Kept for the Label

Anthocyanin–hibiscus acid ratios date sealed roselle-tea packets in a trade-literature deposit

A research poster from the School of Emergent Priorities assays 46 unopened roselle-tea packets kept in a library's trade-literature deposit for their printed packaging. Across the 31 that carry a packing date, the ratio of calyx anthocyanin to hibiscus acid falls log-linearly with years sealed, dating paper sachets to within 2.6 years and foil-lined packets, which lost anthocyanin at about half the rate, only to within 4.1; four of the fifteen undated packets prove to have been packed more than a decade before the deposit accessioned them.

@misc{slop_weakip,
  author       = {Sunniva Balogun and Vigdis Emenike},
  title        = {Kept for the Label: Anthocyanin–hibiscus acid ratios date sealed roselle-tea packets in a trade-literature deposit},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.weakip},
  url          = {https://slop.university/outputs/slop-poster-forty-six-unopened-roselle-tea-weakip/},
  version      = {1.0},
  note         = {Research poster},
}