Levels and management of glycosidic nitrile production in North American grown barley varieties
Bibliographic record
Abstract
Glycosidic nitrile (GN) from malted barley has been identified as the primary precursor of ethyl carbamate (urethane) in new-make whiskey. A specific GN, epiheterodendrin (EPH), is responsible. EPH is a type of cyanogenic glycoside, forming toxic hydrogen cyanide in the pathway leading to ethyl carbamate (EC). The presence of EC, a known carcinogen in many fermented foods, is regulated to varying degrees. For whiskey, the Canadian government has mandated a 150 ppb limit, while the US has a voluntary limit of 125 ppb. In Europe, standards call for newly released distilling barleys to be of the non-GN type. North American breeders are just beginning to select for non-GN and options are likely a decade away. This work considers GN levels of common North American varieties and evaluates malting regime variations, including steep out moisture (40 percent and 45 percent), length of germination (two, four, and six days), and temperature (14 °C, 15 °C and 16 °C) to determine impacts on GN. General standards hold that low producers fall under 0.5 g/tonne GN while high producers sit over 1.5 g/tonne. Varieties tested here averaged 0.20 – 1.52 g/tonne across treatments. As expected, management to minimize acrospire growth mitigated GN while all three process variations had significant impacts: ranges being 0.70 – 1.38 g/tonne (germination time), 0.83 – 1.09 g/tonne (temperature) and 0.56 – 0.96 g/tonne (steep out moisture). While this work does not provide a long-term solution, management is a tool while breeding programs develop North Americana non-GN varieties.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".