A partial least squares model for non-volatile residue quantification using diffuse reflectance infrared reflectance spectroscopy

2016 ◽  
Author(s):  
Amylynn Chen ◽  
Robert M. Moision
2016 ◽  
Vol 1 (1) ◽  
pp. 1059-1068
Author(s):  
Masdar Masdar ◽  
Agus Arip Munawar ◽  
Zulfahrizal Zulfahrizal

Rendahnya pengawasan mutu kakao menyebabkan harga jual di pasar dunia menurun akibat kurangnya pengawasan kadar air. Salah satu metode yang tepat dan cepat dalam penentuan kadar air adalah menggunakan atau Near Infrared Reflectance Spectroscopy (NIRS). Tujuan penelitian adalah melihat kemampuan NIRS dalam memprediksi kadar air bubuk biji kakao dengan menggunakan metode Partial Least Squares (PLS) serta membandingkan dua metode pretreatment De-trending dan Derivatif ke-2.Alat yang digunakan FT-IR IPTEK T-1516, dan pengolahan data dengan unscrambler software® X version 10. Hasil penelitian menunjukkan NIRS mampu menduga kadar air dalam jumlah 10 gram dengan selang kadar air 7.42 – 11.09 % menggunakan PLS secara non pretreatment maupun pretreatment. Panjang gelombang relevan dalam menduga kadar air bubuk biji kakao adalah  1400-1450 nm dan 1800-1950 nm. Peningkatkan kinerja PLS yang paling bagus menggunakan pretreatment derivative ke-2.Abstract The lowest quality of cocoa supervision cause the selling price descrease due to the lack of supervision on the water content. One of the exact method in determining the water content is Near Infrared Reflectance Spectroscopy (NIRS). The purpose of this study is to know the capability of NIRS in order to predict the water content of cocoa by using Partial Least Squares (PLS) method then compared the two pretreatment methods namely De-trending and second Derivative. The instrument used was FT-IR IPTEK T-1516, and the spectra data were analyzed by using unscrambler software® X version 10. The results showed that NIRS can be used to predict the water content in amount 10 grams in a range of water content 7:42 to 11:09% by using PLS non pretreatment and vice versa. The relevantwavelengthsused to predict water content of cocoa powder ware1400-1450 nm and 1800-1950 nm. The optimum best pretreatment method was found to be second Derivative.


1994 ◽  
Vol 2 (3) ◽  
pp. 153-162 ◽  
Author(s):  
James B. Reeves

The objective of this work was to explore the relative merits of near and mid-infrared diffuse reflectance spectroscopy in determining the composition of sodium chlorite treated forages and by-products. Sixteen feed-stuffs (174 total samples treated at one of 11 levels of sodium chlorite, 0 to 0.394 g per gram of feedstuff) were examined in the near and mid-infrared spectral regions using diffuse reflectance on a Fourier transform spectrometer, and in the near infrared region using a grating monochromator. Samples were scanned as is and as 5% sample in KBr on the Fourier spectrometer and as is on the grating monochromator. Samples were analysed chemically and spectroscopically for neutral and acid detergent fibre, in vitro digestibility, permanganate lignin, crude protein and lignin nitrobenzene oxidation products. Results showed that diffuse mid-infrared reflectance spectroscopy can perform as well as, and sometimes better than, diffuse near infrared reflectance spectroscopy in determining the composition of chlorite-treated forages and by-products. In addition, Fourier near infrared spectroscopy did not perform as well as either near infrared using a grating monochromator or the Fourier mid-infrared spectrometer. Finally, diluting samples with KBr was often beneficial for mid-infrared based determinations.


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