不同载体预混合饲料中维生素E近红外光谱模型

【目的】维生素E是重要饲料添加剂,其含量的准确测定对饲粮配制具有重要意义。文章探讨了不同载体稀释剂预混合饲料中维生素E的快速定量方法,旨在说明近红外光谱分析方法对不同载体预混合饲料的适用性,对日后建立预混合饲料中维生素含量的近红外速测方法提供参考。【方法】采集商品维生素E粉剂,以市场上常见的二氧化硅、脱脂米糠和石粉为载体稀释剂,通过混匀机混匀配制了浓度范围为5—250 IU·g~(-1)的维生素E预混合饲料,并采集其近红外光谱。研究比较了不同扫描次数和分辨率对近红外光谱质量的影响,比较了不同载体稀释剂预混合饲料中维生素E的特征峰及不同光谱预处理方式下维生素E偏最小二乘回归模型的定量精度,并从PLS模型中的VIP Score值的角度来分析模型的差异性。【结果】16 cm~(-1)分辨率和32次扫描次数为适宜的光谱采集参数;不同载体稀释剂预混合饲料的近红外光谱差异明显,二氧化硅、脱脂米糠和石粉为载体的预混合饲料维生素E主要特征吸收峰不同,分别位于8 700—8 200、7 100—7 450、6 020—5 550、4 440—4 200、5 210—4 760,8 550—8 050、7 410、5 950—5 200、4 400—4 050、4 750—4 600 cm-1和8 550—8 050、7 250、5 950—5 200、4 600—4 000、4 800—4 700 cm~(-1)其近红外定量模型的最佳光谱预处理方法分别为SNV+1st Deriv.(2,15)、MSC+1st Deriv(2,21)和SNV+2st Deriv(2,15),其校正决定系数

Effects of Different Carriers on Near Infrared Quantitative Model of Vitamin E in Premix

【Objective】Vitamin E is an important feed additive, the accurate determination of its content is of great significance for the preparation of dietary. In this paper, the rapid quantitative method of vitamin E in different carrier premixed feeds was studied. The aim of this paper was to describe the applicability of near infrared spectroscopy to different carrier premixed feeds, and to establish a near-infrared rapid measuring method for vitamin content in premixed feed.【Method】Commercial vitamin E powder was collected and mixed with the silica, defatted rice bran and stone powder. The premix of vitamin E in the concentration range of 5-250 IU·g^-1was prepared by blending and collected its near-infrared spectra. This study compared the effects of different scanning times and resolution on the quality of the near infrared spectroscopy, compared the characteristic peak of vitamin E in premix of different carrier and different spectral preprocessing methods quantitative accuracy of PLS model and the difference of the model was analyzed from the point of view of VIP Score in PLS model. 【Result】 The results showed that 16 cm^-1 resolution and 32 scans were suitable for spectral acquisition. There were significant differences in NIR spectra of premix with different carriers. The vitamin E absorption peaks of silica, defatted rice bran and stone powder as the carriers of the premix were 8 700-8 200, 7 100-7 450, 6 020-5 550, 4 440-4 200, 5 210-4 760, 8 550-8 050, 7 410, 5 950-5 200, 4 400-4 050, 4 750-4 600 cm^-1 and 8 550-8 050, 7 250, 5 950-5 200, 4 600-4 000, and 4 800-4 700 cm^-1, respectively. The optimal spectral pretreatment methods for the near-infrared quantitative models were SNV+1stDeriv（2，15）, MSC+1stDeriv（2，21）and SNV+2stDeriv（2，15）, respectively, the calibration （R_c²）were 0.988, 0.949 and 0.941, respectively, the standard error of calibration （SEP）were 8.86, 10.36 and 23.37, respectively, the validation (R_p²) are 0.989, 0.980 and 0.921 respectively, the standard error of prediction（SEP）were 8.86, 10.36 and 23.37 respectively, and ratio of performance to standard deviation（RPD）were 8.10, 6.90 and 3.07 respectively. The VIP Scores value of PLS model with three different carrier diluents were extracted, and the contribution of the VIP Score values of silica were significant and that associated with vitamin E characteristic peaks was the highest, then was the skim rice bran and followed by stone powder.【Conclusion】Near-infrared spectroscopy for the analysis of vitamin E premixed feed, with the silica and skim rice bran as the carriers of the pre-mixed feed is better, with stone powder as the carrier of premixed feed, applicability of the measuring method is poor.