Myo-inositol hexakisphosphate degradation by Bifidobacterium pseudocatenulatum ATCC 27919 improves mineral availability of high fibre rye-wheat sour bread.

The goal of this investigation was to develop baking products using Bifidobacterium pseudocatenulatum ATCC27919, a phytase producer, as a starter in sourdough for the production of whole rye-wheat mixed bread. This Bifidobacterium strain contributed to myo-inositol hexakisphosphate (phytate) hydrolysis, resulting in breads with higher mineral availability as was predicted by the phytate/mineral molar ratios, which remained below the inhibitory threshold values for Ca and Zn intestinal absorption. The products with sourdough showed similar technological quality as their homologous without sourdough, with levels of acetic and d/l lactic acids in dough and bread baking significantly higher with the use of sourdough. The overall acceptability scores showed that breads with 25% of whole rye flour were highly accepted regardless of the inclusion of sourdough. This work emphasises that the in situ production of phytase during fermentation by GRAS/QPS microorganisms constitutes a strategy which is particularly appropriate for reducing the phytate contents in products for human consumption.

García-Mantrana I ，Monedero V ，Haros M 《-》

Expression of bifidobacterial phytases in Lactobacillus casei and their application in a food model of whole-grain sourdough bread.

Phytases are enzymes capable of sequentially dephosphorylating phytic acid to products of lower chelating capacity and higher solubility, abolishing its inhibitory effect on intestinal mineral absorption. Genetic constructions were made for expressing two phytases from bifidobacteria in Lactobacillus casei under the control of a nisin-inducible promoter. L. casei was able of producing, exporting and anchoring to the cell wall the phytase of Bifidobacterium pseudocatenulatum. The phytase from Bifidobacterium longum spp. infantis was also produced, although at low levels. L. casei expressing any of these phytases completely degraded phytic acid (2mM) to lower myo-inositol phosphates when grown in MRS medium. Owing to the general absence of phytase activity in lactobacilli and to the high phytate content of whole grains, the constructed L. casei strains were applied as starter in a bread making process using whole-grain flour. L. casei developed in sourdoughs by fermenting the existing carbohydrates giving place to an acidification. In this food model system the contribution of L. casei strains expressing phytases to phytate hydrolysis was low, and the phytate degradation was mainly produced by activation of the cereal endogenous phytase as a consequence of the drop in pH. This work shows the capacity of lactobacilli to be modified in order to produce enzymes with relevance in food technology processes. The ability of these strains in reducing the phytate content in fermented food products must be evaluated in further models.

García-Mantrana I ，Yebra MJ ，Haros M ，Monedero V ... -  《-》

Phytate reduction in bran-enriched bread by phytase-producing bifidobacteria.

Sanz-Penella JM ，Tamayo-Ramos JA ，Sanz Y ，Haros M ... -  《-》

Making bread with sourdough improves mineral bioavailability from reconstituted whole wheat flour in rats.

Lopez HW ，Duclos V ，Coudray C ，Krespine V ，Feillet-Coudray C ，Messager A ，Demigné C ，Rémésy C ... -  《NUTRITION》

Profile and bioavailability analysis of myo-inositol phosphates in rye bread supplemented with phytases: a study using an in vitro method and Caco-2 monolayers.

Duliński R ，Cielecka EK ，Pierzchalska M ，Byczyński Ł ，Żyła K ... -  《-》