL). FTIR analysis demonstrated characteristic absorption bands of phenolic functional groups, while correlation analysis revealed associations between individual phenolics and antioxidant activity. The findings highlight the influence of phenolic form and maturity on the bioactive potential of WMF.

• Publication year

  2026

• Venue

  Journal of Agricultural and Food Chemistry

• Publication date

  2026-01-08

• Fields of study

  Biology, Medicine, Environmental Science

• Identifiers
  DOI 10.1021/acs.jafc.5c13295PMID 41503960
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar, PubMed

• No claims are published for this paper.

• No concepts are published for this paper.

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