Influence of origin, harvesting time and weather conditions on content of inositols and methylinositols in sea buckthorn (Hippophaë rhamnoides) berries

Inositols and methylinositols play an important role in human physiology. Inositols and methylinositols in berries of three subspecies of sea buckthorn (Hippophaë rhamnoides) were analysed using gas chromatography combined with a flame ionisation detector and mass spectrometry. The wild Chinese berries (H. rhamnoides ssp. sinensis) contained higher levels of l-quebrachitol (1l-2-O-methyl-chiro-inositol) and methyl-myo-inositol (average 615 and 58 mg/100 ml juice, respectively) than the Finnish (H. rhamnoides ssp. rhamnoides, 276 and 11 mg/100 ml juice, respectively) and the Russian (H. rhamnoides ssp. mongolica, 228 and 16 mg/100 ml juice, respectively) berries (P < 0.001). The content of myo-inositol was higher in the Chinese and the Russian berries than in the Finnish berries (26 and 20 mg/100 ml juice vs. 8 mg/100 ml juice, P < 0.001). In the Chinese berries, the contents of methyl-myo-inositol and l-quebrachitol increased, whereas that of myo-inositol decreased from late September to late November. The content of the l-quebrachitol in the Chinese berries correlated negatively with the air temperature and the number of frost-free days, suggesting a possible role of the compound in the cold resistance of sea buckthorn.