Füstös Z., Antal O. T., Naár Z., Kiss A., Némedi E.
NARIC FSRI (National Agricultural Research and Innovation Center Food Science Research Institute), Budapest, Hungary

Nowadays consumption of healthy foodstuffs are becoming widespread, but a lot of people frequently consume ready-to-eat or semi-ready-to-eat foods. Among these products pastas play a key role, thus it is of great significance to provide pasta-based foodstuffs with justified health-promoting effect. Prebiotic index (PI) is considered as a reliable measure of prebiotic effect, however several distinctive methods are available. Our major goal was to accomplish comparative assessment of the most frequent PI-estimating methods, and point out the most relevant one. Hence an efficient tool is gained for estimation of the prebiotic content of selected foodstuffs, whose prebiotic effect is featured in highly authentic way. In this study prebiotic effects of pastas prepared from different flour-combinations were evaluated by using 5 distinctive methods, subsequent to in vitro digestion, modelling the real human metabolism.

In total 8 distinctive pastas and 21 pasta-fillings were analysed. Pastas were prepared from wheat, buckwheat, amaranth flour, supplemented with CaCO3, MgCO3, and vitamin D. Self-developed in vitro digestion model was applied to implement the studies (NAIK-ÉKI model) based on Versantvoort et al. (2005) protocol, but supplemented with a colon modelling phase. Colon phase was constructed by inoculating the digested samples with a bacterial mixture made of Bifidobacterium, Lactobacillus, Escherichia coli, Clostridium and followed by a 24-hour-long anaerobic incubation. Changes in bacterial populations were measured by plate counting on selective media. PIs were calculated by using the Palframan et al. (2003), logarithmic values of Palframan et al. (2003), Olano-Martin et al. (2002), Vulevic et al. (2004) and NAIK-ÉKI model equations.

According to PIs, with the exceptions of Palframan et al. (2003) equation based PIs, it can be observed that pastas supplemented with buckwheat and amaranth flours have positive prebiotic indices (0.28-0.33). Similar results were obtained for fruit jam fillings, supplemented with vitamin D (0.33). Rest of the samples showed mainly negative values (-0.06 - -1.09) or close to zero (0.03-0.09). PI values calculated with Palframan et al. (2003) and logarithmic values of Palframan et al. (2003) equations were higher in absolute terms (0.07-13) than that of the others (0.01-1.09). Likewise, in some cases Palframan et al. (2003) equation gave negative values for samples showed positive values when using the other equations. The remaining three equations provided nearly the same values for all samples.

Our results suggested that pastas prepared from different flours and filled with fruit jam, could exert considerable prebiotic effects in the human colon. Taking into account the different equations used for PI calculation, it can be concluded that most of them, except Palframan et al. (2003) equation, can be used for assessment of experimental data gained by the NAIK-ÉKI digestion model, since they are showing similar trends for all samples. We suggest that Palframan et al. (2003) equation should be used with precaution, as with this model PI can not be significantly influenced by the other three bacteria if one bacterial strain is represented in high ratio at the end of the experiments.
This work was supported by the project AGR_PIAC_13-1-2013-0084

Keywords: Probiotics, Prebiotics, Vitamin D

Füstös Z., et al. (2016). Comparative assessment of different model-methods used for the estimation of prebiotic effects of in vitro digested pastas. Conference Proceedings of IPC2016. Paper presented at the International Scientific Conference on Probiotics and Prebiotics, Budapest (p. 93.). IPC2016

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