Identification Of The Characteristic Aroma Components Of Highland Barley Tsampa Flour And Preliminary Study On The Production Mechanism

Highland barley is an important cereal crop in the alpine region of Qinghai Tibet,on the plateau lacking fruits and vegetables,the Tibetan people who regularly eat highland barley are able to survive in a healthy way because of its unique health effects.Tsampa,commonly known as highland barley stir-fried noodles,it is a powdery food made from whole highland barley seeds after high-temperature stir-fried and crushed.This product has a unique aroma and has long been a traditional staple food of Tibetan compatriots.However,the aroma components of the existing tincture products produced on the market are inconsistent and the quality varies.The reason is that because the species and production mechanism of highland barley Tsampa aroma are not clear at present,the industrial production of highland barley Tsampa is restricted.which together give the highland barley Tsampa flour unique sensory aroma.In this paper,10 different varieties of highland barley were used as raw materials to prepare highland barley Tsampa flour,the composition of its characteristic aroma was analyzed,the highland barley varieties with the most flavor substances were determined,and on this basis,the characteristic aroma fingerprint of highland barley Tsampa flour was constructed;at the same time,the formation rules of the characteristic aroma of highland barley Tsampa flour in different stir-fried times and methods were studied,and the best process for processing the highland barley Tsampa flour was determined.The preliminary exploration and determination of the key precursors of the characteristic aroma of highland barley Tsampa flour can provide a scientific basis for the aroma substance maintenance of highland barley Tsampa flour in industrial production.The main research contents and results are as follows:(1)Stir-fried increased the aroma components of highland barley and changed the types of volatile substances.The aroma substances were increased from 48 to 60.The contents of esters(31.9%)and alcohols(9.78%)were higher before stir-fring,mainly fruity and sweet,and the contents of heterocyclics(39.87%)and esters(35.98%)were higher after stir-fried.Cocoa,roasted and nut aromas are the main ingredients of stir-fried highland barley.There are significant differences in the types and contents of various aromas of different varieties of highland barley.DLH highland barley is the most volatile species after being stir-fry.The alcohol and heterocyclic content Bq8 highland barley(12.80% and 64.42%)is the highest,the aldehyde content WL highland barley(21.79%)is the highest,and the ester content Kl15 highland barley(35.98%)is the highest.The acid content Kq7 highland barley(7.92%)is the highest,and there are few hydrocarbons and nitriles in fried highland barley.It was screened that DLH highland barley was the most suitable for stir-fried and processing of highland barley,followed by Bq8 highland barley and WL highland barley.(2)The fingerprint of characteristic aroma of highland barley Tsampa flour was established,and volatile aroma substances common to 23 different varieties of highland barley Tsampa flour were screened out,mainly including 3 alcohols,1 esters,and 2 aldehydes.There are 2 types of acids,13 types of heterocycles,1 type of phenols,and 1 type of alkanes.Among them,the most representative aroma in highland barley Tsampa flour is 10 types of pyrazines in heterocyclic compounds.(3)Using DLH highland barley as raw material,the effect of frying method and time on the aroma components of highland barley Tsampa flour was studied.The study found that the two kinds of volatile flavor substances obtained by different processing methods:first crushed and then stir-fried and first stir-fried and then crushed were different.25 kinds of flavors were obtained after first crushed and then stir-fried,and 41 kinds were obtained after first stir-fried and then crushed.The method of stir-fried first and then crushed was selected as the method of stir-fried the highland barley;the volatile content of DLH highland barley was increased from 14 to 41 at different stir-fried times.Among them,heterocyclic compounds are the most abundant,and the highest content is 46.09% when the stir-fried time is 8 minutes,and 8 minutes is selected as the suitable stir-fried time for highland barley.(4)It was initially determined that the characteristic aroma precursors of stir-fried highland barley Tsampa were mainly related to lysine,arginine,glucose,rhamnose,and Related to palmitic acid and linoleic acid.The verification of the model Maillard reaction and fatty acid thermal degradation showed that the characteristic aroma components of highland barley Tsampa were mainly derived from the Maillard reaction and fatty acid oxidation reaction during the stir-fried process.