Application Of Metal Oxide Array Sensor In Quality Control Of Honey And Spices

With the development of China's economy,the quality of people's life has been significantly improved.People pay more attention to the quality of product.Since flavors and fragrances have the effect of improving products,they have been widely used in the tobacco industry and food industry in recent years.In the production of cigarettes,commonly used flavors include natural flavors and synthetic flavors.Among them,honey is a kind of natural spice,which has high nutritional value.At the same time,with the development of science and technology,more kinds of flavors are artificially synthesized to meet people's diverse needs.For example,manufacturers add flavors to the tobacco to improve the taste of the cigarette.The composition and quality of spices will be affected by many factors,for example,honey will be affected by the type of flowers,the type of bees,the month of collection,and the place of production.The quality of synthetic flavors will also be affected by the production process,raw materials,and by-products.As honey and synthetic spices are used as food additives,their quality control has an important impact on the final quality of the product.It is very necessary to control and screen the quality of honey and spices.Traditional quality control testing methods mainly include chromatographic analysis,isotope analysis,and spectral analysis.These methods restrict their application in practical production due to the complex operation,too expensive equipment,and the need for a professional operating environment.In this paper,a 4-array sensor based on metal-oxide semiconductor gas-sensing technology was used to detect the volatile components of honey and a 6-array sensor was used to detect the volatile components of flavor samples,and successfully distinguished the samples.Firstly,it was determined that the highest components in the honey samples were mainly alcohols,aldehydes,aromatics and esters.The corresponding sensitive materials Sn O₂,WO₃,Ti O₂,In₂O₃ were screened for the four main components,then the suitable methods were selected for preparing metal oxide materials and characterize these materials.The selectivity of the materials were determined by gas-sensitivity testing of50 ppm acetone,formaldehyde,and ethanol gas.Then the coplanar sensor array was prepared by screen printing technology.Saturated headspace method was used to perform gas-sensing test on 11 kinds of honey samples using the prepared sensor array to obtain characteristic odor fingerprints.Principal component dimensionality reduction analysis(PCA)was performed on the obtained characteristic odor fingerprints using SPSS tools,standard sample No.1 can be effectively distinguished from other samples except sample No.11;standard sample No.2 can be effectively distinguished from all samples to be identified;standard sample No.3 can be distinguished from samples other than sample No.4;three standard samples can be distinguished from each other.The precious metal Pt was used to sensitize the sensor array,and successfully distinguished the standard sample No.3 from the sample No.4.It showed that the prepared sensor array can effectively distinguish honey samples that are different due to different flower types,different bee species or different collection time.Next,gas chromatographic analysis was performed on the samples of synthetic fragrances,and the main components were determined to be ketones,aldehydes,alcohols,and other small amounts of pyridines and esters.Based on this,the sensitive materials WO₃,Ti O₂,Sn O₂,Cu O,Zn O,In₂O₃ were screened and the suitable methods were selected for preparing metal oxide materials.The gas-sensitivity test of acetone,formaldehyde and ethanol gas using WO₃ confirmed that it had good selectivity to acetone.The sensor array was prepared by screen printing technology,and the saturated headspace method was used to detect the volatile components of the 22 groups of sample samples to obtain the characteristic odor fingerprint.The SPSS tool was used to perform PCA analysis on the obtained characteristic odor fingerprints,the 19 groups of standard samples were distinguished from the samples to be identified.The failure to distinguish a few samples may be due to their similar composition and content or the sensor's selectivity for ketones and alcohols needed to be further improved.