Traceability Analysis Of Blueberry Origin Based On Strontium Isotopes And Mineral Elements

With the continuous improvement of living standards,people pay more and more attention to food nutrition and food health.The proportion of fruits and their products in the production and consumption of agricultural products is gradually increasing because of their rich nutrition.Fruit safety has become the focus of consumers’attention.It is inevitable to establish the corresponding product quality and safety traceability system.Blueberry is the second largest berry in the world.With the continuous expansion of blueberry planting scale and the increasing number of blueberry brands,the price of blueberry fresh fruit from different regions varies greatly.The label of blueberry fresh fruit in the market mainly depends on the external packaging,and the phenomenon that blueberries from different regions are fake sometimes occurs.The mineral elements of blueberry fruit mainly come from the soil supply,and the content of mineral elements in blueberry fruit can represent the local mineral element status to a large extent.⁸⁷Sr/⁸⁶Sr is mainly related to the formation time of strontium content in rocks and minerals.In areas with similar climate and environment,⁸⁷Sr/⁸⁶Sr can usually provide better origin identification information Taking Ziyun and Majiang as examples,this paper discusses the origin identification of blueberry based on stable isotope and mineral element fingerprint,which is of great significance to maintain the order of blueberry market,ensure fair competition and protect the interests of consumersIn order to explore the feasibility of mineral elements and ⁸⁷Sr/⁸⁶Sr in blueberry origin traceability,the contents of K,Al,Mg and other 28 mineral elements in 104 blueberry samples from Huangping,Majiang and Ziyun counties of Guizhou Province were determined,and the ⁸⁷Sr/⁸⁶Sr in 48 blueberries and their growing soil were determined.Principal component analysis and linear discriminant analysis were used to analyze the mineral elements;Cluster analysis and stepwise discriminant analysis of Sr isotope ratio were carried out;Based on the joint discriminant analysis of ⁸⁷Sr/⁸⁶Sr and mineral elements,the main conclusions are as follows（1）Huangping blueberry had the highest content of major elements,while Ziyun and Majiang blueberry had the highest content of trace elements,while Majiang blueberry had the highest content of alkali metals and alkaline earth elements.Among the mineral elements,18 elements had significant differences（P<0.05）The results show that the mineral elements can be used to trace the origin of blueberry in Guizhou Province.Through the principal component analysis,a total of 11 elements,such as Ca,Mn,Th,Mg,Rb,P,S,K,Al,Sr,Ba,were selected as the traceability indexes.Further,the stable discriminant model established by canonical discriminant analysis selected elements as Ca,Mn,Th,Mg,Rb,P,Cr,Cs,Sb,Y,the discriminant accuracy was 89.4%,and the cross detection accuracy was 89.4%The accuracy of the results was 83.6%.（2）The strontium isotope ratios of soil and blueberry fruit samples in the three counties were:Huangping>Majiang>Ziyun.In blueberry fruit samples,only Ziyun and Majiang blueberry samples had no significant difference in strontium isotope ratios,while the other blueberry samples had significant differences in strontium isotope ratios,and there were significant differences in strontium isotope ratios of soil samples in the three regions ⁸⁷Sr/⁸⁶Sr can be used to trace the origin of blueberry in Guizhou Province.The linear analysis of strontium isotope ratio of soil blueberry has obvious effect,and when the cluster analysis grade is 4～7,blueberry samples from three places can be well separated,and the discrimination accuracy is 81.25%.In stepwise discriminant analysis,the accuracy of strontium isotope ratio for blueberry origin traceability in Guizhou Province is 81.3%,and the accuracy of cross detection is 81.3%It is better to identify the origin of the products in the regions with different geological background by strontium isotope ratio.（3）The combined analysis of mineral elements and strontium isotope ratio,the accuracy rate of origin discrimination reached 95.8%,and the accuracy rate of cross detection was 93.8%.Mineral elements and ⁸⁷Sr/⁸⁶Sr are indicators that can be used for Guizhou blueberry origin traceability,and the effect of combined discriminant analysis is better.From the analysis method,the identification effect of step-by-step discriminant analysis（LDA）is the best,and cluster analysis（CA）is better than principal component analysis（PCA）more ideal.