Study On Screening And Quantitative Identification Of Plant-derived Ingredients In Cherry Products

With the improvement of national economic level and people's life quality in China,people's demand for cherries and other third-generation fruits and their products keeps increasing,and the quality and safety of products have been attracting public great attentions.The phenomena such as illegal addition and uneven quality have been greatly improved under the joint efforts of supervision authorities and enterprises.However,the adulteration problem of cherry products has not been resolved yet due to the lack of corresponding detection methods.The adulteration of cherry products not only severely injuries the consumers'health and infringes their economic interests,but also seriously restricts the development of high-value-added berries industry.Therefore,the research on high-throughput screening and quantitative identification methods of plant-derived ingredients in cherry products will be of great significance for enhancing the quality of high-value-added berries industry,strengthening the supervision and management of cherry products and promoting the healthy development of high-value-added berries industry.The specific study on the high-throughput screening and quantitative identification methods of plant-derived ingredients in cherry products is as follows:(1)For genomic DNA extraction of cherry and its products,an improved deep-processed food DNA extraction kit method was determined to have the best effect and was used as genomic extraction for the juices in subsequent experiments by comparing the extraction effects of genomic DNA of cherry and its products with four kinds of commercial DNA extraction kits.(2)For the influence of chemosynthesis food additives residues on molecular detection,an evaluation method combining fluorescent PCR with ultraviolet spectrophotometry was set up to evaluate the usual 10 kinds of chemosynthesis food additives.The test result proved that citric acid,sodium citrate,sodium carbonate and sodium bicarbonate would inhibit the detection of fluorescent PCR when the concentration exceeded a certain concentration,and the ultraviolet absorption peak appeared offset.(3)For plant-derived food additives,a combination screening method of ITS2 and trnH-psbA primers based on DNA barcode technology was set up.By taking cassava as a model,the functional relationship between cassava quality and amplified DNA copy number was constructed,and a quantitative detection method based on droplet digital PCR(ddPCR)technology was set up.(4)In response to the demand for high-throughput screening of plant-derived ingredients in cherry products,sequencing primers were designed with ITS2 as the sequencing gene,and a high-throughput screening method based on second-generation sequencing technology for cherry and its products was set up.The results showed that,at species level,this method could only conduct second-generation sequencing high-throughput screening to cherry,red raspberry,black currant,cranberry,apricot,grape,apple and pear.At genera level,this method could perform second-generation sequencing high-throughput screening to the species involved in this research.However,it was not suitable for the quantitative screening at species or genus level.(5)To cater for the demand for quantitative identification of plant-derived ingredients in cherry and its products,a digital PCR quantitative detection method was set up for 8 kinds of berries such as cherry,small cherry,red raspberry,pear,peach,grape,apple and apricot.The specific primers and probes of ddPCR for each species were designed,and the relationship curve between the quality and DNA content of 8 kinds of berries was set up.The fitting curve of DNA content and amplified DNA copy number of 8 kinds of berries was also set up.The linear fitting degree and the maximum variation coefficientsw were met the experimental requirements.DNA concentration was taken as the intermediate conversion value for two curves,and the calculation formulas of berry mass and amplified DNA copy number were as follows:cherry:M cherry=0.0833C-3.8420,small cherry:M small chery=0.0434C-2.5028,red raspberry:M red raspberry=0.0161C-1.4329,pear:M pear=0.3092C-11.7040,peach:Mpeach-0.0933C-2.2654,grape:M grape=0.1899C-3.9500,apple:M apple=1.6333C-6.3074,and apricot:M apricot=0.0281C-0.7585.(6)The digital PCR detection method as shown in(5)was used to set up the adulteration model for the digital PCR test of cherry and small cherry.The relative maximum errors and the maximum variation coefficients in adulteration models were met the experimental requirements.Tests proved that this method could be effectively applied to the sample test of commercially available fruits.The research on high-throughput screening and quantitative identification methods of plant-derived ingredients in cherry products has a role in shortening the detection cycle,realizing rapid identification of adulterated ingredients,and providing strong technical support for governmental supervision authority to supervise and govern the cherry products industry and combat the illegal behaviors such as adulteration of cherry products.It will be of great significance for safeguarding food safety and consumers'rights and interests and promoting the healthy development of berries and their products industry.