Quantification and Determination of Starch in Diets Using Different Methodologies: Infrared Spectroscopy with Fourier Transformer, Laser Diffraction and Enzymatic Analysis

Abstract

A digestibility experiment was conducted in the Animal Nutrition Laboratory of the Veterinary School of the Federal University of Minas Gerais (UFMG), Protocol ethics committee for work with animal experimentation CETEA/ UFMG 212/2010, in order to validate the instrumental techniques Laser Diffraction (Partica) and Infrared Spectroscopy with Fourier Transformer (FTIR) method, as replacement methods of the reference (Enzymatic Analysis) Technique, of starch quantification in diets of growing pigs. The experiment lasted 12 days (7 days of adaptation to the cage and diet and 5 days of total collection). Fifteen barrows with average weight of ±25 kg and 65 days old were used for this study. A completely randomized experimental design was adopted, with split plots and subplots. The plots were the diets (1—Reference, 2—Reference + inclusion of 30% micronized soybean and 3—Reference +30% substitution of plasma) and the subplots were the techniques (Partica, FTIR and Enzymatic Technique, with five repetitions (animals) per diet). The results obtained with the Partica and FTIR techniques were compared to the reference method. There was no statistical difference (p > 5%) between these techniques evaluated in comparison to the reference method to quantify starch. However, it was observed that the FTIR technique was different from the reference method for (p > 5%) overestimating the means of evaluated samples.