16 varieties ranked by proline content (mg/kg) — the dominant free amino acid in genuine honey and the primary Codex Alimentarius authenticity marker. Buckwheat leads at ~925 mg/kg. HFCS carries <10 mg/kg. Tap any bar to explore.
Acacia's Narrow-Margin Problem — Acacia honey (Robinia pseudoacacia) is the world's most-faked premium honey and its proline confirms the structural vulnerability: authentic acacia sits at 180–320 mg/kg, clearing the Codex floor by the narrowest margin of any major variety. Just 15–25% corn syrup dilution can trigger a Codex failure — which is why NMR profiling is the only fully reliable authentication method for acacia.
Proline Survives Ultra-Filtration — At 115 g/mol (0.115 kDa), proline is hundreds of times smaller than any food-grade membrane cutoff (10,000–100,000 Da). Ultra-filtration strips pollen (enabling origin fraud) but leaves proline completely unchanged. This makes proline the primary authenticity marker for ultra-filtered honey, where traditional pollen analysis is impossible.
Dark Colour as Proline Proxy — The correlation between honey colour and proline content is r ≈ 0.76 (Hermosín et al. 2003). Buckwheat, Heather, and Chestnut are the darkest and most proline-rich varieties because the same phenolic, nitrogen-rich plant chemistry drives both. When a jar claims to be buckwheat or chestnut but its colour is unusually pale, low proline is one of several expected flags.
Sources: White & Rudyj (1978) J. Apic. Res. 17:235–241; Bogdanov et al. (2004) J. Agric. Food Chem. 52:4560–4567; Hermosín et al. (2003) Food Chemistry 83:263–268; Oddo et al. (2008) Apidologie 35(Suppl.1):S56–S70. Codex CXS 12-1981 (rev. 2001) min: 180 mg/kg.