Study Of Bitter Compounds And De-bittering Technology Of Hangbaizhi(Angelica Dahurica)

As a traditional Chinese medicine,Angelica dahurica(Fisch.ex Hoffm.)Benth.et Hook.f.ex Franch.et Sav.cv.Hangbaizhi(Hangbaizhi)is not only used for the curative treatment of diseases such as the common cold and toothache,but also is an important spice that is used to increase the aroma and remove the unpleasant odor in many foods.Hangbaizhi has however,been reported to cause a bitter taste.In this study,the bitter compounds in Hangbaizhi after three hot-working process(boiling,frying and boiling after frying)were studied.The appropriate method of removing bitter was explored from the effect of de-bittering and the degree of influence on aroma.Bitter compounds in three kinds of Hangbaizhi samples were separated and identified by high performance liquid chromatography(HPLC),preparative liquid chromatography(Pre-HPLC),liquid chromatography-mass spectrometry(LC-MS)and sensory evaluation.The results show that the bitter compounds(oxypeucedanin hydrate and xanthotoxol)identified in the boiled Hangbaizhi were the same as those identified in the boiled after frying one.In the boiled Hangbaizhi,the bitterness contribution of oxypeucedanin hydrate and xanthotoxol was the same.In the Hangbaizhi samples which were boiled after frying,the main bitter active substance was oxypeucedanin hydrate.Meanwhile,in the fried Hangbaizhi,the oxypeucedanin hydrate was the most predominate bitter substance.Bergapten,imperatorin,isoimpinellin and oxypeucedanin are the special bitter compounds in fried Hangbaizhi samples.The bitter contributions of the main bitter compounds in different Hangbaizhi samples were ordered by taste dilution analysis(TDA).In the samples of boiled Hangbaizhi,the taste dilution factor(TD)of both xanthotoxol and oxypeucedanin hydrate was 64,and their contribution to bitterness was the same.In fried Hangbaizhi and boiled after frying Hangbaizhi,the TD values of oxypeucedanin hydrate were the highest,which were 32 and 64 respectively.Therefore,both of them were the most critical bitter compounds.Then,the effects of water soaking pretreatment and Baijiu(Chinese liquor)soaking pretreatment on removing and suppressing bitterness of Hangbaizhi were compared.Upon the assessment of methods to reduce the bitter flavor,it was found that the dissolution rate of the total bitter compounds(coumarin)was significantly higher after Baijiu soaking treatment,which were respectively 74.3%(boiled Hangbaizhi),83.9%(fried Hangbaizhi)and 86.5%(boiled after frying Hangbaizhi).Therefor Baijiu pretreatment was more effective than water-pretreatment.Finally,the influence of soaking pretreatment on the aroma profile of Hangbaizhi was investigated by gas chromatography-olfactometry-mass spectrometry(GC-O-MS).The results of GC-OMS and principal component analysis showed that water soaking and Baijiu soaking had a negative influence on the composition and content of aroma compounds in Hangbaizhi.From the perspective of the effect of removing bitterness and the effect of de-bittering on aroma compounds,the Baijiu soaking removing bitterness process is suitable for boiled and fried Hangbaizhi.However,for the samples of boiled after frying Hangbaizhi,the water soaking process is more suitable for it,because the Baijiu soaking removing bitterness process has a more negative influence on the types and contents of aroma compounds.