Laura Monica Dale, Ioan Rotar, Roxana Vidican, Vasile Florian, Alin Mogos
Using NIRS technique it becomes more frequently used for determining physico-chemical properties of feed, especially chemical composition (dry matter, protein, ash, fiber, fat, non-nitrogenous extractive substances.This technique is an elegant and very precise. The contents of dry matter, crude protein, crude ash, crude fiber, crude fat, non – nitrogenous extractive substances of biological material Medicago sativa are determined by destructive methods and then using them was build the calibration curve for NIRS with which we will determine all the chemical properties of the material using prediction. For each property we have used these method assessment: for the crude protein was used Kjeldahl method, for crude fat was used Soxhlet method, for crude ash performed Hennenberg – Stohmann method, for crude fiber was used Hennenberg - Stohmann method and for non – nitrogenous extractive substances was used mathematical calculation. This paper aims to highlight a way of direct analysis method undestructive of crude protein, crude fat, crude fiber, crude ash, non-nitrogenous extractive substances using near infrared spectrometry technique in conjunction with reflected attenuated total. All these results determined by the classical method, the destructive method, were used to build the calibration curve for device FT-NIR Spectrometer Perkin Elmer Spectrum 100 N with accessory N NIRA. Mathematical model was built using the near infrared spectrofotoscopiei tehnique in conjunction with multivariable calibration techniques using the Perkin Elmer program Spectrum Quant + 4.60. These techniques based on multivariated analysis allow the determination of an error prediction for the best crude protein content is 0.00 %, for crude fat the content ranges from 0.003 to 0.062 %, the crude ash from 0.00 to 1.17 %, for crude cellulose the content ranges from 0.30 to 3,30 % and for non – nitrogenous extractive substances 0.10 - 4.20 %.The method provides a rapid and reliable alternative to traditional quantitative methods for determining which usually requires several hours to complete.
NIRS; protein; fat; ash; cellulose; non – nitrogenous extractive substances; Medicago sativa
Presentation: oral