Study On The Optimization Of ?-aminobutyric Acid Detection Method And Its Variation Rule In Jujube

It has been reported that ?-aminobutyric acid(GABA)may be a functional ingredient in red dates to promote sleep.However,there are few reports on GABA in jujube,in order to better grasp the biological activity function of GABA in jujube.Therefore,taking jujube as the research object,this paper firstly optimized the determination method of GABA by HPLC derived from OPA column.Then the changes of Glu and GABA in jujube growth were analyzed.Finally,the changes of Glu and GABA in jujube were studied.The main conclusions are as follows:1.HPLC method for determination of Glu and GABA in jujube was optimizedThe results showed that the concentration of sodium borate was 0.05 mol/L,the flow rate was 0.7mL/min,the mobile phase was methanol(A),the concentration of formic acid was 0.1 %(B),and the elution gradient was 0-15 min,35 %-28 %(B).15-16 min,28 %-35 %(B);16-20 min,35 %(B).The optimized conditions have the advantages of convenient preparation of mobile phase,short analysis period,small amount of mobile phase and low system pressure.Under this sub-analysis condition,Glu and GABA in jujube can achieve baseline separation,peak time is short,stability,repeatability and recovery are good.The content of Glu and GABA in 8 different jujube cultivars was analyzed,and it was found that the content of Glu was different among different jujube cultivars(P<0.05),in which the Mamazao and Shuangrenzao Glu content in the highest,164.84 ?g/g DW and 164.87 ?g/g DW,Xiangfenmuzao Glu content lowest 127.44 ?g/g DW.The GABA content of jujube varied among different varieties(p<0.05).Mamazao GABA content is the highest,474.46 ?g/g DW,Jinjun1 hao has the lowest GABA content,202.12 ?g/g DW.2.Changes of Glu and GABA during the growth of jujubeThere were significant differences in Glu content in different growing periods and varieties(P<0.05).In the growth and development of jujube,Glu content will continue to decrease.Glu content in the 8jujubes was the highest in the young fruit stage,while Glu content in Junyou and Junzao was the highest in1487.57 ?g/g DW and 1220.82 ?g/g DW.Glu content in the Dabailing was the lowest in 556.11 ?g/g DW and no Glu content in the whole red jujube period was higher than 250 ?g/g DW.There were significant differences in GABA content between different growing periods and varieties(P <0.05).During the growth and development of jujube,the content of GABA will gradually decrease.the content of GABA was the highest in the young fruit stage of the eight varieties of jujube,the content of GABA in Junzao and Junyou was the highest at 1228.65 ?g/g DW and 1222.81 ?g/g DW,the content of GABA in Suanzao was the lowest at 422.62 ?g/g DW.3.Changes of Glu and GABA during storage of jujubeDuring the storage period,Glu content in Junzao was related to the storage time(p<0.05).With the prolonging of storage time,the content of Glu in Junzao increased.the content of Glu in the Junzao treated with 8 kinds of pepper was the highest in week 9,The content of Glu in blank control jujube was the highest189.05 ?g/g DW,the content of Glu in the Junzao treated with 1 % chitosan,0.5 g/L salicylic acid and1-MCP compound treatment was the lowest in 158.48 ?g/g DW.During the storage period,GABA content in Junzao was related to the storage time(p<0.05).With the prolonging of storage time,the content of Glu in Junzao increased.the content of GABA in the Junzao treated with 8 kinds of pepper was the highest in week 9,The content of GABA in blank control jujube was the highest 638.95 ?g/g DW,and the content of GABA in the Junzao treated with 0.5 g/L salicylic acid and1-MCP compound treatment was the lowest in 537.53 ?g/g DW.