Study On The Spicy Materials Of Moso Bamboo Shoot

Moso bamboo shoot(Phyllostachys heterocycla)is one of the most important edible bamboo shoots in China.It was used to be eaten raw or processed and as well as nutrient-rich,fruitful.However,it was one of the obstacles to the development of bamboo shoots which the moso bamboo shoot tasted much spicy seriously when it was exposed to the sunlight.The taste quality of bamboo shoot was greatly affected.With the development of society and the improvement of consumption level,the taste quality of food for consumers was getting higher and higher.It was imminent to improve the quality of bamboo shoots.Therefore,the flavour materials of bamboo shoots were studied by chromatography-mass spectrometer(GC-MS),sensory evaluation,high performance liquid chromatography(HPLC),as well as ultraviolet spectrophotometry.Moso bamboo,ma bamboo(Dendrocalamus latiflorus),bitter bamboo(Pleioblastus amarus),four season bamboo(Oligostachyum lubricum)and green bamboo(Dendrocalamopsis oldhami)were included,which was mainly on the spicy materials of moso bamboo shoot.All bamboo shoots were tested and analyzed to identify their flavour materials for future improving the quality and to promote the development of bamboo shoot industry.The results were as follows:1.The compounds were detected by GC-MS in 5 species fresh bamboo shoots(Above-ground of moso bamboo shoots-AS;Under-ground of moso bamboo shoots-BS;Moso bamboo rhizome shoots-CS;Above-ground of ma bamboo shoots-DS;Under-ground of ma bamboo shoots-ES;Bitter bamboo shoots-FS;Four seasons bamboo shoots-GS;Green bamboo shoots-HS).A total of 43 compounds were detected by GC-MS.The number of ingredients in moso bamboo shoots was 43,shoots of ma bamboo,bitter bamboo,four season bambooand green bamboo were 39,38,38 and 35 respectively.It can be seen that the species composition of bamboo shoots was different.All compounds including esters,alcohols,acids,phenols,ketones,aldehydes,hydrocarbons and some other compounds in fresh bamboo shoots,and their numbers were 9,6,5,3,2,3,4 and 11 respectively.There were 11 kinds common ingredients contained which the relative content was more than 5% in all bamboo shoots.After analysis,the results indicated that the flavour materials which impact of moso bamboo shoots were tannin and oxalic acid.2、The sensory evaluation of bamboo shoots.Sensory assessment team members were taste normal personnel,which were selected and trained with national standards.The results of the evaluation were calculated by the volumetric method or the linear scale method.The sensory evaluation results of bamboo shoots were followed by spicy,bitter-astringent,bitter,bitter and sweet on moso bamboo,ma bamboo,bitter bambooand four season bamboo.The taste was increasingly enhanced from base to top of the 4types of bamboo shoots.It was sweetness of green bamboo,and the trend of taste was opposite to other bamboo shoots.At the same time,the results of the assessment of different types of moso and ma bamboo shoots showed that,the unpleasant taste intensity of the bamboo shoots which exposed to the sunlight was significantly higher than the darkness,indicating that the darkness could effectively reduce the unpleasant taste of the bamboo shoots.3、The trend of the content and taste intensity of each bamboo shootsections were analysised.Combined with GC-MS results and previous studies,bitter amino acids,cyanide,cyanoglycoside,tannin,oxalic acid and ephedrine were selected as flavour materials that affected the taste of bamboo shoots.The content of flavour materials of each the bamboo shoot were measured,and the trend of content and taste intensity were compared.The results showed that the components that affected the spicy of moso bamboo shoot were cyanide,tannin,oxalic acid and ephedrine,and affected the bitter and astringent of ma bamboo shoot were tannin and ephedrine.The bitter taste of the four season bamboo shoot may be caused by cyanide and cyanoglycoside.The bitter materials of bitter bamboo shoot yet to be further studied.The decrease in sweetness of green bamboo shoot may be due to the increase in cyanide and tannin content.4、The correlation analysis was made between the concentrations of flavour materials and the flavour intensities of 3 types of fresh moso bamboo shoots.At the same time,the boiled test of AS were carried out.Sensory evaluation,determination of substance content and its correlation with taste intensity were analysised.The boiled test time setting was 0,0.5,2.5,6,10,20 min.Shoot dregs and shoot soups were separated,cooling,and sent to the sensory assessment group immediately.Sensory evaluation results were as follows: The taste of boiled shoot dregs was spicy,and the intensity was decreased with the extension of boiling time.But the bamboo shoot soups were bitter and astringent,and the intensity was increased along with the time of boiling.It showed that the taste materials of the unpleasant taste were water-soluble to a certain extent,and different concentrations of taste materials leaded to the different taste.The results of the correlation analysis indicated that the principal materials significantly associated with the spicy taste of AS and BS were cyanide,cyanoglycoside,tannin and ephedrine.The correlation coefficients of AS were 0.812**,0.850**,0.939** and 0.818**,and those of BS were 0.905**,0.857**,0.939** and 0.937**.The effect of ephedrine was ruled out by the analysis of the content and taste intensity,and the constituents of the spicy of moso bamboo shoot were cyanide,cyanide and tannin.The relationship between cyanide,cyanoglycoside,tannin and spicy taste intensity was highly significant in bamboo shoot dregs,and the correlation coefficients were 0.859**,0.861* and 0.933** respectively.The results were consistent with the results of moso fresh bamboo shoot.The main materials attributing to bitter and astringent were cyanide,tannin and oxalic acid in bamboo shoot soups,and the correlation coefficients were 0.982**,0.945** and 0.976** respectively.In summary,the main spicy materials of moso bamboo shoot were concluded as cyanide,cyanogen and tannin,and their affected the spicy together.