Objective 3 types of fresh moso bamboo (Phyllostachys edulis) shoots were tested and analyzed to identify the spicy substances in order to further improving the quality and economic value.

Method The bamboo shoots above the ground (AS), bamboo shoots under the ground (US) and rhizome shoots (RS) were analyzed by means of sensory evaluation, gas chromatography-mass spectrometer (GC-MS), high performance liquid chromatography (HPLC), and the correlation analysis between the concentrations of flavor substances and the flavor intensities of 3 types of fresh bamboo shoots, shoot residues after boiling and shoot soups.

Result (1) The sensory evaluation of AS and US showed that the pungency was increasingly enhanced from base to top of bamboo shoot, and the range of AS was 2 to 9.5, which was apparently higher than that of the US which changed from 1 to 6. The taste of RS was slightly sweet, and there was no significant difference from base to top. The taste of boiled bamboo shoot residues was spicy, and the intensity decreased with the extension of boiling time. But the bamboo shoot soups were bitter and astringent, and the intensity increased along with the time of boiling. (2) A total of 43 compounds including 9 kinds of esters, 6 kinds of alcohols, 5 kinds of acids, 3 kinds of phenols, 2 kinds of ketones, 3 kinds of aldehydes, 4 kinds of hydrocarbons and 11 kinds of other compounds in fresh bamboo shoot were detected by GC-MS. The substances in bamboo shoots with high content and pungent taste were oxalic acid, tannin and ephedrine. (3) The results showed that the principal materials significantly associated with the spicy taste of AS and US were cyanide, cyanogenetic glycoside, tannin and ephedrine. The correlation coefficients of AS were 0.812, 0.850, 0.939 and 0.818 (P < 0.01), and those of US were 0.905, 0.857, 0.939 and 0.937 (P < 0.01). The relationship between cyanide, cyanogenetic glycoside, tannin and spicy taste intensity was highly significant in bamboo shoot residues, and the correlation coefficients were 0.859, 0.861, and 0.933 (P < 0.01) respectively. The main substances attributing to bitter and astringent were cyanide, tannin and oxalic acid, and the correlation coefficients were 0.982, 0.954, and 0.976 (P < 0.01) respectively.

Conclusion The main spicy flavor substances of moso bamboo shoots were concluded as cyanide, cyanogenetic glycoside and tannin, and their interaction enhanced the strong spicy flavor of moso bamboo shoots.