Fast Extraction Of Fat、Analysis Of Fatty Acid And Establish Of Detection Model Of Capsaicin In Pepper

Pepper(Capicum spp.L)was crop of solanaceae capsicum, originated from the tropical area of South America. Pepper was a worldwide vegetable and seasoning. The fat of pepper and capsaicin were the important index to evaluate pepper quality. Most of the extraction methods of the fat and capsaicin were time-consuming, higher consumption of materials, higher costs. So we explored the rapid extraction and detection methods of the fat and capsaicin with46pepper material in this paper. Specific research results were as follows:1. Fast extraction of fat in pepper seedsThe quick fat extraction conditions from pepper seeds were investigated by using the Ultrasound-assisted Soxhlet extraction method, the effects on the extraction rate of grain degrees, ultrasound power, ultrasound time, temperature were studied in this paper. Based on single factor experiment and orthogonal test, the optimum extraction conditions were obtained as follows:grain degree of80mesh, ultrasound power of70W, ultrasound time of30min at room temperature. The fat extraction rate of19pepper varieties ranged from13.37%to28.81%with the average of18.92%under the optimum conditions.2. Analysis of fatty acid composition in pepperFatty acid composition in pericarp of pepper were studied by gas chromatography, and were compared with the fatty acid composition in the seed. The results showed that there were9kinds of fatty acids in pericarp of pepper, including Lauric acid, Myristic acid, Palmitic acid, Stearic acid, Oleic acid, Linoleic acid, Linolenic acid,Arachidic acid and Behenic acid, which the variation coefficients were with in the range from8.16-53.37%. The major acids were Linoleic acid (37.32%), Linolenic acid (22.94%) and Palmitic acid (18.12%), The Lauric acid was not detected in pepper seeds, the major fatty acid is Linoleic acid (73.45%), coefficient of variation of0.01%-0.21%. Significant difference revealed in fatty acid composition and content in different parts of pepper and pepper varieties. 3. Establish of near infrared detection model of capsaicinIn order to detect the contents of capsaicin in pepper rapidly, the calibration models were established by relating the NIR spectra of33pepper samples to their HPLC detected capsaicin contents with partial least square method and OPUS software. The effects of the spectrum pretreatment and the spectral range of the models were investigated. The internal cross validation, external validation and P-values of paired-samples t test. The results indicated that:1) The optimal conditions for the model:Pretreatment:Minimum-maximum Normalized method; Dimension:7, Spectral scale:6102-4598cm-1.2) The determination coefficients (R2) and RMSECV of Cross validation, External validation were92.64,0.0873and92.09,0.0708, respectively. There was no significant difference between Model prediction and HPLC measured values, which indicate this NIRS model had very good precision. Therefore the NIR models are able to analyse capsaicin in large number pepper rapidly.