Graduate students of the food College of South China Agricultural University published papers in internationally renowned journals in the field of food
By: Date: 2022-07-14 Categories: foodtechnology Tags: ,
Recently, the school of food science of South China Agricultural University published an article entitled”effective and repeatable chromatographic separation of 5 nuclei in important formula milk powder by ion pair high performance liquid chromatography – ultraviolet” online in the Journal of Dairy Science (zone 1, Chinese Academy of Sciences, if=4.225). The corresponding author of the article is Wei Xiaoqun, an associate researcher, and the first author is Chen Yuanjia, a 2019 master.
Adding an appropriate amount of nucleotides to infant formula milk powder plays an important role in the growth and development of infants. However, excessive addition will increase the risk of disease. Therefore, countries restrict the content of nucleotides in infant formula milk powder products and need corresponding detection technical support. Lactose in milk powder is similar to nucleotide structure, which interferes with the detection, and usually requires complex pretreatment methods or high-cost isotope internal standard methods. To solve the above problems, we choose C18 chromatographic column, add ion pair reagent to combine with phosphoric acid in nucleotide to prolong its retention time in the chromatographic column to achieve the purpose of separation, and use HPLC-UV detector to avoid the pollution of reagent. In order to improve the accuracy and repeatability of the quantitative method, a hydrophilic C18 diisopropyl HPLC-UV method was established by studying the relationship between column temperature, mobile phase pH value, ion pair reagent concentration and the retention time of five nucleotides (CMP, cytosine nucleotide; UMP, uracil nucleotide; amp, adenine nucleotide; GMP, guanine nucleotide; imp, hypoxanthine nucleotide). The best separation conditions were selected and the mechanism was explained. The tautomeric structure model of nucleotides is proposed to show the different effects of conditions on their polarity. This result shows that the efficient separation of nucleotides cannot be achieved without strict conditions. The linear range of single nucleotide detected by this method is 10~1000 mg/kg, which meets the requirements of conventional nucleotide addition. The standard addition recovery of the method is 80.0~110.0%, and the relative standard deviation range is 0.5~3.5%(n=6). By applying this method to a series of infant formula products in the Chinese market, we found that a few of them exceeded the legal limit of nucleotides.
The research was supported by the science and technology planning project in key regions of Guangdong Province (No. 2019b020211001), the science and technology planning project in Guangzhou, China (no.20180300044), the national key research and development plan (No. 2017yfc1601705) and the Department of agriculture of Guangdong Province (No. 2019kj130).
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Brief introduction of corresponding author
Wei Xiaoqun, male, associate researcher of South China Agricultural University, master’s supervisor, doctor of polymer chemistry and physics of Sun Yat sen University, postdoctoral fellow of agricultural and forestry economic management of Renmin University of China, and senior engineer of the former Guangdong Inspection and Quarantine Technology Center (now Guangzhou Customs Technology Center). Research interests include food quality and safety testing technology, food processing and manufacturing, functional food development, etc. He has won two second prizes of Guangdong Provincial Science and technology award, one second prize and two third prizes of the science and technology inspection Promotion Award of the General Administration of quality supervision, inspection and Quarantine of the people’s Republic of China; Presided over or participated in the formulation and revision of 4 standards; Participated in publishing 9 monographs. In the past three years (2020 to now), it has authorized 6 national invention patents and published 7 top scientific research papers in the first district of the Chinese Academy of Sciences.