nomilin

Nomilin is a limonoid that may be involved in the bitterness of citrus fruits; its concentration changes with processing conditions. A study combining sensory evaluation by 13 panelists and HPLC analysis of single and blended marmalades made from yuzu, konattsu, kumquat, and navel orange reported that in these sample groups, the bitterness assessed by sensory evaluation corresponded to nomilin content. However, this result was from a small-scale single preparation condition, and it is not treated as the sole factor common to marmalades in general. Aroma, sourness, and sweetness also affect perception.

In an analytical study using thin-layer chromatography and HPLC to analyze Hassaku fruit (juice, inner peel, outer peel), in addition to limonin-type glycosides, 5 types of nomilin-type limonoid glycosides—deacetylnomilin acid, deacetylnomilin, nomilin, nomilin acid, and obakunone—have been detected. This analysis pertains to component detection; direct correspondence with sensory bitterness cannot be confirmed from this source material.

In a bitter-component survey of 8 citrus cultivars conducted by the Kumamoto Prefecture Industrial Technology Center, it is recorded that among the 8 tested cultivars, only Kawachi bankan contains nomilin in the peel. Other cultivars such as Kawanoka-natsudaidai, Daio, and Banpeiyu show no mention of nomilin, and within the scope of this survey, nomilin is positioned as a compound characteristic of Kawachi bankan.