Liči (lychee)

Lychee — crystalline, transparent, faintly rose-adjacent — is used in PREMIEREPEAU's Rose Monotone to refract rose oxide and Brazilian pink pepper.

Lychee is a member of the Sapindaceae family, which also includes longan and rambutan. There are three distinct subspecies of lychee. Litchi chinensis subsp. chinensis is the only commercialized lychee, and it grows wild in southern China, northern Vietnam, and Cambodia.

The outside of the fruit is a pink-red, rough-textured soft shell. The edible aril is juicy and translucent. At full maturity the flesh is a white, juicy aril surrounding a large brown seed. The seeds contain methylene cyclopropyl glycine, which has caused hypoglycemia linked to outbreaks of encephalopathy in undernourished Indian and Vietnamese children who ate the fruit. Lychee's sweetness is primarily due to sucrose, glucose, and fructose, while malic and citric acids provide acidity.

Aroma-active compounds in the flesh include the monoterpenes linalool, geraniol, nerol, limonene, and cis-rose oxide, which contribute rose-like and citrus-like notes. The flesh also contains furaneol, methional and sulfur volatiles such as dimethyl trisulfide.

In the 'Sweetheart' cultivar, methional and geraniol showed the highest flavor dilution factors, 1024 and 512 respectively. Geraniol, nerol and linalool are the most aroma-active terpenes due to their low sensory threshold. The strong combination of these three volatiles explained the most intense floral note of lychee fruit perceived in the sensory evaluation. Besides giving the impression of a floral note, linalool can also contribute sweet and citrus scents to the overall aroma profile of lychee.

Rose oxide is an organic compound of the pyran class of monoterpenes. Rose oxide also contributes to the flavor of some fruits, such as lychee. Only the (-)-cis isomer of rose oxide, with an odor threshold of 0.5 ppb, is responsible for the typical rose (floral green) fragrance.

A comparison of Gewürztraminer wine, fresh lychees and canned lychees detected 12 odorants common to all three samples. Among them, cis-rose oxide, β-damascenone, ethyl 2-methylpropanoate, linalool and geraniol consistently showed concentrations beyond their odor threshold concentrations. Together with geraniol, nerol and citronellol, linalool is one of the rose alcohols.

The aroma-active compounds of 'Sweetheart' lychee were isolated with solvent assisted flavor evaporation and examined by gas chromatography-olfactometry/mass spectrometry. The most important odorants were then characterized by aroma extract dilution analysis. Thirty-one key aroma-active odorants were identified, with flavor dilution factors from 2 to 1024.

In the distilled spirit, linalool, cis-rose oxide and trans-rose oxide had the highest odor activity values, which may explain its rose and flower aroma. Some yeast strains can metabolize geraniol into cis-rose oxide.

In the PREMIEREPEAU collection, lychee appears in Rose Monotone, where its crystalline fruitiness amplifies the cooler, mineral quality of the rose accord.

Related Notes

This note in PREMIEREPEAU. Rose Monotone. Sample all seven extraits in the Discovery Set.