Avaliação dos teores de fibra insolúvel em detergente neutro em tortas de oleaginosas através de diferentes métodos analíticos.

Abstract

The quantification of the fiber contents of food is important, mainly, in the nutrition of the ruminants, since its physical and chemical characteristics can directly affect the digestive physiology of the rumen. This study aimed to evaluate the fiber content of oil cake, concentrate ration and roughage in different analytical methods and to compare them with the official method of the Association of Official Analytical Chemists (AOAC, method 2002.04), with or without the use of partial degreasing of samples. The experiment was conducted in four laboratories: Animal Nutrition Laboratory belonging to the Institute of Veterinary Medicine at the Federal University of Pará, in Castanhal-Pará and at the Federal Rural University of Amazonia, Belém campus and Parauapebas-PA. The dry matter and ethereal extract contents of the samples were evaluated. Neutralizing detergent fiber (NDF) were analyzed using AOAC 2002.04 methodologies (use of the reflux extractor and the retention of the insoluble residue in filter crucibles) without the use of sulphite and modification of the use of the enzyme alpha amylase , Ankom2000 fiber analyzer (pressure extraction and the use of 100 g / m2 non-woven fabric bags), Autoclave (use of pressurized environment and 100g/m2 non-woven bags) and Tecnal TE-149® (use of non-pressurized environment and nonwoven bags (TNT), 100 g / m2) with and without partial degreasing of samples. A completely randomized experimental design was used in a 13 x 4 x 2 factorial arrangement (thirteen oilseed byproducts x four methodologies x with or without partial degreasing). The data were submitted to analysis of variance (ANOVA) and the means were compared by the Tukey test (P <0.05) through the statistical package SAS (Statistical Analisys System Institute). No interaction (p> 0.05) was observed for the type of sample, type of method and partial degreasing processing. There was no interaction (p> 0.05) between the methods and the type of processing with and without partial degreasing. The NDF values obtained by the Alternative Filter Bag Technique methods from Ankom (FBT), Autoclave (AUT) and Tecnal (TEC) did not differ among themselves (p>0.05), but differed from the CONV method. have been compromised by the loss of particles through the nonwoven bags (TNT) used in alternative methods. In relation to the NDF results evaluated, there was interaction between the method and the sample type (p <0.05), where the bacuri, brown nut, passion fruit and coconut by-product samples did not present a significant difference (p> 0,05) between the methods. However, differences (p <0.05) of the CONV method were observed in relation to the alternative methods of by-product samples such as andiroba, ucuúba, cocoa, murumuru, patauá, tucumã and palm oil. In the evaluation of the NDF of oilseed by-product samples with lipid contents above 10%, regardless of the method of analysis, the samples should be degreased. The observed variability among the NDF analysis methods makes it difficult to establish an analytical standard that is capable of accurately evaluating the estimates.