ALIFE:The “as eaten” method to measure the Total Dietary Fibre content was implemented at the Hanze University of Applied Sciences (WP 4). The enzymatic treatment with the GtfB enzyme clearly resulted in an increased fibre content of starch from 1.6% to approx. 20% (fig A). When using this modified starch (“as eaten” treated) in an incubation with colon bacteria we see a similar pattern as when using FOS and GOS (fig B). The qPCR results indicate a significant stimulation of the growth of gut bacteria by the GtfB modified starch, as shown by the relative increase of Bacteroides and to a lesser extent Lactobacilli (fig.C). The prebiotic effect remains to be evaluated.
ALIFE The “all-in-one” method to measure the Total Dietary Fibre content was implemented at the Hanze University of Applies Sciences. Wholemeal bread and crackers showed the expected % of TDF (approx. 6 and10 %, respectively). Enzymatic treatment with a novel starch-modifying enzyme clearly resulted in an increased TDF content of starch from 1.6% to approx. 27%. Due the limited amount of sample material and low ash-content of starch, ash values were abberant. In the near future, on-going research will reveal whether the MWSDF+IDF of these enzymatically modified starches also possess any prebiotic activity and stimulate growth of probiotic bacteria.
Granular 2-nitropropyl potato starch was synthesized by reaction with 2-nitropropyl acetate in an aqueous suspension. Nitroalkylation occurs preferentially with the amylose fraction of potato starch, as was confirmed by leaching experiments and digestion of the modified starch with α-amylase. The 2-nitropropyl substituent is a mixture of the nitroalkane and nitronic acid tautomer. Some grafting occurs and to a lesser extent additional reactions (formation of carbonyls and oximes) of the nitro group take place. After catalytic hydrogenation of water soluble 2-nitropropyl starch only a small amount of the nitro functionality was reduced to the corresponding amine. Reduction of granular 2-nitropropyl starch with sodium dithionite did not go to completion and led to a complex mixture of starting material, several intermediates and side products (for example sulfamates). © 2001 Elsevier Science Ltd.
LINK
