Bosch Guido, Heesen Lisa, de Melo Santos Karine, Pellikaan Wilbert F, Cone John W, Hendriks Wouter H
Animal Nutrition Group, Wageningen University, PO Box 338, 6700 AH Wageningen, The Netherlands.
Faculty of Veterinary Medicine, Utrecht University, PO Box 80·151, 3508 TD Utrecht, The Netherlands.
J Nutr Sci. 2017 May 24;6:e25. doi: 10.1017/jns.2017.22. eCollection 2017.
To gain knowledge on the precision of an method for characterisation of the fermentability of dietary fibres, this study aimed to evaluate the repeatability and reproducibility of such a method. Substrates used were citrus pectin (CP), fructo-oligosaccharides (FOS), guar gum (GG), sugar beet pulp (SBP) and wheat middlings (WM). Each substrate was incubated with faecal inoculum from five cats with three replicates for each substrate-cat combination. Gas production was measured continuously during the 48 h incubation and SCFA and organic matter disappearance (only SBP and WM) were determined after incubation. Four consecutive runs were performed. The within-run variability (repeatability) was generally lower for the more simple and pure substrates (CP, FOS, GG) than for the more complex substrates containing mixtures of fibres (SBP, WM). Replicates showed high variability, in particular for SCFA profiles and parameters of gas production kinetics. The between-run CV (reproducibility) for the measured parameters were, in general, below 10 % for CP, FOS and GG and higher values were obtained for SBP and WM. It is concluded that for precise dietary fibre characterisation, the number of replicates should be multiple and adjusted according to the variability of the parameters of interest and the complexity of fibres. The method yielded reproducible results with some variation in absolute values obtained, which may have an impact on the significance level of the differences among substrates.
为了解一种膳食纤维发酵特性表征方法的精密度，本研究旨在评估该方法的重复性和再现性。所用底物为柑橘果胶（CP）、低聚果糖（FOS）、瓜尔豆胶（GG）、甜菜粕（SBP）和小麦麸（WM）。每种底物与五只猫的粪便接种物一起孵育，每种底物 - 猫的组合设置三个重复。在48小时孵育期间连续测量气体产生量，并在孵育后测定短链脂肪酸（SCFA）和有机物消失量（仅针对SBP和WM）。进行了连续四次运行。对于较简单和纯净的底物（CP、FOS、GG），运行内变异性（重复性）通常低于含有纤维混合物的较复杂底物（SBP、WM）。重复实验显示出较高的变异性，特别是对于SCFA谱和气体产生动力学参数。所测参数的运行间变异系数（再现性），一般来说，CP、FOS和GG低于10%，而SBP和WM则获得较高的值。得出的结论是，为了精确表征膳食纤维，重复次数应该是多次的，并根据感兴趣参数的变异性和纤维的复杂性进行调整。该方法产生了可重复的结果，但所获得的绝对值存在一些变化，这可能会对底物之间差异的显著性水平产生影响。
