A Colorimetric Sensor Array Based On Anthocyanins For The Discrimination Of Saccharides

With the acceleration of industrialization process and people's multi-faceted demand in food safety and nutrition,rapid and safe detection and identification methods have attracted people more and more attention.As a fast analysis technology,colorimetric array sensor technology is used to detect and distinguish complex components through visual digital imaging method.Although colorimetric array sensors show many advantages in food safety and quality monitoring,there are still many unsolved problems.The use of chemical reactive dyes pose a great hidden danger in food safety,so people are increasingly interested in synthetic colorant alternatives that have toxic effects on the human body.The research of natural pigments is a broad and active research field.The anthocyanins,the pH-sensitive natural pigment,have wide range of color changes.And they are beneficial to people health.Therefore,anthocyanin as a sensitive material for identification is an ideal choice.In this paper,anthocyanins were extracted from natural raw materials,combined with colorimetric array sensor technology,which were used to distinguish the saccharides.The main research contents are as follows:1.The extraction and determination of anthocyanins from different sources.Anthocyanins were extracted from five kinds of natural materials(Lycium ruthenicum,Rosa chinensis,Mulberry,Myositis sylvatica,Carnation).The characterization of the extracted natural extracts which contain anthocyanins was carried out by means of response to color changes at different pH,the determination of ultraviolet spectra,and the determination of anthocyanin content by pH differential method.We found that the color of anthocyanins was different at different pH.At the same pH,the color of different anthocyanins was also various.This color difference response provides the possibility of subsequent sugar identification.2.We constructed a visual colorimetric sensor array based on anthocyanins.Because the types and contents of anthocyanins contained in each extract are different,we try to mix the extracts of the five anthocyanins in different proportions.And we analyzed the response signal value by one-way analysis of variance to complete the optimization process of array sensing elements.3.The visible colorimetric array sensor technology was used to distinguish the saccharides.The reaction between saccharides and boric acid results in the change of pH value in the solution.Because of the different color of anthocyanins in different pH value,the anthocyanin natural pigment is used as a sensing unit to develop a saccharides colorimetric array sensor based on natural pigments.By measuring the R,G,and B differences of anthocyanin color changes,eleven kinds of saccharides can be distinguished only by visually observing the color difference map.Combined with pattern recognition such as linear discriminant analysis(LDA)and principal component analysis(PCA),the colorimetric sensor array can distinguish eleven kinds of saccharides into two major categories: sugar and sugar alcohol with high accuracy and clarity,and each kind of saccharides can be aggregated into a separate cluster.The identification accuracy of eleven saccharides was 100%.Furthermore,the colorimetric sensor array was successfully applied to distinguish maltitol and fructose at different concentrations,proving that natural anthocyanins have great potential for application as healthy pigments.4.We showed that the practical performance of the colorimetric sensor array in commercial soft drinks.It can replace traditional and complicated instruments,realizing convenient,fast and real-time soft drink quality monitoring.The potential application prospect in beverage market has been verified successfully.