Yield, Content, and Composition of Peppermint and Spearmints as a Function of Harvesting Time and Drying
Bibliographic record
Abstract
Peppermint ( Mentha × piperita L.) and spearmints ('Scotch' spearmint, M. × gracilis Sole, and 'Native' spearmint, Mentha spicata L.) are widely grown essential oil crops in more northern latitudes; however, there is limited information on how harvest time and drying influence peppermint and spearmint yield, oil composition, and bioactivity, when grown south of the 41st parallel. In this 2-year study, the effects of harvest time and drying on the yield, oil composition, and bioactivity of peppermint ('Black Mitcham' and 'B90-9'), 'Scotch' spearmint, and 'Native' spearmint were evaluated. Peppermint oil from the dried material had higher menthol and eucalyptol concentrations. Menthone in both peppermint cultivars decreased from harvest 1 (late June) to harvest 5 (late August) or 6 (early September), whereas menthol increased. (-)-Carvone in spearmints accumulated early, before flowering, allowing for early harvest. Oil yields from the dried spearmint biomass reached the maximum at harvest 3 (mid-July). The essential oil compositions of the four mint genotypes were similar to that of 11 commercially available oils, suggesting that these genotypes can be grown in the hot, humid environment of the southeastern United States. The antioxidant activities (ORAC(oil) values) of the essential oils were 4372, 1713, 1107, and 471 μmol of TE L(-1) for 'Scotch' spearmint, 'Native' spearmint, peppermint, and Japanese cornmint ( Mentha canadensis ), respectively. The oils of the four mint genotypes did not affect ruminal fermentation in vivo, and did not exhibit antimicrobial, antileishmanial, or antimalarial activity at levels that would warrant bioassay-directed fractionation in a drug-discovery screening program. Specifically, the oils did not show greater than 50% growth inhibition against Leishmania donovani , Plasmodium falciparum clones D6 and W2, Candida albicans , Escherichia coli , Pseudomonas aeruginosa , Cryptococcus neoformans , Mycobacterium intracellulare , or Aspergillus fumigates at 50 μg mL(-1).
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".