This study was aimed to optimize the extraction process conditions of lycopene in tomato. Ketchup was used as raw material. Method verification, single factor experiment and orthogonal method were used in the study on extraction process of lycopene. The results showed that the best optimization process conditions of lycopene extraction with ethyl acetate: extraction temperature at 50℃, extraction time for 40 min, ethyl acetate concentration of 80%, solid-to-liquid ratio of 1?2 (g·mL-1). Under these conditions, the extraction rate of lycopene reached 15.564 mg·100g-1. It was concluded that the extraction process of lycopene can provide experimental basis for further development and utilization of lycopene.

Objective To establish the enzyme-linked immunosorbent assay (ELISA) methods for the quantitative determination of IgG antibodies against diphtheria (DT) and tetanus (TT).MethodsPurified diphtheria toxiod and tetanus toxoid were respectively used as the coating antigens,the human-derived serum antibody standard substance of DT and TT served as the standard substance.The dose-response curves of the tested samples and standard substance were fitted.Then the two quantitative ELISA methods for determining the antibody to DT (Anti-DT) and antibody to TT (Anti-TT) were established with the parallel lines method.Then the methodological verification and application study were conducted.Results The validation results of the two quantitative ELISA measurement methods were in accordance with the regulations.The quantity limit of ELISA method for quantitative detection of Anti-DT demonstrated to be 0.084 mIU/mL,its average recovery rate was 97.6%.The intra-assay coefficient of variation(CV) and inter-assay CV of this Anti-DT assay were ≤ 3.40% and ≤5.05%,respectively.The quantity limit of ELISA method for quantitative detection of Anti-TT demonstrated to be 0.175 mIU/mL,its average recovery rate was 97.5%.The intra-assay CV and inter-assay CV of this Anti-TT assay were ≤ 2.42% and ≤5.58%,respectively.These two methods were applied for the immunogenicity evaluation after infantile basic immunization by diphtheria and tetanus vaccines.Conclusion The two established quantitative ELISA methods demonstrate high accuracy and good reproducibility,which are suitable for the ordinary laboratory to carry out the work and can be used in the serological effect evaluation after diphtheria and tetanus vaccine immunization and epidemiological study of diphtheria and tetanus disease.