Analysis On The Differences In The Starchy And Crunchy Quality Of Elian No.5 And Elian No.6

Lotus root which underground stem commonly known as Nelumbo nucifera Gaertn is an important aquatic vegetable in central and southern China for its good economic value.The palatability characteristics of lotus root can generally be classified into two major types: starchy and crunchy,according to its physical quality.In order to analyze the physicochemical differences between the starchy and crunchy quality of lotus root,samples of Elian No.5(starchy type)and Elian No.6(crunchy type)were selected from Hanchuan,Honghu and Jiangxia in Hubei,and the physicochemical properties quality were analyzed by rapid viscosity analyzer,differential scanning calorimeter,optical microscope,texture analyzer and ultra-high performance liquid chromatography.The correlation analysis between these properties and its starchy or crunchy type were carried out.Meanwhile,the principal component analysis based on these parameters and the liquid chromatography profile analysis based on UPLC-PDA data were also used to find the characteristic indicators for differentiating the lotus root’s tastes type.The main results were as follows:(1)The water content of Elian No.6 was higher than Elian No.5.This result was consistent with the moisture content of crunchy lotus roots higher than that of starchy one.The enthalpy change of starch was positively correlated with the starchy characteristics,and the whole flour gel highest viscosity,gelatinization temperature,enthalpy change,slice hardness,cohesiveness,chewiness were negatively correlated with the starchy characteristics.(2)The lotus root stem protein content of Elian No.5 was about 1.2 times of Elian No.6 with significant difference,and the protein content from different lotus root part was node > stem > skin.The order of taste amino acid content was deliciousamino acid > bitter amino acid > sweet amino acid > aromatic amino acid,and the delicious amino acid content was about 3 times of the bitter amino acid content,and the different in lotus root flavor amino acid content between Elian No.5and Elian No.6 from the three origins was not significant(P>0.05).The UPLC-PDA fingerprints of the alcoholic extract of Elian No.5 and Elian No.6 were different,but obtaininig the qualitative indicators for these differentiated peaks were difficult,and further analysis was needed.(3)According to the results of the principal component analysis,the whole flour highest viscosity,starch pasting temperature and protein content were the characteristic indicators of starchy quality,and the starch gel texture hardness,chewiness,slice texture hardness,cohesiveness and chewiness were the characteristic indicators of crunchy quality.