基于电子舌技术的不同产地枸杞子鉴别研究

Application of Electronic Tongue in Identification of Goji from Different Production Regions

目的研究不同产地枸杞子“味”的不同,以此建立起不同产地枸杞子的判别模型。方法采集宁夏、内蒙古、青海、甘肃不同产地枸杞子药材,选取16名味觉良好的成员对各样品进行感官评价,再利用电子舌对样品进行检测,得到7根传感器(AHS、PKS、CTS、NMS、CPS、ANS、SCS)响应值,并分析两者的相关性。通过主成分分析(PCA)、偏最小二乘判别分析(PLS-DA)、正交偏最小二乘判别分析(OPLS-DA)对4个产地枸杞子的响应值进行处理和分析,同时建立起能够区分4个产地枸杞子的Fisher判别模型。结果通过相关性分析显示人工感官评价的酸、咸、鲜、甜、苦与5根传感器AHS、CTS、NMS、ANS、SCS具有不同程度的相关关系(r>0.6,P<0.01),说明电子舌技术能够代替人工口尝对枸杞子进行滋味评价;通过PCA可以区分甘肃及内蒙古产枸杞子,但对青海及宁夏产枸杞子不能进行有效区分;通过PLS-DA分析及对青海和宁夏产枸杞子进行OPLS-DA分析则可区分4个产地枸杞子;通过Fisher判别分析可以建立不同产地枸杞子的判别模型,并进行验证,正确率达到100%。结论电子舌技术能够代替人工口尝对枸杞子的酸、苦、咸、甜、鲜进行评价,并结合多元统计分析能够为不同产地枸杞子的区分提供一种快速、便捷的技术手段。

OBJECTIVE To study the taste of goji from different producing regions and establish a taste discrimination model.METHODS Samples of goji were collected from Ningxia,Inner Mongolia,Qinghai and Gansu.Five sensory attributes(sour,salty,fresh,sweet,and bitter)were evaluated by artificial tasting,and the response values of 7 sensors(AHS,ANS,PKS,CTS,NMS,CPS,SCS)representing the taste of pieces were detected by electronic tongue.The correlation between sensory evaluation and response values of the electronic tongue were analyzed.Principal component analysis(PCA),partial least square discriminant analysis(PLS-DA)and orthogonal partial least square discriminant analysis(OPLS-DA)were used to process and analyze the response values of the four producing areas,and a Fisher discriminant model was established to distinguish four producing areas.RESULTS Correlation analysis showed that the sensory evaluation of sour,salty,fresh,sweet,bitter and AHS,CTS,NMS,ANS,SCS sensors had different degrees of correlation(r>0.6,P<0.01).This indicated that the electronic tongue technology could be used as an alternative of artificial taste;Goji from Gansu and Inner Mongolia could be distinguished by PCA;Goji from four regions could be distinguished by PLS-DA and OPLS-DA of goji from Qinghai and Ningxia;The Fisher discriminant model for goji which from different producing regions was established,and it could effectively discriminate them with a recognition rate of 100%.CONCLUSION Electronic tongue technology can replace artificial taste to evaluate the sour,bitter,salty,sweet and fresh of goji,and provide a fast and convenient technical means for the differentiation of goji from different regions with multivariate statistical analysis.