食品中植物源性成分非定向筛查技术的应用

Application of non-directional screening technology for plant-derived components in food

目的实现食品中植物源性成分非定向筛查技术在实际样品中的检测应用,为打击植物源性成分的掺伪掺假提供技术支撑。方法采用改良CTAB法、SDS法和试剂盒法对多种植物源性食品基因组DNA进行提取,对获得的脱氧核糖核酸(DNA)质量、浓度和纯度进行比较。以植物中叶绿体基因组中的RbcL基因为条形码,选用30种常见植物物种对该引物进行通用性、特异性验证。将二代高通量测序与DNA条形码技术相结合,对山东省市售的4个混合植物样本进行种属鉴别。结果改良CTAB法和试剂盒法可有效去除植物中多糖类和多酚类物质的干扰,DNA提取效果较理想,SDS法较差;CTAB法获得的DNA浓度高于试剂盒法。该方法对选用的30种植物物种通用性、特异性良好。在属和种水平下,混合样本中植物物种的同步检出率较高,种水平的物种检出率达到98%,出现非目标匹配。结论RbcL基因片段可以作为植物种属鉴别的条形码,在属水平下的鉴别率较高,在种水平下存在高检出、低分辨率的问题,后期可以通过增加条形码长度等方法进行进一步改善,以期推进DNA宏条形码方法在植物鉴定领域的常规化应用奠定基础。

Objective To provide technical support for combating adulteration of plant-derived ingredients,the detection application of non-directional screening of plant-derived ingredients in food was realized.Methods Modified CTAB,SDS,and kit methods were used to extract genomic DNA from various plant-derived foods.Quality,concentration,and purity of the obtained DNA were compared.Using the RbcL gene in the chloroplast genome of plants as a barcode,30 plant species were selected to verify the universality and specificity of this primer.Combining the secondgeneration high-throughput sequencing with DNA barcode technology,species identification of four mixed plant samples sold in Shandong Province was performed.Results DNA extraction using the improved CTAB and kit methods removed the interference of polysaccharides and polyphenols,which was an ideal effect,whereas that of the SDS method was poor.The DNA concentration obtained by CTAB method was higher than that obtained using the kit method.This method had a good performance in universality and specificity of 30 selected plant species.At the genus and species level,the identification rate of plant species in mixed samples was high.The detection rate at the species level was 98%,and resulted in non-target matching.Conclusion The RbcL gene can be used as a barcode for plant species identification.The discrimination rate is high at the genus level.At the species level,detection rate was high and discrimination rate was low.To provide a foundation for the advancement of DNA metabarcoding method in the field of identification for plantderived components in food,the method can be further improved by increasing the barcode length.