Analysis On The Differences Of Capsaicin And Main Nutrient Substances In Pepper Fruits At Different Mature Stages

Pepper is rich in nutrients such as capsaicin,which determines the quality of pepper.At present,highquality pepper varieties are more able to meet the needs of the market.Therefore,in this experiment,pepper fruits at different maturity stages were used as test materials to study the capsaicin and other nutrients in pepper fruits.This study optimized the extraction process of capsaicin from pepper fruit and screened out the best extraction method.The accumulation differences of capsaicin and main nutrients in different tissues during the growth and development of different pepper varieties were clarified.The expression patterns of genes related to capsaicin synthesis pathway were analyzed;the effects of different light intensities on capsaicin and main nutrients in pepper fruit were discussed,which laid a foundation for cultivating new pepper varieties with rich capsaicin content and good quality.The main research results are as follows:1.The extraction system of capsaicin in capsicum was optimized by single factor experiment and response surface methodology with capsicum placenta as experimental material.The optimal extraction conditions were determined as follows: sample mass 0.2 g,solid-liquid ratio 1: 25 g·m L-1,extraction time35 min,and methanol concentration 90 %.2.The capsaicin and main nutrients in the pericarp and placenta of different varieties of pepper fruits during their growth and development were analyzed.The results showed that the capsaicin content in the pericarp and placenta was significantly higher than that in the dihydro capsaicin content,and the capsaicin and dihydro-capsaicin content in the placenta was significantly higher than that in the pericarp.The capsaicin content was between 0-6.7915 mg·g^-1,and the capsaicin content in placenta was the highest in the red ripe fruit of variety C1;dihydrocapsaicin content in 0-5.329 mg·g-1,and variety W6 in the green ripe fruit placenta rich dihydrocapsaicin;Principal component analysis was used to comprehensively analyze and evaluate different pepper varieties.The comprehensive score of variety W8 was the highest and the quality was the best,followed by varieties B7 and C1.3.Expression patterns of capsaicin biosynthesis related genes Pun1、Co MT、p AMT、KAS、Ca4H in varieties C1,C2 and Wu were analyzed.The results showed that the expression level of genes was closely related to capsaicin biosynthesis.The expression level of genes in placenta was significantly higher than that in pericarp,and the expression level of genes in green maturity was higher than that in red maturity.Pun1 gene has the largest variation in the synthesis of capsaicin,which is the main gene affecting the accumulation of capsaicin.The gene expression of C2 was higher than other varieties.4.The effects of light intensity on capsaicin and main nutrients in pepper fruits were explored through different shading treatments.The results showed that under 70 % natural light,the contents of capsaicin,flavonoids and total phenols increased the most,indicating that moderate shading was conducive to the synthesis and accumulation of these substances,while the contents of Vc,soluble sugar and soluble protein decreased with the decrease of light intensity.