Optimization And Application Of Total Purine Content Detection Method In Soybean Seed

Soybeans contain high-quality plant protein and edible vegetable oil resources,which are favored by people.However,studies have shown that soybean grain purine content is high,resulting in beans and soy products that are not suitable for gout patients.Therefore,it is important to screen or create soybean germplasm with low purine content.In order to solve this problem,this study further optimized the extraction of purines by acid hydrolysis,improved the detection methods,and established a detection system for total purines in soybean grain,which can be applied to the exploration of excellent low-purine germplasm resources and the detection of purine content in soybean products.The purine in soybean grain was removed by adsorption by salting out method,and the purine content in soybean grain was reduced.The main findings are as follows:1.In this study,the total purine content identification system of soybean was established by optimizing the extraction and detection methods of total purine in soybean kernel.The optimized method is to use a 35%concentration of perchloric acid water bath for 30 min at 100℃,and adjust the final pH value of the sample to 4,which reduces the sample dosage and reagent dosage by 50%compared with the previous method,and increases the extraction efficiency by 2.5 times.Using an ultra-micro spectrophotometer to absorb 1μL sample at a wavelength of 272 nm for detection,the detection time can be shortened from15 min to 15 s,and the detection efficiency can be increased by 60 times.The optimal detection wavelength of four different purine components by high performance liquid chromatography can improve the detection accuracy of samples by 7%～10%.The average relative spike recovery of the four purines ranged from 90.22%to 98.49%.The results show that the whole detection system has good accuracy,accuracy and stability for the detection of total purine content in soybean grain,and has high credibility,which has universal application value.2.The total purine content of 3000 soybean germplasms was detected and analyzed byultra-micro method,and 11 low-purine（purine content<100 mg/100 g）germplasm and 17very high purine（purine content>350 mg/100 g）germplasm were discovered.The results of high-performance liquid chromatography were further used to analyze the purine components of extremely different purine cultivars,and the results showed that the content of purine in soybean grain between varieties was mainly affected by guanine and adenine.3.The detection and analysis of purine content in different beans and soy products found that the distribution of total purine content was:bean condiments>edible beans>dried soy products>bean drinks.At the same time,the salting out adsorption method was used to establish a purine adsorption system,when the whole soybean grain and 4%concentration CaCl₂ solution were in a ratio of 1:5,and the water bath treatment at 60℃ for 2.5 h could adsorb and remove 25.43%of the purine content in the soybean kernel.This adsorption method can be applied to the processing field of low-purine soy products,reduce the purine content of soy products,and create characteristic low-purine soy products.In summary,the research of this topic further optimizes the extraction method of soybean purine,and establishes a more simple,rapid,accurate and reliable purine detection system,which not only facilitates the identification of large-scale germplasm resources,but also improves the efficiency of soybean quality trait aggregation breeding and germplasm innovation.Combined with the salting out adsorption method,part of the purine in the soybean grain is removed during the processing of soy products,so as to create characteristic low-purine soy products,expand the consumption group of soy products,and better meet people’s needs for soybean health products.